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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]

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 paper reports an investigation on the bacteria-based enzyme's cottonization of industrial hemp fibre. The industrial hemp fibres are enzyme processed to eliminate massive non-cellulosic portions from the fibre to enhance their fineness and softness. Box-Behnken response surface methodology is applied to optimize the effect of different concentrations, temperature and time by using enzymes on chemical and physical properties, like weight loss, average strength, length, chemical composition, and surface modification to simulate cotton feel touch. The results show that the pectin, lignin, hemicellulose, and other impurities are removed under the enzyme and alkali refining processes. The effect of the enzyme concentration, treatment time, and treatment temperature is found significant on weight loss, fibre diameter, crystallinity, cellulose, hemicelluloses content, and tenacity. The effluent load of the enzyme process by measuring COD is also found less than that of the alkali processing for industrial hemp fibre. Industrial hemp fibre can be a perfect model of the sustainability of fibre from the plant's inception into the entire life cycle, leading to the biodegradable product reducing less effluent load in an environment. [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]

Biological soil crusts (BSC) are considered as pivotal ecological elements among different ecosystems of the world. The effects of these BSC at the micro-site scale have been related to the development of diverse plant species that, otherwise, might be strongly limited by the harsh abiotic conditions found in environments with low water availability. Here, we describe for the first time the bacterial composition of BSCs found in the proximities of Admiralty Bay (Maritime Antarctica) through 16S metabarcoding. In addition, we evaluated their effect on soils (nutrient levels, enzymatic activity, and water retention), and on the fitness and performance of Colobanthus quitensis , one of the two native Antarctic vascular plants. This was achieved by comparing the photochemical performance, foliar nutrient, biomass, and reproductive investment between C. quitensis plants growing with or without the influence of BSC. Our results revealed a high diversity of prokaryotes present in these soil communities, although we found differences in terms of their abundances. We also found that the presence of BSCs is linked to a significant increase in soils' water retention, nutrient levels, and enzymatic activity when comparing with control soils (without BSCs). In the case of C. quitensis , we found that measured ecophysiological performance parameters were significantly higher on plants growing in association with BSCs. Taken together, our results suggest that BSCs in Antarctic soils are playing a key role in various biochemical processes involved in soil development, while also having a positive effect on the accompanying vascular flora. Therefore, BSCs would be effectively acting as ecosystem engineers for the terrestrial Antarctic ecosystem. [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.

Biological soil crusts (BSC) are considered as pivotal ecological elements among different ecosystems of the world. The effects of these BSC at the micro-site scale have been related to the development of diverse plant species that, otherwise, might be strongly limited by the harsh abiotic conditions found in environments with low water availability. Here, we describe for the first time the bacterial composition of BSCs found in the proximities of Admiralty Bay (Maritime Antarctica) through 16S metabarcoding. In addition, we evaluated their effect on soils (nutrient levels, enzymatic activity, and water retention), and on the fitness and performance of Colobanthus quitensis, one of the two native Antarctic vascular plants. This was achieved by comparing the photochemical performance, foliar nutrient, biomass, and reproductive investment between C. quitensis plants growing with or without the influence of BSC. Our results revealed a high diversity of prokaryotes present in these soil communities, although we found differences in terms of their abundances. We also found that the presence of BSCs is linked to a significant increase in soils’ water retention, nutrient levels, and enzymatic activity when comparing with control soils (without BSCs). In the case of C. quitensis, we found that measured ecophysiological performance parameters were significantly higher on plants growing in association with BSCs. Taken together, our results suggest that BSCs in Antarctic soils are playing a key role in various biochemical processes involved in soil development, while also having a positive effect on the accompanying vascular flora. Therefore, BSCs would be effectively acting as ecosystem engineers for the terrestrial Antarctic ecosystem.

