Combined cross-linked enzyme aggregates of horseradish peroxidase and glucose oxidase for catalyzing cascade chemical reactions
In this study, we develop combined cross-linked enzyme aggregates (combi-CLEA) to catalyze a cascade reaction which involves unstable hydrogen peroxide as an intermediate. The combi-CLEA contain two enzymes ̶ glucose oxidase (GOx) and horseradish peroxidase (HRP) which are cross-linked together as solid aggregates. The first enzyme GOx catalyzes the oxidation of glucose and produces hydrogen peroxide, which is used by the second enzyme HRP to oxidize 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The apparent reaction rate of the cascade reaction reaches 10.5±0.5μM/min when the enzyme ratio is 1...
Source: Enzyme and Microbial Technology - February 16, 2017 Category: Biotechnology Source Type: research

Enzymatic synthesis of phenethyl ester from phenethyl alcohol with acyl donors
This study may contribute to environment-friendly synthesis of phenethyl ester based on optimal conditions, and enzyme reusability for high conversion of phenethyl acetate. Graphical abstract (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - February 16, 2017 Category: Biotechnology Source Type: research

Alleviation of metabolic bottleneck by combinatorial engineering enhanced astaxanthin synthesis in Saccharomyces cerevisiae
Publication date: Available online 14 February 2017 Source:Enzyme and Microbial Technology Author(s): Pingping Zhou, Wenping Xie, Aipeng Li, Fan Wang, Zhen Yao, Qi Bian, Yongqiang Zhu, Hongwei Yu, Lidan Ye Highly efficient biosynthesis of the commercially valuable carotenoid astaxanthin by microbial cells is an attractive alternative to chemical synthesis and microalgae extraction. With the goal of enhancing heterologous astaxanthin production in Saccharomyces cerevisiae, metabolic engineering and protein engineering were integrated to improve both the expression and activity of rate-limiting enzymes. Firstly, to increase...
Source: Enzyme and Microbial Technology - February 15, 2017 Category: Biotechnology Source Type: research

One-Step Combined focused epPCR and Saturation Mutagenesis for Thermostability Evolution of a New Cold-Active Xylanase
Publication date: Available online 13 February 2017 Source:Enzyme and Microbial Technology Author(s): Juan Pablo Acevedo, Manfred T. Reetz, Juan A. Asenjo, Loreto P. Parra Enzymes active at low temperature are of great interest for industrial bioprocesses due to their high efficiency at a low energy cost. One of the particularities of naturally evolved cold-active enzymes is their increased enzymatic activity at low temperature, however the low thermostability presented in this type of enzymes is still a major drawback for their application in biocatalysis. Directed evolution of cold-adapted enzymes to a more thermostable...
Source: Enzyme and Microbial Technology - February 13, 2017 Category: Biotechnology Source Type: research

Changing the electron donor improves azoreductase dye degrading activity at neutral pH
Publication date: Available online 9 February 2017 Source:Enzyme and Microbial Technology Author(s): Jingxian Qi, Caroline E. Paul, Frank Hollmann, Dirk Tischler The oxygen-insensitive azoreductase AzoRo originating from Rhodococcus opacus 1CP was found to be most active at low pH (ca. 4) and high temperature (ca. 50°C). AzoRo is not an efficient biocatalyst when used at low pH due to stability problems. To overcome this issue, we discovered that AzoRo accepts an alternative electron donor, 1-benzyl-1,4-dihydronicotinamide (BNAH), which allows fast turnover at neutral pH. In order to screen this nicotinamide coenzyme ...
Source: Enzyme and Microbial Technology - February 9, 2017 Category: Biotechnology Source Type: research

Enzymatic biosensor based on entrapment of d-amino acid oxidase on gold nanofilm/MWCNTs nanocomposite modified glassy carbon electrode by sol-gel network: analytical applications for d-Alanine in human serum
Publication date: Available online 2 February 2017 Source:Enzyme and Microbial Technology Author(s): Yalda Shoja, Amir Abbas Rafati, Javad Ghodsi Sensing and determination of D-Alanine is studied by using an enzymatic biosensor which was constructed on the basis of D-amino acid oxidase (DAAO) immobilization by sol-gel film onto glassy carbon electrode surface modified with nanocomposite of gold nanofilm (Au-NF) and multiwalled carbon nanotubes (MWCNTs). The Au-NF/MWCNT nanocomposite was prepared by applying the potentiostatic technique for electrodeposition of Au-NF on the MWCNT immobilized on glassy carbon electrode surf...
Source: Enzyme and Microbial Technology - February 2, 2017 Category: Biotechnology Source Type: research

An improved amperometric triglyceride biosensor based on co-immobilization of nanoparticles of lipase, glycerol kinase and glycerol 3-phosphate oxidase onto pencil graphite electrode
Publication date: Available online 30 January 2017 Source:Enzyme and Microbial Technology Author(s): Vinay Narwal, C.S. Pundir Nanoparticles (NPs) of commercial lipase from Candida rugosa, of glycerol kinase (GK) from Cellulomonas species, of glycerol-3- phosphate oxidase (GPO) from Aerococcus viridans were prepared, characterized and co-immobilized onto a pencil graphite (PG) electrode. The morphological and electrochemical characterization of PG electrode was performed by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) before and after co-immobilization of enz...
Source: Enzyme and Microbial Technology - January 30, 2017 Category: Biotechnology Source Type: research

