Effects of N-glycosylation on the Biochemical Properties of Recombinant bEKL Expressed in Pichia pastoris
In conclusion, this study demonstrated that the effects of glycosylation at different degrees and sites in bEKL were diverse. Moreover, this work will provide theoretical support for designing enzymes on the basis of N-glycosylation to meet the demands of the biochemical industry. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - March 17, 2018 Category: Biotechnology Source Type: research

Stability of lipases in miniemulsion systems: Correlation between secondary structure and activity
Publication date: Available online 12 March 2018 Source:Enzyme and Microbial Technology Author(s): Ana C.D. Pfluck, Dragana P.C. de Barros, Luís P. Fonseca, Eduardo P. Melo The exploitation of an efficient enzymatic system to perform biopolymers synthesis, namely polyesters from dicarboxylic acids and dialcohols, requires the evaluation of the enzyme operational stability. This becomes particularly relevant when non-conventional media, such as miniemulsions, are used due to the inhomogeneity of the reaction media and presence of surfactants and high concentrations of organic compounds which might be deleterious to ...
Source: Enzyme and Microbial Technology - March 13, 2018 Category: Biotechnology Source Type: research

Biosynthesis of Pd and Au as nanoparticles by a marine bacterium Bacillus sp. GP and their enhanced catalytic performance using metal oxides for 4-nitrophenol reduction
In this study, we first reported that a marine Bacillus sp. GP was capable of producing Pd and Au NPs in the presence of sodium lactate. Ultraviolet visible spectrometer (UV-Vis), transmission electron microscopy (TEM), X-ray diffraction patterns (XRD), X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FTIR) analyses were employed to explain the process and mechanism of Pd(II)/Au(III) reduction through GP. Additionally, we also found that bio-Pd/Au NPs could be used as catalysts in chemical reduction of 4-nitrophenol (4-NP). Moreover, the catalytic activity of bio-Pd NPs could be enhanced ...
Source: Enzyme and Microbial Technology - March 11, 2018 Category: Biotechnology Source Type: research

Engineering the residues on “A” surface and C-terminal region to improve thermostability of nitrilase
Publication date: Available online 5 March 2018 Source:Enzyme and Microbial Technology Author(s): Zhe Xu, Ting Cai, Neng Xiong, Shu-Ping Zou, Ya-Ping Xue, Yu-Guo Zheng Nitrilases can hydrolyze nitriles to corresponding carboxylic acids in one single step, which have great potential as valuable biocatalysts for chemical synthesis. However, the poor thermostability of the nitrilases restrict their applications in industry. In this work, error-prone PCR and site-directed mutagenesis were utilized to improve the thermostability of nitrilases. Several mutants (AcN-Q339K, AcN-Q343K, AcN-T201F, AcN-T201W, AcN-T201L, AcN-T201I) w...
Source: Enzyme and Microbial Technology - March 6, 2018 Category: Biotechnology Source Type: research

Fabrication of an amperometric sarcosine biosensor based on sarcosine oxidase/Chitosan/CuNPs/c-MWCNT/Au electrode for detection of prostate cancer
Publication date: Available online 1 March 2018 Source:Enzyme and Microbial Technology Author(s): Vinay Narwal, Parveen Kumar, Pooja Joon, C.S. Pundir An amperometric sarcosine biosensor was fabricated based on covalent immobilization of sarcosine oxidase (SarOx) onto the nanocomposite of carboxylated multi-walled carbon nanotubes (cMWCNT)/chitosan (CHIT) and copper nanoparticles (CuNPs), electrodeposited on gold (Au) electrode. The SarOx/CHIT/CuNPs/c-MWCNT/Au electrode was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The enzyme electrode ex...
Source: Enzyme and Microbial Technology - March 2, 2018 Category: Biotechnology Source Type: research

Optical method for detecting oxygen via the chromogenic reaction catalyzed by polyphenol oxidase
Publication date: Available online 1 March 2018 Source:Enzyme and Microbial Technology Author(s): Abdelaziz Bouchaib, Abdellatif Ben abdellah, Mohamed Bakkali, Amine Laglaoui, Abdelhay Arakrak, Carlo Carboni, Abdelaziz Benjouad, Amal Maurady The present work describes a method for detecting the ingress of gas phase oxygen into packed food. It uses the enzyme polyphenol oxidase (PPO)from Mushroom and Mediterranean dwarf palm. The PPO is incorporated into an indubiose film along with a non-toxic polyphenol such as gallic acid or chlorogenic acid. If exposed to oxygen, the test spot undergoes an irreversible and visible colo...
Source: Enzyme and Microbial Technology - March 2, 2018 Category: Biotechnology Source Type: research

Enantioselective sulfoxidations employing the thermostable cyclohexanone monooxygenase from Thermocrispum municipale
Publication date: Available online 21 February 2018 Source:Enzyme and Microbial Technology Author(s): Gonzalo de Gonzalo, Antonio Franconetti The recently discovered cyclohexanone monooxygenase from Thermocrispum municipale (TmCHMO) was employed in the preparation of different optically active sulfoxides. This novel Baeyer-Villiger monooxygenase (BVMO) shows a similar substrate specificity and selectivity when compared with the prototype CHMO from Acinetobacter calcoaceticus. Interestingly, TmCHMO is able to catalyse the asymmetric sulfoxidations at relatively high temperatures, substrate concentrations and in the presenc...
Source: Enzyme and Microbial Technology - February 22, 2018 Category: Biotechnology Source Type: research

