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Macroalgae are one of various groups of multicellular algae include some types of Rhodophyta (red), Phaeophyta (brown), and Chlorophyta (green) macroalgae. They are now a source for biorefineries, as they contribute to energy production as biomass. Algae are worth noting because of their high content in compounds with separate biological activities, including agar, agarose, and carrageenan in red algae; alginates, laminarin, and fucoidan in brown algae; and ulvan, sulfated galactans, and xylans in green algae. Skeletal polysaccharides of red algae are composed of cellulose 1,β-1,3-mannan and β-1,4-acrylic acid. More than half of the dry weight of brown algae is made up of the polysaccharides alginate, laminarin, and fucoidan, and this percentage can even exceed 70% in some species. They are converted to monosaccharides that can be easily used by using polysaccharide hydrolysis enzymes. This process has the potential to maximize biofuel yields. Compared with the enzymatic depolymerization of brown and red algae polysaccharides, the depolymerization of green algae polysaccharides has been less extensively investigated. However, the use of ulvan lyase is very promising because it can degrade ulvan with good specificity, high efficiency, and mild reaction conditions, and it can well maintain the rare sugar structure properties of ulvan. The depolymerization process of macroalgae by chemical hydrolysis requires high cost, causes environmental pollution, and has limited use due to problems such as low yield. Therefore, an environmentally friendly, energy efficient and economical enzymatic depolymerization process of macroalgae using degrading enzyme will be needed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Enzymatic process is the most promising alternative to achieve sustainable development of collagen fiber purification from animal hide/skin. • Protease, lipase, and glycosidase are used in collagen fiber purification processing. • Key mechanisms and application technologies of enzymatic processes were overviewed. • Recent progress and challenges of enzymatic collagen fiber purification strategies were analyzed. • Recommendations for the development of effective application technologies and new special enzymes were put forward. Collagen fiber purification is the most important pretreatment process in the recycling of animal hide/skin, by-products of meat production, and can be utilized to produce value-added materials. Traditional animal hide/skin resource utilization technologies face serious challenges in the aspect of production efficiency and environmental sustainability. Enzymatic collagen fiber purification processing is thought to be one of the most promising technologies that can minimize the use of chemicals and energy, reduce CO 2 -eq emissions, and achieve sustainable development of animal hide/skin reutilization. However, enzymatic processes have not been well accepted for industrial-scale applications in factories so far. In this review, recent progress and challenges of enzymatic collagen fiber purification processing were comprehensively overviewed in the aspect of the key mechanisms and technologies of enzyme application. Recommendations for the direction of enzyme selection and development were put forward, which is expected to pave the way for the industrial-scale application of enzymes in animal hide/skin collagen fiber purification processing. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish an efficient bioprocess for the synthesis of trehalulose as a novel sweetener. This disaccharide has 70% of the sweetness of sucrose and bioactive properties such as anti-cariogenicity and anti-oxidizing activity. In this study, amylosucrase from the Deinococcus deserti (Dd AS) gene was expressed and purified. When Dd AS was reacted with 2 M sucrose at 35 °C for 120 h, the yield ratio of trehalulose to turanose was approximately 2:1. The trehalulose yield increased when extrinsic fructose was added. Under optimum conditions for trehalulose synthesis, the yield reached 36% (246 g/L, sucrose basis) starting with 2 M sucrose + 0.75 M fructose and showed the highest trehalulose productivity (1.94 g/L/h). As a result, a novel amylosucrase that synthesized trehalulose as the major product was developed, in contrast to other studied amylosucrase-type enzymes. Dd AS could be utilized industrially in a bioprocess for producing trehalulose as a functional sucrose alternative. • A novel amylosucrase was found to synthesize trehalulose as a main product. • The enzyme from Deinococcus sp. was expressed in E. coli. • Yield ratio of trehalulose to turanose was 2:1 with 2 M sucrose at 35 °C and pH7.5. • Maximum trehalulose yield reached 36% with 2 M sucrose + 0.75 M fructose. • Industrial application of this enzyme may lead to development of a valuable sweetener. [ABSTRACT FROM AUTHOR]