Autodisplay of the La/SSB protein on LPS-free E. coli for the diagnosis of Sj ögren’s syndrome
The objective of this study was to present an immunoassay for the diagnosis of Sjögren’s syndrome based on the autodisplayed La/SSB protein on the outer membrane of intact E. coli (strain UT-5600) and LPS-free E. coli (ClearColi™). As the first step, an autodisplay vector (pCK002) was transfected into intact E. coli and LPS-free E. coli for comparison of efficiency of autdisplay of La/SSB. The maximal level of La/SSB expression was estimated to be similar for LPS-free E. coli and intact E. coli at different optimal induction periods. Intact E. coli was found to grow twofold faster than LPS-free E. coli, an...
Source: Enzyme and Microbial Technology - January 25, 2017 Category: Biotechnology Source Type: research

Analysis of Agaricus meleagris pyranose dehydrogenase N-glycosylation sites and performance of partially non-glycosylated enzymes
Publication date: Available online 22 January 2017 Source:Enzyme and Microbial Technology Author(s): Christoph Gonaus, Daniel Maresch, Katharina Schropp, Peter ÓConghaile, Dónal Leech, Lo Gorton, Clemens K. Peterbauer Pyranose Dehydrogenase 1 from the basidiomycete Agaricus meleagris (AmPDH1) is an oxidoreductase capable of oxidizing a broad variety of sugars. Due to this and its ability of dioxidation of substrates and no side production of hydrogen peroxide, it is studied for use in enzymatic bio-fuel cells. In-vitro deglycosylated AmPDH1 as well as knock-out mutants of the N-glycosylation sites N75 and N1...
Source: Enzyme and Microbial Technology - January 22, 2017 Category: Biotechnology Source Type: research

Colorimetric enumeration of bacterial contamination in water based on β-galactosidase gold nanoshell activity
In this study we report a method for the rapid and sensitive estimation of bacterial cell concentration in solution based on a colorimetric enzyme/gold nanoshells conjugate system. The CTAB capped gold nanoshells are electrostatically attracted by both the bacterial surface and the enzyme β-galactosidase. The preferential binding of cationic (CTAB)-functionalized gold nanoshells to the more negative bacterial surfaces leaves active β-galactosidase in solution, providing an enzyme-amplified colorimetric response of the binding event. A progressive increase in the enzyme activity is evidenced by the conversion of t...
Source: Enzyme and Microbial Technology - January 21, 2017 Category: Biotechnology Source Type: research

Characterization and crystal structure of a thermostable glycoside hydrolase family 45 1,4- β-endoglucanase from Thielavia terrestris
Publication date: Available online 17 January 2017 Source:Enzyme and Microbial Technology Author(s): Jian Gao, Jian-Wen Huang, Qian Li, Weidong Liu, Tzu-Ping Ko, Yingying Zheng, Xiansha Xiao, Chih-Jung Kuo, Chun-Chi Chen, Rey-Ting Guo 1,4-β-Endoglucanase is one of the most important biocatalysts in modern industries. Here, a glycoside hydrolase (GH) family 45 endoglucanase from thermophilic fungus Theilavia terrestris (TtCel45A) was expressed in Pichia pastoris. The recombinant protein shows optimal activity at 60°C, pH 4-5. The enzyme exhibits extraordinary thermostability that more than 80% activity was detecte...
Source: Enzyme and Microbial Technology - January 17, 2017 Category: Biotechnology Source Type: research

Conversion of cysteine to 3 ‐mercaptopyruvic acid by bacterial aminotransferases
In this study, we selected eight bacterial AT based on sequence homology to CAT of Rattus norvegicus (Got1). The AT included four aspartate aminotransferases (AATs) and four aromatic amino acid aminotransferases (ArATs) from Advenella mimigardefordensis DPN7, Escherichia coli MG1655, Shimwellia blattae ATCC 33430, Ralstonia eutropha H16 and Paracoccus denitrificans PD1222. For a more detailed characterization, all selected AAT or ArAT encoding genes were heterologously expressed in E. coli and purified. CAT activity was detected for all AT when a novel continuous coupled enzyme assay was applied. Kinetic studies revealed t...
Source: Enzyme and Microbial Technology - January 16, 2017 Category: Biotechnology Source Type: research

Engineering Neurospora crassa for cellobionate production directly from cellulose without any enzyme addition
In this study, we report engineering recombinant Neurospora crassa strains which are able to produce cellobionate, an organic acid, from cellulose without any enzyme addition. Recombinant strains were constructed by heterologously expressing laccase genes from different sources under different promoters in N. crassa F5Δmus-51Δace-1Δcre-1ΔndvB which has six out of seven β-glucosidase (bgl), two transcription factor (cre1 and ace-1), and the cellobionate phosphorylase (ndvB) genes deleted. The strain expressing laccase from Botrytis aclada under a copper metallothionein promoter (HL10) produced t...
Source: Enzyme and Microbial Technology - January 7, 2017 Category: Biotechnology Source Type: research