Characterization of Regioselective Flavonoid O-methyltransferase from the Streptomyces sp. KCTC 0041BP
Publication date: Available online 21 February 2018 Source:Enzyme and Microbial Technology Author(s): Sumangala Darsandhari, Dipesh Dhakal, Biplav Shrestha, Prakash Parajuli, Joo-Hyun Seo, Tae-Su Kim, Jae Kyung Sohng A flavonoid comprises polyphenol compounds with pronounced antiviral, antioxidant, anticarcinogenic, and anti-inflammatory effects. The flavonoid modification by methylation provides a greater stability and improved pharmacokinetic properties. The methyltransferase from plants or microorganisms is responsible for such substrate modifications in a regiospecific or a promiscuous manner. GerMIII, originally char...
Source: Enzyme and Microbial Technology - February 22, 2018 Category: Biotechnology Source Type: research

Biochemical characterization and substrate profiling of a reversible 2,3-dihydroxybenzoic acid decarboxylase for biocatalytic Kolbe-Schmitt reaction
Publication date: Available online 21 February 2018 Source:Enzyme and Microbial Technology Author(s): Xuemei Zhang, Jie Ren, Peiyuan Yao, Rui Gong, Min Wang, Qiaqing Wu, Dunming Zhu Reversible benzoic acid decarboxylases are versatile biocatalysts by taking advantage of both decarboxylation and carboxylation reactions, especially for the biocatalytic Kolbe-Schmitt reaction. In the course of developing a benzoic acid decarboxylase tool-box, a putative benzoic acid decarboxylase gene from Fusarium oxysporum was heterologously over-expressed in Escherichia coli, the recombinant protein was purified and characterized. The pur...
Source: Enzyme and Microbial Technology - February 22, 2018 Category: Biotechnology Source Type: research

Cloning, expression and characterisation of P450-Hal1 (CYP116B62) from Halomonas sp. NCIMB 172: A self-sufficient P450 with high expression and diverse substrate scope
Publication date: Available online 17 February 2018 Source:Enzyme and Microbial Technology Author(s): Joanne L. Porter, Selina Sabatini, Jack Manning, Michele Tavanti, James L. Galman, Nicholas J. Turner, Sabine L. Flitsch Cytochrome P450 monooxygenases are able to catalyse a range of synthetically challenging reactions ranging from hydroxylation and demethylation to sulfoxidation and epoxidation. As such they have great potential for biocatalytic applications but are underutilised due to often-poor expression, stability and solubility in recombinant bacterial hosts. The use of self-sufficient P450 s with fused haem and...
Source: Enzyme and Microbial Technology - February 18, 2018 Category: Biotechnology Source Type: research

A simplified method for active-site titration of lipases immobilised on hydrophobic supports
Publication date: Available online 17 February 2018 Source:Enzyme and Microbial Technology Author(s): Tim D. Nalder, Ivan Kurtovic, Colin J. Barrow, Susan N. Marshall The aim of this work was to develop a simple and accurate protocol to measure the functional active site concentration of lipases immobilised on highly hydrophobic supports. We used the potent lipase inhibitor methyl 4-methylumbelliferyl hexylphosphonate to titrate the active sites of Candida rugosa lipase (CrL) bound to three highly hydrophobic supports: octadecyl methacrylate (C18), divinylbenzene crosslinked methacrylate (DVB) and styrene. The method uses...
Source: Enzyme and Microbial Technology - February 18, 2018 Category: Biotechnology Source Type: research

Characterisation of novel biomass degradation enzymes from the genome of Cellulomonas fimi
This report demonstrates a simple method of quickly screening and characterising putative genes as BioBricks. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - February 16, 2018 Category: Biotechnology Source Type: research

Characterization of two styrene monooxygenases from marine microbes
Publication date: May 2018 Source:Enzyme and Microbial Technology, Volume 112 Author(s): Wei Pu, Can Cui, Chao Guo, Zhong-Liu Wu Styrene monooxygenases (SMOs) are highly stereoselective enzymes that catalyze the formation of chiral epoxides as versatile building blocks. To expand the enzyme toolbox, two bacterial SMOs were identified from the genome of marine microbes Paraglaciecola agarilytica NO2 and Marinobacterium litorale DSM 23545, and heterologously expressed in Escherichia coli in soluble form. Both of the resulting whole-cell biocatalysts exhibited maximal activity at 30 °C and pH 8.0. They catalyzed the su...
Source: Enzyme and Microbial Technology - February 12, 2018 Category: Biotechnology Source Type: research

