Combination of Physico-Chemical Entrapment and Crosslinking of Low Activity Laccase-Based Biocathode on Carboxylated Carbon Nanotube for Increasing Biofuel Cell Performance
Publication date: Available online 27 June 2017 Source:Enzyme and Microbial Technology Author(s): Marcelinus Christwardana New laccase-based catalysts to improve oxygen reduction reactions (ORR) are described, and enzymatic biofuel cells (EBCs) adopting these catalysts were developed. These new catalysts are synthesized by combining laccase, poly(ethylenimine) and carbon nanotubes, with attachment of selected elements using the crosslinker, glutaraldehyde (GA). Several characterization approaches are implemented to evaluate catalytic electron transfer in both the absence and presence of mediators and their effects on gluc...
Source: Enzyme and Microbial Technology - June 28, 2017 Category: Biotechnology Source Type: research

Mutagenesis of Met-151 and Thr-153 to Alanine in Thermoanaerobacter ethanolicus Secondary Alcohol Dehydrogenase Changes Substrate Specificity for Acetophenones
Publication date: Available online 23 June 2017 Source:Enzyme and Microbial Technology Author(s): Christopher M. Nealon, Chang Sup Kim, Amos K. Dwamena, Robert S. Phillips Secondary alcohol dehydrogenase (SADH) from Thermoanaerobacter ethanolicus reduces ketones to chiral alcohols, and generally obeys Prelog's Rule, with binding pockets for large and small alkyl substituents, giving (S)-alcohols. We have previously shown that mutations in both the large and small pockets can alter both substrate specificity and stereoselectivity. In the present work, Met-151 and Thr-153, residues located in the small pocket, were mutated ...
Source: Enzyme and Microbial Technology - June 23, 2017 Category: Biotechnology Source Type: research

IMMOBILIZATION-STABILIZATION OF A COMPLEX MULTIMERIC SUCROSE SYNTHASE FROM Nitrosomonas europaea. SYNTHESIS OF UDP-GLUCOSE
In this study, we present the first report of the immobilization-stabilization of a SuSy by multipoint covalent attachment. This stabilization strategy is very complex for multimeric enzymes because a very intense multipoint attachment can promote a dramatic loss of activity and/or stability. The homotetrameric SuSy from Nitrosomonas europaea (SuSyNe) was immobilized on a glyoxyl agarose support through two different orientations. The first occurred at pH 8.5 through the surface area containing the greatest number of amino termini from several enzyme subunits. The second orientation occurred at pH 10 through the region of ...
Source: Enzyme and Microbial Technology - June 16, 2017 Category: Biotechnology Source Type: research

Improvement of activity and stability of Chondroitinase ABC I by introducing an aromatic cluster at the surface of protein
In conclusion, the data revealed that structural features and activity of ChABC I can be improved by introducing appropriate aromatic clusters at the surface of the enzyme. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - June 16, 2017 Category: Biotechnology Source Type: research

Preparation and characterization of carbonic anhydrase-conjugated liposomes for catalytic synthesis of calcium carbonate particles
Publication date: October 2017 Source:Enzyme and Microbial Technology, Volume 105 Author(s): Keisuke Maeshima, Makoto Yoshimoto The biomimetic approach using immobilized enzymes is useful for the synthesis of structurally defined inorganic materials. In this work, carbonic anhydrase (CA) from bovine erythrocytes was covalently conjugated at 25°C to the liposomes composed of 15mol% 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine-N-(glutaryl) (NG-POPE), and the zwitterionic and anionic phospholipids with the same acyl chains as NG-POPE. For the conjugation, the carboxyl groups of liposomal NG-POPE were activated w...
Source: Enzyme and Microbial Technology - June 15, 2017 Category: Biotechnology Source Type: research

A quenched-flow system for measuring heterogeneous enzyme kinetics with sub-second time resolution
Publication date: Available online 13 June 2017 Source:Enzyme and Microbial Technology Author(s): Johan P. Olsen, Jeppe Kari, Kim Borch, Peter Westh Even though many enzyme processes occur at the interface of an insoluble substrate, these reactions are generally much less studied than homogenous enzyme reactions in the aqueous bulk. Interfacial (or heterogeneous) enzyme reactions involve several reaction steps, and the established experimental approach to elucidate multi-step reactions is transient (or pre steady-state) kinetics. A key requirement for pre steady-state measurements is good time resolution, and while this h...
Source: Enzyme and Microbial Technology - June 13, 2017 Category: Biotechnology Source Type: research

Preparation of glutaraldehyde-treated lipase-inorganic hybrid nanoflowers and their catalytic performance as immobilized enzymes
Publication date: Available online 13 June 2017 Source:Enzyme and Microbial Technology Author(s): Hye Rin Lee, Minsoo Chung, Moon Il Kim, Sung Ho Ha The use of protein-inorganic hybrid nanoflowers for the immobilization of enzymes has received a significant degree of attention owing to their capability to retain high enzymatic activity and stability. However, the relative lack of reusability due to the weakness of the flower-like structure has limited their practical applications. Herein, we have developed a simple but efficient method to synthesize highly robust enzyme-inorganic hybrid nanoflowers, which relies on furthe...
Source: Enzyme and Microbial Technology - June 13, 2017 Category: Biotechnology Source Type: research

