49,622 results on '"IMMOBILIZATION"'
Search Results
2. Expanding the high-pH range of the sucrose synthase reaction by enzyme immobilization.
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Liu, Hui, Borg, Annika J.E., and Nidetzky, Bernd
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EQUILIBRIUM reactions , *FRUCTOSE , *BIOCHEMICAL substrates , *URIDINE , *GLYCOSYLATION , *SUCROSE , *CELLULOSE synthase - Abstract
The glycosylation of an alcohol group from a sugar nucleotide substrate involves proton release, so the reaction is favored thermodynamically at high pH. Here, we explored expansion of the alkaline pH range of sucrose synthase (SuSy; EC 2.4.1.13) to facilitate enzymatic glycosylation from uridine 5'-diphosphate (UDP)-glucose. The apparent equilibrium constant of the SuSy reaction (UDP-glucose + fructose ↔ sucrose + UDP) at 30 °C increases by ∼4 orders of magnitude as the pH is raised from 5.5 to 9.0. However, the SuSy in solution loses ≥80 % of its maximum productivity at pH ∼7 when alkaline reaction conditions (pH 9.0) are used. We therefore immobilized the SuSy on nanocellulose-based biocomposite carriers (∼48 U/g carrier; ≥ 50 % effectiveness) and reveal in the carrier-bound enzyme a substantial broadening of the pH-productivity profile to high pH, with up to 80 % of maximum capacity retained at pH 9.5. Using reaction by the immobilized SuSy with automated pH control at pH ∼9.0, we demonstrate near-complete conversion (≥ 96 %) of UDP-glucose and fructose (each 100 mM) into sucrose, as expected from the equilibrium constant (K eq = ∼7 × 102) under these conditions. Collectively, our results support the idea of glycosyltransferase-catalyzed synthetic glycosylation from sugar nucleotide donor driven by high pH; and they showcase a marked adaptation to high pH of the operational activity of the soybean SuSy by immobilization. • Synthesis from UDP-glucose by sucrose synthase favored at high pH • pH Dependence of apparent reaction equilibrium analyzed • Sucrose synthase from soybean immobilized on nanocellulose biocomposite carriers • Sucrose synthase enabled to application in high-pH synthesis by immobilization • High-yielding reaction with automated pH control at pH 9.0, giving 100 mM product [ABSTRACT FROM AUTHOR]
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- 2024
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3. Unlocking the potential of neuromuscular electrical stimulation: achieving physical activity benefits for all abilities.
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Ackermann, Paul W., Juthberg, Robin, and Flodin, Johanna
- Abstract
Neuromuscular Electrical Stimulation (NMES) uses electrical impulses to induce muscle contractions, providing benefits in rehabilitation, muscle activation, and as an adjunct to exercise, particularly for individuals experiencing immobilization or physical disability. NMES technology has significantly progressed, with advancements in device development and a deeper understanding of treatment parameters, such as frequency, intensity, and pulse duration. These improvements have expanded NMES applications beyond rehabilitation to include enhanced post-exercise recovery, improved blood glucose uptake, and increased lower limb venous return, potentially reducing thrombotic risks. Despite its benefits, NMES faces challenges in user compliance, often due to improper electrode placement and discomfort during treatment. Research highlights the importance of optimizing stimulation parameters, including electrode positioning, to improve both comfort and treatment efficacy. Recent innovations, such as automated processes for locating optimal stimulation points and adaptable electrode sizes, aim to address these issues. When combined with wearable technologies, these innovations could improve NMES treatment adherence and deliver more consistent, long-term therapeutic outcomes for patients with various physical limitations. Together, these developments indicate a promising future for NMES, presenting a valuable tool to enhance the benefits of physical activity across diverse populations, from rehabilitative care to broader health and wellness applications. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Effect of the activation strategy of nickel oxide‐multi‐walled carbon nanotubes on the immobilization of xylanase for synthesis of xylooligosaccharides.
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Varan, Nazli Ece, Yildirim, Deniz, Toprak, Ali, Fernandéz‐Lafuente, Roberto, and Alagöz, Dilek
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CARBON nanotubes , *NICKEL oxide , *THERMAL stability , *GLUTARALDEHYDE , *ALDEHYDES , *XYLANASES - Abstract
Magnetic nickel oxide multi‐walled carbon nanotubes (MWCNT‐NiO) were employed in the immobilization of xylanase from
Thermomyces lanuginosus , after modification with (3‐glycidoxypropyl)trimethoxysilane or 3‐aminopropyltriethoxysilane (APTES). The APTES‐derivatized MWCNT‐NiO particles were activated with glutaraldehyde to immobilizeT. lanuginosus xylanase via covalent attachment. The (3‐glycidoxypropyl)trimethoxysilane‐derivatized MWCNT‐NiO particles were directly used for the covalent immobilization ofT. lanuginosus xylanase, or the formed epoxy groups were converted to aldehyde groups. The free xylanase had maximum activity at pH 7.5, whereas the immobilized samples showed an optimum pH of 7.0. The optimum temperature was 60°C for the xylanase samples. The thermal stability of xylanase increased at 7 and/or 12 folds after immobilization. The results of xylooligosaccharide synthesis showed that the main formed xylooligosaccharides were xylobiose, xylotriose, and xylotetraose for the immobilized xylanase samples. Furthermore, an effect of the enzyme loading could be found, an increase in this parameter promoted that xylobiose and xylotriose amounts slightly increased, whereas xylotetraose amount slightly decreased. The immobilized xylanase samples retained at least 80% of their initial activity after five reuses at pH 7.0 and 60°C. The results show that the new xylanase preparations were easily separable, thermally stable, and reusable in the synthesis of xylooligosaccharides. [ABSTRACT FROM AUTHOR]- Published
- 2024
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5. Changes in Ibuprofen Toxicity and Degradation in Response to Immobilization of Bacillus thuringiensis B1(2015b).
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Marchlewicz, Ariel, Dzionek, Anna, Wojcieszyńska, Danuta, Borgulat, Jacek, Jałowiecki, Łukasz, and Guzik, Urszula
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Ibuprofen is one of the most commonly used anti-inflammatory drugs by humans, resulting in its appearance in the environment, which can negatively affect organisms living in it. The studies undertaken have shown that the immobilized Bacillus thuringiensis B1(2015b) strain can decompose this drug at a rate of qmax = 0.36 mg/L*h, with a Ks constant of 0.95 mg/L for this process. An analysis of the effect of ibuprofen on the metabolic profile of the immobilized strain B1(2015b) showed an increase in the consumption of carbon, nitrogen, phosphorus, and sulfur compounds by this strain compared to the free strain. Studies on the toxicity of ibuprofen against the B1(2015b) strain indicated a small protective effect of the carrier, manifested by a slightly higher EC50 value = 1190 mg/L (for the free strain EC50 = 1175 mg/L). A toxicity analysis of intermedia formed during ibuprofen degradation indicated that the increase in toxicity is positively correlated with the degree of hydroxylation of ibuprofen metabolites. A toxicity analysis of the post-culture fluid obtained after ibuprofen degradation by the immobilized and free strain indicated that the products formed due to this process are completely safe. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Bacterial Cellulose Membranes Incorporated with Lipase for Oil Degradation.
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Silveira, Victória Fonseca, da Silva, Victória Mendes, Junior, Sandro Rogério Kumineck, Garcia, Michele Cristina Formolo, Pezzin, Ana Paula Testa, de Oliveira, Therezinha Maria Novais, and Schneider, Andrea Lima dos Santos
- Abstract
The immobilization of enzymes increases their stability and allows their reuse, and bacterial cellulose (BC) is a material that can be used in this technique. This work aims to produce an enzymatic product to degrade oils and fats using BC as a matrix. Komagataeibacter hansenii bacteria produce BC membranes, and lipase is immobilized on the membranes by ex situ method. Then, the surface of the membranes is modified with zein, a hydrophobic corn protein. The membranes are characterized by TGA, FTIR, scanning electron microscopy (SEM) analysis and oil degradation test. TGA demonstrates higher stability for the membranes with lipase and zein. The FTIR spectrum of pure BC membrane and zein‐modified membrane are very similar because of the high zein coating. SEM analysis shows that zein‐modified membranes with lipase present smaller amounts of pores. Finally, using soy oil, lipase degrades oil even after immobilization during the degradation test. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Composites Based on Natural Zeolites and Green Materials for the Immobilization of Toxic Elements in Contaminated Soils: A Review.
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Senila, Marin and Cadar, Oana
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Soil contamination by toxic elements is a global problem, and the remediation of contaminated soils requires complex and time-consuming technology. Conventional methods of soil remediation are often inapplicable, so an intensive search is underway for innovative and environmentally friendly ways to clean up ecosystems. The use of amendments that stabilize the toxic elements in soil by reducing their mobility and bioavailability is one of the simplest and most cost-effective ways to remediate soil. This paper provides a summary of studies related to the use of composites based on natural zeolites and green materials for the immobilization of toxic elements in contaminated soils and highlights positive examples of returning land to agricultural use. The published literature on natural zeolites and their composites has shown that combinations of zeolite with biochar, chitosan and other clay minerals have beneficial synergistic effects on toxic element immobilization and soil quality. The effects of zeolite properties, different combinations, application rates, or incubation periods on toxic elements immobilization were tested in laboratory scale or field experiments, whereas the mobility of toxic elements in soil was evaluated by chemical extractions of toxic elements transferred to the plants. This review highlights the excellent potential of natural zeolites to be used as single or combined sustainable green materials to solve environmental pollution problems related to the presence of toxic elements. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Production, Purification and Immobilization of Laccase from Trametes versicolor HBB 7328 for its Role in Decolorization of Textile Dyes.
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Goyat, Nikita, Kapoor, Rajeev Kumar, Saharan, Baljeet Singh, Kapoor, Prexha, Kumari, Kajal, and Singh, Namita
- Abstract
Laccase is an extracellular enzyme that is widely used in the decolonization of textile dyes in waste water. The aim of our study was to isolate, purify, characterize and immobilize the laccase enzyme produced by Trametes versicolor HBB 7328. Purified laccase enzyme was immobilized in polyacrylamide gel to explore its ability in decolonization of textile dyes. Laccase purification process was carried out by fractionation using ammonium sulphate (80%) followed by DEAE Sepharose column (30 × 3 cm) chromatography method. Recovery and fold purification in this step were 27.35 and 16.23%. Purified laccase (named as LAC1) revealed its optimum activity at pH 5.0 and 35 °C temperature, and displayed remarkable stability in the range of 30–40 °C and in the pH range (pH 3.0–7.0). The single bands on SDS-PAGE represent the purity of LAC1 with molecular weight of 60 kDa. Both free and immobilized laccase assessed for their ability to decolorize textile dyes. Free laccase decolorized Methyl red to 72.705%, Reactive orange to 57.851%, Reactive blue to 37.231%, Bromophenol blue to 24.412% however Immobilized laccase decolorized Methyl red to 89.823%, Reactive orange to 63.151%, Reactive blue to 59.548%, Bromophenol blue to 49.421% respectively. This study proposes the role of laccase from Trametes versicolor HBB 7328 in decolonization of textile dyes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Comparison of the synthesis of the alpha-amylase enzyme by the native strain Bacillus licheniformis in immobilized and immersed cells.