Heterologous expression of γ-glutamyl transpeptidase from Bacillus atrophaeus GS-16 and its application in the synthesis of γ-D-glutamyl-L-tryptophan, a known immunomodulatory peptide
Publication date: Available online 6 January 2017 Source:Enzyme and Microbial Technology Author(s): Meenu Saini, Shruti Bindal, Rani Gupta Gamma-glutamyl transpeptidase from a mesophilic bacterium Bacillus atrophaeus GS-16 (BaGGT) was expressed heterologously in E.coli using pET-51b vector. Maximum production of BaGGT was obtained at 16°C after 16h of IPTG induction and the protein, in its native conformation, was active as a heterooctamer which was composed of four heterodimeric units combined together. One heterodimeric unit constituted two subunits with molecular masses of 45kDa and 21kDa, respectively. The recombi...
Source: Enzyme and Microbial Technology - January 7, 2017 Category: Biotechnology Source Type: research

Glutamate dehydrogenase (RocG) in Bacillus licheniformis WX-02: Enzymatic properties and specific functions in glutamic acid synthesis for Poly- γ-glutamic acid production
Publication date: Available online 6 January 2017 Source:Enzyme and Microbial Technology Author(s): Guang-ming Tian, Qin Wang, Xuetuan Wei, Xin Ma, Shouwen Chen Poly-γ-glutamic acid (γ-PGA), a natural biopolymer, is widely used in cosmetics, medicine, food, water treatment, and agriculture owing to its features of moisture sequestration, cation chelation, non-toxicity and biodegradability. Intracellular glutamic acid, the substrate of γ-PGA, is a limiting factor for high yield in γ-PGA production. Bacillus subtilis and Bacillus licheniformis are both important γ-PGA producing strains, and B. ...
Source: Enzyme and Microbial Technology - January 7, 2017 Category: Biotechnology Source Type: research

Microbial BOD sensors based on Zr (IV)-loaded collagen fiber
Publication date: March 2017 Source:Enzyme and Microbial Technology, Volume 98 Author(s): Lei Zhao, Li He, Shujuan Chen, Likou Zou, Kang Zhou, Xiaolin Ao, Shuliang Liu, Xinjie Hu, Guoquan Han Biochemical oxygen demand (BOD) sensors based on Zr (IV)-loaded collagen fiber (ZrCF), a novel material with great porous structure, were developed. This novel material shows adsorbability by microorganisms. Saccharomyces cerevisiae and Escherichia coli were used for the construction of BOD sensors. Factors affecting BOD sensor performance were examined. The ZrCF-based BOD sensor showed different sensitivities and linear response ran...
Source: Enzyme and Microbial Technology - January 6, 2017 Category: Biotechnology Source Type: research

Properties of a novel thermostable glucose isomerase mined from Thermus oshimai and its application to preparation of high fructose corn syrup
Publication date: Available online 5 January 2017 Source:Enzyme and Microbial Technology Author(s): Dong-Xu Jia, Lin Zhou, Yu-Guo Zheng Glucose isomerase (GI) is used in vitro to convert D-glucose to D-fructose, which is capable of commercial producing high fructose corn syrup (HFCS). To manufacture HFCS at elevated temperature and reduce the cost of enriching syrups, novel refractory GIs from Thermoanaerobacterium xylanolyticum (TxGI), Thermus oshimai (ToGI), Geobacillus thermocatenulatus (GtGI) and Thermoanaerobacter siderophilus (TsGI) were screened via genome mining approach. The enzymatic characteristics research sho...
Source: Enzyme and Microbial Technology - January 5, 2017 Category: Biotechnology Source Type: research

Extremely low frequency magnetic field enhances glucose oxidase expression in Pichia pastoris GS115
In this study attempts were made to investigate the effect of extremely low frequency magnetic field (ELF-MF) on expression of glucose oxidase gene from Aspergillus niger Z-25 in Pichia pastoris GS115 at optimal environmental conditions. GOX encoding gene from A. niger was expressed in P. pastoris GS115 employing methanol inducible AOX1 promoter. From resistant transformants to high zeocin concentrations, maximum GOX expressing was isolated and used throughout the study. Optimal environmental conditions for achieving maximum glucose oxidase (GOX) production was determined by varying temperature (20–30°C) and fina...
Source: Enzyme and Microbial Technology - January 3, 2017 Category: Biotechnology Source Type: research

A novel thermophilic and halophilic esterase from Janibacter sp. R02, the first member of a new lipase family (Family XVII)
Publication date: Available online 31 December 2016 Source:Enzyme and Microbial Technology Author(s): Agustín Castilla, Paola Panizza, Diego Rodríguez, Luis Bonino, Pilar Díaz, Gabriela Irazoqui, Sonia Rodríguez Giordano Janibacter sp. strain R02 (BNM 560) was isolated in our laboratory from an Antarctic soil sample. A remarkable trait of the strain was its high lipolytic activity, detected in Rhodamine-olive oil supplemented plates. Supernatants of Janibacter sp R02 displayed superb activity on transesterification of acyl glycerols, thus being a good candidate for lipase prospection. Consideri...
Source: Enzyme and Microbial Technology - January 1, 2017 Category: Biotechnology Source Type: research