Hydration-aggregation pretreatment for drastically improving esterification activity of commercial lipases in non-aqueous media
Publication date: Available online 12 June 2017 Source:Enzyme and Microbial Technology Author(s): Maho Katayama, Takashi Kuroiwa, Kenya Suzuno, Ayumi Igusa, Toru Matsui, Akihiko Kanazawa We investigated a novel, simple method for activating lipases in non-aqueous reaction media. Lipase powders were suspended in n-fatty alcohols and were then hydrated by adding a small amount of water. A paste-like aggregate was recovered from the mixture followed by lyophilization for obtaining activated lipases as dry powders. Lipase activity was evaluated for esterification between myristic acid and methanol in n-hexane. The activated l...
Source: Enzyme and Microbial Technology - June 12, 2017 Category: Biotechnology Source Type: research

Interaction of “Candidatus Accumulibacter” and Nitrifying Bacteria to Achieve Energy-efficient Denitrifying Phosphorus Removal via Nitrite Pathway from Sewage
Publication date: Available online 10 June 2017 Source:Enzyme and Microbial Technology Author(s): Wei Zeng, Xinlong Bai, Yu Guo, Ning Li, Yongzhen Peng To achieve energy-efficient denitrifying phosphorus removal via nitrite pathway from sewage, interaction of “Candidatus Accumulibacter” and nitrifying bacteria was investigated in a continuous-flow process. When nitrite in returned sludge of secondary settler was above 13mg/L, nitrite inhibition on anaerobic P-release of poly-phosphate organisms (PAOs) occurred. Clades IIC and IID were dominant, reaching 3.1%-11.9% of total bacteria. Clade IIC was sensitive to ...
Source: Enzyme and Microbial Technology - June 10, 2017 Category: Biotechnology Source Type: research

A highly sensitive carbapenemase assay using laser desorption/ionization mass spectrometry based on a parylene-matrix chip
Publication date: Available online 7 June 2017 Source:Enzyme and Microbial Technology Author(s): Jong-Min Park, Jo-Il Kim, Joo-Yoon Noh, Mira Kim, Min-Jung Kang, Jae-Chul Pyun A quantitative carbapenemase assay was developed using laser desorption/ionization mass spectrometry (LDI-MS) based on a parylene-matrix chip. As a first step, the reproducibility (spot-to-spot, shot-to-shot, and day-to-day) of LDI-MS based on a parylene-matrix chip and the quantification ranges for four carbapenem antibiotics (doripenem, ertapenem, imipenem, and meropenem) were determined. A carbapenem-susceptibility test was performed using the fo...
Source: Enzyme and Microbial Technology - June 7, 2017 Category: Biotechnology Source Type: research

Species specific substrates and products choices of 4-O-acetyltransferase from Trichoderma brevicompactum
Publication date: Available online 3 June 2017 Source:Enzyme and Microbial Technology Author(s): Shikha Sharma, Indu Kumari, Razak Hussain, Mushtaq Ahmed, Yusuf Akhter The antagonistic species of Trichoderma such as T.harzianum, T.viride, T.virens and T.koningii are well-known biocontrol agents that have been reported to suppress pathogenic soil microbes and enhance the growth of crop plants. Secondary metabolites (SMs) including trichothecenes are responsible for its biocontrol activities. The trichothecenes, trichodermin and harzianum A (HA) are produced in species dependent manner respectively, by Trichoderma brevicomp...
Source: Enzyme and Microbial Technology - June 4, 2017 Category: Biotechnology Source Type: research

FT-Raman spectroscopic analysis of enhanced activity of supercritical carbon dioxide treated bacterial alpha-amylase
Publication date: Available online 4 June 2017 Source:Enzyme and Microbial Technology Author(s): Kaninika Paul, Sayantani Dutta, Paramita Bhattacharjee Our previous investigation on high pressure supercritical carbon dioxide treatment of a bacterial α-amylase had revealed enhanced activity of the same. 1H NMR analysis of the activity enhanced enzyme led the authors to hypothesize that the enhancement was possibly owing to alterations at the active site of the enzyme. In the present study, the changes in the active site of the treated enzyme was analysed by Fourier-transform Raman (FT-Raman) spectroscopy. The spectra...
Source: Enzyme and Microbial Technology - June 4, 2017 Category: Biotechnology Source Type: research