This study evaluates the feasibility of using enzymatic technology to produce novel nanostructures of cellulose nanomaterials, specifically cellulose nanospheres (CNS), through enzymatic hydrolysis with endoglucanase and xylanase of pre-treated cellulose fibers. A statistical experimental design facilitated a comprehensive understanding of the process parameters, which enabled high yields of up to 82.7 %, while maintaining a uniform diameter of 54 nm and slightly improved crystallinity and thermal stability. Atomic force microscopy analyses revealed a distinct CNS formation mechanism, where initial fragmentation of rod-like nanoparticles and subsequent self-assembly of shorter rod-shaped nanoparticles led to CNS formation. Additionally, adjustments in process parameters allowed precise control over the CNS diameter, ranging from 20 to 100 nm, highlighting the potential for customization in high-performance applications. Furthermore, this study demonstrates how the process framework, originally developed for cellulose nanocrystals (CNC) production, was successfully adapted and optimized for CNS production, ensuring scalability and efficiency. In conclusion, this study emphasizes the versatility and efficiency of the enzyme-based platform for producing high-quality CNS, providing valuable insights into energy consumption for large-scale economic and environmental assessments. [Display omitted] • The same enzyme-based process can produce nanomaterials with distinct morphologies. • The diameter of the cellulose nanospheres can be tailored, ranging from 20 to 100 nm. • The maximum production yield of cellulose nanospheres reached 82.7 %. • The specific surface area of cellulose was the most significant variable in CNS production. • A high CNS yield was associated with low energy consumption (39.36 kWh/Kg). [ABSTRACT FROM AUTHOR]

This study evaluates the feasibility of using enzymatic technology to produce novel nanostructures of cellulose nanomaterials, specifically cellulose nanospheres (CNS), through enzymatic hydrolysis with endoglucanase and xylanase of pre-treated cellulose fibers. A statistical experimental design facilitated a comprehensive understanding of the process parameters, which enabled high yields of up to 82.7 %, while maintaining a uniform diameter of 54 nm and slightly improved crystallinity and thermal stability. Atomic force microscopy analyses revealed a distinct CNS formation mechanism, where initial fragmentation of rod-like nanoparticles and subsequent self-assembly of shorter rod-shaped nanoparticles led to CNS formation. Additionally, adjustments in process parameters allowed precise control over the CNS diameter, ranging from 20 to 100 nm, highlighting the potential for customization in high-performance applications. Furthermore, this study demonstrates how the process framework, originally developed for cellulose nanocrystals (CNC) production, was successfully adapted and optimized for CNS production, ensuring scalability and efficiency. In conclusion, this study emphasizes the versatility and efficiency of the enzyme-based platform for producing high-quality CNS, providing valuable insights into energy consumption for large-scale economic and environmental assessments. [Display omitted] • The same enzyme-based process can produce nanomaterials with distinct morphologies. • The diameter of the cellulose nanospheres can be tailored, ranging from 20 to 100 nm. • The maximum production yield of cellulose nanospheres reached 82.7 %. • The specific surface area of cellulose was the most significant variable in CNS production. • A high CNS yield was associated with low energy consumption (39.36 kWh/Kg). [ABSTRACT FROM AUTHOR]

Background and purpose: So far, different methods have been used to remove residual antibiotics from aquatic environments. This study investigated the efficiency of enzyme horseradish peroxidase (HRP) in presence of hydrogen peroxide in removal of Tetracycline and Ciprofloxacin in a batch system. Materials and methods: In an experimental study on laboratory scale, the effects of contact time, concentrations of H2O2, the antibiotics, and enzyme, and reaction pH on the performance of pure HRP enzyme in the presence of H2O2, were investigated. To measure the efficiency of the enzymatic process, the residual antibiotics were measured using HPLC equipped with a reverse phase column (C-18, 5% micrometer, 250 * 4.6 mm). The flow rate was 1 ml/min and the injection volume was 40 μl. The mobile phase of Tetracycline was 0.1 M TFA- methanol (60:40) used at 254 nm and the mobile phase of ciprofloxacin was 0.01 M acetonitrile- phosphate (8:92) at 220 nm. All experiments were performed in a discontinuous system at laboratory temperature. Results: Removal efficiencies of Tetracycline and Ciprofloxacin were 40% and 95%, respectively, at 10 mg/l initial concentrations of antibiotics, 10-min contact time, Tetracycline pH= 4, and Ciprofloxacin pH= 7. The removal efficiency of Ciprofloxacin was two times more than that of Tetracycline. Conclusion: The free HRP could be used as an effective process in removing Tetracycline and Ciprofloxacin from wastewater. [ABSTRACT FROM AUTHOR]