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Mahmoudnia, Fahimeh
- Abstract
Background and Objectives: The study focused on the amylase enzyme, widely used in the industrial starch liquefaction process. We looked into the best way to immobilize the native strain Bacillus licheniformis, which is the only alpha-amylase-producing bacterium, by trapping it in calcium alginate gel. This is a promising way to increase enzyme output. Materials and Methods: We examined the effects of alginate content, biomass age, initial cell loading (ICL), bead size, and solidification duration in calcium chloride solution on enzyme synthesis. We conducted batch fermentations using both immobilized and free cells. Results: Alpha-amylase production significantly increased with the alginate concentration ratio, achieving a maximum enzyme yield of 23.5 U/mL at a 30 g/l alginate concentration, utilizing an initial cell loading of 1.5 g in 150-200 beads per flask. These involved cells from a 12-hour culture with a bead size of 5.0 mm, were solidified for 24 hours in a 2.5% (w/v) calcium chloride solution. The yield of the immobilized cells was approximately 111.71% higher than that of the free cells, which produced 11.1 U/ml. The immobilized cells consistently generated alpha-amylase over five repeated cycles, attaining a peak value of 23.5 U/ml during the first cycle, which was 2.2-fold more than the control (free cells). Conclusion: We used a basic mass balance analysis to understand the growth of both fractions and the dynamics of amylase production in free cells and cells immobilized in Ca-alginate beads. The production of alpha-amylase in immobilized cells results in enhanced volumetric activities during fermentation. Notable advantages of this technique encompass prolonged stability, reuse and recycling, and the potential for adaptable regeneration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
10. Catalytically active inclusion bodies as a potential tool for biotechnology.
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Bello, Muhammad Nura, Sabri, Suriana, Mohd Yahaya, Normi, Mohd Shariff, Fairolniza, and Mohamad Ali, Mohd Shukuri
- Abstract
The initial assumption that viewed inclusion bodies as a hindrance to the efficient production of protein is no longer held due to the emergence of catalytically active inclusion bodies (CatIBs). Recent studies revealed their potential to be used in free form or immobilized as biocatalysts. The curiosity to acquire suitable catalysts has remained the measure of concern for researchers and industrialists. Numerous processes and production in various sectors of food industries, petroleum, pharmaceutical, cosmetics, and many others are still searching for a robust catalyst with outstanding features such as recyclability, resistance to pH, as well as temperature. CatIBs are forms of inclusion bodies that possess catalytic activity, which can improve catalysis efficiency, stability, and recyclability. One of the advantages of CatIBs is their potential to be used as catalysts for numerous bioprocesses when generated by an enzyme. These aggregates can efficiently be used as a replacement for traditional enzyme immobilization. This review tends to focus on the possibility of its application in various processes. The novelty of this review is that it considered the production of CatIBs both from artificial and natural perspectives, as well as how to improve it. Inclusion bodies' immobilization may provide an efficient alternative in the area of biocatalysis, and hence it will improve industrial sectors and substantially provide a means of achieving excellent performance in the near future. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Leveraging bacterial laccases to facilitate the decomposition of xenobiotic compounds: a review.
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Bera, Kalyanee, Bhattacharya, Debalina, and Mukhopadhyay, Mainak
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XENOBIOTICS , *CHILD behavior , *PROSTATE , *CHEMICAL decomposition , *FOOD chains - Abstract
Xenobiotic compounds are artificial substances that are essential in our lives. These substances have a negative impact on the environment because they are long-lasting and biodegrade slowly or not at all in ecosystems. When xenobiotics leak into the ecosystem, they enter the food chain and negatively impact animals' and people's health across all trophic levels. Moreover, these pollutants have toxic, mutagenic, carcinogenic, and teratogenic effects on all living organisms. They can affect humans in ways such as brain and prostate gland abnormalities, abnormalities of children's behavior, skin disorders, liver issues, immune system impairment, and endocrine system distribution. Consequently, it is essential to remove harmful, non-biodegradable xenobiotics from the ecosystem. Degradation of these chemicals hence requires immediate attention and awareness. The physical–chemical methods for removing the pollutants are costly. Bioremediation is a concept that uses organisms to control the environment faster and with less labor. Bacterial laccase-mediated bioremediation offers inexpensive, environmentaly sustainable, and potential degradation mechanisms for different recalcitrant chemicals. At the high temperature, high pH, contact time, and concentration, bacterial laccase can degrade the xenobiotic compounds. After degradation, convert them into low-toxic, non-hazardous substances in the environment by oxidation, reduction, elimination, and ring-opening processes. The aspects of this review article are bacterial laccase-mediated xenobiotic compound degradation. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Short-Term Bed Rest is not a Risk Factor for Venous Thromboembolism After Endoscopic Skull Base Surgery.
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Abello, Eric H., Feier, Joel S., Abiri, Arash, Pang, Jonathan C., Liu, Lauren, Nguyen, Cecilia H.H., Chung, Dean D., Hsu, Frank P.K., and Kuan, Edward C.
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CEREBROSPINAL fluid leak , *VENOUS thrombosis , *SKULL base , *SKULL surgery , *THROMBOEMBOLISM , *BED rest - Abstract
Venous thromboembolism (VTE) increases morbidity in postoperative patients. No current guidelines identify which patients undergoing endoscopic endonasal approach (EEA) to the skull base may be at increased risk. Postoperative care for these patients often includes a period of inactivity to prevent transient intracranial pressure shifts that may impact skull base reconstruction. We sought to characterize if postoperative bed rest puts patients undergoing EEA at increased risk of developing thromboembolic complications. Retrospective chart review of patients undergoing intradural surgery with primary skull base reconstruction for intraoperative cerebrospinal fluid leak via EEA for any skull base pathology between July 2018 and May 2024 yielded 221 patients who met inclusion criteria. Univariate and multivariable regressions were performed with patient demographics, extent of approach, intraoperative leak flow rate, bed rest duration, presence and length of postoperative lumbar drainage, and use of postoperative mechanical VTE prophylaxis. Mean age of included patients was 52.6 ± 16.8 years, 48% of patients were male, and 3.6% of patients had DVTs. Age (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.96–1.06, P = 0.83), sex (OR 0.40, 95% CI 0.05–2.19, P = 0.31), body mass index (OR 0.98, 95% CI 0.87–1.07, P = 0.74), extended approach (OR 0.80, 95% CI 0.13–4.36, P = 0.80), cerebrospinal fluid leak flow rate (OR 5.71, 95% CI 0.77–118.90, P = 0.14), bed rest duration (OR 1.06, 95% CI 0.77–1.27, P = 0.60), and presence of lumbar drainage (OR 1.10, 95% CI 0.55–2.02, P = 0.76) were not significant predictors of postoperative VTE incidence on multivariable analysis. Short-term bed rest after EEA is not a risk factor for development of VTE in the immediate postoperative period. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Potential of iron oxide-modified biochar in simultaneous mitigation of lead and nickel toxicity in wheat (Triticum aestivum L.).
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Shah, Tufail, Irshad, Muhammad Kashif, Javed, Wasim, Sheraz, Mahshab, Muhmood, Atif, Noman, Ali, Alomran, Maryam M., Lee, Sang Soo, and Shang, Jianying
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AGRICULTURAL productivity , *CROPS , *LEAD , *WHEAT farming , *SOIL pollution - Abstract
Lead (Pb) and nickel (Ni) contamination of soil is a global environmental threat, compromising agricultural productivity, human health, and ecosystems. Therefore, it is imperative to develop new and sustainable approaches for the mitigation of Pb and Ni toxicity in crop plants. In the current study, iron oxide-modified biochar (FMBC) was prepared and evaluated to determine its effectiveness in improving wheat growth and reducing Pb and Ni uptake by wheat plants. In the pot experiment, varying levels of pristine biochar (BC) and FMBC were incorporated into Pb- and Ni-contaminated soil. The data showed that growth of wheat plants was significantly improved by FMBC application at its highest level (1.5 %) resulting in increased root, shoot, husk, grain dry weights, and root and shoot lengths. Similarly, FMBC (1.5 %) significantly increased photosynthesis, transpiration rates, stomatal conductance, intercellular CO 2 , chlorophyll-a, and chlorophyll-b contents of wheat plants by 110.4 %, 44.5 %, 169.5 %, 47.6 %, 125 %, and 148 %, respectively. Plants treated with 1.5 % FMBC showed reduced oxidative stress in terms of suppressed hydrogen peroxide, electrolyte leakage, and malondialdehyde contents by 53.2 %, 52.7 %, and 41.3 %, respectively. FMBC application significantly reduced Pb and Ni bioavailability in soil and its uptake by plants. The FMBC amendment (1.5 %) decreased Ni concentrations in roots, shoots, husks, and grains by 31.6 %, 19.4 %, 24 %, and 24.3 % and Pb content by 60.1 %, 59.5 %, 79.6 %, and 76.1 %, respectively. The findings of the current study demonstrated that FMBC is an environment-friendly and sustainable amendment for reducing the risks associated with the uptake of Pb and Ni by wheat grown in contaminated soils. [Display omitted] • FMBC significantly improved wheat growth by reducing oxidative stress. • FMBC application boosted wheat photosynthesis by increasing the availability of nutrients. • FMBC decreased Pb and Ni bioavailability and uptake in wheat roots, shoots, husks, and grains. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Effect of electrical muscle stimulation on the improvement of deltoid muscle atrophy in a rat shoulder immobilization model.