Identification of a novel Penicillium chrysogenum rhamnogalacturonan rhamnohydrolase and the first report of a rhamnogalacturonan rhamnohydrolase gene
Publication date: Available online 29 December 2016 Source:Enzyme and Microbial Technology Author(s): Shotaro Matsumoto, Hiroyuki Yamada, Yuika Kunishige, Shigeo Takenaka, Masami Nakazawa, Mitsuhiro Ueda, Tatsuji Sakamoto Rhamnogalacturonan (RG) I is one of the main components of pectins in the plant cell wall. We recently reported two RG I-degrading enzymes, endo-RG and exo-RG lyases, secreted by Penicillium chrysogenum 31B. Here, our aims were to purify a RG rhamnohydrolase (PcRGRH78A) from the culture filtrate of this strain and to characterize this enzyme. On the basis of the internal amino acid sequences, the encodin...
Source: Enzyme and Microbial Technology - December 29, 2016 Category: Biotechnology Source Type: research

Oxidative cleavage and hydrolytic boosting of cellulose in soybean spent flakes by Trichoderma reesei Cel61A lytic polysaccharide monooxygenase
Publication date: Available online 29 December 2016 Source:Enzyme and Microbial Technology Author(s): Brian C. Pierce, Jane Wittrup Agger, Jesper Wichmann, Anne S. Meyer The auxiliary activity family 9 (AA9) copper-dependent lytic polysaccharide monooxygenase (LPMO) from Trichoderma reesei (EG4; TrCel61A) was investigated for its ability to oxidize the complex polysaccharides from soybean. The substrate specificity of the enzyme was assessed against a variety of substrates, including both soy spent flake, a by-product of the soy food industry, and soy spent flake pretreated with sodium hydroxide. Products from enzymatic t...
Source: Enzyme and Microbial Technology - December 29, 2016 Category: Biotechnology Source Type: research

Cloning, expression, and biochemical characterization of a novel NADP+-dependent 7 α-hydroxysteroid dehydrogenase from Clostridium difficile and its application for the oxidation of bile acids
Publication date: Available online 27 December 2016 Source:Enzyme and Microbial Technology Author(s): Daniel Bakonyi, Werner Hummel A gene encoding a novel 7α-specific NADP+-dependent hydroxysteroid dehydrogenase from Clostridium difficile was cloned and heterologously expressed in Escherichia coli. The enzyme was purified using an N-terminal hexa-his-tag and biochemically characterized. The optimum temperature is at 60°C, but the enzyme is inactivated at this temperature with a half-life time of 5min. Contrary to other known 7α-HSDHs, for example from Clostridium sardiniense or E. coli, the enzyme from C....
Source: Enzyme and Microbial Technology - December 28, 2016 Category: Biotechnology Source Type: research

Use of one- and two-mediator systems for developing a BOD biosensor based on the yeast Debaryomyces hansenii
Publication date: Available online 26 December 2016 Source:Enzyme and Microbial Technology Author(s): A.S. Zaitseva, V.A. Arlyapov, N.Yu. Yudina, S.V. Alferov, A.N. Reshetilov We investigated the use of one- and two-mediator systems in amperometric BOD biosensors (BOD, biochemical oxygen demand) based on the yeast Debaryomyces hansenii. Screening of nine mediators potentially capable of electron transfer − ferrocene, 1,1′-dimethylferrocene, ferrocenecarboxaldehyde, ferroceneacetonitrile, neutral red, 2,6-dichlorophenolindophenol, thionine, methylene blue and potassium ferricyanide − showed only ferrocene...
Source: Enzyme and Microbial Technology - December 27, 2016 Category: Biotechnology Source Type: research

Preparation of A. succinogenes Immobilized Microfiber Membrane for Repeated Production of Succinic acid
Publication date: Available online 21 December 2016 Source:Enzyme and Microbial Technology Author(s): Peng-Cheng Chen, Pu Zheng, Xiang-Yu Ye, Fan Ji A new applicability of cell-immobilized system for biological production of target chemical was reported in this work. A. succinogenes CCTCC M2012036 was immobilized on positively charged polypropylene microfiber membrane by physical interaction and were used for converting glucose into succinic acid. Glucose consumption and succinic acid production kinetics were investigated for optimizing the operational parameters. The cell-immobilized membrane presented good reuse stabili...
Source: Enzyme and Microbial Technology - December 22, 2016 Category: Biotechnology Source Type: research