Anticancer drugs are a class of pharmaceutical compounds that have been found in hospital, domestic, and industrial wastewaters and also in surface waters. They have been showing recalcitrance to conventional wastewater treatment technologies and present a potential risk to environment and human health, since they exhibit cytotoxic, teratogenic, and carcinogenic among other effects in higher organisms, even at low concentrations. The presence of these compounds in the environment is a recent challenge for wastewater treatment and some alternative strategies to remove them were already studied, such as white-rot fungi (WRF) technologies. Despite promising results, processes involving fungi are complex, have high reaction times, and require nutrient addition for fungus growth and maintenance. Due to this potential, strategies to make the technology feasible were studied, such as the possibility for direct application of enzymes secreted by WRF. Enzymatic processes were studied in the removal of other pharmaceuticals such as antibiotics, anti-inflammatory, and steroid hormones; however, to the best of our knowledge, there is a gap on literature about their direct action on anticancer drugs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Enzymatic hydrolysis and high hydrostatic pressure (HHP) are common processing techniques in the extraction of active compounds from food materials. The aim of this study was to investigate the effects of enzymatic hydrolysis combined with HHP treatments on ginsenoside metabolites in red ginseng. RESULTS: The yield and changes in the levels of polyphenol and ginsenoside were measured in red ginseng treated with commercial enzymes such as Ultraflo L, Viscozyme, Cytolase PCL5, Rapidase and Econase E at atmospheric pressure (0.1 MPa), 50 MPa, and 100 MPa. β‐Glucosidase activity of Cytolase was the highest at 4258.2 mg−1, whereas Viscozyme showed the lowest activity at 10.6 mg−1. Pressure of 100 MPa did not affect the stability or the activity of the β‐glucosidase. Treatment of red ginseng with Cytolase and Econase at 100 MPa significantly increased the dry weight and polyphenol content of red ginseng, compared with treatments at 0.1 MPa and 50 MPa (P < 0.05). The amounts of ginsenoside and ginsenoside metabolites derived from red ginseng processed using Cytolase were higher than those derived from red ginseng treated with the other enzymes. Treatment with Cytolase also significantly increased the skin and intestinal permeability of red ginseng‐derived polyphenols. CONCLUSION: Cytolase could be useful as an enzymatic treatment to enhance the yield of bioactive compounds from ginseng under HHP. In addition, ginsenoside metabolites obtained by Cytolase hydrolysis combined with HHP are functional substances with increased intestinal and skin permeability. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background: Burdock (Arctium lappa L.) is a fructan-rich plant with prebiotic potential. The aimof this study was to develop an efficient enzymatic route to prepare fructooligosaccharides (FOS)-rich and highly antioxidative syrup using burdock root as a raw material. Results: Endo-inulinase significantly improved the yield of FOS 2.4-fold while tannase pretreatment further increased the yield of FOS 2.8-fold. Other enzymes, including endo-polygalacturonase, endo-glucanase and endo-xylanase, were able to increase the yield of total soluble sugar by 11.1% (w/w). By this process, a new enzymatic process for burdock syrup was developed and the yield of burdock syrup increased by 25% (w/w), whereas with FOS, total soluble sugars, total soluble protein and total soluble polyphenols were enhanced to 28.8%, 53.3%, 8.9% and 3.3% (w/w), respectively. Additionally, the scavenging abilities of DPPH and hydroxyl radicals, and total antioxidant capacity of the syrup were increased by 23.7%, 51.8% and 35.4%, respectively. Conclusions: Our results could be applied to the development of efficient extraction of valuable products from agricultural materials using enzyme-mediated methods. [ABSTRACT FROM AUTHOR]

