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In this work, we use an isolated strain of Geotrichum candidum (MH680587) to propose a sustainable treatment technique based on mycoremediation for the biodegradation and decolorization of Congo Red (CR) azo dye. FTIR analysis and UV–vis spectroscopy were used to confirm the decolorization process. Furthermore, a novel mechanism for the fungus's biocatalysis of CR was postulated, based on the discovery of intermediates by LC–MS/MS analysis. Screening and optimization of important cultural parameters to control dye biodegradation were performed using a fractional factorial design (27–4). Optimal decolorization conditions were determined by varying seven factors: agitation, initial dye concentration, (NH4)2SO4 concentration, glucose concentration, inoculum size, pH, and temperature. The results achieved showed that maximum decolorization was reached under static conditions, with of 0.2 g L−1 as an original concentration of dye, (NH4)2SO4 concentration of 2 g. L−1, and inoculum size of 3 g L−1. Biodegradation assays conducted under these optimal conditions resulted in over 90% removal of optical density (OD). Manganese peroxidase (MnP) and lignin peroxidase (LiP) were found to be involved in the degradation process of this dye. Toxicity assessment demonstrated that these intermediate metabolites were less toxic to plant tissues and bacteria compared to the raw azo dye. Overall, the findings indicate that G. candidum (MH680587) possesses a strong decolorization ability for CR under static conditions. It exhibits promising possibility of utilizing in the field of dye wastewater treatment, with the added benefit of low energy consumption. [ABSTRACT FROM AUTHOR]

In the current investigation, crude laccase was utilized to decolorize the leather azo dyes (AB 113 and AB 52). The crude laccase was extracted from Penicillium chrysogenum strain TSV1 pH 5.5, temp. at 32°C for 7 days in a liquid culture medium, and shows maximum enzyme activity of 7.92 U/mL. The crude laccase has been applied and achieved maximum decolorization efficiency up to 83% and 69% respectively for AB 113 and AB 52 within 48-h duration. Furthermore, the addition of 1 mM HOBT mediator has enhanced the dye decolorization rate up to 98% and 85% within 24-h duration respectively for both dyes. Furthermore, the decolorization was confirmed by UV-Vis spectra analysis and has showed peaks at 570 nm and 580 nm which corresponded to chromophores respectively for both dyes and disappeared after decolorization. The bands were observed at the bending region from 1561 to 1494 cm−1 and from 1344 to 1031 cm−1 by FTIR analysis corresponding to an aromatic ring of AB 113. Similarly, the peaks observed at 1589cm−1 and 1451cm−1 corresponded to the aromatic region of AB 52 and indicated the presence of -N=N-. These bands disappeared and new bands appeared after decolorization. The UPLC analysis has shown different peaks at various retention times for both dyes and these peaks disappeared after decolorization. Furthermore, the COD (86.5 ± 5% and 83.52 ± 3%) and TOC (87.86% and 83.82%) have been reduced for both dyes. The toxicity of the dyes also has been reduced after decolorization. The laccase was a more potential enzyme for the decolorization of azo dyes. [ABSTRACT FROM AUTHOR]

Background: Hazardous synthetic dye wastes have become a growing threat to the environment and public health. Fungal enzymes are eco-friendly, compatible and cost-effective approach for diversity of applications. Therefore, this study aimed to screen, optimize fermentation conditions, and characterize laccase from fungal endophyte with elucidating its ability to decolorize several wastewater dyes. Results: A new fungal endophyte capable of laccase-producing was firstly isolated from cladodes of Opuntia ficus-indica and identified as T. harzianum AUMC14897 using ITS-rRNA sequencing analysis. Furthermore, the response surface methodology (RSM) was utilized to optimize several fermentation parameters that increase laccase production. The isolated laccase was purified to 13.79-fold. GFC, SDS-PAGE revealed laccase molecular weight at 72 kDa and zymogram analysis elucidated a single band without any isozymes. The peak activity of the pure laccase was detected at 50 °C, pH 4.5, with thermal stability up to 50 °C and half life span for 4 h even after 24 h retained 30% of its activity. The Km and Vmax values were 0.1 mM, 22.22 µmol/min and activation energy (Ea) equal to 5.71 kcal/mol. Furthermore, the purified laccase effectively decolorized various synthetic and real wastewater dyes. Conclusion: Subsequently, the new endophytic strain produces high laccase activity that possesses a unique characteristic, it could be an appealing candidate for both environmental and industrial applications. [ABSTRACT FROM AUTHOR]

This study explores the efficient decolorization and complete mineralization of the diazo dye Evans blue, using an integrated aerobic bioreactor system coupled with a double-chamber microbial fuel cell (DCMFC) including a bio-cathode and acetate as a cosubstrate. The research addresses the environmental challenges posed by dye-laden industrial effluents, focusing on achieving high decolorization efficiency and understanding the microbial communities involved. The study utilized mixed strains of actinomycetes, isolated from garden compost, to treat initial dye concentrations of 100 mg/L and 200 mg/L. Decolorization efficiency and microbial community composition were evaluated using 16S rRNA sequencing, and electrochemical impedance spectroscopy (EIS) was used to assess anode and DCMFC resistance. The results demonstrated decolorization efficiencies ranging from 90 ± 2% to 98 ± 1.9% for 100 mg/L and from 79 ± 2% to 87% ± 1% for 200 mg/L. An anode resistance of 12.48 Ω indicated a well-developed biofilm and enhanced electron transfer. The microbial community analysis revealed a significant presence of Pseudomonadota (45.5% in dye-acclimated cultures and 32% in inoculum cultures), with key genera including Actinomarinicola (13.75%), Thermochromatium (4.82%), and Geobacter (4.52%). This study highlights the potential of the integrated DCMFC–aerobic system, utilizing mixed actinomycetes strains, for the effective treatment of industrial dye effluents, offering both environmental and bioenergy benefits. [ABSTRACT FROM AUTHOR]

Dye-decolorizing peroxidases (DyPs) belong to a novel superfamily of heme peroxidases that can oxidize recalcitrant compounds. In the current study, the GlDyP2 gene from Ganoderma lucidum was heterologously expressed in Escherichia coli, and the enzymatic properties of the recombinant GlDyP2 protein were investigated. The GlDyP2 protein could oxidize not only the typical peroxidase substrate ABTS but also two lignin substrates, namely guaiacol and 2,6-dimethoxy phenol (DMP). For the ABTS substrate, the optimum pH and temperature of GlDyP2 were 4.0 and 35 °C, respectively. The pH stability and thermal stability of GlDyP2 were also measured; the results showed that GlDyP2 could function normally in the acidic environment, with a T50 value of 51 °C. Moreover, compared to untreated controls, the activity of GlDyP2 was inhibited by 1.60 mM of Mg2+, Ni2+, Mn2+, and ethanol; 0.16 mM of Cu2+, Zn2+, methanol, isopropyl alcohol, and Na2EDTA·2H2O; and 0.016 mM of Fe2+ and SDS. The kinetic constants of recombinant GlDyP2 for oxidizing ABTS, Reactive Blue 19, guaiacol, and DMP were determined; the results showed that the recombination GlDyP2 exhibited the strongest affinity and the most remarkable catalytic efficiency towards guaiacol in the selected substrates. GlDyP2 also exhibited decolorization and detoxification capabilities towards several dyes, including Reactive Blue 19, Reactive Brilliant Blue X-BR, Reactive Black 5, Methyl Orange, Trypan Blue, and Malachite Green. In conclusion, GlDyP2 has good application potential for treating dye wastewater. [ABSTRACT FROM AUTHOR]

A global water crisis is emerging due to increasing levels of contaminated water and decreasing clean water supply on Earth. This study aims to address the removal of azo dye from wastewater to enable its reuse. Recently, utilizing microorganisms has been proven to be a practical choice for the remediation of azo dyes in wastewater. Hence, in this study, we employed a preformed biofilm of Pseudomonas aeruginosa on a solid support (called substrate) to degrade azo dyes. This process offers several advantages, such as stability, substrate portability, more biofilm production in less time, and efficient utilization of enzymes for remediation. From 50 ppm of initial Congo Red concentration, 75.74% decolorization was achieved within ten h using a preformed biofilm on a coverslip. A maximum of 52.27% decolorization was achieved using biofilm during its formation after 72 h of incubation. The Fourier-transform infrared (FTIR) spectroscopic analysis of Congo Red dye before and after remediation revealed a significant change in peak intensity, indicating dye degradation. Phytotoxicity studies performed by seed germination with Vigna radiata revealed that, after 5–7 days, almost 40% more seeds with longer root and shoot lengths were germinated in the presence of treated dye compared to the untreated one. This data indicated that the harmful Congo Red was successfully degraded to a non-toxic product by Pseudomonas aeruginosa biofilm grown on a glass substrate. [ABSTRACT FROM AUTHOR]

Copyright of China Condiment is the property of China Condiment 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.)