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Lee, Jeongkun, Lee, Su Hyun, Kim, Hyuntae, and Chung, Seok Won
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ELECTRIC stimulation , *MUSCULAR atrophy , *DELTOID muscles , *SOLUTION strengthening , *CELL size - Abstract
Immobilization following trauma or surgery induces skeletal muscle atrophy, and improvement in the muscle atrophy is critical for successful clinical outcomes. The purpose of this study is to evaluate the effect of electrical muscle stimulation (EMS) on muscle atrophy. The study design is a controlled laboratory study. Eighty rats (56 to establish the deltoid muscle atrophy [DMA] model and 24 to evaluate the effect of EMS on the model) were used. DMA was induced by completely immobilizing the right shoulder of each rat by placing sutures between the scapula and humeral shaft, with the left shoulder as a control. After establishing the DMA model, rats were randomly assigned into three groups: low‐frequency EMS (L‐EMS, 10 Hz frequency), medium‐frequency EMS (M‐EMS, 50 Hz frequency), and control (eight rats per group). After 3 weeks, the deltoid muscles of each rat were harvested, alterations in gene expression and muscle cell size were evaluated, and immunohistochemical analysis was performed. DMA was most prominent 3 weeks after shoulder immobilization. Murf1 and Atrogin were significantly induced at the initial phase and gradually decreased at approximately 3 weeks; however, MyoD expressed an inverse relationship with Murf1 and Atrogin. IL6 expression was prominent at 1 week. The time point for the EMS effect evaluation was selected at 3 weeks, when the DMA was the most prominent with a change in relevant gene expression. The M‐EMS group cell size was significantly larger than that of L‐EMS and control group in both the immobilized and intact shoulders (all p < 0.05), without significant differences between the L‐EMS and control groups. The M‐EMS group showed significantly lower mRNA expressions of Murf1 and Atrogin and higher expressions of MyoD and Col1A1 than that of the control group (all p < 0.05). In immunohistochemical analysis, similar results were observed with lower Atrogin staining and higher MyoD and Col1A1 staining in the M‐EMS group. DMA model was established by complete shoulder immobilization, with the most prominent muscle atrophy observed at 3 weeks. M‐EMS improved DMA with changes in the expression of relevant genes. M‐EMS might be a solution for strengthening atrophied skeletal muscles and facilitating rehabilitation after trauma or surgery. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Cellulase entrapment into alginate-PEG beads cross-linked with glutaraldehyde: Optimization of the immobilization conditions and kinetic characterization of the immobilized enzyme.
- Author
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Zhu, Tao, Zhao, Fangyuan, Zhang, Yuqing, Ye, Yanxin, Chen, Yanyan, Li, Bingbing, Liu, Junhong, and Liu, Yaqiong
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IMMOBILIZED enzymes , *RESPONSE surfaces (Statistics) , *THERAPEUTIC immobilization , *PROCESS optimization , *GLUTARALDEHYDE - Abstract
Immobilization methods for cellulase entrapped into alginate beads with glutaraldehyde (GA) cross-linking were investigated. Cellulase entrapped into alginate-polyethylene glycol beads with glutaraldehyde cross-linking (SA-PEG-E) showed more superiority both in terms of catalytic performance and reusability than other methods. Several conditions during SA-PEG-E immobilization such as cellulase concentration, GA amount, pH of immobilization, cross-linking time and hardening temperature were evaluated to study their effect on immobilized enzyme activity, immobilization yield and immobilization efficiency. Based on the results, GA amount, pH of immobilization and hardening temperature were selected for process optimization of SA-PEG-E using the Box-Behnken design of response surface methodology. The results showed that the optimum immobilized conditions were obtained with a GA amount of 0.8 mL, pH of immobilization 4.7, and hardening temperature of 47.5 °C when the cellulase concentration was 7.5 mg/mL and cross-linking time was 2 h. Then, the characterization of SA-PEG-E was studied. The optimum pH of SA-PEG-E was observed to be 4, 1 unit lower than that of the free enzyme (pH 5). The optimum temperature was the same for both free and immobilized cellulase at 50 °C. In addition, the SA-PEG-E exhibited broad pH and temperature adaptability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Optimization of biotransformation process for the synthesis of pyrazine-2-carboxylic acid hydrazide using acyltransferase activity of Bacillus smithii IITR6b2 in batch and fed-batch mode.
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Lavania, Swasti and Choudhury, Bijan
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RESPONSE surfaces (Statistics) , *HAZARDOUS substances , *HETEROCYCLIC compounds , *BACILLUS (Bacteria) , *ACYLTRANSFERASES - Abstract
The synthesis of pyrazine-2-carboxylic acid hydrazide, a heterocyclic hydrazide compound, with negligible production of the by-product (pyrazine-2-carboxylic acid) in a solvent-free reaction condition was developed using the acyltransferase activity of amidase of Bacillus smithii strain IITR6b2. This study involves a greener approach with no hazardous chemicals and one-step biotransformation of pyrazinamide to its acid hydrazide (through hydrazinolysis). The Central Composite Design of the Response Surface Methodology was used to find the factors affecting the synthesis of the pyrazine-2-carboxylic acid hydrazide and pyrazine-2-carboxylic acid to find its true optimum. The four factors, namely pyrazinamide, hydrazine dihydrochloride, temperature, and cell concentrations, were considered during optimization. The optimized reaction conditions from the Central Composite Design for achieving the 32.26 mM of pyrazine-2-carboxylic acid hydrazide involve 40 mM of pyrazinamide, 1000 mM of hydrazine dihydrochloride with 2.5 mg/mL cell concentration at 20 °C. It resulted in an optimum production of pyrazine-2-carboxylic acid hydrazide utilizing the acyltransferase activity of amidase of Bacillus smithii IITR6b2, and the results obtained through the Design of Experiments were validated. The fed-batch biotransformation was carried out with alginate-entrapped whole-cell enzyme with the following parameters: agitation at 200 rpm, a pyrazinamide concentration of 40 mM, and 1000 mM of hydrazine dihydrochloride. The final pyrazine-2-carboxylic acid hydrazide concentration of 126 mM was obtained, corresponding to a 63% molar conversion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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17. Acrylic modification as an environmentally acceptable supporter for improving peroxidase enzyme: stability and reusability.
- Author
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Almulaiky, Yaaser Q.
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ENZYME stability , *GOLD nanoparticles , *ACRYLIC textiles , *SILVER nanoparticles , *METAL nanoparticles - Abstract
This study focuses on the immobilization of horseradish peroxidase (HRP) on modified acrylic fabrics incorporating gold and silver nanoparticles. The process involves treating the acrylic fabrics with hydroxylamine hydrochloride and then coating them with silver and gold nanoparticles. Both obtained materials, treated acrylic fabrics-coated with silver nanoparticles (AgNPs@TA-HAC) and treated acrylic fabrics-coated with gold nanoparticles (AuNPs@TA-HAC), were utilized as supporters for HRP. The physicochemical properties of modified acrylic fabrics were investigated using FTIR, SEM, and zeta potential. HRP immobilized on AgNPs@TA-HAC displayed an activity of 69 units/g support with a specific activity of 4.55 units/mg protein, whereas HRP immobilized on AuNPs@TA-HAC demonstrated an activity of 76 units/g support with a specific activity of 4.75 units/mg protein. After the 15 repetitive cycles, the immobilized HRP on AuNPs@TA-HAC and AgNPs@TA-HAC retained 75 and 59% of their enzymatic activity, respectively. The immobilized HRP on both material supporters retained its activity better compared to the free HRP when exposed to all tested organic solvents. The Michaelis constant (Km) for free HRP and HRP immobilized on AuNPs@TA-HAC and AgNPs@TA-HAC were determined to be 6.23, 8.65, and 9.11 mM, respectively. The maximum reaction rates (Vmax) for the immobilized HRP on both supports were slightly reduced at 0.71 and 0.69 U/mL, compared to 0.74 U/mL for free HRP. This approach of utilizing acrylic fabrics and metal nanoparticles provides a promising method for enzyme immobilization, with potential applications in various industries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Functionalized magnetic nanoparticles for Cellic Ctec2 cellulase immobilization: Allowing reusability of enzyme in the conversion of cellulosic biomass.
- Author
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Punia, Pallavi and Singh, Lakhvinder
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ENZYME stability , *IMMOBILIZED enzymes , *HYDROLASES , *FOURIER transform infrared spectroscopy , *FIELD emission electron microscopy , *CELLULASE - Abstract
The method of enzyme immobilization can ameliorate the overall stability and restoration of enzymes, hence facilitating their broader application in several sectors. This investigation utilized cellulase as a hydrolytic enzyme. In order to enhance the stability and performance of the cellulase enzyme, the research employed immobilization technology to secure the Cellic Ctec2 cellulase to the synthesized Cs@Fe3O4 nanocomposites. Fe3O4 nanoparticles (NPs) were coated with chitosan obtained from co-precipitation method that served as enzyme carrier. The NPs (Cs@ Fe3O4) were observed under XRD; VSM (vibrating-sample magnetometer) shows saturation magnetizations (Ms), UV–vis, field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FT-IR). Response surface approach was applied to optimize the conditions for immobilization of cellulase. The optimum immobilization of cellulase reaches to 99.1% of loading efficiency and 69.7% of recovery activity with 2.5% of glutaraldehyde concentration. Furthermore, under ideal circumstances the immobilized enzyme's thermostability, pH stability, temperature tolerance and reusability, were studied with respect to free cellulase. Higher relative activity of cellulase enzyme was observed at pH 5 with 50 °C temperature than free enzyme. One percent CMC hydrolysis is considered for reusability of free and immobilized enzyme and releases 222 mg glucose/g substrate at 24 h, showing great quiescence in cellulosic biomass conversion. Immobilized cellulase demonstrated high reusability by retaining almost 61.2% up to the 5th cycles and 51.2% of activity-maintained 10th cycle of hydrolysis. Reusability of cellulase enzyme can attain a gradual decrease in relative activity as number of repeats of the cycle increases to 10 during hydrolysis and increases in glucose yield after hydrolysis. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Synthesis of dioctyl sebacate catalysed by cellulose-immobilized lipase.