以油酸和三油酸甘油酯混合物（酸值(KOH)42.52 mg/g）为原料，利用两步法生产精制生物柴油。采用Aspen Plus V10软件对整个工艺流程进行模拟，先以超声辅助低共熔溶剂酶法制备粗生物柴油，再以乙醇、甘油等为携带剂精馏分离游离脂肪酸，并对精馏工艺进行优化。结果表明：制备粗生物柴油过程中油酸和三油酸甘油酯转化率分别为88.19%与 92.71%，粗生物柴油酸值（KOH）为5.07 mg/g；最佳精馏工艺条件为压力0.9 MPa、回流比0.7、理论塔板数31、粗生物柴油进料为第14块塔板、携带剂进料为第2块塔板，在此条件下精制生物柴油酸值（KOH）降至0.36 mg/g，精馏得率为95.27%。 A two-step process was developed to refine biodiesel with oleic acid (C18H34O2) and triolein (C57H104O6) mixture (acid value 42.52 mgKOH/g). The whole process was simulated by Aspen Plus V10. Firstly, crude biodiesel was prepared by ultrasound-assisted deep eutectic solvent enzymatic method, and then free fatty acids were separated by distillation with ethanol and glycerol as carrier agent, and the distillation process was optimized. The results showed that the conversion rates of oleic acid and triolein were 88.19% and 92.71% respectively, and the acid value of crude biodiesel was 5.07 mgKOH/g. The optimal distillation process conditions were obtained as follows: pressure 0.9 MPa, reflux ratio 0.7, theoretical tray number 31, crude biodiesel feed from the 14th tray and carrier agent feed from the second tray. Under the optimal conditions, the acid value of refined biodiesel reduced to 0.36 mgKOH/g, and the yield of distillation was 95.27%.

Cytochrome P450 enzymes have attracted much interest over the years given their ability to insert oxygen into saturated carbon-hydrogen bonds, a difficult feat to accomplish by traditional chemistry. Much of the activity in this field has centered on the bacterial enzyme CYP102A1, or BM3, from Bacillus megaterium, as it has shown itself capable of hydroxylating/acting upon a wide range of substrates, thereby producing industrially relevant pharmaceuticals, fine chemicals, and hormones. In addition, unlike most cytochromes, BM3 is both soluble and fused to its natural redox partner, thus facilitating its use. The industrial use of BM3 is however stifled by its instability and its requirement for the expensive NADPH cofactor. In this work, we added several mutations to the BM3 mutant R966D/W1046S that enhanced the turnover number achievable with the inexpensive cofactors NADH and NBAH. These new mutations, A769S, S847G, S850R, E852P, and V978L, are localized on the reductase domain of BM3 thus leaving the oxidase domain intact. For NBAH-driven reactions by new mutant NTD5, this led to a 5.24-fold increase in total product output when compared to the BM3 mutant R966D/W1046S. For reactions driven by NADH by new mutant NTD6, this enhanced total product output by as much as 2.3-fold when compared to the BM3 mutant R966D/W1046S. We also demonstrated that reactions driven by NADH with the NTD6 mutant not only surpassed total product output achievable by wild-type BM3 with NADPH but also retained the ability to use this latter cofactor with greater total product output as well. [ABSTRACT FROM AUTHOR]

Every year, considerable amount of pistachio by-products is generated in pistachio processing industry which their disposal is an important challenge. Our study aimed to produce valuable prebiotic xylooligosaccharides (XOS) from pistachio shell (PS) that have no particular uses. Alkaline hydrogen peroxide application yielded 32.85% xylan with low residual lignin content (2.48%). Structural characterization of mentioned xylan determined. Enzymatic hydrolysis of xylan with commercial endoxylanase afforded breakdown into XOS containing xylobiose and xylotriose. Response surface methodology (RSM) disclosed the optimized condition as: enzyme dose of 85 (U/g), the concentration of substrate (6%) and the reaction time (10 h) corresponding to maximum yield of xylobiose (1.86 mg/ml) and xylotriose (0.818 mg/ml). Application of the two-step process consisting of xylan extraction pursued by enzymatic hydrolysis enabled prebiotic XOS production for food and pharmaceutical industrial uses, from the pistachio shell as a novel raw material. [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]

Hemicellulose and lignin removal process or degumming of bamboo fibre using cellulase and xylanase was conducted. The objectives of the study were to obtain suitable type of bamboo used in the enzymatic degumming process and to determine the optimum xylanase concentration for the hemicellulose hydrolysis of the selected bamboo. The types of bamboos used in this study were yellow bamboo,ropebamboo,and black bamboo. The study was conducted by enzymatic hydrolyses of the bamboo fibres, and measuring the yield, cellulose content, hemicellulose content, and reducing sugar content. Fibre hydrolysis used the cellulase concentration of 25 U/g and xylanase concentrationsof 50 to 500 U/g. The result showed that yellow bamboo contained cellulose and hemicellulose contents which most susceptible to hydrolysis resulting in reducing sugars, and decreasing cellulose and hemicellule contents of 6.40 % and 12.71%, respectively. The optimum xilanase concentration for the yellow bamboohydolysis was 400 U/g which could hydrolyze hemicellulose by 54.31% in 24 hours.