Proline Dehydrogenase-entrapped mesoporous magnetic silica nanomaterial for electrochemical biosensing of L-proline in biological fluids
Publication date: Available online 4 June 2017 Source:Enzyme and Microbial Technology Author(s): Mohammad Hasanzadeh, Soodabeh Hassanpour, Arezoo Saadati Nahr, Nasrin Shadjou, Ahad Mokhtarzadeh, Jalal Mohammadi In this work, physical adsorption was used for immobilization of proline dehydrogenase onto a magnetic mesoporous silica nanomaterial. The immobilization and electrocatalytical activity of proline dehydrogenase entrapped in a magnetic mesoporous silica nanomaterial was studied using cyclic voltammetry, differential pulse voltammetry, and square wave voltammetry. The magnetic mesoporous silica networks having a high...
Source: Enzyme and Microbial Technology - June 4, 2017 Category: Biotechnology Source Type: research

Characterization of Ruminiclostridium josui arabinoxylan arabinofuranohydrolase, RjAxh43B, and RjAxh43B-containing xylanolytic complex
Publication date: Available online 4 June 2017 Source:Enzyme and Microbial Technology Author(s): Taku Orita, Makiko Sakka, Tetsuya Kimura, Kazuo Sakka A novel gene (axh43B) from Ruminiclostridium josui encoding a cellulosomal enzyme consisting of a catalytic module of subfamily GH43_10, a family-6 carbohydrate-binding module, and a dockerin module, was expressed using Escherichia coli. RjAxh43B released only arabinose from arabinoxylan and 23,33-di-α-L-arabinofuranosyl xylotriose, but not 32-α-L-arabinofuranosyl xylobiose or 23-α-L-arabinofuranosyl xylotriose, strongly suggesting that RjAxh43B is an arab...
Source: Enzyme and Microbial Technology - June 4, 2017 Category: Biotechnology Source Type: research

Kinetic study on anaerobic oxidation of methane coupled to denitrification
Publication date: Available online 4 June 2017 Source:Enzyme and Microbial Technology Author(s): Hou Yu, Hiroyuki Kashima, John M. Regan, Abid Hussain, Elsayed Elbeshbishy, Hyung-Sool Lee Monod kinetic parameters provide information required for kinetic analysis of anaerobic oxidation of methane coupled to denitrification (AOM-D). This information is critical for engineering AOM-D processes in wastewater treatment facilities. We first experimentally determined Monod kinetic parameters for an AOM-D enriched culture and obtained the following values: maximum specific growth rate (μmax) 0.121/d, maximum substrate-utilizat...
Source: Enzyme and Microbial Technology - June 4, 2017 Category: Biotechnology Source Type: research

Enzymatic phosphorylation of Mannose by Glucomannokinase from Mycobacterium phlei using Inorganic Polyphosphate
This study has focused upon the direct synthesis of M6P by glucomannokinase using inorganic polyphosphate without involvement of ATP. The gene cloned for glucomannokinase has been sequenced from Mycobacterium phlei and it is transformed into Escherichia coli for expression. After purification involving affinity chromatography, a band of 30kDa corresponding to the enzyme has been isolated from induced crude supernatant. A total amount of 0.69mg/ml of enzyme has been successively obtained and the purity exceeds 90%. The kinetic assay studies show that this enzyme has more affinity towards polyphosphate and glucose than ATP a...
Source: Enzyme and Microbial Technology - May 29, 2017 Category: Biotechnology Source Type: research

Action of a GH115 α-glucuronidase from Amphibacillus xylanus at alkaline condition promotes release of 4-O-methylglucopyranosyluronic acid from glucuronoxylan and arabinoglucuronoxylan
Publication date: Available online 24 May 2017 Source:Enzyme and Microbial Technology Author(s): Ruoyu Yan, Thu V. Vuong, Weijun Wang, Emma R. Master Glucuronic acid and/or 4-O-methyl-glucuronic acid (GlcA/MeGlcA) are substituents of the main xylans present in hardwoods, conifers, and many cereal grains. α-Glucuronidases from glycoside hydrolase family GH115 can target GlcA/MeGlcA from both internally and terminally substituted regions of xylans. The current study describes the first GH115 α-glucuronidase, AxyAgu115A, from the alkaliphilic organism Amphilbacillus xylanus. AxyAgu115A was active in a wide pH ran...
Source: Enzyme and Microbial Technology - May 24, 2017 Category: Biotechnology Source Type: research

Synthesis of fibrous and non-fibrous mesoporous silica magnetic yolk –shell microspheres as recyclable supports for immobilization of Candida rugosa lipase
Publication date: August 2017 Source:Enzyme and Microbial Technology, Volume 103 Author(s): Zafar Ali, Lei Tian, Baoliang Zhang, Nisar Ali, Muhammad Khan, Qiuyu Zhang The mesoporous yolk–shell nanoparticles (MYSNs), with a movable Fe3O4 core inside the hollow capsules, with two different morphologies (1) Fe3O4@SiO2@hollow@fibrous SiO2 (Yolk Shell-1) (2) Fe3O4@SiO2@hollow@mesoporousSiO2 (Yolk Shell-2) were fabricated as carriers for Candida rugosa lipase (CRL) immobilization, through a template-assistant selectively etching method. Firstly the hydrophilic Fe3O4 nanoparticles were synthesized according to the solvothe...
Source: Enzyme and Microbial Technology - May 15, 2017 Category: Biotechnology Source Type: research