Biological treatment is currently a favorable option to treat wastewater due to its environmentally friendly methods and minimal toxic by-products. The majority of biological wastewater treatment uses bacteria as treatment agents, which are known to have excellent capabilities for removing various pollutants. Researchers have extensively explored the use of extracellular polymeric substances (EPSs) generated by bacteria in wastewater treatment. This review focuses on the sources of EPSs, factors influencing their production, and their role in wastewater treatment. Bacterial species, nutrient availability, pH, temperatures, and the presence of toxins were mentioned to be the factors influencing EPS production by bacteria in wastewater treatment. Produced EPSs by bacteria may promote the aggregation, adsorption, decolorization, and degradation of pollutants. This review highlights the challenges of discovering new potential bacterial species and complex EPS extraction methods, as well as the importance of mass production for larger-scale applications. [ABSTRACT FROM AUTHOR]

The dyeing processes in the textile industry generate substantial wastewater containing various dye compounds, particularly triphenylmethane dyes, which are environmentally problematic due to their persistence and potential toxicity. This study focuses on optimizing the decolorization of three specific triphenylmethane dyes (Basic Green 4, Basic Violet 3, and Bromophenol Blue) using bacterial monoculture and consortium isolated from textile wastewater. Initially, bacterial strains (Agrobacterium radiobacter, Bacillus sp., Sphingomonas paucimobilis, and unidentified filamentous bacteria) were isolated and screened for their decolorization capabilities. The most effective strains were then selected for detailed monoculture and consortium studies. Key parameters such as pH, temperature, stirring, initial dye concentration, glucose, and yeast extract were optimized to enhance decolorization efficiency. The results showed that both monocultures and consortium had significant decolorization capabilities, with the consortia outperforming the monocultures under optimized conditions. The consortia exhibited enhanced decolorization efficiency compared to individual bacterial strains, indicating synergistic interactions among the consortium members. [ABSTRACT FROM AUTHOR]

This inspection explores the potential of 4-nitroaniline's potential as a novel diazo component in synthesizing azo dyes, highlighting the research's novelty. Two new azo dyes, designated 4-(4-nitrophenylazo) salicylic acid (SS) and 4-(4-nitrophenylazo) catechol (OH), were prepared by diazotization of 4-nitroaniline followed by coupling with salicylic acid and catechol, respectively. Fourier transform infrared spectroscopy and other analytical techniques confirmed the structural integrity of the dyes before and after application to cotton, wool, acrylic, and polyester fabrics. The dyes exhibited the best color strength (K/S) and fastness properties on cotton. The exhaustion and fixation of the dyes onto cotton fibers improved with increasing temperature, reaching optimal efficiencies (83.92 and 80.34% for SS and 89 and 84.36% for OH) at 95 °C. Furthermore, the study investigates a sustainable method for removing the dyes from textile wastewater. Sugarcane bagasse, a cost-effectiveness and environmentally friendly sorbent, achieved effectual dye elimination from wastewater after sulfuric acid pre-treatment (superior to formaldehyde). This treatment achieved a remarkable 99.34% removal efficiency under optimal conditions (2.5 g, 50 ppm, pH 9, 200 rpm, 120 min). Adsorption exhibited characteristics of both Langmuir isotherm and pseudo-second order kinetics. Diffusion studies revealed intraparticle diffusion as the rate-controlling step, with film diffusion likely governing the adsorption. Regression modeling yielded an R2 of 93.89% between process factors and dye removal. The effectiveness was further validated by treating real-world, highly polluted textile wastewater obtained from an Egyptian factory. The sugarcane bagasse treatment effectively removed dyes (almost 98.8%) under optimal conditions, demonstrating its reusability after multiple dye-removal cycles. [ABSTRACT FROM AUTHOR]

This study investigated the decolorization and detoxification of a dye originating from a feather-dyeing house using the laccase enzyme. Efficient decolorization was achieved under a wide range of environmental conditions, including pH, temperature, enzyme loading, and dye concentration. The decolorization rate reached up to 98% within 10 min when the mediator acetosyringone was present. Decolorization was attributed to the degradation of the dye by laccase, as analyzed using liquid chromatography-mass spectrometry (LC–MS). At least three dominant intermediates (m/z 167.993, 194.475, 118.040) were identified, deriving from the original dye (m/z 521.044). Compared to the non-decolorized dye solution, the decolorized dye ones at various concentrations exhibited lower toxicity towards aerobic activated sludge (AS). This was evident from the significantly higher respiratory intensity of AS, with an O₂ uptake of 35 mg for the decolorized solution versus 11 mg for the non-decolorized solution after 12 h at a 100 mg/L dye concentration. The results suggest that laccase-catalyzed decolorization could serve as an effective pretreatment method for traditional activated sludge (AS)-based processes, thereby enhancing the overall treatment performance of dye wastewater. [ABSTRACT FROM AUTHOR]

It is very important and challenging to efficiently and eco-friendly recycle the waste cotton textiles, especially for the dyed cotton-polyester blended textiles due to their complex dye composition and recovery of cotton components from them. Here, we proposed a recycling route for waste dark-colored cotton-polyester denim fabrics containing sulphur dyes, involving decolorization, alkali cooking for pulp and bleaching. Thiourea dioxide (TDO) was utilized as a reducing agent to remove the sulphur dyes of the fabrics in NaOH solution system, and the effects of TDO dosage, temperature and time on decoloring efficiency were discussed. Alkali cooking with hydrogen peroxide was used to prepare cellulose pulp and remove polyester fiber components simultaneously. Then the prepared pulp was bleached through the hydrogen peroxide/tetraacetylethylenediamine to further improve its whiteness. The dissolving pulp obtained from the dark-blue and black denim fabrics had the CIE whiteness indices of 89 and 65, and the degrees of polymerization of 522 and 565, respectively. This study provided a new approach for the recycling and reuse of waste cotton textiles. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department 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.)