Understanding the process-induced formation of minor conformational variants of Erwinia chrysanthemi L-asparaginase
Publication date: Available online 19 December 2016 Source:Enzyme and Microbial Technology Author(s): David Gervais, Justin Hayzen, Charlotte Orphanou, Alexandra McEntee, Christine Hallam, Rossalyn Brehm During Erwinia chrysanthemi L-asparaginase (ErA) manufacture, minor conformational variants are formed that elute in the acidic region of the analytical ion-exchange HPLC chromatogram. These variants retain enzymatic activity and form part of the biopharmaceutical product, but must be kept within acceptable limits through controlled operation of the manufacturing process. The high isoelectric point of the ErA native tetra...
Source: Enzyme and Microbial Technology - December 20, 2016 Category: Biotechnology Source Type: research

Effect of protein load on stability of immobilized enzymes
Publication date: Available online 16 December 2016 Source:Enzyme and Microbial Technology Author(s): Laura Fernandez-Lopez, Sara G. Pedrero, Nerea Lopez-Carrobles, Beatriz C. Gorines, Jose J. Virgen-Ortíz, Roberto Fernandez-Lafuente Different lipases have been immobilized on octyl agarose beads at 1mg/g and at maximum loading, via physical interfacial activation versus the octyl layer on the support. The stability of the preparations was analyzed. Most biocatalysts had the expected result: the apparent stability increased using the highly loaded preparations, due to the diffusional limitations that reduced the ini...
Source: Enzyme and Microbial Technology - December 17, 2016 Category: Biotechnology Source Type: research

In vitro screening and in silico validation revealed key microbes for higher production of significant therapeutic enzyme L-asparaginase
Publication date: Available online 9 December 2016 Source:Enzyme and Microbial Technology Author(s): Archana Vimal, Awanish Kumar L-asparaginase is an enzyme of medical prominence and reputable as a chemotherapeutic agent. It also has immense potential to cure autoimmune and infectious diseases. The vast application of this enzyme in healthcare sector increases its market demand. However, presently the huge market demand is not achieved completely. This serves the basis to explore better producer microbial strains to bridge the gap between huge demand and supply of this therapeutic enzyme. The present study deals with the...
Source: Enzyme and Microbial Technology - December 10, 2016 Category: Biotechnology Source Type: research

Synthesis of high 4-hydroxybutyrate copolymer by Cupriavidus sp. transformants using one-stage cultivation and mixed precursor substrates strategy
Publication date: March 2017 Source:Enzyme and Microbial Technology, Volume 98 Author(s): Ishak Muhammad Syafiq, Kai-Hee Huong, K. Shantini, S. Vigneswari, Nursolehah Abd Aziz, Al-Ashraf Abdullah Amirul, Kesaven Bhubalan Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] copolymer is noted for its high biocompatibility, which makes it an excellent candidate for biopharmaceutical applications. The wild-type Cupriavidus sp. USMAA1020 strain is able to synthesize P(3HB-co-4HB) copolymers with different 4HB monomer compositions (up to 70mol%) in shaken flask cultures. Combinations of 4HB carbon precursors consisting...
Source: Enzyme and Microbial Technology - December 10, 2016 Category: Biotechnology Source Type: research

Quantification of immobilized Candida antarctica lipase B (CALB) using ICP-AES combined with Bradford method
Publication date: February 2017 Source:Enzyme and Microbial Technology, Volume 97 Author(s): Paula Nicolás, Verónica L. Lassalle, María L. Ferreira The aim of this manuscript was to study the application of a new method of protein quantification in Candida antarctica lipase B commercial solutions. Error sources associated to the traditional Bradford technique were demonstrated. Eight biocatalysts based on C. antarctica lipase B (CALB) immobilized onto magnetite nanoparticles were used. Magnetite nanoparticles were coated with chitosan (CHIT) and modified with glutaraldehyde (GLUT) and aminopropyltriet...
Source: Enzyme and Microbial Technology - December 8, 2016 Category: Biotechnology Source Type: research

Hypersensitive antibiotic susceptibility test based on a β-lactamase assay with a parylene-matrix chip
Publication date: February 2017 Source:Enzyme and Microbial Technology, Volume 97 Author(s): Jong-Min Park, Jo-Il Kim, Joo-Yoon Noh, Mira Kim, Min-Jung Kang, Jae-Chul Pyun Many kinds of susceptibility test for β-lactam antibiotics have been used to determine the antibiotic resistance of bacterial strains. Here, a sensitive antibiotic susceptibility test was presented by using a specialized reaction tool for laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) based on parylene-matrix chip. The β-lactamase assay was carried out in a specialized reaction tool by (1) concentrating the bacterial...
Source: Enzyme and Microbial Technology - December 5, 2016 Category: Biotechnology Source Type: research

The catalytic domain of Penicillium crustosum endoglucanase EGL1 has cellulose-binding capacity and cellulolytic activity
In this study, we found that both the full-length enzyme and the catalytic domain of endoglucanase EGL1 cloned from Penicillium crustosum strain 601 have CMCase and FPase activity. A cellulose-binding assay using green fluorescent protein as a marker further showed that the catalytic domain could also bind the cellulose substrate. The three-dimensional structure of the catalytic domain of EGL1 revealed that this cellulose substrate-binding capacity of the catalytic domain may come from the hydrophobic core formed by aromatic amino acids distributed in or outside the (α/β)8 barrel fold. A glycine scanning mutagen...
Source: Enzyme and Microbial Technology - November 25, 2016 Category: Biotechnology Source Type: research