- Author
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Zhou, Yuyang, Mang, Rongchen, Long, Huiyi, Li, Yamiao, Zhou, Hua, and Lu, Dingqiang
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IMMOBILIZED enzymes , *MOLECULAR sieves , *POLYETHYLENE glycol , *LIPASES , *POLLUTION , *CELLULOSE - Abstract
Dioctyl sebacate is a long carbon chain dibasic acid ester with methylene as the main body. It is widely used in plasticizers because of its good cold resistance and high viscosity. And it has excellent properties of non-toxicity and easy biodegradation, so it can be used as a potential new green bio-based plasticizer. At present, most of the preparation methods of dioctyl sebacate are chemical methods, which have many by-products and cause environmental pollution. In this article, cellulose microspheres were used as a carrier to immobilize Candida antarctica lipase B (CALB) to catalyse the esterification of sebacic acid and n-octanol to prepare dioctyl sebacate. Through single factor experiments, the lipase immobilized on cellulose microspheres was optimized to determine the best process conditions: add 500 µL CALB to the erlenmeyer flask, and then add 0.02 mol/L PBS buffer (pH 8.0). After being prepared into a 5 mL system, 0.1 g of cellulose microspheres were added as a carrier and reacted for 3 h at 35 °C and 180 r/min. Added 0.5 vt% polyethylene glycol diglycidyl ether (PEGDEG) to the system for crosslinking. The final immobilization rate of lipase immobilized on cellulose microspheres was 80.06%, and the enzyme activity was 288.07 U/g. Using the cellulose-immobilized lipase as a catalyst, in the toluene system, the molar ratio of n (sebacic acid)/n (n-octanol) substrate was 1:3.5, the amount of immobilized enzyme was 0.04 g, 4 Å molecular sieve 1.5 g, 40 °C, and 150 r/min for 30 h, the conversion rate of dioctyl sebacate was 76.45%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Enzyme Engineering: Performance Optimization, Novel Sources, and Applications in the Food Industry.
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Mao, Shucan, Jiang, Jiawen, Xiong, Ke, Chen, Yiqiang, Yao, Yuyang, Liu, Linchang, Liu, Hanbing, and Li, Xiang
- Abstract
This review summarizes the latest progress in enzyme preparation, including enzyme design and modification technology, exploration of new enzyme sources, and application of enzyme preparation in food processing, detection, and preservation. The directed evolution technology improved the stability and catalytic efficiency of enzymes, while enzyme immobilization technology enhanced reusability and industrial applicability. Extremozymes and biomimetic enzymes exhibit excellent performance under harsh conditions. In food processing, enzyme preparation can improve food quality and flavor. In food detection, enzymes combined with immune detection and biosensors realize rapid detection of allergens, pollutants, and pesticide residues. In food preservation, enzymes enhance food quality by extending shelf life and inhibiting microbial growth. In the future, enzyme engineering will be combined with computer-aided design, artificial intelligence, and new material technology to promote intelligent enzyme design and multifunctional enzyme preparation development and help the technological upgrading and sustainable development of the food industry and green chemistry. [ABSTRACT FROM AUTHOR]
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- 2024
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21. Covalent Immobilization of Cellulase Enzyme on Chitosan and Eudragit S-100 Biopolymers for Recovery and Reusability in Denim Fading Application.
- Author
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Madhu, Amit and Chakraborty, Jadunandan
- Abstract
The cellulase enzyme has significant potential for applications in textile chemical processing, offering an environmentally friendly alternative to traditional chemical methods. In conventional enzymatic treatments, the enzymes act as biocatalysts and are typically discarded as effluent after completing their function. However, the single-use nature, high production costs, and limited biological activity of cellulase enzymes hinder their widespread commercial use in the textile industry. This study focuses on the immobilization of a commercial cellulase enzyme onto two distinct reversible soluble–insoluble polymers Chitosan and Eudragit S-100 for the recovery and reusability. Chitosan and Eudragit were chosen as support materials due to their pH-dependent soluble–insoluble properties. These properties allow them to act as homogeneous catalysts in their soluble phase during application (since textile materials are heterogeneous) and enable easy recovery in their insoluble phase for subsequent reuse. The immobilization process was optimized to achieve maximum enzyme activity with ideal enzyme loading percentages. After immobilization on chitosan, the cellulase retained 92% of its initial activity with a loading efficiency of 73.7%, while on Eudragit, it maintained 86.5% activity with a loading efficiency of 75.6%. Fourier-transform infrared spectroscopy (FTIR) was employed to confirm the successful attachment of the cellulase enzyme to the polymers. The immobilized cellulase demonstrated equivalent fading effects compared to the native cellulase in terms of color depth (K/S value) and color metrics (L*, a*, b*), while also reducing physical damage and back-staining—common issues in the traditional denim fading process. Scanning electron microscopy (SEM) and back-staining analyses of the denim samples provided further evidence of these benefits. Moreover, the immobilized cellulase maintained approximately 50% of its activity even after recovery from five denim washing cycles, showcasing the potential for reuse across multiple applications, particularly in textile processing. Thus, cellulase immobilized on chitosan and Eudragit S-100 represents a promising solution for the sustainable use of enzymes in the textile industry. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Synergistic sodium alginate- and biochar-immobilized cells for enhancing fermentative hydrogen production from food waste.
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Ngamnurak, Phonsini, Plangklang, Pensri, Pomdaeng, Prakaidao, Ko, Ting-Wu, Reungsang, Alissara, and Chu, Chen-Yeon
- Abstract
An immobilized hydrogen-producing consortium investigated biohydrogen production from food waste using a combination of sodium alginate and cassava rhizome biochar. We investigated the effect of varying the biochar concentration from 0 to 3% and the size of immobilized cells from 1 to 7 mm. Immobilized cells were prepared using 50% (v/v) enriched hydrogen-producing consortium, 2% (w/v) sodium alginate, and 0 to 3% (w/v) cassava rhizome biochar. The optimal conditions for achieving the highest hydrogen production in the batch fermentation reactor were identified as a biochar concentration of 2% (w/v) and an immobilized cell size of 2 mm. The highest hydrogen yield, maximum hydrogen production rate, and lag time recorded were 0.69 mmol H
2 /g-COD, 0.02 mmol H2 /g-COD.h, and 41.51 h, respectively. This research highlights the potential of cassava biochar technology for efficient biohydrogen production from food waste, contributing to renewable energy generation and sustainable waste management. [ABSTRACT FROM AUTHOR]- Published
- 2024
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23. Immobilization of pullulanase from Bacillus licheniformis on magnetic multi-walled carbon nanotubes for maltooligosaccharide production.
- Author
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Varan, Nazli Ece, Alagöz, Dilek, Toprak, Ali, Korkmaz Güvenmez, Hatice, and Yildirim, Deniz
- Abstract
In this study, Fe
3 O4 -coated multi-walled carbon nanotubes (MWCNT-Fe3 O4 ) or nickel oxide-coated multi-walled carbon nanotubes (MWCNT-NiO) were activated with 3-Glycidyloxypropyl)trimethoxysilane (3-GPTMS) to create oxirane groups. Pullulanase from Bacillus licheniformis was covalently immobilized on these magnetic MWCNTs to obtain magnetically separable immobilized pullulanase preparations (MWCNT-Fe3 O4 @Pul or MWCNT-NiO@Pul) for producing maltooligosaccharides (MOSs) from pullulan. The highest recovered activity values were 78% and 85% respectively, for MWCNT-Fe3 O4 @Pul and MWCNT-NiO@Pul after 24 h of immobilization at pH 7.0. The optimal pH and temperature were found to be 5.5 and 45 °C for free pullulanase, whereas the corresponding values were 5.5 and 50 °C for both immobilized pullulanase preparations. The thermal stabilities of MWCNT-Fe3 O4 @Pul and MWCNT-NiO@Pul increased by 6.2- and 8.2-fold, respectively, at 50 °C. The catalytic efficiencies of MWCNT-Fe3 O4 @Pul and MWCNT-NiO@Pul were calculated to be 0.8- and 1.1-fold that of free pullulanase, respectively. After 24 h of hydrolysis, MOS yields were determined to be 470 and 490 mg MOS/g pullulan for MWCNT-Fe3 O4 @Pul and MWCNT-NiO@Pul, respectively. The remaining activities were 86% and 85% for MWCNT-Fe3 O4 @Pul and MWCNT-NiO@Pul after 10 reuses, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2024
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24. Immobilization of Phenazine-1-carboxylic Acid on Chitosan/Polyvinyl Alcohol Gel and its Enhancement Effect on the Decolorization of Disperse Red S-R by Shewanella oneidensis.
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Li, Yanbo, Liu, Guohong, and Shi, Huai
- Abstract
Soluble electron shuttles have been found to facilitate the biodecolorization of azo dyes, yet their loss due to water flow can escalate costs and risk secondary pollution. This issue can be mitigated by immobilizing the shuttles. In this study, we immobilized phenazine-1-carboxylic acid (PCA) using a chitosan/polyvinyl alcohol gel carrier and investigated its effect on the degradation of disperse red S-R (DR S-R) by Shewanella oneidensis FJAT-2478. Both free and immobilized PCA significantly increased the decolorization rate within a 50–400 mg/L concentration range for DR S-R, without affecting the final efficiency. Immobilized PCA was slightly less effective than free PCA (4.18-fold at 100 mg/L DR S-R), but was 3.63-fold more effective than the control group without PCA. It also demonstrated excellent reusability, retaining 83% of its initial activity after 10 cycles. Unlike free PCA, which reduced flavin secretion of FJAT-2478 by 36.4%, immobilized PCA increased it by 19.5%, indicating potential differences in their electron transfer modes. This study highlights the potential of immobilized phenazine-based electron shuttles in biologically decolorizing disperse dye wastewater. [ABSTRACT FROM AUTHOR]
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- 2024
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25. 基于聚乙烯亚胺改性纳米磁球的木瓜 蛋白酶固定化.
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梁 杰, 林国荣, 邹汉勋, 周凤超, 郭天章, 曾 捷, 刘 涛, 杨 磊, and 蔡力锋
- Abstract
Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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26. Syngas production and heavy metal dynamics during supercritical water gasification of sewage sludge.
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Yan, Mi, Liu, Shuai, Zhang, Haihua, Zheng, Rendong, Cui, Jintao, Wang, Dan, Rahim, Dicka Ar, and Kanchanatip, Ekkachai
- Abstract
The rising production of sewage sludge, characterized by high organic content and excessive heavy metals, necessitates an effective treatment method. This study investigated the production of syngas and the migration and transformation behavior of heavy metals such as Zn, Ni, Cr, Cu, and As during supercritical water gasification (SCWG) of sewage sludge. The experiments were conducted without or with alkaline additives at temperatures between 380 to 420 °C and retention time from 15 to 60 min. The results revealed that the highest syngas yield reached 10.9 mol/kg with an H
2 concentration of 44.7% at 420 °C and 60 min. In this process, heavy metals were effectively immobilized and converted into a more stable form, whereas higher temperatures and longer retention time enhanced this effect. The introduction of alkaline additives (NaOH, KOH, Ca(OH)2 , Na2 CO3 , and K2 CO3 ) led to the redistribution of heavy metals, further promoting the stabilization of Zn, Cr, and Cu. An environmental risk assessment showed that SCWG could significantly lower the risk associated with heavy metals to a low or negligible level. [ABSTRACT FROM AUTHOR]- Published
- 2024
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27. Fermented antler extract attenuates muscle atrophy by regulating the PI3K/Akt pathway and inflammatory response in immobilization-treated C57BL/6J mice.