Biocontrol Activity of Recombinant Aspartic Protease from Trichoderma harzianum against Pathogenic Fungi
In this study, recombinant P6281 (rP6281) expressed in Pichia pastoris showed high activity of 321.8 U/mL. Maximum activity was observed at pH 2.5 and 40 °C, and the enzyme was stable in the pH range of 2.5–6.0. rP6281 significantly inhibited spore germination and growth of plant and animal pathogenic fungi such as Botrytis cinerea, Mucor circinelloides, Aspergillus fumigatus, Aspergillus flavus, Rhizoctonia solani, and Candida albicans. Transmission electron microscopy revealed that rP6281 efficiently damages the cell wall of Botrytis cinerea. In addition, the protease significantly inhibited the development...
Source: Enzyme and Microbial Technology - February 6, 2018 Category: Biotechnology Source Type: research

d-Xylose and l-arabinose laurate esters: Enzymatic synthesis, characterization and physico-chemical properties
Publication date: May 2018 Source:Enzyme and Microbial Technology, Volume 112 Author(s): Thomas Méline, Murielle Muzard, Magali Deleu, Harivony Rakotoarivonina, Richard Plantier-Royon, Caroline Rémond Efficient enzymatic synthesis of d-xylose and l-arabinose lauryl mono- and diesters has been achieved by transesterification reactions catalysed by immobilized Candida antarctica lipase B as biocatalyst, in organic medium in the presence of d-xylose or l-arabinose and vinyllaurate at 50 °C. In case of l-arabinose, one monoester and one diester were obtained in a 57% overall yield. A more complex mixture w...
Source: Enzyme and Microbial Technology - February 4, 2018 Category: Biotechnology Source Type: research

Identification and characterization of GH62 bacterial α-l-arabinofuranosidase from thermotolerant Streptomyces sp. SWU10 that preferentially degrades branched l-arabinofuranoses in wheat arabinoxylan
Publication date: Available online 31 January 2018 Source:Enzyme and Microbial Technology Author(s): Pornpimol Phuengmaung, Yuika Kunishige, Wasana Sukhumsirichart, Tatsuji Sakamoto We previously described thermotolerant Streptomyces sp. SWU10, which produced four endo-xylanases and one xylosidase able to digest xylan backbones. To achieve arabinoxylan degradation, the swu62A gene was cloned and overexpressed in Escherichia coli, and the recombinant enzyme, termed SWUAbf62A, was characterized. The 438 amino acids of SWUAbf62A revealed Glyco_hydro_62 and closely related with putative α-l-arabinofuranosidases belongin...
Source: Enzyme and Microbial Technology - February 1, 2018 Category: Biotechnology Source Type: research

Production of myo-inositol from glucose by a novel trienzymatic cascade of polyphosphate glucokinase, inositol 1-phosphate synthase and inositol monophosphatase
Publication date: Available online 31 January 2018 Source:Enzyme and Microbial Technology Author(s): Yiping Lu, Lei Wang, Fei Teng, Jianing Zhang, Meirong Hu, Yong Tao myo-Inositol (inositol) is important in the cosmetics, pharmaceutical and functional food industries. Here, we report a novel pathway to produce inositol from glucose by a trienzymatic cascade system involving polyphosphate glucokinase (PPGK), inositol 1-phosphate synthase (IPS) and inositol monophosphatase (IMP). The system contained three highly active enzymes, AspPPGK from Arthrobacter sp. OY3WO11, TbIPS from Trypanosoma brucei TREU927, and EcIMP from Es...
Source: Enzyme and Microbial Technology - January 31, 2018 Category: Biotechnology Source Type: research

Chemoenzymatic lignin valorization: Production of epoxidized pre-polymers using Candida antarctica lipase B
Publication date: May 2018 Source:Enzyme and Microbial Technology, Volume 112 Author(s): Francisco Vásquez-Garay, Regis Teixeira Mendonça, Steven W. Peretti An innovative chemoenzymatic catalytic system for functionalizing lignin from Organosolv and Kraft pulping processes to obtain oxirane rings was investigated. Novozym435 (immobilized C. antarctica lipase B: CalB) was used to catalyze the peroxidation of caprylic acid to peroxycaprylic acid, which in turn reacted with unsaturated CC bonds to form the oxirane ring. The conversion of OH groups to oxirane rings (epoxides) reached 90% and 55% after 12 h for...
Source: Enzyme and Microbial Technology - January 20, 2018 Category: Biotechnology Source Type: research

Enzymatically and chemically oxidized lignin nanoparticles for biomaterial applications
Publication date: April 2018 Source:Enzyme and Microbial Technology, Volume 111 Author(s): Maija-Liisa Mattinen, Juan José Valle-Delgado, Timo Leskinen, Tuomas Anttila, Guillaume Riviere, Mika Sipponen, Arja Paananen, Kalle Lintinen, Mauri Kostiainen, Monika Österberg Cross-linked and decolorized lignin nanoparticles (LNPs) were prepared enzymatically and chemically from softwood Kraft lignin. Colloidal lignin particles (CLPs, ca. 200 nm) in a non-malodorous aqueous dispersion could be dried and redispersed in tetrahydrofuran (THF) or in water retaining their stability i.e. spherical shape and size. Two fung...
Source: Enzyme and Microbial Technology - January 11, 2018 Category: Biotechnology Source Type: research