Hydrothermal preparation of reduced graphene oxide –silver nanocomposite using Plectranthus amboinicus leaf extract and its electrochemical performance
In this study, a facial synthesis of a reduced graphene oxide-silver nanocomposite (RGO-Ag) was carried out from Plectranthus amboinicus leaf extract. The synthesized nanocomposite was characterized by using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscope and UV–vis spectroscopy for structural confirmation. The reduction of graphene oxide and silver ions was achieved simultaneously due to the reducibility of the Plectranthus amboinicus leaf extract. We further investigated the electrochemical properties of the...
Source: Enzyme and Microbial Technology - November 18, 2016 Category: Biotechnology Source Type: research

Biosynthetic nanoparticles for biotechnological and biomedical applications
Publication date: December 2016 Source:Enzyme and Microbial Technology, Volume 95 Author(s): Enrico Marsili, Sujoy K. Das (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - November 18, 2016 Category: Biotechnology Source Type: research

Super RLuc8: A novel engineered Renilla luciferase with a red-shifted spectrum and stable light emission
In this study, a novel luciferase with desired light emission wavelength and thermostability is reported. The results indicated that the new luciferase, namely super RLuc8, had a red-shifted spectrum and showed stable light emission. Super RLuc8 showed a 10-fold (p-value=0.0084) increase in the thermostability at 37°C after 20min incubation, in comparison to the native enzyme. The optimum temperature of the mutant increased from 30 to 37°C. Molecular dynamics simulation analysis indicated that the increased thermostability was most probably caused by a better structural compactness and more local rigidity in the re...
Source: Enzyme and Microbial Technology - November 18, 2016 Category: Biotechnology Source Type: research

Heterologous expression in Pichia pastoris and characterization of a β-glucosidase from the xylophagous cockroach Panesthia angustipennis spadica displaying high specific activity for cellobiose
Publication date: Available online 15 November 2016 Source:Enzyme and Microbial Technology Author(s): Yihai Li, Gaku Arakawa, Gaku Tokuda, Hirofumi Watanabe, Manabu Arioka A β-glucosidase (BG), PaBG1b, from the xylophagous cockroach Panesthia angustipennis spadica was heterologously expressed in the methylotrophic yeast Pichia pastoris, purified, and biochemically characterized. Post-translational modification and N-terminal sequencing analysis demonstrated that the expression product was comprised of two polypeptides with different N-terminal sequences, presumably due to the presence of lysine-arginine (KR) sequence...
Source: Enzyme and Microbial Technology - November 16, 2016 Category: Biotechnology Source Type: research

Biosynthesis of silver nanoparticles using pre-hydrolysis liquor of Eucalyptus wood and its effective antimicrobial activity
Publication date: Available online 15 November 2016 Source:Enzyme and Microbial Technology Author(s): M. Shivakumar, K.L. Nagashree, S. Yallappa, S. Manjappa, K.S. Manjunath, M.S. Dharmaprakash Herein, we described for the first time, biosynthesis of silver nanoparticles (AgNPs) using pre-hydrolyzed liquor of Eucalyptus wood under ambient conditions. The pre-hydrolyzed liquor containing a high amount of metabolites such as polyphenols, hemicelluloses and its derivatives are mainly assisted for the reduction and stabilization process of Ag+ ions to AgNPs. The formation of AgNPs is monitored by recording the UV–Vis sp...
Source: Enzyme and Microbial Technology - November 16, 2016 Category: Biotechnology Source Type: research

Rational design for the stability improvement of Armillariella tabescens β-mannanase MAN47 based on N-glycosylation modification
In this study, we sought to improve the stability and protease resistance of a recombinant β-mannanase, MAN47 from Armillariella tabescens, through rationally designed N-glycosylation. Based on homology modeling, molecular docking, secondary structure analysis and glycosylation feasibility analysis, an enhanced aromatic sequon sequence was introduced into specific MAN47 loop regions to facilitate N-glycosylation. The mutant enzymes were expressed in Pichia pastoris SMD1168, and their thermal stability, pH stability, trypsin resistance and pepsin resistance were determined. Two mutant MAN47 enzymes, g-123 and g-347, we...
Source: Enzyme and Microbial Technology - November 15, 2016 Category: Biotechnology Source Type: research

Highly regioselective hydroxylation of polydatin, a resveratrol glucoside, for one-step synthesis of astringin, a piceatannol glucoside, by P450 BM3
Publication date: Available online 9 November 2016 Source:Enzyme and Microbial Technology Author(s): Thien-Kim Le, Hyun-Hee Jang, Ha Thi Huong Nguyen, Tiep Thi My Doan, Ga-Young Lee, Ki Deok Park, Taeho Ahn, Young Hee Joung, Hyung-Sik Kang, Chul-Ho Yun Enzymatic conversion of natural glycosides to their corresponding hydroxylated products using cytochromes P450 has significant advantages over synthetic chemistry and even enzyme-catalyzed glycosylation of chemicals. At present, the basic strategy for making glycosides of stilbenoid compounds is to use the glycosylation activity of enzymes, such as glycosyltransferases. Her...
Source: Enzyme and Microbial Technology - November 10, 2016 Category: Biotechnology Source Type: research