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]

Abstract: Reactive absorption promoted by carbonic anhydrase (CA, E.C. 4.2.1.1.) catalysis has been proposed for CO2 capture from exhaust gas as an alternative to the reactive absorption in amine solutions. Potassium carbonate solutions allow feasible CO2 capture assisted by CA. This paper reports on the characterization of a CA form supplied by Novozymes as a catalyst for CO2 capture in K2CO3 solutions at operating conditions relevant for industrial processes (2–3 M K2CO3, 298–313 K, 0–40% carbonate to bicarbonate conversion). CO2 absorption tests were carried out in a batch‐stirred cell apparatus at constant gas volume and temperature by measuring gas pressure decay. The enhancement ratio between CO2 absorption rate with and without the enzyme at biocatalyst concentration above 0.3 kg m−3 ranged between 5 and 8 depending on the solvent composition and temperature. Active enzyme aggregates formed at protein concentration larger than 0.3 kg/m3 and their contribution to the absorption rate enhancement was remarkable. Assessment of enzyme kinetics in homogeneous solutions at enzyme concentration lower than 0.018 kg·m−3 showed that kcat/KM increased with both temperature and salt concentration. kcat/KM ranged between 9.0·103 and 7.0·104 m3·kg−1·s−1 in agreement with literature data on carbonic anhydrase kinetics. Reliability of the adopted method for kinetic characterization was confirmed. The activity of enzyme aggregates formed in the carbonate solvent was verified and CA aggregates can be used to select the proper CA based biocatalyst for CO2 capture application as an alternative to free and immobilized enzyme. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd. [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]

ABSTRACT Corn husks are the major wastes of corn industries with meagre economic significance. The present study was planned for value addition of corn husk through extraction of xylan, followed by its enzymatic hydrolysis into xylooligosaccharides, a pentose based prebiotic. Compositional analysis of corn husks revealed neutral detergent fibre 68.87%, acid detergent fibre 31.48%, hemicelluloses 37.39%, cellulose 29.07% and crude protein 2.68%. Irrespective of the extraction conditions, sodium hydroxide was found to be more effective in maximizing the yield of xylan from corn husks than potassium hydroxide (84% vs. 66%). Application of xylanase over the xylan of corn husks resulted into production of xylooligosaccharides with different degree of polymerization namely, xylobiose and xylotriose in addition to xylose monomer. On the basis of response surface model analysis, the maximum yield of xylobiose (1.9 mg/ml) was achieved with the enzymatic hydrolysis conditions of pH 5.8, temperature 44°C, enzyme dose 5.7U/ml and hydrolysis time of 17.5h. Therefore, the corn husks could be used as raw material for xylan extraction vis a vis its translation into prebiotic xylooligosaccharides.

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]

Polyhydroxyalkanoates (PHAs) are intracellular material accumulated by several bacteria. Commercial production of PHAs faces the issue of high production cost especially substrate cost and recovery/separation cost. An alternative to reduce the production cost is to use enzyme and or chemical to recover PHAs from bacterial cells. Recovery of PHAs from bacterial cells was done using enzyme, chemical, and a mixture of enzyme and chemical. Enzyme (s) and or chemical(s) were added into culture broth to disrupt cells after adjusting pH and temperature of the culture broth. Treatment by adding enzyme or chemical only into culture broth showed a low level of PHAs recovered from bacterial cells. Treatment by adding a mixture of enzymes and chemicals showed the best result among 22 examined combinations, i.e. a mixture of EDTA, lisozyme, papain enzyme, and SDS. This combination gave a PHA recovery of 65 % w/w.