Dyes can be considered the main contaminants of textile effluents, which have a heterocyclic complicated structure. Disperse dyes are one of the most commonly used classes of dyes with an insoluble nature and low molecular weight. In this study, the elimination of disperse dyes from aqueous medium was investigated by Aspergillus niger fungi using in vivo and in vitro methods. According to the in vitro decolorization results, the fungi showed high biosorption capacity for three different disperse dyes. At an initial dye concentration of 330 mg/l , the adsorption capacity of A. niger measured 225.3 mg/g for Disperse Yellow 23, 127.4 mg/g for Disperse Blue 183, and 176.3 mg/g for Disperse Red 1. Complete dye removal was achieved at lower initial concentrations after a 6-h operation. The results showed that the biosorption process favored acidic conditions, and the adsorption capacity and rate were higher at pH 4.5. Moreover, the kinetics of the adsorption process for all dyes followed the pseudo–second-order kinetic model. An in vivo decolorization test was also performed, in which A. niger was inoculated in a dye-containing medium to investigate the possible biodegradation of the dye by fungi during its growth. The biodegradation process was studied by Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC) methods. The results obtained showed a maximum biodegradation of 49.77% for Disperse Red 1, whereas the decolorization for other dyes was mainly based on biosorption. Practical Applications: The industrial wastewater treatment plans in most dyeing houses consist of preliminary coagulation and flocculation tanks followed by biological wastewater treatment by activated sludge. According to the results of this study, A. niger could be applicable in both wastewater treatment steps in industrial plans. A. niger, as a nonharmful microorganism, could be used as a good adsorbent in the coagulation tanks, replacing the chemical coagulants. The adsorbed dye in A. niger's body mass could easily be separated because of its bulky structure. Because dye removal in this method is nearly complete, the effluent could be used in the same dyeing process without much refining process. Using A. niger in biological aerobic procedures could also be practicable according to the results. A. niger could grow in the aerobic condition of biological tanks and simultaneously degrade and adsorb dye molecules. On the other side, A. niger is commercially used for the production of citric acid, and some enzymes and the body mass produced by these industries could be considered for dye removal processes. The use of A. niger as a biosorbent or degradant for dyes still could be studied in several aspects. The study of the degradation mechanism of different dyes by precise tests like liquid chromatography (LC)-mass is an ongoing study by the current team. Also, using A. niger for real wastewater from dyeing houses and optimizing the dye removal parameters for industrial application is a future research perspective in this case. [ABSTRACT FROM AUTHOR]

Trametes hirsuta GMA-01 was cultivated in a culture medium supplemented with orange waste, starch, wheat bran, yeast extract, and salts. The fungus produced several holoenzymes, but the laccase levels were surprisingly high. Given the highlighted applicability of laccases in various biotechnological areas with minimal environmental impact, we provided a strategy to increase its production using response surface methodology. The immobilization of laccase into ionic supports (CM-cellulose, DEAE-agarose, DEAE-cellulose, DEAE-Sephacel, MANAE-agarose, MANAE-cellulose, and PEI-agarose) was found to be efficient and recuperative, showcasing the technical prowess of research. The crude extract laccase (CE) and CM-cellulose-immobilized crude extract (ICE) showed optimum activity in acidic conditions (pH 3.0) and at 70 °C for the CE and 60 °C for the ICE. The ICE significantly increased thermostability at 60 °C for the crude extract, which retained 21.6% residual activity after 240 min. The CE and ICE were successfully applied to sugarcane bagasse hydrolysis, showing 13.83 ± 0.02 µmol mL−1 reducing sugars after 48 h. Furthermore, the CE was tested for dye decolorization, achieving 96.6%, 71.9%, and 70.8% decolorization for bromocresol green, bromophenol blue, and orcein, respectively (0.05% (w/v) concentration). The properties and versatility of T. hirsuta GMA-01 laccase in different biotechnological purposes are interesting and notable, opening several potential applications and providing valuable insights into the future of biotechnological development. [ABSTRACT FROM AUTHOR]

Azo dye degradation utilizing microorganisms has acquired significance over the last decades, owing to its beneficial properties such as rapid degradation, economic feasibility, and eco‐friendly. In this work, azo dyes (Methyl red and methylene blue) degradation efficacy using indigenous bacterial strains Pseudomonas sp. and Bacillus sp. as free and immobilized cells were investigated under in vitro batch decolorization setup was carried. Most importantly, the bacterial cells of both strains were immobilized with sodium alginate and the immobilized cells were evaluated for dye decolorization efficacy under laboratory conditions. An eco‐toxic assessment of the degraded products was done using in vitro phytotoxicity tests and in silico analyses. Among the free and immobilized cells, maximum decolorization efficacy was observed in the Pseudomonas sp. immobilized cells which exhibited 74.5% decolorization efficacy, and the maximum decolorization efficacy of free cells was 63% of was observed. Ecotoxicity of the dye‐degraded products was screened by determination of phytotoxicity. Seedlings emergence of groundnut seeds exposed to degraded dye products revealed phytotoxicity. Results indicated that degraded dye products of methyl red derived from Pseudomonas sp. showed 93.0% seedling emergence, and methylene blue‐degraded products Pseudomonas sp. degraded dye products supported 92.0% seedling emergence, respectively. Bacterial cells immobilized with biocompatible polymers can be effectively utilized in wastewater treatment without affecting the ecological components. The findings highlight the value of this work in contributing to the domain of sustainable and eco‐friendly wastewater treatment technology. [ABSTRACT FROM AUTHOR]

The color of textile wastewater is still a main problem in wastewater treatment by biological processes. The colored effluents from textile factories usually exceed effluent standards. Therefore, various innovations were developed to treat textile wastewater for decolorization in the effluents. This research aims to decolorize textile wastewater by immobilizing white rot fungi degradation. At first, the 11 fungal stains were tested to find the decolorized efficiency then the high decolorized efficiency fungal stains were immobilized on four material media, namely water hyacinth stalks, coconut husk, corn cob, and loofah. After that, the immobilized fungi were cultivated in the culture media at 30, 60, and 120 C/N ratios, respectively. The results showed that Trametes sanguinea and Perenniporia tephropora were two stains with a high decolorized efficiency of 68.8% and 67.5% respectively, and the decolorized efficiency was increased when immobilized on loofahs and fed with 120 C/N ratio medium. In a comparison of two fungal stains, P. tephropora was found more suitable for the decolorization of textile wastewater than T. sanguinea because T. sanguinea could produce red-orange pigments that induced the colored enhancement in wastewater over time. Finally, immobilized P. tephropora was cultivated in a 120 C/N ratio medium within a 10 L continuous stirred tank reactor (8 L working volume) to investigate the decolorized efficiency, enzymatic activity, and repeated batch. It was found that three repeated cycles were carried out by reusing the immobilized P. tephropora and the highest decolorized efficiency was 63.4%. The enzymatic activity of laccase, manganese peroxidase, and lignin peroxidase was 15.5 U/L, 85.9 U/L, and 0 U/L, respectively [ABSTRACT FROM AUTHOR]

Abstract Background Hazardous synthetic dye wastes have become a growing threat to the environment and public health. Fungal enzymes are eco-friendly, compatible and cost-effective approach for diversity of applications. Therefore, this study aimed to screen, optimize fermentation conditions, and characterize laccase from fungal endophyte with elucidating its ability to decolorize several wastewater dyes. Results A new fungal endophyte capable of laccase-producing was firstly isolated from cladodes of Opuntia ficus-indica and identified as T. harzianum AUMC14897 using ITS-rRNA sequencing analysis. Furthermore, the response surface methodology (RSM) was utilized to optimize several fermentation parameters that increase laccase production. The isolated laccase was purified to 13.79-fold. GFC, SDS-PAGE revealed laccase molecular weight at 72 kDa and zymogram analysis elucidated a single band without any isozymes. The peak activity of the pure laccase was detected at 50 °C, pH 4.5, with thermal stability up to 50 °C and half life span for 4 h even after 24 h retained 30% of its activity. The Km and Vmax values were 0.1 mM, 22.22 µmol/min and activation energy (Ea) equal to 5.71 kcal/mol. Furthermore, the purified laccase effectively decolorized various synthetic and real wastewater dyes. Conclusion Subsequently, the new endophytic strain produces high laccase activity that possesses a unique characteristic, it could be an appealing candidate for both environmental and industrial applications.