Improvement in thermostability of Xylanase from Geobacillus thermodenitrificans C5 by site directed mutagenesis
Publication date: Available online 6 January 2018 Source:Enzyme and Microbial Technology Author(s): Muhammad Irfan, Claudio F. Gonzalez, Saad Raza, Muhamamd Rafiq, Fariha Hasan, Samiullah Khan, Aamer Ali Shah Enzymes activity and stability at extreme temperature can be intensified by regularly applying protein engineering. In the present study, two amino acids were perceived to mark the temperature dependability of xylanase from Geobacillus thermodenitrificans C5. Six mutants of G. thermodenitrificans C5 were built through site-directed mutagenesis by interchanging the residue with proline and glutamic acid (R81P, H82E, W...
Source: Enzyme and Microbial Technology - January 7, 2018 Category: Biotechnology Source Type: research

Producing functional recombinant human keratinocyte growth factor in Pichia pastoris and investigating its protective role against irradiation
Publication date: Available online 5 January 2018 Source:Enzyme and Microbial Technology Author(s): Zahra Bahadori, Hamid Reza Kalhor, Seyed Javad Mowla Keratinocyte Growth Factor (KGF) is a paracrine-acting, epithelial mitogen that plays a prominent role in the regeneration of damaged epithelial tissues. In spite of different attempts to produce recombinant human KGF in many organisms, including bacteria, mammalian cells, plant cells and insect cells; production of recombinant form suffers from lower yields and recovery relative to other recombinant proteins of similar size and properties. Due to many advantages of Pichi...
Source: Enzyme and Microbial Technology - January 6, 2018 Category: Biotechnology Source Type: research

Stereoselective hydroxylation of isophorone by variants of the cytochromes P450 CYP102A1 and CYP101A1
Publication date: Available online 5 January 2018 Source:Enzyme and Microbial Technology Author(s): Shaghayegh Dezvarei, Joel H.Z. Lee, Stephen G. Bell The stereoselective oxidation of hydrocarbons is an area of research where enzyme biocatalysis can make a substantial impact. The cyclic ketone isophorone was stereoselectively hydroxylated (≥95%) by wild-type CYP102A1 to form (R)-4-hydroxyisophorone, an important chiral synthon and flavour and fragrance compound. CYP102A1 variants were also selective for 4-hydroxyisophorone formation and the product formation rate increased over the wild-type enzyme by up to 285-fold, ...
Source: Enzyme and Microbial Technology - January 6, 2018 Category: Biotechnology Source Type: research

Essential role of amino acid position 71 in substrate preference by meso-diaminopimelate dehydrogenase from Symbiobacterium thermophilum IAM14863
Publication date: Available online 3 January 2018 Source:Enzyme and Microbial Technology Author(s): Yanan Zhang, Qinyuan Ma, Miaomiao Dong, Xianhai Zhang, Yichu Chen, Xiuzhen Gao, Yuanda Song meso­-Diaminopimelate dehydrogenase (meso-DAPDH) catalyzes the reversible oxidative deamination of the d­configuration of meso-2,6­diaminopimelate (meso-DAP) and is thought to have substrate specificity toward meso-DAP. The discovery of the meso-DAPDH from Symbiobacterium thermophilum IAM14863 (StDAPDH) revealed meso-DAPDH members with broad substrate specificity. In order to elucidate the substrate-preference mechanism o...
Source: Enzyme and Microbial Technology - January 4, 2018 Category: Biotechnology Source Type: research

Biodegradation of Fibrillated Oil Palm Trunk Fiber by a Novel Thermophilic, Anaerobic, Xylanolytic Bacterium Caldicoprobacter sp. CL-2 Isolated from Compost
Publication date: Available online 30 December 2017 Source:Enzyme and Microbial Technology Author(s): Erma Widyasti, Ayumi Shikata, Rokiah Hashim, Othman Sulaiman, Kumar Sudesh, Edi Wahjono, Akihiko Kosugi Oil palm trunk (OPT) is one of the most promising lignocellulosic bioresources. To develop effective biodegradation, thermophilic, anaerobic microorganisms were screened from bovine manure compost using fibrillated OPT (f-OPT) pretreated by wet disk milling as the substrate. One thermophilic, anaerobic bacterium, strain CL-2, whose 16S rDNA gene has 98.6% sequence identity with that of Caldicoprobacter faecale DSM 20678...
Source: Enzyme and Microbial Technology - December 31, 2017 Category: Biotechnology Source Type: research

A thermophilic enzymatic cocktail for galactomannans degradation
Publication date: Available online 29 December 2017 Source:Enzyme and Microbial Technology Author(s): Aulitto Martina, Fusco Francesca Anna, Fiorentino Gabriella, Bartolucci Simonetta, Contursi Patrizia, Limauro Danila The full utilization of hemicellulose sugars (pentose and exose) present in lignocellulosic material, is required for an efficient bio-based fuels and chemicals production. Two recombinant thermophilic enzymes, an endo-1,4-β-mannanase from Dictyoglomus turgidum (DturCelB) and an α-galactosidase from Thermus thermophilus (TtGalA), were assayed at 80 °C, to assess their heterosynergystic asso...
Source: Enzyme and Microbial Technology - December 30, 2017 Category: Biotechnology Source Type: research