Biotransformation of Pyridoxal 5 ′-phosphate from Pyridoxal by Pyridoxal Kinase (pdxY) to Support Cadaverine Production in Escherichia coli
Publication date: Available online 13 May 2017 Source:Enzyme and Microbial Technology Author(s): Jung-Ho Kim, Junyoung Kim, Hyun-Joong Kim, Ganesan Sathiyanarayanan, Shashi Kant Bhatia, Hun-Suk Song, Yong-Guen Choi, Yun-Gon Kim, Kyungmoon Park, Yung-Hun Yang Cadaverine, a five-carbon diamine (1,5-diaminopentane), can be made by fermentation or direct bioconversion and plays an important role as a building block of polyamides. Lysine decarboxylase (CadA) transforms L-lysine to cadaverine and pyridoxal 5′-phosphate (PLP) can increases conversion rate and yield as a cofactor. Biotransformation of cadaverine using whole...
Source: Enzyme and Microbial Technology - May 13, 2017 Category: Biotechnology Source Type: research

Functionalization of pectin with laccase-mediated oxidation products of ferulic acid
Publication date: Available online 13 May 2017 Source:Enzyme and Microbial Technology Author(s): N. Karaki, A. Aljawish, L. Muniglia, S. Bouguet-Bonnet, S. Leclerc, C. Paris, J. Jasniewski, C. Humeau-Virot Pectin is a natural biopolymer extracted mostly from citrus peel, sugar beet and apple pomace. In order to improve its functional properties and then to enlarge the field of its potential applications, functionalization reaction of citrus pectin with ferulic acid (FA)-oxidation products was performed in aqueous medium, at 30°C and pH7.5, in the presence of Myceliophthora thermophila laccase as biocatalyst. The conju...
Source: Enzyme and Microbial Technology - May 13, 2017 Category: Biotechnology Source Type: research

Synthesis and characterization of novel astragalin galactosides using β-galactosidase from Bacillus circulans
In this study, novel astragalin galactosides (Ast-Gals) were synthesized using β-galactosidase from Bacillus circulans and reaction conditions were optimized to increase the conversion yield of astragallin. Purified Ast-Gal1 (11.6% of Ast used, w/w) and Ast-Gal2 (6.7% of Ast used, w/w) were obtained by medium pressure chromatography (MPLC) with silica C18 column and open column packed with Sephadex LH-20. The structures of Ast-Gal1 and Ast-Gal2 were identified by nuclear magnetic resonance (NMR) to be kaempferol-3-O-β-D-glucopyranosyl-(1→6)-β-D-galactopyranoside and kaempferol-3-O-β-D-glucopyranosy...
Source: Enzyme and Microbial Technology - May 12, 2017 Category: Biotechnology Source Type: research

Co-overexpression of Mgat1 and Mgat4 in CHO cells for production of highly sialylated albumin-erythropoietin
Publication date: Available online 6 May 2017 Source:Enzyme and Microbial Technology Author(s): Hyun-Myoung Cha, Jin-Hyuk Lim, Jung-Heum Yeon, Jeong-Min Hwang, Dong-Il Kim Terminal sialic acids on N-glycan of recombinant human erythropoietin are very important for in vivo half-life, as this glycoprotein has three N-glycosylation sites. N-acetylglucosaminyltransferases I, II, IV, and V (i.e. Mgat1, Mgat2, Mgat4, and Mgat5) catalyze the formation of a glycan antennary structure. These enzymes display different reaction kinetics for a common substrate and generally show low expression in Chinese hamster ovary (CHO) cells. Th...
Source: Enzyme and Microbial Technology - May 6, 2017 Category: Biotechnology Source Type: research

A novel α-galactosidase from Fusarium oxysporum and its application in determining the structure of the gum arabic side chain
In conclusion, rFoGP1 is highly active toward α-1,3-galactosyl linkages but negligibly or not active toward α-1,6-galactosyl linkages. The novel FoGP1 might be used to modify the physical properties of gum arabic, which is an industrially important polysaccharide used as an emulsion stabilizer and coating agent. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - April 29, 2017 Category: Biotechnology Source Type: research

Synthesis of Fibrous and non-fibrous mesoporous silica Magnetic yolk –shell microspheres as a recyclable supports for immobilization of Candida rugosa Lipase
Publication date: Available online 28 April 2017 Source:Enzyme and Microbial Technology Author(s): Zafar Ali, Lei Tian, Baoliang Zhang, Nisar Ali, Muhammad Khan, Qiuyu Zhang The mesoporous yolk-shell nanoparticles (MYSNs), with a movable Fe3O4 core inside the hollow capsules, with two different morphologies (1) Fe3O4@SiO2@hollow@fibrous SiO2 (Yolk Shell-1) (2) Fe3O4@SiO2@hollow@mesoporousSiO2 (Yolk Shell-2) were fabricated as carriers for Candida rugosa lipase (CRL) immobilization, through a template-assistant selectively etching method. Firstly the hydrophobic Fe3O4 nanoparticles were synthesized according to the solvoth...
Source: Enzyme and Microbial Technology - April 28, 2017 Category: Biotechnology Source Type: research