- Author
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Yoo, Jihee, Kim, Changhee, Lee, Hyerin, Ko, Bong Soo, Lee, Dong-Woo, and Hwang, Jae-Kwan
- Abstract
Muscle atrophy or muscle wasting, which is featured by reduced muscle function and mass, typically results from disuse, aging, and chronic diseases. The deer antler, which refers to the young and non-ossified antlers of various species of deer-related animals, is not fully calcified and comprises of densely growing hair. Here, we investigated whether Bacillus subtilis-fermented antler extract (FAE) inhibits immobilization-induced muscle atrophy in C57BL/6J mice. Oral administration of FAE increased grip strength, exercise performance, muscle mass, and volume in mice. FAE stimulated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, enhancing the mammalian target of rapamycin pathway for muscle synthesis. FAE phosphorylated Forkhead box O3 and downregulated muscle RING finger-1 and atrogin-1 for proteolysis. FAE inhibited the mRNA expression of tumor necrosis factor alpha and interleukin-6 through nuclear factor kappa B. Consequently, FAE attenuated muscle atrophy by regulating the PI3K/Akt pathway and inflammation. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Strategies for cadmium remediation in nature and their manipulation by molecular techniques: a comprehensive review.
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Iqbal, K., Yahya, S., Jadoon, M., Yaseen, E., and Nadeem, Z.
- Abstract
The entire environmental integrity is intrinsically tied to the quality of life on earth. The protection of freshwater resources for present and future use is one of the significant global issues. Industrialization introduces toxic metals such as Cadmium, Lead, Mercury, Arsenic, Copper, etc. and their derivatives in the environment which are mutagenic and cancerous even at low doses. Cadmium (Cd) is categorized as a group 1 human carcinogen. Considering its possible removal from the environment, different strategies are used to lessen its concentration in the ecosystem. The conventional techniques used to remove heavy metals have some limitations. Given the restrictions of traditional approaches, the requirements for innovative technologies becomes evident. This narrative review is focused on the following three key aspects. How gene modifications in microorganisms enhance their biodegradation capabilities with the help of overexpression of different metal binding proteins in microbes, such as phytochelatins, glutathione, metallothioneins, CrMTP4, pyrroline-5-carboxylate synthetase and histidine oligopeptide, for the removal of contaminants, specifically Cd. Use of agricultural waste for phytoremediation: The description of genetically and chemically modified wastes from agriculture such as husks, sugarcane bagasse, wheat bran, pineapple waste, date pit, pomegranate and orange peel and different modified strategies for Cd removal, is also provided. Nanotechnology in microbial cell immobilization: The achievements of different strategies especially immobilization and its advantages over free cells. This review discusses the advantages of immobilization of genetically engineered microorganisms are a favored innovation for harnessing the extraordinary metabolic pathway characteristics of microorganisms and nanomaterials enhancement of efficiency and stability of such cells. [ABSTRACT FROM AUTHOR]
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- 2024
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29. Innovative application of Myrrh resin (<italic>Commiphora molmol</italic>) as new biocarrier for immobilization of bacterial cells mix for biodegradation of anionic surfactant in airlift bioreactor: Assessment of hydrodynamic parameters.
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Najim, Aya A. and Ismail, Zainab Z.
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SEWAGE , *ANIONIC surfactants , *BACTERIAL cells , *SODIUM sulfate , *CIRCULATION models , *BIOSURFACTANTS - Abstract
AbstractImmobilization of bacterial cells proved to offer remarkable advantages over conventional biotreatment systems using free cells. In this study, Myrrh resin (MR) was utilized as a new nonconventional biocarrier for bacterial cells immobilization used for aerobic degradation of sodium dodecyl sulphate (SDS) in a lab-scale airlift bioreactor (ALBR). Biodegradation of SDS was individually accomplished in four different actual SDS loaded-wastewaters including municipal wastewater (MWW), detergents industry wastewater (DWW), laundry wastewater (LWW) and carwash garage wastewater (CWW). Effects of air and wastewater flowrates on SDS biodegradation rate were determined in the ALBR. The results indicated that by increasing the flowrate of air from 1.5 to 2.5 L/min, the SDS biodegradation increased, whereby, it decreased by increasing the liquid flowrate from 1.2 to 2 mL/min. The power input in the ALBR increased from 0.09 to 0.72 W, as the air flowrate into the riser increased from 1.5 to 2.5 L/min. Experimental data of the overall gas holdup fitted well with the predicted data obtained by Chisti correlation with coefficient of determination (
R 2) equal 0.939 and sum-squared error (SSE) of 6.2 × 10−4. The liquid circulation velocity model obtained by Chisti fitted well the experimental value with (R 2) of 0.950. [ABSTRACT FROM AUTHOR]- Published
- 2024
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30. Enhanced biosorption of cadmium ions on immobilized surface-engineered yeast using cadmium-binding peptides.
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Wang, Songting, Sun, Yongmei, Wang, Shihong, Fan, Chunkun, Wang, Daojie, Liu, Fei, and Zhang, Haiyan
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SURFACES (Technology) ,PEPTIDES ,BIOSORPTION ,SODIUM alginate ,SACCHAROMYCES cerevisiae - Abstract
A new type of cadmium (Cd) ion cell surface adsorbent was developed by integrating bacteriophage display peptide library technology with cell surface display technology. Cd
2+ chelating resin served as the target molecule in screening experiments, leading to the identification of four Cd2+ −binding peptides. These peptides were introduced into Saccharomyces cerevisiae via the pYD1 plasmid using lithium acetate heat shock transformation. Adsorption efficiency tests indicated that the engineered yeasts adsorbed more Cd2+ than the control strain EBY100 when exposed to the same amount of Cd2+ . Among these peptides, sequence 3-containing strain was demonstrated to have the highest Cd2+ adsorption efficiency, being 35% higher than the control strain. Additionally, when this recombinant yeast strain was immobilized using sodium alginate, the adsorption efficiency was increased by 55.7% compared to the control strain. [ABSTRACT FROM AUTHOR]- Published
- 2024
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31. Comparison of protein immobilization methods with covalent bonding on paper for paper-based enzyme-linked immunosorbent assay.
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Chen, Yang, Danchana, Kaewta, and Kaneta, Takashi
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ENZYME-linked immunosorbent assay , *CHEMICAL reduction , *THERAPEUTIC immobilization , *SCHIFF bases , *CHEMICAL bonds - Abstract
In this study, two methods were examined to optimize the immobilization of antibodies on paper when conducting a paper-based enzyme-linked immunosorbent assay (P-ELISA). Human IgG, as a test-capture protein, was immobilized on paper via the formation of Schiff bases. Aldehyde groups were introduced onto the surface of the paper via two methods: NaIO4 and 3-aminopropyltriethoxysilane (APTS) with glutaraldehyde (APTS-glutaraldehyde). In the assay, horseradish peroxidase-conjugated anti-human IgG (HRP-anti-IgG) binds to the immobilized human IgG, and the colorimetric reaction of 3,3′,5,5′-tetramethylbenzyzine (TMB) produces a blue color in the presence of H2O2 and HRP-anti-IgG as a model analyte. The immobilization of human IgG, the enzymatic reaction conditions, and the reduction of the chemical bond between the paper surface and immobilized human IgG all were optimized in order to improve both the analytical performance and the stability. In addition, the thickness of the paper was examined to stabilize the analytical signal. Consequently, the APTS-glutaraldehyde method was superior to the NaIO4 method in terms of sensitivity and reproducibility. Conversely, the reduction of imine to amine with NaBH4 proved to exert only minimal influence on sensitivity and stability, although it tended to degrade reproducibility. We also found that thick paper was preferential when using P-ELISA because a rigid paper substrate prevents distortion of the paper surface that is often caused by repeated washing processes. [ABSTRACT FROM AUTHOR]
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- 2024
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32. Study of the poly (butylene adipate-co-terephthalate)/poly (vinyl alcohol) coated recycled Fe3O4 magnetic particle carriers for immobilization penicillin G acylase.
- Author
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Abdelrahman Mohammed, Monier Alhadi, Wang, Nan, Chen, Zhenbin, Jin, Pen, Du, Xueyan, and Li, Bin
- Subjects
- *
INDUCTIVELY coupled plasma mass spectrometry , *ELECTRON spectroscopy , *PENICILLIN G , *MAGNETIC particles , *INFRARED spectroscopy - Abstract
AbstractIn this work, the process began by coating a layer of poly (butylene adipate-co-terephthalate) (PBAT)/poly (vinyl alcohol) (PVA) on the surface of magnetic Fe3O4 particles (MPs) obtained from the nickel slag. Then, it was grafted by glutaraldehyde (GA) to obtain Fe3O4@PBAT/PVA-g-GA MPs, which were used as a carrier. Finally, the immobilized PGA was achieved by forming a covalent bond through the Schiff base reaction. To confirm each stage, employed Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibration sample magnetometer (VSM), scanning electron microscope-energy spectroscopy of dispersive x-rays (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS), and x-ray photoelectron spectrophotometry (XPS). The immobilization conditions were studied and optimized to improve immobilized PGA stability and catalytic activity. The immobilization of PGA demonstrated its optimal performance under the process conditions. The results were achieved using a 2.5 vol.% enzyme solution concentration, a pH of 8.0, an immobilization time of 24 h, and an immobilization temperature of 37 °C. Under these conditions, the immobilized PGA exhibited an enzyme activity recovery (
EAR ) of 93.71%, an enzyme activity (EA ) of 31,367 U/g, and an enzyme loading capacity (EL C) of 111 mg/g. The operating stability, reusability, and storage stability of Fe3O4@PBAT/PVA-g-GA-PGA MPs were investigated. Comparatively, immobilized PGA exhibited superior operational and storage stability compared to free PGA. Even after 11 repeated uses, the immobilized PGA retained 58% of its initial activity, while the carrier recovery (Re ) reached 82%. This indicated that the immobilized PGA MPs offer improved longevity and efficiency, making them a promising choice for practical applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
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33. Immobilization of radioactive borate liquid waste using calcined laterite–phosphoric acid–Fe3O4-based geopolymer waste forms.