Identification of (R)-selective ω-aminotransferases by exploring evolutionary sequence space
Publication date: Available online 23 December 2017 Source:Enzyme and Microbial Technology Author(s): Eun-Mi Kim, Joon Ho Park, Byung-Gee Kim, Joo-Hyun Seo Several (R)-selective ω-aminotransferases (R-ωATs) have been reported. The existence of additional R-ωATs having different sequence characteristics from previous ones is highly expected. In addition, it is generally accepted that R-ωATs are variants of aminotransferase group III. Based on these backgrounds, sequences in RefSeq database were scored using family profiles of branched-chain amino acid aminotransferase (BCAT) and D-alanine aminotrans...
Source: Enzyme and Microbial Technology - December 24, 2017 Category: Biotechnology Source Type: research

Stabilization of dimeric β-glucosidase from Aspergillus niger via glutaraldehyde immobilization under different conditions.
Publication date: Available online 22 December 2017 Source:Enzyme and Microbial Technology Author(s): Perla Guadalupe Vazquez-Ortega, Maria Teresa Alcaraz-Fructuoso, Juan A. Rojas-Contreras, Javier López-Miranda, Roberto Fernandez-Lafuente The dimeric enzyme β-glucosidase from Aspergillus niger has been immobilized on different amino-agarose beads at pH 5 and 7, exploiting the versatility of glutaraldehyde. The stability of the free enzyme depended on enzyme concentration. Immobilization via ion exchange improved enzyme stability/activity, depending on the immobilization pH. However, the enzyme was desorbed in...
Source: Enzyme and Microbial Technology - December 23, 2017 Category: Biotechnology Source Type: research

Chemoenzymatic synthesis of sucuronic acid using D-glucurono-6,3-lactone and sucrose as raw materials, and properties of the product
Publication date: Available online 21 December 2017 Source:Enzyme and Microbial Technology Author(s): Hiroki Hosaka, Saori Mizoguchi, Mitsuru Tashiro, Takashi Fujimoto, Takako Hirano, Wataru Hakamata, Toshiyuki Nishio Using D-glucurono-6,3-lactone (GlcL) and sucrose (Suc) as raw materials, we synthesized sucuronic acid (SucA), in which the D-glucose (Glc) residue of Suc was replaced with D-glucuronic acid, by a three-step chemoenzymatic method. In the 1 st chemical step, methyl D-glucuronate (GlcAM) was synthesized by treating GlcL with a strong base anion exchange resin, Amberlite IRA402BL OH AG, in anhydrous methanol....
Source: Enzyme and Microbial Technology - December 22, 2017 Category: Biotechnology Source Type: research

Immobilization of β-1,3-1,4-glucanase from Bacillus sp. on porous silica for production of β-glucooligosaccharides
This study showed that the Imbg1314 applied economical production of β-GOS. Graphical abstract (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - December 21, 2017 Category: Biotechnology Source Type: research

Enhancement of n-3 polyunsaturated fatty acid glycerides in Sardine oil by a bioimprinted cross-linked Candida rugosa lipase
Publication date: Available online 19 December 2017 Source:Enzyme and Microbial Technology Author(s): S. Charanyaa, Prasanna D. Belur, I. Regupathi Considering the advantages of bioimprinting and carrier free immobilization, cross-linked enzyme aggregates (CLEA) were prepared by using bioimprinted Candida rugosa lipase (CRL) with Bovine serum albumin (BSA), Polyethyleneimine and glutaraldehyde. Effect of various factors such as CRL-Oleic acid ratio, CRL-BSA ratio, CRL- Polyethyleneimine ratio, glutaraldehyde loading, cross-linking time etc., on lipase activity recovery and aggregate yield were studied and optimized. This ...
Source: Enzyme and Microbial Technology - December 20, 2017 Category: Biotechnology Source Type: research

An enzymatic alternative for the synthesis of nucleoside 5 ′-monophosphates
Publication date: Available online 19 December 2017 Source:Enzyme and Microbial Technology Author(s): Esteban D. Gudiño, Julia Y. Santillán, Luis E. Iglesias, Adolfo M. Iribarren A new procedure was carried out for the synthesis of nucleoside 5′-monophosphates, involving the use of two enzymes. The first step applied phospholipase D from Streptomyces netropsis and phosphatidylcholine as phosphatidyl donor, to give 5′-(3-sn-phosphatidyl) nucleosides (C, U, A, I). These were selectively hydrolysed in the second step by the action of phospholipase C from Bacillus cereus to produce the respective 5&p...
Source: Enzyme and Microbial Technology - December 20, 2017 Category: Biotechnology Source Type: research

Enantioselective synthesis of (R)-phenylephrine by Serratia marcescens BCRC10948 cells that homologously express SM_SDR
Publication date: Available online 10 December 2017 Source:Enzyme and Microbial Technology Author(s): Yi-Chia Kuan, Yue-Bin Xu, Wen-Ching Wang, Ming-Te Yang A short-chain dehydrogenase/reductase from Serratia marcescens BCRC10948, SM_SDR, has been cloned and expressed in Escherichia coli for the bioconversion of 1-(3-hydroxyphenyl)-2-(methylamino) ethanone (HPMAE) to (R)-phenylephrine[(R)-PE]. However, only 5.11mM (R)-PE was obtained from 10mM HPMAE after a 9h conversion in the previous report. To improve the biocatalytic efficiency, the homologous expression of the SM_SDR in S. marcescens BCRC10948 was achieved using the...
Source: Enzyme and Microbial Technology - December 10, 2017 Category: Biotechnology Source Type: research