Trametes hirsuta GMA-01 was cultivated in a culture medium supplemented with orange waste, starch, wheat bran, yeast extract, and salts. The fungus produced several holoenzymes, but the laccase levels were surprisingly high. Given the highlighted applicability of laccases in various biotechnological areas with minimal environmental impact, we provided a strategy to increase its production using response surface methodology. The immobilization of laccase into ionic supports (CM-cellulose, DEAE-agarose, DEAE-cellulose, DEAE-Sephacel, MANAE-agarose, MANAE-cellulose, and PEI-agarose) was found to be efficient and recuperative, showcasing the technical prowess of research. The crude extract laccase (CE) and CM-cellulose-immobilized crude extract (ICE) showed optimum activity in acidic conditions (pH 3.0) and at 70 °C for the CE and 60 °C for the ICE. The ICE significantly increased thermostability at 60 °C for the crude extract, which retained 21.6% residual activity after 240 min. The CE and ICE were successfully applied to sugarcane bagasse hydrolysis, showing 13.83 ± 0.02 µmol mL−1 reducing sugars after 48 h. Furthermore, the CE was tested for dye decolorization, achieving 96.6%, 71.9%, and 70.8% decolorization for bromocresol green, bromophenol blue, and orcein, respectively (0.05% (w/v) concentration). The properties and versatility of T. hirsuta GMA-01 laccase in different biotechnological purposes are interesting and notable, opening several potential applications and providing valuable insights into the future of biotechnological development.

Abstract Efficiently mitigating and managing environmental pollution caused by the improper disposal of dyes and effluents from the textile industry is of great importance. This study evaluated the effectiveness of Streptomyces albidoflavus 3MGH in decolorizing and degrading three different azo dyes, namely Reactive Orange 122 (RO 122), Direct Blue 15 (DB 15), and Direct Black 38 (DB 38). Various analytical techniques, such as Fourier Transform Infrared (FTIR) spectroscopy, High-Performance Liquid Chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze the degraded byproducts of the dyes. S. albidoflavus 3MGH demonstrated a strong capability to decolorize RO 122, DB 15, and DB 38, achieving up to 60.74%, 61.38%, and 53.43% decolorization within 5 days at a concentration of 0.3 g/L, respectively. The optimal conditions for the maximum decolorization of these azo dyes were found to be a temperature of 35 °C, a pH of 6, sucrose as a carbon source, and beef extract as a nitrogen source. Additionally, after optimization of the decolorization process, treatment with S. albidoflavus 3MGH resulted in significant reductions of 94.4%, 86.3%, and 68.2% in the total organic carbon of RO 122, DB 15, and DB 38, respectively. After the treatment process, we found the specific activity of the laccase enzyme, one of the mediating enzymes of the degradation mechanism, to be 5.96 U/mg. FT-IR spectroscopy analysis of the degraded metabolites showed specific changes and shifts in peaks compared to the control samples. GC-MS analysis revealed the presence of metabolites such as benzene, biphenyl, and naphthalene derivatives. Overall, this study demonstrated the potential of S. albidoflavus 3MGH for the effective decolorization and degradation of different azo dyes. The findings were validated through various analytical techniques, shedding light on the biodegradation mechanism employed by this strain.

In this work, the green H 2 production and decolorization of industrial distillery effluent were carried out by the photocatalytic process via a gold-decorated TiO 2 photocatalyst synthesized by the photodeposition. Effects of dilution (0–150 folds), decorated gold content on TiO 2 (0.1–0.7 wt%), ethanol concentration (0–20 vol%) and photocatalyst loading (2–5 g/L) on the photocatalytic activity were explored. The preliminary results illustrated that neither H 2 production nor decolorization were achieved via the fresh distillery effluent. The maximum H 2 production of 210 μmol/g with 64.4 % decolorization was achieved with the 100-fold diluted-distillery effluent using the 0.3 wt% gold decorated on TiO 2 (Au 0.3 T) photocatalyst at loading of 3 g/L and ethanol concentration of 15 vol%. The characterization and experiment results pointed out that the improved photocatalytic activity of Au 0.3 T photocatalyst was based on the available area of decorated gold nanoparticles (NPs), the Au–TiO 2 interface area and interface perimeters. Via the distillery effluent, the water splitting was the dominate reaction for H 2 production, accounting of around 93% of overall produced H 2. Although a low recycling stability was observed from this work, attributing to the accumulation of organic contaminants founded in the distillery effluent on the surface of the photocatalyst, this finding may pave the way for the design of metal-decorated semiconductors for simultaneous green H 2 production and pollutant removal from actual industrial wastewater. • The H 2 production and decolorization of distillery effluent were conducted via Au/TiO 2. • About 210 μmol H 2 /g with 64.4 % decolorization was achieved via Au 0.3 T photocatalyst. • Area of decorated gold and interface area/perimeters affected the H 2 production. • 93% of overall produced H 2 from was distillery effluent coming from water splitting. [ABSTRACT FROM AUTHOR]

AbstractLaccase has a wide range of substrates and the oxidation product is water, providing an ideal choice for the biological degradation and decolorization of dyeing wastewater. This study extracted laccase from the fruiting body of Agaricus bisporus, then used o-phthalaldehyde (OPA) as a cross-linking agent and added surface-aminated Fe3O4 nanoparticles (NH2-nanoFe3O4) to prepare magnetic cross-link enzyme aggregates (MCLEAs) of laccase, which was characterized by scanning electron microscope and vibrating sample magnetometer. The optimal temperature for the catalytic reaction of the MCLEAs was 35 °C, and the optimal pH was 3.0. The stability to temperature pH and storage stability were all enhanced. The immobilized laccase was utilized to treat amido black 10B solution, and the decolorization rate reached 92.48%. After five cycles of use, the MCLEAs of laccase could maintain 42.91% of the relative activity and 32.31% of the relative degradation ability to amido black 10B. [ABSTRACT FROM AUTHOR]

Synthetic dyes pose a significant environmental threat due to their complex structures and resistance to microbial degradation. S. commune 15R-5-F01 exhibited over 96% degradation efficiency of Methyl Red in a medium with 100 mg L−1 Methyl Red within 3 h. The fungus demonstrated adaptability to various environmental conditions, including different pH levels, temperatures, oxygen concentrations, salinity, and heavy metals. S. commune 15R-5-F01 is capable of achieving repeated cycles of Methyl Red reduction with sustained degradation duration minimum of 6 cycles. It showed a maximum Methyl Red biodegradation capacity of at least 558 mg g−1 dry mycelia and a bioadsorption capacity of 57 mg g−1. Gas chromatography–mass spectrometry analysis confirmed the azo reduction of Methyl Red into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Enzymatic activity assays indicated the involvement of lignin peroxidases, laccases, and manganese peroxidase in the biodegradation process. Phytotoxicity tests on Triticum eastivum, Oryza sativa, and Vigna umbellata seeds revealed reduced toxicity of the degradation products compared to Methyl Red. This study identifies S. commune 15R-5-F01 as a viable candidate for the sustainable degradation of synthetic dyes in industrial wastewater. [ABSTRACT FROM AUTHOR]

The present study focuses on investigating the decolorization of Ponceau 4R in aqueous solutions using peroxydisulfate. The impact of the initial dye concentration, as well as the concentrations of peroxydisulfate and Fe2+, temperature, and pH on the decolorization of Ponceau 4R was investigated. The experimental data were examined employing kinetics of both first and second order. The decolorization kinetics of Ponceau 4R in the peroxydisulfate process adhered to the principles of second-order reaction kinetics, with a rate constant of 1.47 × 10–4 M–1 min–1 at 2.5 mM S2O concentration. Decolorization efficiency above 90% was achieved in 120 min under optimal reaction conditions. The rate constants pertaining to the second-order chemical process demonstrated a positive association with both S2O concentration and temperature. Fe2+ activates S2O to generate sulfate radical ion, amplifying Ponceau 4R decolorization. At higher pH, sulfate-free radical production decreases, limiting Ponceau 4R decolorization. Peroxydisulfate decolorized Ponceau 4R with a low activation energy of 42.8 ± 0.23 kJ mol–1 at 2.5 mM starting concentration. The positive ΔG value indicates the non-spontaneity of the decolorization process. [ABSTRACT FROM AUTHOR]