- Author
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Xu, Zhonghui, Li, Chao, and Peng, Xi
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IRON oxides , *LIQUID waste , *COMPRESSIVE strength , *LATERITE , *TETRAHEDRA - Abstract
In this study, the feasibility of preparing a calcined laterite–phosphoric acid–Fe 3 O 4 -based geopolymer is investigated and its application for immobilizing radioactive borate liquid waste (RBLW) is explored. The addition of Fe 3 O 4 enhances the compressive strength of the geopolymer and mitigates the retardation effects on the geopolymer caused by RBLW. Reactions between Fe 3 O 4 and H 3 PO 4 not only promote the geopolymerization process by generating heat and forming additional geopolymer gel, but also produce amorphous iron–phosphorus phases, contributing to higher compressive strength of the waste forms. Moreover, partial replacement of [AlO 4 ] tetrahedra with [FeO 6 ] octahedra creates stable –Fe–O–P–O–Al–O–Si– network structures. The geopolymer waste forms exhibit remarkable leaching resistance after Fe 3 O 4 addition owing to the reduced open porosity, leading to radionuclide immobilization through physical encapsulation more efficiently. Furthermore, residual Fe 3 O 4 may contribute to Co2+ immobilization through magnetic adsorption. Overall, the calcined laterite–phosphoric acid–Fe 3 O 4 -based geopolymer waste forms exhibit excellent performance in immobilizing RBLW, offering a new strategy for RBLW treatment. [ABSTRACT FROM AUTHOR]
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- 2024
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34. Aldoxime dehydratases: production, immobilization, and use in multistep processes.
- Author
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Martínková, Ludmila, Kotik, Michael, Kulik, Natalia, Křístková, Barbora, Šťastná, Katarína, and Winkler, Margit
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- *
CHEMICAL reactions , *ORGANIC chemistry , *LYASES , *CHEMICAL synthesis , *ALDOXIMES - Abstract
The synthesis of nitriles is of utmost importance for preparative organic chemistry. The classical routes are often associated with disadvantages such as toxicity of the reagents and drastic conditions. The uses of enzymes like aldoxime dehydratases (Oxds) and hydroxynitrile lyases constitute attractive benign alternatives. In this review, we summarize the recent trends regarding Oxds. Thousands of oxd genes were sequenced but less than thirty Oxds were investigated on protein level. We give an overview of these Oxds, their sequence analysis, conditions required for their overexpression, and their purification and assays. We then focus on the use of Oxds especially in multistep reactions combining the chemical or chemoenzymatic synthesis of aldoximes from different starting materials with the enzymatic dehydration of aldoximes to nitriles, possibly followed by the hydration of nitriles to amides. Progress in Oxd immobilization is also highlighted. Based on data published mainly in the last 5 years, we evaluate the industrial prospects of these enzyme processes in comparison with some other innovations in nitrile synthesis. Key points: • Aldoxime dehydratases (Oxds) are promising for cyanide-free routes to nitriles • A comprehensive overview of wet-lab explored Oxds is provided • Recent trends include combining Oxds with other enzymes or chemical catalysts [ABSTRACT FROM AUTHOR]
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- 2024
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35. Biochemical properties of immobilized horseradish peroxidase on ceramic and its application in removal of azo dye.
- Author
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Salah, Hala A., Elsayed, Alshaimaa M., Abdel-Aty, Azza M., Khater, Gamal A., El-Kheshen, Amany A., Farag, Mohammad M., and Mohamed, Saleh A.
- Subjects
- *
HORSERADISH peroxidase , *SCANNING electron microscopes , *CERAMIC materials , *TRITON X-100 , *DIMETHYL sulfoxide , *AZO dyes - Abstract
In the current work, electrostatic interactions were used to immobilize the horseradish peroxidase (HRP) onto five types of ceramic materials (C) with different concentrations of oxidized metals (C1–C5). The highest immobilization efficiency (70 and 77%) was detected at 6 mg C3 and 18 enzyme units. Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) and Fourier Transform Infrared (FTIR) analysis of C3-HRP confirmed the immobilization of the enzyme. After ten reuses, the reusability analysis showed that (66%) of the C3-HRP enzyme activity was retained. For C3-HRP, the optimum pH and temperature of the soluble enzyme were shifted from 7.0 and 30 °C to 6.0 and 50 °C. Up to 40 °C and 50 °C, respectively, the soluble HRP and C3-HRP remained steady. The kinetic analysis revealed that the Km and Vmax of soluble HRP and C3-HRP were, respectively, 5.5 mM, 0.66 units, and 8 mM, 0.52 units for hydrogen peroxide (H2O2) and 35.5 mM, 3.4 units and 40 mM, 1.1 units for guaiacol. Compared to soluble-HRP, the C3-HRP exhibited a greater oxidizing affinity toward several phenolic compounds (Guaiacol, o-dianisidine, o–phenylenediamine, pyrogallol, p-aminoantipyrine). In comparison with soluble-HRP, the C3-HRP showed increased stress tolerance with Triton X-100, urea, metals, isopropanol, and dimethyl sulfoxide. The C3-HRP removed methyl orange more effectively compared to soluble-HRP. [ABSTRACT FROM AUTHOR]
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- 2024
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36. 3D-environment and muscle contraction regulate the heterogeneity of myonuclei.
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Nicolas, Rosa, Bonnin, Marie-Ange, Blavet, Cédrine, de Lima, Joana Esteves, Legallais, Cécile, and Duprez, Delphine
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- *
CONNECTIVE tissue cells , *MYOTENDINOUS junctions , *MUSCLE contraction , *CHICKEN embryos , *MUSCLE cells - Abstract
Skeletal muscle formation involves tight interactions between muscle cells and associated connective tissue fibroblasts. Every muscle displays the same type of organisation, they are innervated in the middle and attached at both extremities to tendons. Myonuclei are heterogeneous along myotubes and regionalised according to these middle and tip domains. During development, as soon as myotubes are formed, myonuclei at muscle tips facing developing tendons display their own molecular program. In addition to molecular heterogeneity, a subset of tip myonuclei has a fibroblastic origin different to the classical somitic origin, highlighting a cellular heterogeneity of myonuclei in foetal myotubes. To gain insights on the functional relevance of myonucleus heterogeneity during limb development, we used 2D culture and co-culture systems to dissociate autonomous processes (occurring in 2D-cultures) from 3D-environment of tissue development. We also assessed the role of muscle contraction in myonucleus heterogeneity in paralysed limb muscles. The regionalisation of cellular heterogeneity was not observed in 2D cell culture systems and paralyzed muscles. The molecular signature of MTJ myonuclei was lost in a dish and paralysed muscles indicating a requirement of 3D-enviroment and muscle contraction for MTJ formation. Tip genes that maintain a regionalized expression at myotube tips in cultures are linked to sarcomeres. The behaviour of regionalized markers in cultured myotubes and paralyzed muscles allows us to speculate whether the genes intervene in myogenesis, myotube attachment or MTJ formation. Highlights: • The molecular signature of MTJ myonuclei is lost in cultured myotubes and paralysed muscles • Genes expressed in muscle tips that maintain their regionalised expression in cultured myotubes are linked to sarcomeric proteins • Cellular heterogeneity of myonuclei is observed in cultured myotubes but with no regionalisation • BMP signalling regulates fibroblast nucleus incorporation into cultured myotubes [ABSTRACT FROM AUTHOR]
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- 2024
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37. Yeast Surface Display Enables One‐Step Production and Immobilization of Unspecific Peroxygenases.
- Author
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Teetz, Niklas, Lang, Selina, Liese, Andreas, and Holtmann, Dirk
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- *
ENCAPSULATION (Catalysis) , *CHIMERIC proteins , *BATCH processing , *SACCHAROMYCES cerevisiae , *GENETIC code , *FUNGAL cell walls - Abstract
Unspecific peroxygenases (UPOs) are regarded as a "dream catalyst" for selective oxyfunctionalization reactions like oxygenations. We present the display of the model UPO rAaeUPO (PaDa−I) on the cell surface of the heterologous production host Komagataella phaffii as a one‐step production and immobilization process. The coding sequence for PaDa−I was combined with genes coding for cell wall proteins from Saccharomyces cerevisiae and transformed into K. phaffii. The fusion proteins were compared among each other and with secreted, free PaDa−I. One system in particular, a C‐terminal fusion of PaDa−I and Sag1 yielded near identical activity per volume culture broth to the secreted PaDa−I with ~90 % of the activity being at the cell wall. The surface display simplifies downstream processing and includes immobilization on a cheap, retainable and replaceable matrix, that is the production host itself. The enzymes remained active in a repeated batch process for 10 batches and 200 h of catalysis. [ABSTRACT FROM AUTHOR]
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- 2024
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38. Nitrite Electroreduction Enhanced by Hybrid Compounds of Keggin Polyoxometalates and 1‐Butyl‐3‐Vinylimidazolium.
- Author
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Zhou, Yulin, Sun, Jing, Gallet, Sébastien, Raya, Jesus, Boudon, Corinne, Bonnefont, Antoine, Ruhlmann, Laurent, and Badets, Vasilica
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- *
CARBON electrodes , *HYBRID materials , *CHEMICAL structure , *THERAPEUTIC immobilization , *CHEMICAL yield - Abstract
We describe here an immobilization method of four Keggin‐type polyoxometalates (POMs) ([H2W12O40]6−, [BW12O40]5− [SiW12O40]4−, [PW12O40]3−) by using the reaction with an ionic liquid, 1‐butyl‐3‐vinylimidazolium (BVIM) bromide. The reaction yields a hybrid material (BVIM‐POM) as a water‐insoluble salt. The chemical structure of both compounds is preserved, as indicated by infrared spectroscopy (FT‐IR), although with a reduced crystallinity (shown by X‐ray diffraction analysis) due to a decrease of water content (shown by thermogravimetric analysis). Cross polarization 1H‐31P NMR evidenced the presence of BVIM in the structure of (BVIM)3[PW12O40]. The salt is mixed with carbon powder and Nafion to prepare an ink and casted on glassy carbon electrodes. The electrochemical behavior of immobilized POMs material is preserved. The electrochemical activity for nitrite reduction is measured by cyclic voltammetry and differential electrochemical mass spectrometry (DEMS). It was observed that the reduction current of 10 mM HNO2 at pH 1 in 0.5 M Na2SO4 is enhanced in the presence of these hybrid materials. DEMS has evidenced the formation of nitrous oxide (N2O) at potentials more positive compared to the use of parent POMs in solution. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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39. Hydrophobic Ionic Liquid Gel Microspheres as Bi‐Component Carriers with a Liquid Phase to Immobilize Enzymes for Enhanced Performance.