A Process for Production of Trehalose by Recombinant Trehalose Synthase and Its Purification
In this study, a TreS from Pseudomonas putida ATCC47054 was expressed in E. coli BL21(DE3) via plasmids pET15b and pET22b. pET15b-treS showed better plasmid stability and TreS expression, which revealed that the highest activity, 39866±1420U/(g dry cell weight) at the final lactose concentration of 4g/L for 7h at 27°C in a 5-L fermentor at pH 8.0. The use of 30% (w/v) high-maltose syrup as a substrate can extend the temperature tolerance of TreS to 60°C. More than 64% of maltose can be converted into trehalose by adding 200U of TreS per gram of maltose at 50°C for 24h. The total sugar content of the treh...
Source: Enzyme and Microbial Technology - December 2, 2017 Category: Biotechnology Source Type: research

Utilization of distillery wastewater for hydrogen production in one-stage and two-stage processes involving photofermentation
In this study, distillery wastewater was treated by dark fermentation or photofermentation alone, and by sequential dark and photofermentation processes using anaerobic saccharolytic consortium and purple nonsulfur bacteria. Combination of dark and photofermentation resulted in the maximal H2 yield of 17.6L/L of distillery waste with chemical oxygen demand 40g/L. It is equivalent to 205kJ/L distillery wastewater and corresponds to recovery of approximately 4-8% of energy consumed during ethanol production. Optimal performance of photofermentation was observed at 20% concentration of pre-fermented distillery waste. In photo...
Source: Enzyme and Microbial Technology - November 29, 2017 Category: Biotechnology Source Type: research

An OPAA enzyme mutant with increased catalytic efficiency on the nerve agents sarin, soman, and GP
Publication date: Available online 21 November 2017 Source:Enzyme and Microbial Technology Author(s): Sue Y. Bae, James M. Myslinski, Leslie R. McMahon, Jude J. Height, Andrew N. Bigley, Frank M. Raushel, Steven P. Harvey The wild-type OPAA enzyme has relatively high levels of catalytic activity against several organophosphate G-type nerve agents. A series of mutants containing replacement amino acids at the OPAA Y212, V342, and I215 sites showed several fold enhanced catalytic efficiency on sarin, soman, and GP. One mutant, Y212F/V342L, showed enhanced stereospecificity on sarin and that enzyme along with a phosphotriest...
Source: Enzyme and Microbial Technology - November 23, 2017 Category: Biotechnology Source Type: research

Kinetic resolution of sec-alcohols catalysed by Candida antarctica lipase B displaying Pichia pastoris whole-cell biocatalyst
Publication date: Available online 21 November 2017 Source:Enzyme and Microbial Technology Author(s): Kun Zhang, Zhiyou Pan, Zhoujian Diao, Shuli Liang, Shuangyan Han, Suiping Zheng, Ying Lin Kinetic resolution of sec-alcohols is a green process with biocatalyst. Candida antarctica lipase B (CALB) displayed on Pichia pastoris cell-surface (Pp-CALB) was characterized in kinetic resolution of sec-alcohols with different structures. The reaction parameters including acyl donors, molar ratio of substrates, solvents and temperatures were examined with 2-octanol as model substrate. 47.4% molar conversion of 2-octanol and 99.7% ...
Source: Enzyme and Microbial Technology - November 23, 2017 Category: Biotechnology Source Type: research

The effect of a lytic polysaccharide monooxygenase and a xylanase from Gloeophyllum trabeum on the enzymatic hydrolysis of lignocellulosic residues using a commercial cellulase
Publication date: Available online 22 November 2017 Source:Enzyme and Microbial Technology Author(s): Cynthia Sanhueza, Gonzalo Carvajal, Javiera Soto-Aguilar, Maria Elena Lienqueo, Oriana Salazar Hydrolysis of lignocellulosic biomass depends on the concerted actions of cellulases and accessory proteins. In this work we examined the combined action of two auxiliary proteins from the brown rot fungus Gloeophyllum trabeum: a family AA9 lytic polysaccharide monooxygenase (GtLPMO) and a GH10 xylanase (GtXyn10A). The enzymes were produced in the heterologous host Pichia pastoris. In the presence of an electron source, GtLPMO i...
Source: Enzyme and Microbial Technology - November 23, 2017 Category: Biotechnology Source Type: research

Improved peroxide biosensor based on Horseradish Peroxidase/Carbon Nanotube on a thiol-modified gold electrode
Publication date: Available online 16 November 2017 Source:Enzyme and Microbial Technology Author(s): A.K.M. Kafi, M. Naqshabandi, Mashitah M. Yusoff, Maxwell J. Crossley A new 3-dimensional (3D) network of crosslinked Horseradish Peroxidase/Carbon Nanotube (HRP/CNT) on a thiol-modified Au surface has been described in order to build up the effective electrical wiring of the enzyme units with the electrode. The synthesized 3D HRP/CNT network has been characterized with cyclic voltammetry and amperometry which results the establishment of direct electron transfer between the redox active unit of HRP and the Au surface. Ele...
Source: Enzyme and Microbial Technology - November 17, 2017 Category: Biotechnology Source Type: research