A Cu-tolerant strain, isolated from the soil of Mountain Qixia in Nanjing, was selected and used for enzyme digestion and identification. The was decomposited urea by enzymatic process during its growth and metabolism to produce CO3M2-, and combined with Cu2++ in solution to turned to precipitation, which were analyzed using EDS, XRD, SEM and other analytical methods. The results showed that the strain Cu11 is a carbonate mineralization microbe and identified as Cupriavidus necator, the main products are CuCO3 and Cu2+(OH)2CO3. The analysis of different influence on the rate of consolidation of Cu2++ showed that the Cu2++ consolidation rate increased with the increase of pH, and it reached 97% when pH was 13, the difference of inoculation amount of Cu2++ on Cu2++ consolidation rate was small, which was maintained at 85%-90%, the Cu2++ consolidation rate could reach 97.7% when the Cu2++ concentration being lower(0.005, 0.01 mol/L), while the Cu2++ concentration was high(0.03-0.09 mol/L), the Cu2++ concentration rate was only stable at about 80%, With the increase of substrate concentration, the Cu2++ consolidation rate increased first and then decreased, reaching a maximum of 96% at 25 g/L. [ABSTRACT FROM AUTHOR]

Background Seaweeds are a large and diverse group of photosynthetic macro-algae found across the world's oceans. There is a growing recognition that they are important sources of bioactive compounds with a variety of biological activities that could potentially contribute to functional food and nutraceutical industries. Scope and approach The complex structure and distinctive components of seaweed cell walls, which differ significantly from terrestrial plants, presents a major challenge for the effective extraction of bioactive compounds from inside the cells. Enzyme technologies have been used to improve the extraction, hydrolysis, and structure modification efficiently with a high degree of environmental sustainability. This review critically analyses the advances, challenges, and future directions in applying enzyme technologies to improve the extraction and processing of bioactive compounds from seaweeds and their potential applications in functional foods and nutraceuticals. Key findings and conclusions Different enzymatic processes have been demonstrated to (1) assist the extraction by breaking down the seaweed cell walls, and (2) degrade or hydrolyse macromolecules including polysaccharides and proteins. These enzymatic processes improve the yield and recovery of bioactive compounds and enhance their biological properties with regard to prebiotic, antioxidant, ACE inhibitory, anti-inflammatory, and antiviral effects. Seaweed-derived bioactive compounds from these processes present significant new opportunities in developing novel food applications. The current food regulations and safety requirements for seaweeds and their products are addressed for commercial product development. [ABSTRACT FROM AUTHOR]

Background: As an important bulk chemical for synthetic rubber, isoprene can be biosynthesized by robust microbes. But rational engineering and optimization are often demanded to make the in vivo process feasible due to the complexities of cellular metabolism. Alternative synthetic biochemistry strategies are in fast development to produce isoprene or isoprenoids in vitro. Results: This study set up an in vitro enzyme synthetic chemistry process using 5 enzymes in the lower mevalonate pathway to produce isoprene from mevalonate. We found the level and ratio of individual enzymes would significantly affect the efficiency of the whole system. The optimized process using 10 balanced enzyme unites (5.0 μM of MVK, PMK, MVD; 10.0 μM of IDI, 80.0 μM of ISPS) could produce 6323.5 μmol/L/h (430 mg/L/h) isoprene in a 2 ml in vitro system. In a scale up process (50 ml) only using 1 balanced enzyme unit (0.5 μM of MVK, PMK, MVD; 1.0 μM of IDI, 8.0 μM of ISPS), the system could produce 302 mg/L isoprene in 40 h, which showed higher production rate and longer reaction phase with comparison of the in vivo control. Conclusions: By optimizing the enzyme levels of lower MVA pathway, synthetic biochemistry methods could be set up for the enzymatic production of isoprene or isoprenoids from mevalonate. [ABSTRACT FROM AUTHOR]