Recombinant cellulolytic or xylanolytic complex comprising the full-length scaffolding protein RjCipA and cellulase RjCel5B or xylanase RjXyn10C of Ruminiclostridium josui
Publication date: Available online 9 November 2016 Source:Enzyme and Microbial Technology Author(s): Taku Orita, Makiko Sakka, Tetsuya Kimura, Kazuo Sakka Three cellulosomal subunits of Ruminiclostridium josui, the full-length scaffolding protein CipA (RjCipA), a cellulase Cel5B (RjCel5B) and a xylanase Xyn10C (RjXyn10C), were successfully produced by Escherichia coli recombinant clones. RjCel5B and RjXyn10C were characterized as an endoglucanase and an endoxylanase, respectively. RjCipA, RjCel5B and Xyn10C adsorbed to microcrystalline cellulose (Funacel) and rice straw powder. Interaction between RjCel5B and RjCipA, and ...
Source: Enzyme and Microbial Technology - November 9, 2016 Category: Biotechnology Source Type: research

A single and two step isomerization process for D-Tagatose and L-Ribose bioproduction using L-arabinose isomerase and D-lyxose isomerase
Publication date: Available online 9 November 2016 Source:Enzyme and Microbial Technology Author(s): Manisha J. Patel, Rekha C. Akhani, Arti T. Patel, Samir R. Dedania, Darshan H. Patel L-ribose and D-tagatose are biochemically synthesized using sugar isomerases. The L-arabinose isomerase gene from Shigella flexneri (Sf-AI) was cloned and expressed in Escherichia coli BL-21. Sf-AI was applied for the bioproduction of D-tagatose from D-galactose. L-ribose synthesis was performed by two step isomerization using Sf-AI and D-lyxose/ribose isomerase from Cohnella laevoribosii. The overall 22.3% and 25% conversion rate were obs...
Source: Enzyme and Microbial Technology - November 9, 2016 Category: Biotechnology Source Type: research

Characterization of Clostridium thermocellum (B8) secretome and purified cellulosomes for lignocellulosic biomass degradation
Publication date: Available online 8 November 2016 Source:Enzyme and Microbial Technology Author(s): Karen O. Osiro, Brenda R. de Camargo, Rachel Satomi, Pedro Ricardo V. Hamann, Jéssica Pinheiro Silva, Marcelo Valle de Sousa, Betania F. Quirino, Elaine N. Aquino, Carlos R. Felix, André Melro Murad, Eliane F. Noronha The main goal of the present study was a complete proteomic characterization of total proteins eluted from residual substrate-bound proteins (RSBP), and cellulosomes secreted by Clostridium thermocellum B8 during growth in the presence of microcrystalline cellulose as a carbon source. The second...
Source: Enzyme and Microbial Technology - November 8, 2016 Category: Biotechnology Source Type: research

UV-irradiated parylene surfaces for proliferation and differentiation of PC-12 cells
Publication date: Available online 3 November 2016 Source:Enzyme and Microbial Technology Author(s): Usman Liaqat, Hyuk Ko, Hwal Suh, Misu Lee, Jae-Chul Pyun PC-12 cells originate from neuroblastic cells, which have an ability to differentiate into neuronlike cells. In this work, the purpose was to estimate the influence of microenvironments on cell attachment and neuritogenesis capacity of PC-12 cells on parylene-N and parylene-C films with and without ultraviolet (UV) light treatment. The estimate of total cell number after incubation for 72h, the ratio of adherent to suspended cells, counting of neurite outgrowths on p...
Source: Enzyme and Microbial Technology - November 4, 2016 Category: Biotechnology Source Type: research

The Effect of Pelargonium endlicherianum Fenzl. root extracts on formation of nanoparticles and their antimicrobial activities
Publication date: Available online 1 November 2016 Source:Enzyme and Microbial Technology Author(s): Gökçe Şeker Karatoprak, Gamze Aydin, Berrak Altinsoy, Cevahir Altinkaynak, Müberra Koşar, Ismail Ocsoy Herein, we report the biosynthesis of Ag NPs, for the first time, using identified antimicrobial molecules (gallic acid+apocynin) and (gallic acid+apocynin+quercetin) from the medicinal plant pelargonium endlicherianum fenzl and dramatically enhanced antimicrobial activity. We also investigate the role of each molecule on formation Ag NPs and explain the increase in the antimicrobial activity of identif...
Source: Enzyme and Microbial Technology - November 2, 2016 Category: Biotechnology Source Type: research