Biochemical characterization of a novel tyrosine phenol-lyase from Fusobacterium nucleatum for highly efficient biosynthesis of l-DOPA
In this study, a novel TPL from Fusobacterium nucleatum (Fn-TPL) was successfully overexpressed in Escherichia coli and screened for l-DOPA synthesis with a specific activity of 2.69Umg−1. Fn-TPL was found to be a tetramer, and the optimal temperature and pH for α, β-elimination of l-tyrosine was 60°C and pH 8.5, respectively. The enzyme showed broad substrate specificity toward natural and synthetic l-amino acids. Kinetic analysis suggested that the k cat/K m value for l-tyrosine decomposition was much higher than that for l-DOPA decomposition, while Fn-TPL exhibited similar catalytic efficiency for s...
Source: Enzyme and Microbial Technology - November 15, 2017 Category: Biotechnology Source Type: research

Identification and characterization of the first β-1,3-d-xylosidase from a gram-positive bacterium, Streptomyces sp. SWU10
Publication date: Available online 10 November 2017 Source:Enzyme and Microbial Technology Author(s): Pornpimol Phuengmaung, Daisuke Fujiwara, Wasana Sukhumsirichart, Tatsuji Sakamoto In previous reports, we characterized four endo-xylanases produced by Streptomyces sp. strain SWU10 that degrade xylans to several xylooligosaccharides. To obtain a set of enzymes to achieve complete xylan degradation, a β-d-xylosidase gene was cloned and expressed in Escherichia coli, and the recombinant protein, named rSWU43A, was characterized. SWU43A is composed of 522 amino acids and does not contain a signal peptide, indicating th...
Source: Enzyme and Microbial Technology - November 10, 2017 Category: Biotechnology Source Type: research

Rational selection of biphasic reaction systems for geranyl glucoside production by Escherichia coli whole-cell biocatalysts
Publication date: Available online 8 November 2017 Source:Enzyme and Microbial Technology Author(s): Xenia Priebe, Maximilian Daschner, Wilfried Schwab, Dirk Weuster-Botz Geranyl glucoside, the glucosylated, high-value derivative of the monoterpenoid geraniol, has various applications in the flavor and fragrance industry and can be produced through whole-cell biotransformation of geraniol with Escherichia coli whole-cell biocatalysts expressing the glucosyltransferase VvGT14a. However, the low water solubility and high cytotoxicity of geraniol require the design of a proper biphasic system where the second, non-aqueous ph...
Source: Enzyme and Microbial Technology - November 9, 2017 Category: Biotechnology Source Type: research

Rational evolution of the unusual Y-type oxyanion hole of Rhodococcus sp. CR53 lipase LipR
Publication date: January 2018 Source:Enzyme and Microbial Technology, Volume 108 Author(s): Belén Infanzón, Pablo H. Sotelo, Josefina Martínez, Pilar Diaz Rhodococcus sp CR-53 lipase LipR was the first characterized member of bacterial lipase family X. Interestingly, LipR displays some similarity with α/β-hydrolases of the C. antartica lipase A (CAL-A)-like superfamily (abH38), bearing a Y-type oxyanion hole, never found before among bacterial lipases. In order to explore this unusual Y-type oxyanion hole, and to improve LipR performance, two modification strategies based on site directed ...
Source: Enzyme and Microbial Technology - November 6, 2017 Category: Biotechnology Source Type: research

FCS and ECH dependent production of phenolic aldehyde and melanin pigment from L-tyrosine in Escherichia coli
In this study, we engineered E. coli cells to express L-tyrosine converting enzymes, including tyrosine ammonia-lyase (TAL), p-coumarate 3-hydroxylase (C3H), feruloyl-CoA synthetase (FCS), and enoyl-CoA hydratase/aldolase (ECH). A catabolic circuit, which consisted of the protocatechualdehyde and p-hydroxybenzaldehyde production pathways, was reconstituted through combinatorial production of discrete enzymes. First, cells expressing FCS and ECH could convert each 5mM of caffeic acid and ferulic acid into protocatechualdehyde (70.5%) and vanillin (96.5%), respectively. Second, TAL and C3H were co-expressed with FCS and ECH....
Source: Enzyme and Microbial Technology - October 28, 2017 Category: Biotechnology Source Type: research

Cloning and characterization of a novel phenylalanine ammonia-lyase gene from Inonotus baumii
Publication date: Available online 26 October 2017 Source:Enzyme and Microbial Technology Author(s): Weiping Lin, Ao Liu, Caihong Weng, Hui Li, Shiwei Sun, Aihuan Song, Hu Zhu Phenylalanine ammonia-lyase (PAL) gene plays an important role in the synthesis of flavones, lignin, and other bioactive compounds in living organisms. Inonotus baumii, the only known flavone-producing filamentous fungus, is of great importance in the investigation of flavone metabolic pathways. To study the function of PAL enzyme in I. baumii flavone synthesis, a full-length cDNA of pal gene was cloned from I. baumii using DOP-PCR and RACE-PCR. The...
Source: Enzyme and Microbial Technology - October 27, 2017 Category: Biotechnology Source Type: research