Malto-oligosaccharide alcohols (MOSA) are one of the most important sugar alcohols widely used as sweetener in food, cosmetic, and pharmaceutical industries in recent years, of which maltotriitol-rich MOSA is much more recognized. With the aim of preparing maltotriitol-rich MOSA from starch, a novel process was developed and optimized. Starch was first liquefied with thermostable Bacillus licheniformis α-amylase. The liquefied starch was then saccharified to yield maltotriose-rich malto-oligosaccharides under the cooperative actions of Bacillus naganoensis pullulanase, Bacillus amyloliquefaciens α-amylase, and barley bran β-amylase. The maltotriitol-rich MOSA was finally prepared by chemical hydrogenation. Under the optimized conditions, maltotriitol-rich MOSA containing 42.18% maltotriitol was obtained with a conversion rate of 104.57% from starch. The process can be employed for large-scale preparation of maltotriitol-rich MOSA, and a further modification of the process can lead to the formulation of various types of MOSA with different percentages of components of sugar alcohols. [ABSTRACT FROM AUTHOR]

For decades, most of the developing nations have relied on chlorpyrifos for insecticidal activity in the agriculture sector. It is a common chlorinated organophosphorus pesticide that has been widely used to control insects to protect plants. This study aimed to investigate the effects of environmental characteristics such as salinity, pH, temperature, and surfactant on Hortaea sp. B15 mediated degradation of chlorpyrifos as well as enzyme activity and metabolic pathway. The highest bacterial growth (4.6 × 1016 CFU/mL) was achieved after 20 h of incubation in a 100 mg/L chlorpyrifos amended culture. The fit model and feasible way to express the chlorpyrifos biodegradation kinetics in normal condition and optimized was a first-order rate equation, with an R 2 value of 0.95–0.98. The optimum pH for chlorpyrifos biodegradation was pH 9, which resulted in a high removal rate (91.1%) and a maximum total count of 3.8 × 1016 CFU/mL. Increasing the temperature over 40 °C may inhibit microbial development and biodegradation. There was no significant effect of culture salinity on degradation and bacterial growth. In the presence of non-ionic surfactant Tween 80, the maximum chlorpyrifos degradation (89.5%) and bacterial growth (3.8 × 1016 CFU/mL) was achieved. Metabolites such as 3,5,6-trichloropyridin-2-ol and 2-pyridinol were identified in the Hortaea sp. B15 mediated degradation of chlorpyrifos. According to the findings, Hortaea sp. B15 should be recommended for use in the investigation of in situ biodegradation of pesticides. [Display omitted] • Hortaea sp. Enzymatic transformation of insecticide chlorpyrifos is studied. • High bacterial growth is achieved after 20 h in the presence of 100 mg/L chlorpyrifos. • The effective pH for chlorpyrifos biodegradation (91.1%) Hortaea sp. Is pH 9. • Non-ionic surfactant Tween 80 exhibits the maximum chlorpyrifos degradation (89.5%). • 3,5,6-Trichloropyridin-2-ol and 2-pyridinol were identified as degradation products. [ABSTRACT FROM AUTHOR]

The use of coconut fiber mature, green coconut shell, mature coconut shell and cactus is an important alternative as substrates for bioethanol production, since these lignocellulosic materials (LCMs) are abundant in Brazil, mainly in the Northeast Region. The first objective of this work was to evaluate the autohydrolysis pretreatment (AP) on these LCMs and the susceptibility of the treated materials to enzymatic hydrolysis (EH). The second part of the work deals with the application of semi-simultaneous saccharification and fermentation (SSSF) and simultaneous saccharification and fermentation (SSF) using Zymomonas mobilis , Pichia stipitis, Saccharomyces cerevisiae and as substrate the green coconut shell (selected according to the results obtained in the first part of the work). The LCMs after AP using the highest severity factor (4.64) showed changes in the chemical composition in comparison to the untreated LCMs: between the LCMs the cellulose increase was 48.55%, the hemicellulose decrease was 76.77% and an increase of 62.26% was observed for lignin. The green coconut shell was characterized by SEM, X-ray and FTIR after AP and its EH conversion into glucose was 92.52%. The best results on ethanol yield (90.09%) and ethanol productivity (0.21 g/(L h)) from green coconut shell were obtained by S. cerevisiae using SSSF. Overall, an efficient process for the bioethanol production from green coconut shell was developed. [ABSTRACT FROM AUTHOR]

The article discusses research on preparation of tulipalin B, antimicrobial α-methylene-β-hydroxy-γ-butyrolactone (PaB), antimicrobial natural product occurring in tulip (Tulipa gesneriana), from tulip biomass. It presents a description of an environmentally benign and facile process for the preparation of PaB based on reaction catalyzed by TCE (trichloroethylene). It also discusses purification of flower extracts with aqueous ethanol with activated charcoal.