Effects of high hydrostatic pressure or hydrophobic modification on thermal stability of xanthine oxidase
Publication date: Available online 28 April 2017 Source:Enzyme and Microbial Technology Author(s): Ali Halalipour, Michael R. Duff, Elizabeth E. Howell, José I. Reyes-De-Corcuera The effect of high hydrostatic pressure (HHP) on the kinetics of thermal inactivation of xanthine oxidase (XOx) from bovine milk was studied. Inactivation of XOx followed pseudo-first-order kinetics at 0.1-300MPa and 55.0-70.0°C. High pressure up to at least 300MPa stabilized XOx at all the studied temperatures. The highest stabilization effect of HHP on XOx were at 200 to 300MPa at 55.0 and 58.6°C, and at 250 to 300MPa at 62.3 to ...
Source: Enzyme and Microbial Technology - April 28, 2017 Category: Biotechnology Source Type: research

Time dependence of enzyme synergism during the degradation of model and natural lignocellulosic substrates
Publication date: Available online 25 April 2017 Source:Enzyme and Microbial Technology Author(s): Samkelo Malgas, Mariska Thoresen, J. Susan van Dyk, Brett I. Pletschke Cellulosic ethanol production relies on the biochemical (enzymatic) conversion of lignocellulose to fermentable sugars and ultimately to bioethanol. However, the cost of lignocellulolytic enzymes is a limiting factor in the commercialisation of this technology. This therefore necessitates the optimisation of lignocellulolytic enzyme cocktails through the elucidation of synergistic interactions between enzymes so as to improve lignocellulose hydrolysis and...
Source: Enzyme and Microbial Technology - April 26, 2017 Category: Biotechnology Source Type: research

Overexpression of hlyB and mdh genes confers halotolerance in Fremyella diplosiphon, a freshwater cyanobacterium
Publication date: Available online 24 April 2017 Source:Enzyme and Microbial Technology Author(s): Behnam Tabatabai, AnithaChristy S. Arumanayagam, Oluwatomisin Enitan, Arunmani Mani, Savithiry S. Natarajan, Viji Sitther Fremyella diplosiphon is a freshwater cyanobacterium that has great potential as a biofuel agent due to its ability to grow in low light intensity and acclimation to different wavelengths. To enhance its halotolerance for growth in 35gL−1 sodium chloride (NaCl), plasmids harboring hemolysin B (hlyB) and malate dehydrogenase (mdh) genes were transformed into wild type F. diplosiphon (WT-Fd33). Electr...
Source: Enzyme and Microbial Technology - April 24, 2017 Category: Biotechnology Source Type: research

High-Level Expression of a bacterial laccase, CueO from Escherichia coli K12 in Pichia pastoris GS115 and its Application on the decolorization of synthetic dyes
This report was aimed to the high-level expression of a laccase, CueO from Escherichia coli K12 in Pichia pastoris GS115 and its application in decolorization of synthetic dyes. The yacK gene coding CueO was cloned into an expression vector of Pichia pastoris, pHBM905BDM and expressed in a secretory form with Pichia pastoris GS115 as the host. The yield of the recombinant protein was 556mg/L with high-density fermentation and the enzyme activity was about 41,000U/L. The recombinant laccase was purified and characterized. Its optimum pH and temperature was 3.0 and 55°C with 2, 2′-azino-bis-(3-ethylbenzothazoline-6...
Source: Enzyme and Microbial Technology - April 21, 2017 Category: Biotechnology Source Type: research

Construction of ferrocene modified conducting polymer based amperometric urea biosensor
Publication date: Available online 7 April 2017 Source:Enzyme and Microbial Technology Author(s): Muamer Dervisevic, Esma Dervisevic, Mehmet Şenel, Emre Çevik, Huseyin Bekir Yildiz, Pınar Çamurlu Herein, an electrochemical urea sensing bio-electrode is reported that has been constructed by firstly electropolymerizing 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline monomer (SNS-Aniline) on Pencil Graphite Electrode (PGE), then modifying the polymer coated electrode surface with di-amino-Ferrocene (DAFc) as the mediator, and lastly Urease enzyme through glutaraldehyde crosslinking. The effect of pH, temperat...
Source: Enzyme and Microbial Technology - April 10, 2017 Category: Biotechnology Source Type: research

Self assembled snowball-like hybrid nanostructures comprising Viburnum opulus L. extract and metal ions for antimicrobial and catalytic applications
Publication date: Available online 8 April 2017 Source:Enzyme and Microbial Technology Author(s): Nilay Ildiz, Ayse Baldemir, Cevahir Altinkaynak, Nalan Özdemir, Vedat Yilmaz, Ismail Ocsoy Herein, we report the production of novel organic-inorganic nanobio-catalytic and antimicrobial agents called “nanosnowball” (NSBs) with a rational design and elucidate the increase in the catalytic and antimicrobial activities. The NSBs resemble to guelder rose were formed of the extract of Viburnum opulus (VO) as the organic component and copper (II) ions (Cu2+) as the inorganic component. The effects of the VO extrac...
Source: Enzyme and Microbial Technology - April 10, 2017 Category: Biotechnology Source Type: research