Microbial degradation represents an eco-friendly alternative to traditional physicochemical treatments in removing persistent and toxic environmental pollutants, including synthetic dyes (i.e., methylene blue, MB) employed in different industries. The exploitation of thermophilic bacilli, such as those isolated from the shallow hydrothermal vents of the Eolian Islands (Italy), could provide valuable resources for the treatment of warm, dye-containing wastewater. In this study, we evaluated the ability of preformed biofilms on polypropylene perforated balls (BBs) of fifteen thermophilic bacilli, to decolor, degrade, and detoxify MB in aqueous solutions. Among them, BBs of Bacillus licheniformis B3-15 and Bacillus sp. s7s-1 were able to decolorize MB more than 50% in saline solution (NaCl 2%), incubated in static conditions at 45 °C for 48 h. At optimized initial conditions (10 mg L−1 MB, pH 5.2 for B3-15 or pH 4 for s7s-1), the two strains enhanced their decolorization potential, reaching 96% and 67%, respectively. As indicated by ATR-FTIR spectroscopy, the treatment with BB B3-15 was the most efficient in degrading the Cl–C and –NH groups of MB. This degraded solution was 40% less toxic than undegraded MB, and it has no impact on the bioluminescence of Vibrio harveyi, nor the growth of the marine diatom Phaeodactylum tricornutum. Biofilm formed by strain B3-15 on polypropylene perforated balls could be proposed as a component of bioreactors in the treatment of warm, dye-containing wastewater to concomitantly remediate MB pollution and simultaneously counteract harmful effects in aquatic environments. [ABSTRACT FROM AUTHOR]

Dye contamination in printing and dyeing wastewater has long been a major concern due to its serious impact on both the environment and human health. In the quest for bioremediation of these hazardous dyes, biological resources such as biodegradation bacteria and enzymes have been investigated in severely polluted environments. In this context, the triphenylmethane transporter gene (tmt) was identified in six distinct clones from a metagenomic library of the printing and dyeing wastewater treatment system. Escherichia coli expressing tmt revealed 98.1% decolorization efficiency of triphenylmethane dye malachite green within 24 h under shaking culture condition. The tolerance to malachite green was improved over eightfold in the Tmt strain compared of the none-Tmt expressed strain. Similarly, the tolerance of Tmt strain to other triphenylmethane dyes like crystal violet and brilliant green, was improved by at least fourfold. Site-directed mutations, including A75G, A75S and V100G, were found to reinforce the tolerance of malachite green, and double mutations of these even further improve the tolerance. Therefore, the tmt has been demonstrated to be a specific efflux pump for triphenylmethane dyes, particularly the malachite green. By actively pumping out toxic triphenylmethane dyes, it significantly extends the cells tolerance in a triphenylmethane dye-rich environment, which may provide a promising strategy for bioremediation of triphenylmethane dye pollutants in the environments. [ABSTRACT FROM AUTHOR]

Seven bacterial strains, isolated from various Tunisian biotopes, were investigated for Congo Red (CR) and Malachite Green (MG) decolorization. The isolated strains underwent morphological and biochemical tests, including assessments for antibiotic sensitivity as well as biofilm formation. One selected strain, ST11, was partially identified as Paenibacillus sp. strain ST11. The newly isolated crude bacterial filtrates (NICBFs) effectively decolorized CR and MG. Specifically, six and seven NICBFs were found to be effective for degrading CR (150 mg l−1) and MG (50 mg l−1), respectively. Under non-optimized conditions, CR and MG could be decolorized up to 80% within 6–12 h. The degradation products of CR and MG, characterized by UV–visible and FT-IR techniques, demonstrated both decolorization and transformation, highlighting the role of enzymes in dye degradation. Phytotoxicity and cytotoxicity studies evaluated the impact of treated and untreated CR and MG. Some NICBFs showed promise as powerful biological tools, reducing and sometimes detoxifying CR and MG, commonly used as fertilizers. The potential applications of these NICBFs in decolorization and bioremediation of dye-rich textile effluents were explored. The screening also identified environmentally friendly, cost-effective bacterial strains adaptable to various conditions through phytotoxicity and cytotoxicity studies. [ABSTRACT FROM AUTHOR]

In this study, the efficiency of poly(ethylene glycol dimethacrylate-N-methacryloyl-amido-l-tryptophan methyl ester) [PEDMT] microbeads (in the diameter range of 106–180 µm) as a support material for HRP immobilization was evaluated and the immobilized-HRP enzyme was used for decolorization of Congo Red (CR) and Reactive Black 5 (RB5) dyes. The specific surface area of the PEDMT microbeads was 1103 m2 g−1, which is very high. The PEDMT microbeads had a pore volume and pore size of 1.94 cm3 g−1 and 9.99–55.3 Å, respectively. The chemical compositions of the PEDMT and PEDMT–HRP microbead surfaces were analyzed using X-ray photoelectron spectroscopy (XPS). Immobilization yield, activity yield, and immobilization efficiency were 84.9 ± 2.1, 73.8 ± 5.9%, and 86.9 ± 6.9%, respectively. Optimum pH (6.0), temperature (45 °C and 50 °C for free and immobilized enzyme), H2O2 concentration (3% v/v) were investigated in detail. Thermal and storage stability was increased after immobilization and immobilized enzyme preserved more than 55% of its initial activity even after 10 consecutive uses. Decolorization studies were also performed by investigating the effects of pH, CR, and RB5 concentration, enzyme amount, H2O2 concentration, contact time on decolorization efficiency. The decolorization efficiency for CR and RB5 by PEDMT–HRP was 98.20% and 47.99% after 30 min at pH 6.0 and 45 °C. The immobilized-HRP retained 89% and 27% of its initial activity after three repeated cycles with CR and RB5, respectively. The PEDMT microbeads with high surface area, porosity, durability, and reusability exactly met the requirements for HRP immobilization and dye decolorization. [ABSTRACT FROM AUTHOR]

The textile industry consumes a large amount of fresh water, resulting in colored effluent due to the incomplete fixation of certain dyes. Traditional textile wastewater treatment such as coagulation-flocculation, membrane filtration, thermal separation and electrochemical processes are expensive and pose significant environmental challenges. To address these issues an alternative technique for decolorizing textile effluent using a modified sparged loop reactor was proposed in this study. The jet loop reactor basically a multiphase reactor was utilized to treat textile wastewater with ozone. In this study, the textile wastewater containing water-soluble basic dyes such as Methylene blue and Congo red was simulated at a concentration of 50 ppm and the color removal efficiency of the reactor was analyzed. The effect of process parameters such as effluent flow rate (0.2– 0.4 Liter/ min), sparger openings (2−4), adsorbent weight (0.5 – 1.5 g) and ozone dosage time (10–30 min) on the decolorization efficiency of the reactor were examined and optimized using Response Surface Methodology. In this study, a maximum color removal of 93 % and 85 % for Congo red dye and Methylene blue dye simulated wastewater was achieved. A correlation was developed using Response Surface Methodology-Box Behnken Design and the developed model was successfully interpreted with experimental values. Based on our results, we believe that it is possible to replace the energy-intensive thermal separation process with jet loop sparged reactor to treat the textile effluent. As a sustainable process, loop reactor may result in a huge reduction of freshwater consumption. [ABSTRACT FROM AUTHOR]

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A significant variation in the relative representation of copies of bacterial genes of dye-decolorizing DyP peroxidases typical for the genus Shewanella and a number of other microorganisms was found in the bottom sediments of freshwater reservoirs. It was found that the specific rate of decolorization of crystal violet in a laboratory bioelectrochemical system by a mixed culture of bottom sediments, which showed the highest representation of DyP genes, depended on the method of electrical stimulation of the external circuit and the concentration of the dye. After an increase in the concentration of more than 20 microns, the maximum speed was achieved in the presence of an ionistor polarly connected to the external electrical circuit of the bioelectrochemical system and amounted to 3.23 ± 0.11 μM/h, while with the opposite polarity connection, a minimum value of 2.07 ± 0.08 μM/h was observed. In the case of an open circuit and a resistor, similar indicators occurred with 2.88 ± 0.09 and 2.67 ± 0.12 μM/h, respectively. When analyzing the decolorization products, a consistent decrease in the maxima of the absorption bands of the dye was noted, indicating its more complete degradation by the mixed culture. The results may be of interest for the development of methods to improve the efficiency of bioelectrochemical methods of environmental biotechnology by electrostimulation of the external circuit. [ABSTRACT FROM AUTHOR]