Highlights: [•] In our study, the source of β-glucans is the cell wall of yeasts, especially the baker’s yeast Saccharomyces cerevisiae. [•] An enzymatic process for the isolation of glucans from yeast cell walls was established. [•] Results showed high yield of β-glucan compared to traditional isolation methods. [Copyright &y& Elsevier]

Seaweeds are the basis of a multibillion-dollar economy with an impact on highly diverse sectors, including food, feed, textile, pharmaceutical, nutraceutical, cosmetic, chemistry, bioactive compounds, and biotechnological sectors like bioenergy. Molecules from seaweed have provided promising drug leads, offered new targets for synthetic chemists, and provided opportunities for the elucidation of unusual biosynthetic pathways. Seaweed farming has developed all over the world. Simultaneously, the increasing report of outbreaks of 'green tides' ('brown or red tides'), fouling species and large piles of decomposing biomass which appear along shallow sandy bays represent a true economic constraint for the affected communities. Harvesting of invasive and proliferative species is an opportunity for collecting an important biomass for research of new compounds of interest. This review describes enzymatic processing of seaweeds as reported for the last 20 years. At this time when sustainable development and environmental protection are regarded as key factors, studies about innovative extraction processes of active compounds from natural products have attracted special attention. The use of enzyme treatment as a tool to improve the extraction efficiency of bioactive compounds from seaweeds shows several benefits. This chapter presents a synthesis of the conditions applied for seaweed cracking. Three different types of hydrolysis are used depending on the process design and the nature of the enzymes. Biochemical composition of hydrolysates, enzymatic hydrolysis efficiency, and biological activities depend on the nature of the macroalgae, the enzyme activity, the experimental conditions and the design process. Among the biological properties, the hydrolysates show various activities: antioxidant, antiviral, antiproliferative, antihypertensive and anticoagulative. These data demonstrate some potential applications of seaweed metabolites obtained by enzymatic hydrolysis and of the prospects for the future. [ABSTRACT FROM AUTHOR]

Over the past several decades, the pharmacological effects of ginsenosides in Panax ginseng roots have been extensively investigated. Here, we developed a method for producing specific ginsenosides (F1 and F2) with good yields (F1:162 mg/g, F2:305 mg/g) using β-glycosidase purified from Aspergillus niger. In addition, each ginsenoside (at least 25 species) was separated and purified by high performance liquid chromatography (HPLC) using five different types of solvents and different purification steps. In addition, the Rg3:Rh2 mixture (1:1, w/w) was shown to inhibit a specific lung cancer cell line (NCI-H232) in vivo, displaying an anticancer effect at a dose lower than achieved using treatments with single Rg3 or Rh2. This finding suggests that the combination of ginsenosides for targeting anticancer is more effective than the use of a single ginsenoside from ginseng or red ginseng. [ABSTRACT FROM AUTHOR]

Abstract: The excess of sugarcane bagasse (SCB) from the sugar-alcohol industry is considered a by-product with great potential for many bioproducts production. This work had as objective to verify the performance of sugarcane bagasse hemicellulosic hydrolysate (SCBHH) as source of sugars for enzymatic or in vitro xylitol production. For this purpose, xylitol enzymatic production was evaluated using different concentrations of treated SCBHH in the commercial reaction media. The weak acid hydrolysis of SCB provided a hydrolysate with 18 g L−1 and 6 g L−1 of xylose and glucose, respectively. Considering the reactions, changes at xylose–xylitol conversion efficiency and volumetric productivity in xylitol were not observed for the control experiment and using 20 and 40% v.v−1 of SCBHH in the reaction media. The conversion efficiency achieved 100% in all the experiments tested. The results showed that treated SCBHH is suitable as xylose and glucose source for the enzymatic xylitol production and that this process has potential as an alternative for traditional xylitol production ways. [Copyright &y& Elsevier]