Construction, expression and characterization of a fusion protein HBscFv-IFN γ in Komagatella (Pichia) pastoris X33
Publication date: Available online 4 April 2017 Source:Enzyme and Microbial Technology Author(s): Ming-Hua Liang, Shi-Shui Zhou, Jian-Guo Jiang HBscFv-IFNγ, a fusion protein constructed by fusing γ-interferon (IFNγ) with an antibody fragment HBscFv for the purpose of targeted delivery of the cytokine IFNγ, was designed in order to enhance its therapeutic efficacy through increasing its hepatoma localization. HBscFv and IFNγ were connected into HBscFv-IFNγ by the linker (Gly4Ser)3, and then the multicopy recombinant plasmids pPICZαA/(HBscFv-IFNγ)1,2,4 were constructed and tra...
Source: Enzyme and Microbial Technology - April 4, 2017 Category: Biotechnology Source Type: research

Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp
Publication date: Available online 2 April 2017 Source:Enzyme and Microbial Technology Author(s): Christian Hutterer, Gerhard Kliba, Manuel Punz, Karin Fackler, Antje Potthast The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further puri...
Source: Enzyme and Microbial Technology - April 2, 2017 Category: Biotechnology Source Type: research

Removal of organic carbon and nitrogen in a membraneless flow-through microbial electrolysis cell
This study evaluated performance of an upflow membraneless microbial electrolysis cell (MEC) with flow-through electrodes for wastewater treatment. First, methane production and COD removal were evaluated in continuous flow experiments carried out using synthetic and municipal wastewater. A 29–75% increase in methane production was observed under bioelectrochemical conditions as compared to an anaerobic control. Next, simultaneous removal of COD and nitrogen was studied under microaerobic conditions created by continuous air injection to the anodic compartment of the MEC. While the presence of oxygen decreased Coulom...
Source: Enzyme and Microbial Technology - April 1, 2017 Category: Biotechnology Source Type: research

Biosynthesis of the fatty acid isopropyl esters by engineered Escherichia coli
Publication date: Available online 28 March 2017 Source:Enzyme and Microbial Technology Author(s): Hong Pan, Lihua Zhang, Xun Li, Daoyi Guo The fatty acid methyl esters and fatty acid ethyl esters are known as biodiesels which are considered to be renewable, nontoxic and biodegradable biofuels. However, the conventional biodiesels show a high crystallization temperature which is one of the most critical obstacles against the widespread biodiesel usage. The high crystallization temperature of biodiesel can be reduced by replacing the methyl or ethyl ester with an isopropyl moiety. Here we report on a strategy to establish ...
Source: Enzyme and Microbial Technology - March 28, 2017 Category: Biotechnology Source Type: research

Functional analysis of truncated and site-directed mutagenesis dextransucrases to produce different type dextrans
This study generated a series of C-terminally truncated variants of dextransucrase and substituting the amino-acid residues in the active site of DSR. With shorter length of DSR, its polysaccharide-synthesizing capability was impaired heavily, whereas oligosaccharide (acting as prebiotics)-synthesizing capability increased significantly, efficiently producing special sizes of dextran. All truncated mutant enzymes were active. Results demonstrated that the catalytic domain dextransucrase was likely in 800 aa or less. Based on the three-dimensional structure model of dextransucrase built through homology modeling methods, th...
Source: Enzyme and Microbial Technology - March 25, 2017 Category: Biotechnology Source Type: research

Establishment and application of a modified membrane-blot assay for Rhizomucor miehei lipases aimed at improving their methanol tolerance and thermostability
In this study, we aimed to establish a membrane-blot assay for use in the high-throughput screening of Rhizomucor miehei lipases (RMLs). With the assistance of the membrane-blot screening assay, a mutant E47K named G10 that showed improved thermal stability was detected in the first round of error-prone PCR. Using G10 as the parent, two variants G10-11 and G10-20 that showed improved thermal stability and methanol tolerance without loss of activity compared to the wild type RML were obtained. The T50 60-value of G10-11 and G10-20 increased by 12°C and 6.5°C, respectively. After incubation for 1h, the remaining resi...
Source: Enzyme and Microbial Technology - March 25, 2017 Category: Biotechnology Source Type: research

Unraveling microbial structure and diversity of activated sludge in a full-scale simultaneous nitrogen and phosphorus removal plant using metagenomic sequencing
This study provides a comprehensive insight into the community structure and diversity of the SNPR system, and will provide foundation for optimal operation of nutrient removal systems. Graphical abstract (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - March 23, 2017 Category: Biotechnology Source Type: research