Commercial direct dyes are frequently employed in the dyeing of Jumputan, a traditional craft originating from South Sumatra, Indonesia. The introduction of synthetic dyes into the environment can have a detrimental impact on ecosystem stability, necessitating the implementation of remedial measures. There has been a growing interest in the utilization of White Rot Fungi (WRF) as a viable biological agent for the purpose of decolorizing and detoxifying synthetic colors. However, it is imperative to investigate the isolated WRF from Berbak-Sembilang National Park (TNBS) due to the varying capacities of decolorization and detoxification exhibited by each WRF. The study involved 5 WRF from TNBS screened in solid media, and grown in a liquid medium containing commercial direct dyes (direct turquoise, direct orange and direct yellow). WRF grown on liquid medium contains a single dye, mixture dyes and temperature characterization. It measured decolorization, biomass and enzyme activities. Toxicity is measured by the BSLT method. The findings indicated that 3 specific fungi, namely Phellinus noxius (BRB 11), Lentinus sajor-caju (BRB 12) and Leotrametes menziesii (BRB 73), exhibited a significant capacity to remove the color from both individual and mixture of direct dyes through the production of laccase and MnP enzymes. The optimal temperature for decolorization of the mixture of direct dyes was 35 °C for BRB 11 (61.4 %) and BRB 73 (60.7 %), whereas BRB 12 (47.4 %) exhibited optimal temperature at 30 °C. The toxicity assay conducted using A. salina showed a progressive rise in the LC50 value, from 15.37 mgL-1 in the control group to a range of 21.63 - 35.84 mgL-1 in the treated group, indicating a detoxification process. However, the most toxic isolate was BRB 12. This study proposes the potential of 2 isolates, Phellinus noxius (BRB 11) and Leotrametes menziesii BRB 73, from TNBS for degradation of single and mixture dye wastewater in the environment. [ABSTRACT FROM AUTHOR]

Discharge of the exhausted dye bath at the end of dyeing imposes a huge waste-water load, necessitating the use of fresh water for further processing. Due to the limited availability of fresh water, industries are compelled to remove the dyes from drained-out liquor to protect the environment and recycle the treated water for future processing. Discharged dyes create a film or layer of color on the water's surface, impeding the natural breakdown of substances and harm aquatic organisms. A significant proportion of effluent comprises synthetic dyes from azo, anthraquinone, triphenylmethane, indigo, and other groups. Several azo dyes and their cleaved by-products have been discovered to impact human health. Various established techniques are commonly employed to remove the color from dye; however, they have inherent restrictions. Due to increased demand, there is a growing need to explore cost-effective alternative treatments, such as biological integrated systems. The utilization of laccase for the decolorization of dyes presents a possible technological solution to address the drawbacks associated with current approaches. These enzymes can chemically react with and break down diverse substances. Laccases have been verified for their capacity to break down synthetic dyes in wastewater, resulting in the degradation of less hazardous products than the original dyes. This study examines the advantages and disadvantages of different technologies used to remove color from dyes. It also discusses the degradation mechanisms of several synthetic dyes catalyzed by laccase and the impact of factors, such as temperature, pH, dye concentration, etc. Additionally, the most recent studies on decolorization utilizing laccase are reviewed. [ABSTRACT FROM AUTHOR]

The bacteria, one of the most pervasive microorganisms globally, are involved in a myriad of roles in the lentic ecosystem. Consequently, the aquatic environment plays a crucial role in fostering soil health and nutrient levels. The present investigation focuses on potential microorganisms capable of decolorizing synthetic dyes, sourced from aquatic environments. The findings reveal that when cultured in broth containing Congo red dyes in varying doses (100, 200, 300, 400, 500, and 800 mg/L), the decolorization efficiency of bacterium TBSP1 was recorded at 99.8%, 99.6%, 95%, 87.8%, and 79.67%, respectively. Similarly, TBSP2 demonstrated an efficiency of 100%, 99%, 98%, 95%, 88.04%, 53.27%, and 65% for Congo red dye after 6 days post-inoculation at concentrations of 100, 200, 300, 400, 500, and 800 mg/L, respectively. At 3-day post-inoculation, TBSP1 and TBSP2 immobilized cells show case decolorization efficiencies of 96.04%, 93.73%, and 88.64% with low concentrations of dyes with Congo red, both with and without immobilization. Furthermore, due to changes in functional group by bacterial enzymatic activity, decolorization efficiency was observed with TBSP1 and TBSP2 at 12, 24, 48, and 72 h post-inoculation. [ABSTRACT FROM AUTHOR]

Synthetic dyes, particularly azo dyes, pose environmental and health risks because of their toxicity and persistence. To reduce these negative effects, it is necessary to degrade and detoxify these dyes into simple, non-toxic substances. Enzymes from various organisms play crucial roles in dye degradation and detoxification, making biological treatments cost-effective and environmentally friendly. Reductases are key players in breaking the azo bonds in azo dyes under limited oxygen conditions. This review emphasizes the importance of reductases in azo dye degradation and the exploration of various organisms that produce these enzymes. Azorereductases and NADH-DCIP reductases have been extensively investigated and have been shown to degrade azo dyes efficiently. These enzymes play key roles in azo dye degradation and detoxification by catalyzing the cleavage of azo linkages in the presence of redox coenzymes, such as NADH, NADPH, and FADH2. However, despite their effectiveness, different conditions, such as pH, temperature, dye concentration, and incubation time, affect enzyme activity during degradation; thus, optimization is required for efficient decolorization. Further studies are necessary to identify new species and strains, isolate and characterize enzymes, and determine the possible pathways for degrading azo dyes.

Coprinus cinereus (NBRC 30628) peroxidase was implemented to eliminate the diazo dye of reactive black 5 (RB5). The optimization was conducted in batch mode using three approaches, i.e., the one-factor-at-a-time (OFAT), factorial design, and response surface methodology (RSM). Based on the results of the OFAT method, the optimum conditions for decolorization of RB5 dye were at a temperature of 30oC, a pH of 9-10, an H2O2 concentration of 3.9 mM, and an RB5 concentration of 40 mg/L. In the first stage of statistical optimization, these factors plus enzyme activity were screened by the 2-factorial design, wherein enzyme activity, temperature, and hydrogen peroxide concentration were distinguished as the most significant parameters in the enzymatic decolorization of RB5. In the second stage, RSM was applied over three adopted factors through the central composite design (CCD), and a reduced cubic polynomial model was generated, which indicated an accurate regression (R2 = 0.997, Adj.R2 = 0.994) and no significant lack of fit (p-value> 0.05). The contour and surface plots suggested that the removal efficiency was enhanced by increased enzyme activity and decreased H2O2 concentration and temperature. The optimum condition was obtained at 1.0 mM H2O2, 6 U/mL enzyme activity, and 35oC for a maximum decolorization efficiency of 96.046%.