Abstract: The conversion of biomass into biofuels can reduce the strategic vulnerability of petroleum-based transportation systems. Bioethanol has received considerable attention over the last years as a fuel extender or even as a neat liquid fuel. Lignocellulosic materials are very attractive substrates for the production of bioethanol because of their low cost and their great potential availability. Two different process alternatives (i.e. the enzymatic hydrolysis and fermentation process and the gasification and fermentation process) for the production of fuel ethanol from lignocellulosic feedstock are considered and analysed. After a rigorous mass and energy balance, design optimisation is carried out. Both processes are assessed in terms of ethanol yield and power generation as well as from a financial point of view. A sensitivity analysis on critical parameters of the processes'' productivity and profitability is performed. [Copyright &y& Elsevier]

High erucic acid (HEA) seed oils can be processed enzymatically to produce biodiesel and erucic acid (EA), a valuable industrial feedstock. This study aimed to conduct a research on an effective reaction pathway to isolate EA from other fatty acids in HEA oils utilizing appropriate lipase specificities. Crambe oil was chosen as the model working feedstock. Rhizomucor miehei lipase was chosen to selectively hydrolyze crambe oil to liberate EA from the HEA oil directly into free EA. The effects of reaction parameters, including water content, lipase concentration, mixing intensity, and reaction temperature, were studied. Experimental results of an orthogonal design showed that the effect of process parameters was significant for the reaction rate, but insignificant for the reaction selectivity. Further statistical analysis revealed that lipase concentration had the most significant effect on the reaction rate, while water content showed a negative effect on the hydrolysis. Individual effects of aqueous phase ratio, initial lipase concentration, and mixing intensity were further investigated separately at the optimal lipase activity temperature. Results showed that water played a role mainly in affecting the specific interracial area in the heterogeneous process of crambe oil hydrolysis. The interracial reaction rate increased with the increase in initial lipase concentration, but was limited by a critical value. Mixing intensity affected the hydrolysis to a certain extent and then leveled off due to the lack of further size reduction of the discrete phase. [ABSTRACT FROM AUTHOR]

Abstract: Polyhydroxybutyrate (PHB) is the most studied among a wide variety of polyhydroxyalkanoates, bacterial biodegradable polymers known as potential substitutes for conventional plastics. This work aimed at evaluating the use of enzymes to recover and purify the PHB produced by Ralstonia eutropha DSM545. Screening experiments allowed the selection of trypsin, bromelain and lysozyme among six enzymes, based on their efficiency in lysing cells of a non-PHB producing R. eutropha strain. Then, process conditions for high efficiency in PHB purification from the DSM545 cells were searched for the enzymes previously selected. The best result was achieved with 2.0% of bromelain (enzyme mass per biomass), equivalent to 14.1Uml−1, at 50°C and pH 9.0, resulting in 88.8% PHB purity. Aiming at improving the process efficiency and reducing the enzyme cost, experiments were carried out with pancreatin, leading to 90.0% polymer purity and an enzyme cost three times lower than the one obtained with bromelain. The molecular mass analysis of PHB showed no polymer degradation. Therefore, this work demonstrates the potential of using enzymes in order to recover and purify PHB and bacterial biopolymers in general. [Copyright &y& Elsevier]

While extraction of carotenoprotein from brown shrimp (Metapenaeus monoceros) shell waste, trypsin showed maximum recovery (55%) of carotenoid pigment in 4 hours at (28 ± 2°C); but pepsin and papain showed about 50% recovery during the same period. The yield of protein paste by trypsin was maximum. The average protein content in the protein paste was about 450 g kg[sup -1]. The percent of recovery of protein by papain and pepsin was close to that of trypsin. During storage at ambient temperature (28 ± 5°C) loss of carotenoids from cake prepared by trypsin was minimum. The cost of trypsin is twenty times that of papain. Thus papain, easily available and the cheapest enzyme, can be used suitably for moderate recovery of carotenoids and good recovery of protein from shrimp shell waste at tropical ambient temperature. The dried colorless solid residue after extraction of carotenoprotein and protein, can be used as raw materials for chitin/chitosan. [ABSTRACT FROM AUTHOR]