Enhanced yield of ethylene glycol production from D-xylose by pathway optimization in Escherichia coli
This report further improved the EG yield by implementing metabolic engineering strategies. First, D-xylonic acid accumulation was reduced by employing a weak promoter which provided a tighter control over Xdh expression. Second, EG yield was further improved by expressing the YjgB, which was identified as the most suitable aldehyde reductase endogenous to E. coli. Finally, cellular growth, D-xylose consumption, and EG yield were further increased by blocking a competing reaction. The final strain (WTXB) was able to reach up to 98% of the theoretical yield (25% higher as compared to the first study), the highest reported v...
Source: Enzyme and Microbial Technology - November 2, 2016 Category: Biotechnology Source Type: research

Green production of microalgae-based silver chloride nanoparticles with antimicrobial activity against pathogenic bacteria
Publication date: Available online 29 October 2016 Source:Enzyme and Microbial Technology Author(s): Veronica da Silva Ferreira, Mateus Eugenio Ferreira Conz, Luís Maurício T.R. Lima, Susana Frasés, Wanderley de Souza, Celso Sant’Anna Silver nanoparticles are powerful antimicrobial agents. Here, the synthesis of silver chloride nanoparticles (AgCl-NPs) was consistently evidenced from a commercially valuable microalgae species, Chlorella vulgaris. Incubation of C. vulgaris conditioned medium with AgNO3 resulted in a medium color change to yellow/brown (with UV–vis absorbance at 415nm), indi...
Source: Enzyme and Microbial Technology - October 30, 2016 Category: Biotechnology Source Type: research

A review on the Biosynthesis of metallic Nanoparticles (Gold and Silver) using Bio-components of microalgae: Formation Mechanism and Applications
Publication date: Available online 29 October 2016 Source:Enzyme and Microbial Technology Author(s): P. Dheeban Shankar, Sutha Shobana, Indira Karuppusamy, Arivalagan Pugazhendhi, Vijayan Sri Ramkumar, Sundaram Arvindnarayan, Gopalakrishnan Kumar The synthesis of nanoparticles (NP) using algae has been underexploited and even unexplored. In recent times, there are few reports on the synthesis of NP using algae, which are being used as a bio-factory for the synthesis. Moreover, the algae are a renewable source, so that it could be effectively explored in the green synthesis of NP. Hence, this review reports on the biosynth...
Source: Enzyme and Microbial Technology - October 30, 2016 Category: Biotechnology Source Type: research

Design and Production of Antibodies for the Detection of Streptococcus uberis
Publication date: Available online 17 October 2016 Source:Enzyme and Microbial Technology Author(s): K. Mihklepp, K. Kivirand, M. Nikopensius, D. Peedel, M. Utt, T. Rinken Streptococcus uberis (S. uberis) is an important environmental pathogen causing mastitis in dairy cattle. Mastitis or mammary gland infection is the most common disease in milking cows and cause significant economic burden to farmers due to the reduction of the amount of milk and its quality. The development of rapid analytical methods for the determination of mastitis-causing pathogens in milk is of utmost importance for the early identification of the...
Source: Enzyme and Microbial Technology - October 29, 2016 Category: Biotechnology Source Type: research

Deciphering the factors defining the pH-dependence of a commercial glycoside hydrolase family 8 enzyme
Publication date: Available online 17 October 2016 Source:Enzyme and Microbial Technology Author(s): Mário Barroca, Gustavo Santos, Björn Johansson, Florian Gillotin, Georges Feller, Tony Collins A prerequisite to the use of any enzyme in any industrial process is an understanding of its activity and stability under process conditions. Glycoside hydrolase family 8 enzymes include many important biotechnological biocatalysts yet little is known of the performance of these with respect to pH. A better understanding of this parameter and its relationship to structure and function in these enzymes will allow for a...
Source: Enzyme and Microbial Technology - October 29, 2016 Category: Biotechnology Source Type: research

Optimization of oligomeric enzyme activity in ionic liquids using Rhodotorula glutinis yeast phenylalanine ammonia lyase
Publication date: Available online 18 October 2016 Source:Enzyme and Microbial Technology Author(s): Christiaan C. Barron, Brandon J.D. Sponagle, Pugazhendhi Arivalagan, Godwin B. D’Cunha Phenylalanine ammonia lyase (E.C.4.3.1.24, PAL) activity of Rhodotorula glutinis yeast has been demonstrated in four commonly used ionic liquids. PAL forward reaction was carried out in 1-butyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and 1-butyl-3-methylimidazolium lactate ([BMIM][lactate]). Our exp...
Source: Enzyme and Microbial Technology - October 29, 2016 Category: Biotechnology Source Type: research

Decolourisation of Acid orange 7 in a microbial fuel cell with a laccase-based biocathode: Influence of mitigating pH changes in the cathode chamber
This study investigated various ways of mitigating pH changes in the cathode of MFCs and their effect on laccase activity and decolourisation of a model azo dye Acid orange 7 in the anode chamber. Experiments were run with catholyte pH automatically controlled via feedback control or by using acetate buffers (pH 4.5) of various strength (100mM and 200mM), with CMI7000 as the cation exchange membrane. A comparison was also made between use of CMI7000 and Nafion 117 as the transport properties of cations for both membranes (hence their potential effects on pH changes in the cathode) are different. Results show that using Naf...
Source: Enzyme and Microbial Technology - October 29, 2016 Category: Biotechnology Source Type: research