旨在为迷迭香脂溶性提取物在食用油保鲜方面的应用提供参考，以玉米油提取的迷迭香脂溶性提取物（可作为抗氧化剂）为原料，对其进行脱色处理，以脱色率为指标，通过单因素试验和响应面试验优化脱色工艺条件，并采用高效液相色谱法测定脱色前后迷迭香脂溶性提取物中脂溶性抗氧化成分（鼠尾草酸和鼠尾草酚）的含量。结果表明：与活性白土及活性白土与活性炭复配（质量比1∶ 1、1∶ 2、2∶ 1）脱色剂相比，活性炭对迷迭香脂溶性提取物的脱色效果最好，最佳脱色工艺为活性炭添加量2.1%、脱色温度50 ℃、脱色时间59 min，在此条件下脱色率为(75.02±0.37)%；脱色前后迷迭香脂溶性提取物中脂溶性抗氧化成分含量分别为4.065 5%和3.883 6%。综上，优化条件下迷迭香脂溶性提取物的脱色效果较好，且脱色对其脂溶性抗氧化成分含量影响较小。In order to provide a reference for the application of rosemary fat-soluble extract in the preservation of edible oil, the rosemary fat-soluble extract (which can be used as an antioxidant) extracted by corn oil was decolorized. With the decolorization rate as the index, the decolorization process conditions were optimized by single factor experiment and response surface methodology, and the content of fat-soluble antioxidant components (carnosic acid and carnosic phenol) in rosemary fat-soluble extract before and after decolorization was determined by high performance liquid chromatography. The results showed that activated carbon had the best decolorization effect on rosemary fat-soluble extract compared with activated clay and compound decolorant of activated clay and activated carbon (mass ratio 1∶ 1,1∶ 2,2∶ 1). The optimal decolorization process conditions were as follows: activated carbon dosage2.1%, decolorization temperature 50 ℃, decolorization time 59 min. Under the optimal conditions, the decolorization rate was (75.02±0.37)%. The antioxidant content before and after decolorization in rosemary fat-soluble extract was 4.065 5% and 3.883 6%, respectively. In summary, the decolorization effect of rosemary fat-soluble extract under optimized conditions was better, and the decolorization had little effect on the content of fat-soluble antioxidant components.

The extraction and decolorization conditions for Spirulina platensis polysaccharides using hot alkali and hydrogen peroxide were investigated, and the process was optimized. Based on the results of a single-factor test, the yield and decolorization rate of polysaccharides were taken as indices to optimize the technological conditions for extracting polysaccharides from Spirulina platensis using the hot alkali method and decolorizing them with hydrogen peroxide using the response surface methodology. The optimal conditions for hot alkali extraction of polysaccharides from Spirulina platensis were determined as follows: NaOH concentration of 1.5%, extraction temperature of 90 ℃, extraction time of 4 hours, and material-to-liquid ratio of 1:20 g/mL. Under these conditions, the yield of polysaccharides from Spirulina platensis was 5.18%±0.23%. The optimal conditions for decolorization using hydrogen peroxide were found to be: 17% hydrogen peroxide solution, decolorization time of 55 minutes, and decolorization temperature of 50 ℃. Under these conditions, the actual decolorization rate was 82.54%±0.03%, and the retention rate of polysaccharides was 83.45%±0.13%. The findings of this study provide valuable insights for the development and utilization of Spirulina platensis polysaccharides.

Synthetic dyes are widely used in various branches of light industry. Due to the insuffi cient effi ciency of industrial painting processes, a large percentage of dyes end up in the wastewater of enterprises in an unmodifi ed form, which creates a huge risk of environmental pollution with these compounds. Triphenylmethane dyes, in particular malachite green, are toxic, allergenic and carcinogenic compounds. To date, biodegradability of triphenylmethane dyes has been shown for some bacteria and fungi producing phenol oxidase complex enzymes, including soil associative bacteria of the genus Azospirillum. Many factors are capable of inducing and inhibiting the biodegradation effi ciency, in particular the enzymatic systems that are involved in bleaching processes. In the present work we studied the eff ects of typical deactivating agents of phenol oxidases, such as H2 O2 , EDTA, SDS-Na, β-mercaptoethanol, dithiothreitol, Tween, and sodium azide, on the azospirilla’s phenol oxidases activity and the ability to decolorize malachite green. It was found that Tween and sodium azide do not have an inhibitory eff ect on azospirillum enzymes and exhibit a total stabilizing eff ect on the entire complex. An inhibitory eff ect from 60 to 100% was noted for laccase and Mn-peroxidase activity under the action of β-mercaptoethanol, dithiothreitol and EDTA, which is directly proportional to the decolorization rate of malachite green. Compared with the latest issues on classical phenol-oxidizing enzymes, our data revealed non-typical properties of the phenol oxidase complex enzymes of azospirillum.

This study refines a single-layer Feed-Forward Neural Network (FFNN) for the treatment of textile dye wastewater, concentrating on percentage decolorization (%DEC) and percentage chemical oxygen demand (%COD) reduction. The optimized neural network configuration comprises four input and one output neuron, fine-tuned based on the mean squared error (MSE). The training phase demonstrates a consistent MSE decline, reaching its lowest at epoch 209 for %DEC and epoch 34 for %COD, with corresponding MSEs of $1.799 \times 10^{-5}$ and $ 1.4 \times 10^{-3} $, respectively. The maximum absolute errors for %DEC and %COD were found to be $ 4.0787 $ and $ 2.4486 $, while the mean absolute errors were $ 0.4821 $ and $ 0.7256 $, respectively. In contrast to second-degree polynomial regression, the FFNN model exhibits enhanced predictive accuracy, as indicated by higher $ R^2 $ values of $ 0.99363 $ for %DEC and $ 0.99716 $ for %COD, and reduced error metrics.

The artisanal textile industry plays a vital role in the economy by providing a wide variety of products. However, this sector generates large quantities of wastewater containing a diversity of organic compounds, including dyes that, when released into the environment, contribute significantly to water pollution. In this research, samples of synthetic wastewater containing green aniline were subjected to decolourization using the photo-Fenton process. Synthetic textile wastewater was prepared at a concentration of 40 mg/L, and a calibration curve was established. During the treatment, ferrous sulfate (at concentrations of 50 and 150 mg/L) and H2O2 (at concentrations of 0.5 and 1.0 g/L) were added to 1 L of the synthetic effluent in a stirring medium (at 1000 rpm) and exposed to solar radiation for 1, 2, or 3 hours, while maintaining a pH of 3. To quantify the degree of decolourization, absorbance was measured at the beginning and end of the treatment using a colourimeter. The optimal conditions for Fe2+ concentration, H2O2 concentration, and treatment time, with an initial concentration of 40 mg/L, were found to be 150 mg/L, 1.0 g/L, and 3 hours, respectively. Under these conditions, the percentage of decolourization reached 97.546%. The study demonstrated that the concentration of Fe2+ and treatment time, as well as the interaction between Fe2+ concentration, H2O2 concentration, and treatment time, significantly influenced the degree of decolourization. Conversely, the concentration of H2O2 and other interactions did not exhibit significant influence.

Camellia seed oil (CSO), as a nutrient-rich edible oil, is widely used in foods, cosmetics, and other fields. In this work, the extraction, deacidification, decolorization, and deodorization processes of CSO were respectively optimized for meeting injectable oil standards. The results showed that the CSO extraction rate reached the highest level of 94% at optimized conditions (ultrasonic time, 31.2 min; reaction pH, 9.2; and reaction time, 3.5 h). The physicochemical indexes of CSO and 10 other vegetable oils were evaluated by the principal component analysis method, and the overall scores of vegetable oils were ranked as camellia seed oil > olive oil > rice oil > peanut oil > sesame oil > corn oil > soybean oil > sunflower oil > rapeseed oil > walnut oil > flaxseed oil. The physicochemical indicators of CSO were the most ideal among the 11 vegetable oils, which means that CSO is suitable as an injectable oil. Through the optimized processes of the deacidification, decolorization, and deodorization, the CSO acid value was reduced to 0.0515 mg KOH/g, the decolorization rate reached a maximum of 93.86%, and the OD430 was 0.015, meeting the requirement (≤0.045 of OD430) of injectable oil. After the deodorization process, these parameters of the refractive index, acid value, saponification value, iodine value, absorbance, unsaponifiable, moisture and volatiles, fatty acid composition, and heavy metal limits all met the pharmacopoeia standards of injectable oil in many countries and regions. The possibility of CSO as an injectable oil was first verified through refining-process optimization and nutritional index analysis, providing an important technical reference for the high-value utilization of vegetable oil. [ABSTRACT FROM AUTHOR]