Influence of support materials on continuous hydrogen production in anaerobic packed-bed reactor with immobilized hydrogen producing bacteria at acidic conditions
This study assesses the impact of different support materials (Mutag BioChip™, expanded clay and activated carbon) on microbial hydrogen production in an anaerobic packed-bed reactor (APBR) treating synthetic waste water containing glucose as the main carbon source at low pH value. The APBRs were inoculated with acid pretreated anaerobic sludge and operated at pH value of 4±0.2 and hydraulic retention time (HRT) of 3h. The maximum hydrogen yield of 1.80mol H2/mol glucose was achieved for the APBR packed with Mutag BioChip™ (R1), followed by expanded clay (R2, 1.74mol H2/mol glucose) and activated carbon ...
Source: Enzyme and Microbial Technology - October 25, 2017 Category: Biotechnology Source Type: research

Development of an electrochemical immunosensor based on gold nanoparticles incorporated chitosan biopolymer nanocomposite film for the detection of prostate cancer using PSA as biomarker
In this study, we have developed an electrochemical immunosensor for the detection of prostate-specific antigen (PSA) based on gold nanoparticles (AuNPs) and a chitosan (CHI) nanocomposite film coated on a screen printed electrode (SPE). The modified SPE was characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The immunosensor was fabricated by sequential immobilization of anti-PSA primary antibody, PSA antigen and HRP-tagged secondary antibody on the surface of AuNPs/CHI/SPE. When this immunosensor was ...
Source: Enzyme and Microbial Technology - October 24, 2017 Category: Biotechnology Source Type: research

Biosynthesis of Gold and Selenium Nanoparticles by Purified Protein from Acinetobacter sp. SW 30
Publication date: Available online 18 October 2017 Source:Enzyme and Microbial Technology Author(s): Sweety A. Wadhwani, Utkarsha U. Shedbalkar, Richa Singh, Balu A. Chopade Synthesis of nanoparticles is an enzymatic reduction process in microorganisms. In the present study, a protein, lignin peroxidase has been purified by DEAE-Cellulose anion exchange chromatography and Biogel P-150 gel filtration chromatography from the cell suspension of Acinetobacter sp. SW30 responsible for the synthesis of gold nanoparticles (AuNP) and selenium nanoparticles (SeNP). The purified fraction has a specific activity of 29.4U/mg/min with...
Source: Enzyme and Microbial Technology - October 19, 2017 Category: Biotechnology Source Type: research

Characterization of a topologically unique oxygenase from Sphingobium sp. PNB capable of catalyzing a broad spectrum of aromatics
Publication date: Available online 18 October 2017 Source:Enzyme and Microbial Technology Author(s): Pratick Khara, Madhumita Roy, Joydeep Chakraborty, Arindam Dutta, Tapan K. Dutta A Rieske non-heme iron ring-hydroxylating oxygenase (RHO) from Sphingobium sp. PNB involved in the initial oxidation of a wide range of low and high molecular weight polycyclic aromatic hydrocarbons (PAHs) was investigated. The RHO was shown to comprise of the gene products of distantly located ahdA1f-ahdA2f, ahdA3 and ahdA4 genes, which encoded the oxygenase α- and β-subunits, ferredoxin and reductase, respectively. In silico struc...
Source: Enzyme and Microbial Technology - October 18, 2017 Category: Biotechnology Source Type: research

Maximize rhamnolipid production with low foaming and high yield
In this study, we assessed the boundaries set by these constraints after optimization of basic parameters such as dissolved oxygen concentration (DO), pH and carbon sources. DO 10% and pH 5.5-5.7 were found optimal; cell growth and/or rhamnolipid production were slower at lower DO (5%) or pH (5.0) while foaming became hard to control at higher DO (30%) or pH (6.0 and 6.5). Although the Pseudomonas aeruginosa strain used was selected for its high rhamnolipid production from glycerol as substrate, soybean oil was still found to be a better substrate that increased specific rhamnolipid productivity to 25.8mg/g cells-h from th...
Source: Enzyme and Microbial Technology - October 17, 2017 Category: Biotechnology Source Type: research

Aspergillus niger whole-cell catalyzed synthesis of caffeic acid phenethyl ester in ionic liquids
Publication date: Available online 16 October 2017 Source:Enzyme and Microbial Technology Author(s): Govindaraju Rajapriya, Vivek Kumar Morya, Ngoc Lan Mai, Yoon-Mo Koo Synthesis of caffeic acid ester essentially requires an efficient esterification process to produce various kinds of medicinally important ester derivatives. In the present study, a comprehensive and comparative analysis of whole-cell catalyzed caffeic acid esters production in ionic liquids (ILs) media was performed. Olive oil induced mycelial mass of halotolerant Aspergillus niger (A.niger) EXF 4321 was freeze dried and used as a catalyst. To ensure maxi...
Source: Enzyme and Microbial Technology - October 17, 2017 Category: Biotechnology Source Type: research