Effects of butanol on high value product production in Schizochytrium limacinum B4D1
This study showed that butanol addition had multiple effects on Schizochytrium limacinum B4D1. First, butanol addition altered the lipid content of cells. Second, 6g/L of butanol decreased the proportion of DHA by nearly 40%. Third, the squalene content increased 31-fold in the presence of 6g/L butanol. Finally, cells accumulated more carotenoids upon butanol addition. Specifically, when cells were treated with 8g/L butanol, the astaxanthin content increased to 245 times than that of the untreated control. These results are helpful for the commercial exploitation of Schizochytrium in producing squalene and carotenoids. (So...
Source: Enzyme and Microbial Technology - March 20, 2017 Category: Biotechnology Source Type: research

Enzymatic synthesis of isomaltotriose palmitate and evaluation of its emulsifying property
Publication date: Available online 18 March 2017 Source:Enzyme and Microbial Technology Author(s): Kuan-Ju Liu Enzymatic syntheses of oligosaccharide fatty acid esters are important owing to their wide range of industrial applications in the food, cosmetic, and pharmaceutical industries. Transesterification of isomaltotriose and palmitic acid vinyl ester, catalyzed by the metalloprotease thermolysin, was performed in organic solvents. The process parameters (reaction time and temperature) were optimized to achieve the highest yield of isomaltotriose palmitate (IP). The water content of the reaction system played a key rol...
Source: Enzyme and Microbial Technology - March 20, 2017 Category: Biotechnology Source Type: research

Metabolic engineering of Saccharomyces cerevisiae for production of spermidine under optimal culture conditions
Publication date: Available online 19 March 2017 Source:Enzyme and Microbial Technology Author(s): Sun-Ki Kim, Jung-Hyun Jo, Yong-Cheol Park, Yong-Su Jin, Jin-Ho Seo Spermidine is a polyamine compound exhibiting important biological activities, such as increasing lifespan, inflammation reduction, and plant growth control. As such, many applications of spermidine as a bio-modulating agent are anticipated. However, sustainable and scalable production of spermidine has not been achieved yet. Therefore, construction of a spermidine production system using Saccharomyces cerevisiae was attempted in this study. In order to secre...
Source: Enzyme and Microbial Technology - March 20, 2017 Category: Biotechnology Source Type: research

A Zymogram technique for preliminary screening and characterization of feruloyl esterases
We report here, for the first time, a zymogram technique designed for rapid screening of feruloyl esterase using ethyl ferulate as enzyme substrate and casein precipitation as enzyme activity indicator. Graphical abstract (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - March 17, 2017 Category: Biotechnology Source Type: research

Synergic Regulation of Redox Potential and Oxygen Uptake to Enhance Production of Coenzyme Q10 in Rhodobacter sphaeroides
Publication date: Available online 15 March 2017 Source:Enzyme and Microbial Technology Author(s): Yongqiang Zhu, Lidan Ye, Zhaofeng Chen, Weijiang Hu, Yanghui Shi, Jianbo Chen, Chenfei Wang, Yong Li, Weifeng Li, Hongwei Yu The physiological role of Coenzyme Q10 (CoQ10) as an electron carrier suggests its association with redox potential. Overexpression of glyceraldehyde-3-phosphate dehydrogenase type I (gapA-1) in Rhodobacter sphaeroides elevated the NADH/NAD+ ratio and meanwhile enhanced the CoQ10 content by 58%, but at the sacrifice of biomass. On the other hand, Vitreoscilla hemoglobin was heterologously expressed to ...
Source: Enzyme and Microbial Technology - March 16, 2017 Category: Biotechnology Source Type: research

Production of L-lactic acid from metabolically engineered strain of Enterobacter aerogenes ATCC 29007
In this study, L-lactic acid production was investigated from metabolically engineered strain of E. aerogenes ATCC 29007. The engineered strain E. aerogenes SUMI01 (Δpta) was generated by the deletion of phosphate acetyltransferase (pta) gene from the chromosome of E. aerogenes ATCC 29007 and deletion was confirmed by colony PCR. Under the optimized fermentation conditions, at 37°C and pH 6 for 84h, the L-lactic acid produced by engineered strain E. aerogenes SUMI01 (Δpta) in flask fermentation using 100g/L mannitol as the carbon source was 40.05g/L as compared to that of the wild type counterpart 20.70g/L....
Source: Enzyme and Microbial Technology - March 14, 2017 Category: Biotechnology Source Type: research

A study of CO/syngas bioconversion by Clostridium autoethanogenum with a flexible gas-cultivation system
Publication date: Available online 12 March 2017 Source:Enzyme and Microbial Technology Author(s): Huijuan Xu, Cuiyi Liang, Zhenhong Yuan, Jingliang Xu, Qiang Hua, Ying Guo Bioconversion of CO/syngas to produce ethanol is a novel route in bioethanol production, which can be accomplished by some acetogens. Specific culture vessels and techniques are needed to cultivate these microorganisms since they are anaerobic and substrates are gaseous. In this work, gas-sampling bag was applied as a gas-cultivation system to study CO/syngas bioconversion by Clostridium autoethanogenum and was demonstrated to be efficient because of i...
Source: Enzyme and Microbial Technology - March 12, 2017 Category: Biotechnology Source Type: research