- Author
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Ben, Chuxuan, Zhao, Shujie, Wu, Qiong, He, Hongjiang, Yu, Meng, Liu, Dong, He, Dongqing, Song, Xi‐Ming, and Song, Zhining
- Subjects
- *
IMMOBILIZED enzymes , *GLYCIDYL methacrylate , *ENCAPSULATION (Catalysis) , *FLUID inclusions , *SMALL molecules - Abstract
This study focuses on incorporating liquid molecules, different from the bulk solution, into the immobilized enzyme carrier to regulate the distribution effect and diffusion‐limiting impact of the carrier's microenvironment for substrates, which generally is difficult to achieve due to the instability of the materials with liquid inclusions. A freestanding liquid‐holding particle carrier, with bi‐component hydrophobic ionic liquid gel microspheres with poly (glycidyl methacrylate) as the network and 1‐butyl‐3‐methylimidazolium hexafluorophosphate as the dispersing medium, is proposed, which is stable in air aqueous solution, and can extract proteins and organic small molecules into its interior due to the mobility of its dispersing medium. Horseradish peroxidase is covalently immobilized into the microspheres, forming a liquid compartment enzyme microreactor. The microreactor exhibits superior stability, enzymatic activity, and catalytic performance for Basic Orange II degradation compared to free enzyme and liquid‐free immobilized enzymes. This is attributed to the biocompatibility of the ionic liquid, its role in substrate enrichment in its interior, and its rapid mass transfer capability. This contribution shows the effectiveness of regulating the carrier's microenvironment with liquid molecules, offering fresh perspectives and strategies for enzyme technology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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40. Physicochemical Characterization of Polysaccharide–Protein Carriers with Immobilized Yeast Cells Obtained Using the Freeze-Drying Technique.
- Author
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Obradović, Nataša, Balanč, Bojana, Salević-Jelić, Ana, Volić, Mina, Đorđević, Verica, Pešić, Mirjana, and Nedović, Viktor
- Subjects
WHEY proteins ,SURFACE charges ,IMMOBILIZED cells ,FREEZE-drying ,BEVERAGE industry ,MALTODEXTRIN ,INULIN - Abstract
New techniques for the immobilization of yeast cells have the potential for enhancement of the beer production process. Alongside conventional materials for cell immobilization, there is a rising trend toward polysaccharide–protein systems. This study focused on the immobilization of yeast cells (Saccharomyces pastorianus) via a freeze-drying process. The whey protein isolate, sodium alginate, maltodextrin, inulin, and their blends were used for carrier preparation. The effect of a 1.0% inulin solution as a cryoprotectant on the viability of the yeast cells after the freeze-drying process was also analyzed. The powders were assessed for cell viability, moisture content, water activity, solubility, particle size, and surface charge. According to the results, the addition of whey proteins reduced the moisture content, while solubility did not significantly decrease. Samples containing whey protein showed slight diameter variations. The negative surface charge observed in all samples, especially the control, indicates a cell's tendency to aggregate, demonstrated by optical microscopy. SEM micrographs showed successful cell immobilization in polysaccharide–protein carriers. Furthermore, inulin and whey protein addition enhanced cell protection during the immobilization of cells. The freeze-drying technique demonstrates efficacy in immobilization of yeast cells, indicating its potential for applications in the food and beverage industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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41. Carbonized biomass as an immobilization carrier in acetone-butanol-ethanol (ABE) fermentation by Clostridium beijerinckii JCM 8026.
- Author
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Sae-hun, Sarita, Chinwatpaiboon, Piyawat, Boonsombuti, Akarin, Savarajara, Ancharida, and Luengnaruemitchai, Apanee
- Abstract
ABE fermentation has been used to produce biobutanol for a long period of time. The main obstacles consisted of low productivity and cell viability. In this work, the immobilization technique was applied to improve cell culture over the free cell fermentation. Three types of carbonized biomass, cassava rhizome charcoal (CRC), bamboo charcoal (BC), and coconut shell activated carbon (CSAC), were selected and used as carriers for the immobilization of Clostridium beijerinckii JCM 8026. They were characterized by Brunauer–Emmett–Teller (BET) surface area analysis, zeta potential, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) to expose their surface and chemical properties. The results pointed out that the immobilized cell onto BC can produce butanol higher than the free cell while lessened by 8.7% and 19.7% in CRC and CSAC, respectively. However, CRC showed the highest cell efficiency after eight sequential reuse cycles. The improvement in butanol production is due to the surface area and the pore size of each of the carbonized materials. This work revealed the potential of carbonized biomass as a carrier, which can result in repeated inoculum and improved cell viability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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42. Cadmium, lead, and zinc immobilization in the soil using a phosphate compound with citric acid present.
- Author
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Islam, Md. Shoffikul, Kashem, Md. Abul, Moniruzzaman, Mohammad, Parvin, Afsana, Das, Suman, and Hu, Hongqing
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LEAD ,METAL compounds ,CITRIC acid ,ZETA potential ,EUROPEAN communities - Abstract
Low molecular weight organic acids (LMWOAs) are common in rhizospheric soil and may impede the interaction between phosphate and metals. Thus, studying how phosphate compounds impact metal immobilization in rhizospheric soil using LMWOAs is crucial. An incubation experiment examined the effects of NaH
2 PO4 (a P compound) (3%), various concentrations of citric acid (CA), and combinations of P and CA, on soil cadmium (Cd), lead (Pb), and zinc (Zn) immobilization using the European Community Bureau of Reference (BCR) sequential extraction method, CaCl2 extraction method, zeta potential, fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The P, low CA (2 mmol kg–1 soil) (CA2), and P-CA2 treatments reduced acid-soluble and CaCl2 -extractable Cd, Pb, and Zn, indicating metal immobilization, with the P-CA2 treatment being the most effective. High CA (>5–20 mmol kg–1 soil) or a P with high CA reversed prior patterns, suggesting metal mobilization. The zeta potential study indicated that when pH increased, treatments became more negative, notably P-CA2 followed by P, suggesting that electrostatic adsorption was the predominant metal immobilization mechanism, especially in P-CA2. XRD tests, however, showed that the P treatment alone produced Cd phosphate, pyromorphite, and hopeite, indicating that sorption and precipitation were the main metal immobilization processes in the P treatment alone. In conclusion, P-CA2 was found to be the most efficient metal immobilization and redistribution treatment for contaminated soils. Rhizospheric CA may alter Cd, Pb, and Zn mineral stability. Therefore, when treating Cd, Pb, and Zn-contaminated soils with a P compound, CA should be addressed. [ABSTRACT FROM AUTHOR]- Published
- 2024
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43. 一种高耐热乳糖酶的异源表达、固定化及酶学性质研究.
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徐惠东, 尤 扬, 游颖欣, 王周平, and 夏 雨
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IMMOBILIZED enzymes ,PYROCOCCUS furiosus ,BACILLUS subtilis ,INDUSTRIAL capacity ,THERMAL stability ,LACTOSE - Abstract
Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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44. Extracellular production of azurin by reusable magnetic Fe3O4 nanoparticle-immobilized Pseudomonas aeruginosa.
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Dagci, Ibrahim, Acar, Melek, Turhan, Fatma, Mavi, Ahmet, and Unver, Yagmur
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IRON oxides , *MAGNETIC nanoparticles , *FERRIC oxide , *PSEUDOMONAS aeruginosa , *THERAPEUTIC immobilization , *IMMOBILIZED cells - Abstract
Azurin, found in the periplasm of Pseudomonas aeruginosa , has garnered significant attention as a potential anticancer agent in recent years. High-level secretion of proteins into the culture medium, offers a significant advantage over periplasmic or cytoplasmic expression. In this study, for the first time, P. aeruginosa cells were immobilized with magnetic nanoparticles (MNPs) to ensure effective, simple and quick separation of the cells and secretion of periplasmic azurin protein to the culture medium. For this purpose, polyethyleneimine-coated iron oxide (Fe 3 O 4 @PEI) MNPs were synthesized and MNPs containing Fe up to 600 ppm were found to be non-toxic to the bacteria. The highest extracellular azurin level was observed in LB medium compared to peptone water. The cells immobilized with 400 ppm Fe-containing MNPs secreted the highest protein. Lastly, the immobilized cells were found suitable for azurin secretion until the sixth use. Thus, the magnetic nanoparticle immobilization method facilitated the release of azurin as well as the simple and rapid separation of cells. This approach, by facilitating protein purification and enabling the reuse of immobilized cells, offers a cost-effective means of protein production, reducing waste cell formation, and thus presents an advantageous method. • Polyethyleneimine-coated iron oxide (Fe 3 O 4 @PEI) magnetic nanoparticles (MNPs) were synthesized. • Magnetic immobilization efficiency of Pseudomonas aeruginosa cells increased by 97 %. • Nano-immobilized cells provided more efficient extracellular secretion of azurin. • The nano-immobilized cells were suitable until the sixth use. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Endoxylanase Immobilized Nanoporous Silica for the Production of Xylooligosaccharides: Equilibrium Kinetics, Thermodynamic Studies, and Enzyme Characteristics.
- Author
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Kartik, Jeevamani P. M., Dutta, Partha, Shivudu, Godhulayyagari, Sowmianarayanan, Parimala, Gardas, Ramesh L., Chandraraj, Krishnan, and Selvam, Parasuraman
- Subjects
- *
SILICA fume , *MESOPOROUS silica , *ACTIVATION energy , *BIOCATALYSIS , *XYLANASES - Abstract
Nanoporous structured silica materials, namely f‐SiO2, SBA‐15, IITM‐41, and MCM‐41 were employed as the matrices for immobilizing endoxylanase by adsorption method. The equilibrium kinetics, activation energy, and thermodynamic parameters associated with endoxylanase adsorption were investigated. Our findings revealed a two‐phase adsorption mechanism: an initial phase featuring rapid adsorption rates, succeeded by a slower phase wherein adsorption gradually progressed until equilibrium was attained. Analysis of the adsorption kinetic data indicated a better fit with the pseudo‐second‐order model, suggesting chemisorption and highlighting its temperature dependency. The calculated activation energy (Ea) values fell within the range of physisorption, indicating the involvement of both types of adsorption processes. Thermodynamic assessments confirmed that the adsorption reactions were spontaneous, feasible, and endothermic. Notably, the immobilization process did not change the optimum pH of the enzyme, while the optimum temperature shifted slightly. Furthermore, immobilized enzymes show a higher reaction rate (Vmax) than the soluble XynC. All immobilized xylanases produced xylobiose (X2) to xylohexose (X6) by hydrolyzing the xylan substrate. Recycling studies showed that up to 80 % of the yield was retained after seven cycles of reuse. Our study demonstrates the potential of nanostructured silica as an effective immobilization matrix for enzymes of industrial significance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Effects of high valency and polarizability ion (W6+) on the phase evolution of CaZr1–2xLn2xTi2–xWxO7 zirconolite-based solid solution (Ln = Nd, Sm, Gd, Ho, Yb).