In the current study, the catalyst for the decolorization of methyl orange (MO) was developed HAp-rGO by the aqueous precipitation approach. Then, bismuth(0) nanoparticles (Bi NPs), which expect to show high activity, were reduced on the surface of the support material (HAp-rGO). The obtained catalyst was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. The parameters that remarkably affect the decolorization process (such as time, initial dye concentration, NaBH4 amount, and catalyst amount) have been examined by response surface methodology (RSM), an optimization method that has acquired increasing significance in recent years. In the decolorization of MO, the optimum conditions were identified as 2.91 min, Co: 18.85 mg/L, NaBH4 amount: 18.35 mM, and Bi/HAp-rGO dosage: 2.12 mg/mL with MO decolorization efficiency of 99.60%. The decolorization process of MO with Bi/HAp-rGO was examined in detail kinetically and thermodynamically. Additionally, the possible decolorization mechanism was clarified. The present work provides a new insight into the use of the optimization process for both the effective usage of Bi/HAp-rGO and the catalytic reduction of dyes. [ABSTRACT FROM AUTHOR]

The identification of microorganisms with excellent flocculants-producing capability and optimization of the fermentation process are necessary for the wide-scale application of bioflocculants. Therefore, we isolated and identified a highly efficient flocculation performance strain of Stenotrophomonas pavanii GXUN74707 from the sludge. The optimal fermentation and flocculation conditions of strain S. pavanii GXUN74707 was in fermentation medium with glucose and urea as the carbon and nitrogen sources, respectively, at pH 7.0 for 36 h, which treatment of kaolin suspension with 0.5 mL of the fermentation broth resulted in a flocculation rate of 99.0%. The bioflocculant synthesized by strain S. pavanii GXUN74707 was found mainly in the supernatant of the fermentation broth. Chemical analysis revealed that the pure bioflocculant consisted of 79.70% carbohydrates and 14.38% proteins. The monosaccharide components of MBF-GXUN74707 are mainly mannose (5.96 mg/mg), galactose (1.86 mg/mg), and glucose (1.73 mg/mg). Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH) groups. The SEM images showed clumps of rod-shaped bacteria with adhesion of extracellular products. Furthermore, the strain decolored dye wastewater containing direct black, direct blue, and Congo red by 89.2%, 95.1%, 94.1%, respectively. The chemical oxygen demand (COD) and biological oxygen demand (BOD) removal rates after treatment of aquaculture wastewater with the fermentation broth were 68% and 23%, respectively. This study is the first to report the performance and application of strain Stenotrophomonas pavanii in wastewater flocculation. The results indicate that strain S. pavanii is a good candidate for the production novel bioflocculants and demonstrates its potential industrial practicality in biotechnology processes. [ABSTRACT FROM AUTHOR]

This study aims to reduce the band gap by doping wide band‐gap TiO2 with CoFe2O4 and PANI to improve the photocatalytic efficiency and examine the decolorization kinetic of Rhodamine B (RhB). The characteristics of the nanocomposites were thoroughly assessed through the utilization of SEM‐EDS, TEM, XRD, FTIR, VSM, UV‐Vis, PL, and XPS analyses. The SEM and TEM analyses revealed that CoFe2O4/TiO2/PANI has a homogeneously porous structure. XRD analysis results were found to show good agreement with the standard diffraction data cards. The band structures obtained by FTIR analyses were compatible with literature studies. The band gap energies determined by UV‐Vis analyses were determined as 2.86 eV for CoFe2O4/TiO2/PANI. The decrease of CoFe2O4/TiO2/PANI recombination rate was proven with PL results. The different initial dye concentrations, temperature, and light intensity parameters were used to determine the decolorization kinetics of RhB over CoFe2O4/TiO2/PANI. The photodegradation rates of RhB in reactions catalyzed by PANI, CoFe2O4, commercial‐TiO2, CoFe2O4/TiO2, and CoFe2O4/TiO2/PANI were determined as 7.6 %, 20.7 %, 26.6 %, 32.4 %, and 48.8 %, respectively. According to data obtained from the decolorization of RhB on CoFe2O4/TiO2/PANI nanocomposite, the appropriate kinetic model was determined Network kinetic. The adsorption equilibrium constant (KB) and activation energy (Ea) were calculated as 0.007 and 7.9 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

Laccases are versatile biocatalysts that are prominent for industrial purposes due to their extensive substrate specificity. Therefore, this research investigated producing laccase from Physisporinus vitreus via liquid fermentation. The results revealed that veratryl alcohol (4mM) was the most effective inducer 7500U/L. On the other hand, Zn ions inhibited laccase production. The optimum carbon and nitrogen sources were glucose and tryptone by 5200 and 3300 U/L, respectively. Moreover, solvents exhibited various impacts on the enzyme activity at three different solvent concentrations (5%, 10% and 20%), however, it showed a highest activity at 5% of the investigated solvent. Ferric ions inhibited the enzyme activity. In addition, the enzyme has a high ability to decolorize azo dyes when using syringaldehyde as a mediator. The purified laccase from Physisporinus vitreus is a promising substance to be used for industrial and environmental applications due to its stability under harsh conditions and efficiency in decolorization of dyes. [ABSTRACT FROM AUTHOR]

This study presents an innovative approach for the reuse and recycling of waste material, brewer's spent grain (BSG) for creating a novel green biocatalyst. The same BSG was utilized in several consecutive steps: initially, it served as a substrate for the cultivation and production of laccase by a novel isolated fungal strain, Coriolopsis trogii 2SMKN, then, it was reused as a carrier for laccase immobilization, aiding in the process of azo dye decolorization and finally, reused as recycled BSG for the second successful laccase immobilization for six guaiacol oxidation, contributing to a zero-waste strategy. The novel fungal strain produced laccase with a maximum activity of 171.4 U/g after 6 days of solid-state fermentation using BSG as a substrate. The obtained laccase exhibited excellent performance in the decolorization of azo dyes, both as a free and immobilized, at high temperatures, without addition of harmful mediators, achieving maximum decolorization efficiencies of 99.0%, 71.2%, and 61.0% for Orange G (OG), Congo Red, and Eriochrome Black T (EBT), respectively. The immobilized laccase on BSG was successfully reused across five cycles of azo dye decolorization process. Notably, new green biocatalyst outperformed commercial laccase from Aspergillus spp. in the decolorization of OG and EBT. GC-MS and LC-MS revealed azo-dye degradation products and decomposition pathway. This analysis was complemented by antimicrobial and phytotoxicity tests, which confirmed the non-toxic nature of the degradation products, indicating the potential for safe environmental disposal. [ABSTRACT FROM AUTHOR]

This study refines a single-layer Feed-Forward Neural Network (FFNN) for the treatment of textile dye wastewater, concentrating on percentage decolorization (%DEC) and percentage chemical oxygen demand (%COD) reduction. The optimized neural network configuration comprises four input and one output neuron, fine-tuned based on the mean squared error (MSE). The training phase demonstrates a consistent MSE decline, reaching its lowest at epoch 209 for %DEC and epoch 34 for %COD, with corresponding MSEs of 1.799 × 10-5 and 1.4 × 10-3, respectively. The maximum absolute errors for %DEC and %COD were found to be 4.0787 and 2.4486, while the mean absolute errors were 0.4821 and 0.7256, respectively. In contrast to second-degree polynomial regression, the FFNN model exhibits enhanced predictive accuracy, as indicated by higher R² values of 0.99363 for %DEC and 0.99716 for %COD, and reduced error metrics. [ABSTRACT FROM AUTHOR]