Evaluation of the effects of isolated lignin on enzymatic hydrolysis of cellulose
In this study, the influence of lignin on enzymatic digestibility of cellulose was assessed. Addition of 20% (4g/L) isolated enzymatic lignin (lignin 2 and 3) and kraft lignin (lignin 4) resulted in 5-20% drop of glucose yield, depending on lignin sources. The inhibitory effect of lignin was abated as the enzyme loading increased from 10 to 20FPU/g dry substrate. However, the increasing lignin amount to 40% (8g/L) did not appear to further decrease the cellulose hydrolysis efficiency. Ethanol lignin (lignin 1) and calcium lignosulfonate (lignin 5) had no negative effect on the enzymatic hydrolysis of cellulose at cellulase...
Source: Enzyme and Microbial Technology - March 12, 2017 Category: Biotechnology Source Type: research

Characterization and Thermal Inactivation Kinetics of Highly Thermostable Ramie Leaf β-amylase
Publication date: Available online 7 March 2017 Source:Enzyme and Microbial Technology Author(s): Liqin He, Sung-Hoon Park, Nguyen Dang Hai Dang, Hoa Xo Duong, Thi Phung Cac Duong, Phuong Lan Tran, Jong-Tae Park, Li Ni, Kwan-Hwa Park We characterized ramie leaf β-amylase, and determined its thermostability and kinetic parameters. The enzyme was purified 53-fold using ammonium sulfate fractionation (40-60% saturation), anion exchange chromatography on DEAE-cellulose and gel permeation chromatography on Superdex-200. The purified enzyme was identified as β-amylase with molecular mass of 42kD. The enzyme displayed ...
Source: Enzyme and Microbial Technology - March 8, 2017 Category: Biotechnology Source Type: research

Regulation of the catalytic behavior of pullulanases chelated onto nickel (II)-modified magnetic nanoparticles
Publication date: Available online 22 February 2017 Source:Enzyme and Microbial Technology Author(s): Jianfeng Wang, Zhongmei Liu, Zhemin Zhou Chelating of pullulanases onto nickel (II)-modified magnetic nanoparticles results in one-step purification and immobilization of pullulanase, and facilitates the commercial application of pullulanase in industrial scale. To improve the catalytic behavior, especially the operational stability, of the nanocatalyst in consecutive batch reactions, we prepared various iminodiacetic acid-modified magnetic nanoparticles differed in surface polarity and spacer length, on which the His6-ta...
Source: Enzyme and Microbial Technology - February 23, 2017 Category: Biotechnology Source Type: research

Dynamic surface tension measurement for the screening of biosurfactants produced by Lactobacillus plantarum
In this study, screening of BSs produced by Lactobacillus plantarum subsp. plantarum PTCC 1896 (probiotic) was performed based on their DST values measured by Wilhelmy plate tensiometry. The relationship between DST and structural and functional properties (anti-adhesive activity) of the BSs was investigated. The results showed that the changes in the yield, productivity and structure of the BSs were growth medium and incubation time dependent (p<0.05). Structurally different BSs produced exhibited identical equilibrium surface tension values. However, differences among the structure/yield of the BSs were observed t...
Source: Enzyme and Microbial Technology - February 22, 2017 Category: Biotechnology Source Type: research

Chitosan-based biocatalytic nanoparticles for pollutant removal from wastewater
Publication date: Available online 20 February 2017 Source:Enzyme and Microbial Technology Author(s): Dulce A. Alarcón-Payán, Rina D. Koyani, Rafael Vazquez-Duhalt Chitosan, a renewable biopolymer has the prospective applications in different fields due to its gelation capacity. Nanoconfiguration of chitosan through ionotropic gelation to encapsulate enzymatic activity offers numerous potential applications. The present study, the preparation and characterization of chitosan nanoparticles loaded with versatile peroxidase are reported. Their performance in bioremediation process and the resistance enhancement...
Source: Enzyme and Microbial Technology - February 21, 2017 Category: Biotechnology Source Type: research

Physico-Cultural Parameters during AgNPs Biotransformation with Bactericidal Activity against Human Pathogens
Publication date: Available online 15 February 2017 Source:Enzyme and Microbial Technology Author(s): Gurusamy Raman, Seon Joo Park, Natarajan Sakthivel, Anil K. Suresh Production of AgNPs with desired morphologies and surface characteristics using facile, economic and non-laborious processes is highly imperative. Cell extract based syntheses are emerging as a novel technique for the production of diverse forms of NPs, and is assured to meet the requirements. Therefore, in order to have a better understanding, and to improvise and gain control over the NPs morphological and surface characteristics, the present investigati...
Source: Enzyme and Microbial Technology - February 16, 2017 Category: Biotechnology Source Type: research