- Author
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Huang, Yahe, Yang, Tonghan, Wang, Keshen, Liao, Chang-Zhong, Huangfu, Zhangyu, Fang, Shuohai, Luo, Hui, Yang, Wenchao, and Ma, Shengshou
- Subjects
- *
ENERGY dispersive X-ray spectroscopy , *SCANNING electron microscopes , *DOPING agents (Chemistry) , *X-ray diffraction , *SOLID solutions , *RARE earth metals , *SAMARIUM - Abstract
Zirconolite-based structures have served as robust matrices for the incorporation of minor actinide-rich high-level waste (HLW). The co-doping effects are critical for exploring the phase evolution of zirconolite-based structures, thereby providing a guide for HLW immobilization. Nevertheless, few studies have studied the synergistic effect of high valent ion W6+ and Lanthanides (Ln, surrogates to minor actinides) co-doping. This study proposed a systematical study on the Ln-W (Ln = Nd, Sm, Gd, Ho, Yb) co-doping in zirconolite-derived structure using X-ray diffraction (XRD) and scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX). The results showed that near-single-phase zirconolite-2M was recorded for samples with low level doping of Ln-W (Nd–W, Sm–W and Gd–W with x = 0.05; Ho–W and Yb–W with x = 0.05–0.1), and its structure underwent a moderate expansion along the c-axis, as revealed by a Pawley refinement method. One key finding is that near-single-phase zirconolite-2M was recorded for samples with low level doping of Ln-W (Nd–W, Sm–W and Gd–W with x = 0.05; Ho–W and Yb–W with x = 0.05–0.1), and its structure underwent a moderate expansion along the c-axis, as revealed by a Pawley refinement method. Notably, in addition to a transformation from zirconolite-2M to pyrochlore, a pseudo-yellow phase CaWO 4 was also noted with increasing co-doping contents. This work demonstrates that the high charge compensator W6+ and lanthanides can be simultaneously incorporated into zirconolite structure, and a different phase transformation was revealed compared to that in low valent element doping system, which gives a new insight into the optimization of HLW immobilization route. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Immobilization of Phospholipase D on Magnetic Graphene Oxide for Efficient Phosphatidylserine Production.
- Author
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Shang, Huiyi, Guo, Bishan, Wang, Juntan, Li, Huijuan, and Zhu, Haihua
- Subjects
- *
PHOSPHOLIPASE D , *PHOSPHATIDYLSERINES , *THERMAL resistance , *FOOD industry , *MAGNESIUM oxide - Abstract
Phosphatidylserine (PS) has significant applications in various sectors, such as the medical and food industries. However, its production relies heavily on phospholipase D (PLD), a crucial tool that is hindered by issues like poor stability and irrecoverability. Immobilization presents itself as an effective solution to overcome these limitations. In this study, magnetic graphene oxide (MGO) modified with an amino (NH2) group was synthesized and utilized for PLD immobilization. The activity of the immobilized PLD (MGO-PLD) reached 3062 U/gMGO, with a specific activity of 33.9 U/mgPLD, virtually identical to that of the free PLD. MGO-PLD was utilized to synthesize PS efficiently in a biphasic system. Under optimal conditions, the PS yield reached 18.66 g/L, with a conversion rate of 92.8% and a productivity of 3.11 g/L/h. Notably, MGO-PLD retained an impressive PS conversion rate of 77.4% even after seven repetitive usages. Moreover, MGO-PLD displayed enhanced thermal and pH resistance properties compared to free PLD, alongside augmented storage stability. After an 8-week preservation at 4 °C, its residual activity was maintained at 76.3%. This study provides a sustainable and highly efficient pathway for the biocatalytic synthesis of PS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Advances in Targeted Microbeam Irradiation Methods for Live Caenorhabditis elegans Charged-particle microbeam irradiation devices, which can convert heavy-ion or proton beams into microbeams and irradiate individual animal cells and tissues, have been developed and used for bioirradiation in Japan, the United States, China, and France. Microbeam irradiation technology has been used to analyze the effects of irradiation on mammalian cancer cells, especially bystander effects. In 2006, individual-level microbeam irradiation of the nematode Caenorhabditis elegans was first realized using JAEA-Takasaki's (now QST-TIAQS's) TIARA collimated microbeam irradiation device. As of 2023, microbeam irradiation of C. elegans has been achieved at five sites worldwide (one in Japan, one in the United States, one in China, and two in France). This paper summarizes the global progress in the field of microbeam biology using C. elegans, while focusing on issues unique to microbeam irradiation of live C. elegans, such as the method of immobilizing C. elegans for microbeam experiments.
- Author
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Suzuki, Michiyo
- Subjects
- *
RADIATION-induced bystander effect , *THERAPEUTIC immobilization , *IONIZING radiation , *HEAVY ions , *CANCER cells , *PROTON beams , *CAENORHABDITIS elegans - Abstract
Simple Summary: The nematode Caenorhabditis elegans, which is only 1 mm long, is used as a model to study the effects of irradiation on tissues (organs) of living organisms. This paper reviews the development of irradiation techniques using charged-particle microbeams in Japan, the U.S., China, and France, in which heavy-ion and proton beams (types of ionizing radiation) are targeted to specific cells or regions of C. elegans, and outlines the progress made over the past 20 years and where we are today. An essential part of irradiating the targeted cell/tissue of microscopic animals is having an immobilization method which does not damage the animals' physiological activity. This article introduces some technical difficulties that differ from those concerning the irradiation of cultured cells, which have been the main target of irradiation in the past. Charged-particle microbeam irradiation devices, which can convert heavy-ion or proton beams into microbeams and irradiate individual animal cells and tissues, have been developed and used for bioirradiation in Japan, the United States, China, and France. Microbeam irradiation technology has been used to analyze the effects of irradiation on mammalian cancer cells, especially bystander effects. In 2006, individual-level microbeam irradiation of the nematode Caenorhabditis elegans was first realized using JAEA-Takasaki's (now QST-TIAQS's) TIARA collimated microbeam irradiation device. As of 2023, microbeam irradiation of C. elegans has been achieved at five sites worldwide (one in Japan, one in the United States, one in China, and two in France). This paper summarizes the global progress in the field of microbeam biology using C. elegans, while focusing on issues unique to microbeam irradiation of live C. elegans, such as the method of immobilizing C. elegans for microbeam experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Combined Application of Biochar and Calcium Superphosphate Can Effectively Immobilize Cadmium and Reduce Its Uptake by Cabbage.
- Author
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Peng, Xinlei, Islam, Md. Shoffikul, Li, Qian, Fu, Qingling, Zhu, Jun, and Hu, Hongqing
- Subjects
- *
PHOSPHATE fertilizers , *SODIC soils , *CORN straw , *SOIL remediation , *SOIL restoration - Abstract
Biochar and phosphate fertilizer are commonly employed for the mitigation of soil cadmium (Cd) contamination. Nevertheless, there is a dearth of research regarding the mechanism behind their joint implementation. In this study, a combination of corn straw biochar (0 (C0), 5 (C5), and 10 (C10) g kg−1) and calcium superphosphate (0 (P0), 0.1 (P1), 0.2 (P2), 0.5 (P5), and 1.0 (P10) g kg−1) was applied in pot experiments, and the effects of the combined application on Cd bioavailability and its uptake by cabbage were investigated in Cd-contaminated soils. The results demonstrated that the combined treatment of applying biochar and Ca(H2PO2)2 yielded a significant decrease in the uptake of Cd by cabbage in alkaline soil, in contrast to the individual treatments of biochar or Ca(H2PO2)2. Compared to the CK treatment (C0P0), the Cd content in the shoots decreased by 46.26% and in the roots decreased by 24.81%, while the biomass of the cabbage demonstrated a noteworthy increase in C5P10 treatment. Compared to the CK treatment, the content of available phosphate (AP) in the soil increased by 17.57 mg kg−1, residual Cd increased by 22.02%, the exchangeable Cd decreased by 45.86%, and carbonate-bound Cd decreased by 20.55% in the C5P10 treatment. Therefore, it is advisable to use a combination of 5 g kg−1 biochar and 1 g kg−1 Ca(H2PO2)2 for the restoration of soil contaminated with Cd. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Optimization, Purification and Characterization of Lipase from Streptomyces sp. A3301, with Application of Crude Lipase for Cooking Oily Wastewater Treatment.
- Author
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Titiporn Panyachanakul, Vichien Kitpreechavanich, Wanlapa Lorliam, Thanasak Lomthong, and Sukhumaporn Krajangsang
- Subjects
- *
BIOCHEMICAL oxygen demand , *ION exchange chromatography , *CHEMICAL oxygen demand , *LIPASES , *SYNTHETIC lubricants , *WASTEWATER treatment - Abstract
Streptomyces sp. A3301, which produces lipase isolated by Panyachanakul et al. [1]. This optimization was done for the subsequent purification and characterization of the biological lipase produced by the isolate. The results showed that the strain produced lipase with a maximum activity of 321 U/mL using the optimal medium and conditions (1.5% (w/v) xylose and 2% (w/v) yeast extract, pH 7.0 at 30 °C, 150 rpm for 3 days). The specific activity of the purified lipase was 27,000 U/mg, which was 544 times the pre-purification level, based on hydrophobic chromatography. After ion-exchange chromatography, the specific activity was 5,600 U/mg, which was 113 times the pre-purification level, with a single-peak purification profile. The purified lipase had a single band based on SDS-PAGE analysis and the molecular mass was 45 kDa. The optimum temperature and thermo-stability of A3301 lipase were 60 and 30 - 55 °C, respectively. The optimum pH of the purified enzyme was pH 9.0, and the enzyme was stable in the pH range of 8.0 - 9.0. The purified lipase was stable in acetone, chloroform and toluene, with a high relative activity of 63 - 76%. The immobilized strain was then applied to oily-wastewater treatment. The strain can remove oil and grease in synthetic wastewater containing oil at 1 - 3% (v/v), with removal rates of 100, 99.82 and 99.68%, respectively, after incubation for 6 days. It was then applied to oily-wastewater treatment from a restaurant, achieving the highest degradation rates of 98.53% after treatment for 6 days. In addition, it also affected the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values decreasing. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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