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Enzyme and Microbial Technology

Jung-Ho Kim, Junyoung Kim, Hyun-Joong Kim, Ganesan Sathiyanarayanan, Shashi Kant Bhatia, Hun-Suk Song, Yong-Keun 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 Escherichia coli cells that overexpress the lysine decarboxylase has many merits, such as the rapid conversion of l-lysine to cadaverine, possible application of high concentration reactions up to the molar level, production of less byproduct and potential reuse of the enzyme by immobilization...
September 2017: Enzyme and Microbial Technology
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 four carbapenems and 51 bacterial strains that displayed (1) carbapenem resistance with carbapenemase, (2) carbapenem resistance without carbapenemase, or (3) carbapenem susceptibility...
September 2017: Enzyme and Microbial Technology
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-utilization rate (qmax) 28.8mmol CH4/g cells-d, half maximum-rate substrate concentration (Ks) 83μΜ CH4, growth yield (Y) 4...
September 2017: Enzyme and Microbial Technology
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. (1)H NMR analysis of the activity enhanced enzyme led the authors to hypothesize that the enhancement was possibly owing to alterations in 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 obtained revealed shifting of bands in the active site of α-amylase indicating a nudging effect of the bonds in this region consequent to high pressure treatment...
September 2017: Enzyme and Microbial Technology
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 2(3),3(3)-di-α-l-arabinofuranosyl xylotriose, but not 3(2)-α-l-arabinofuranosyl xylobiose or 2(3)-α-l-arabinofuranosyl xylotriose, strongly suggesting that RjAxh43B is an arabinoxylan α-l-1,3-arabinofuranohydrolase capable of cleaving α-1,3-linked arabinose residues of doubly arabinosylated xylan...
September 2017: Enzyme and Microbial Technology
Shikha Sharma, Indu Kumari, Razak Hussain, Mushtaq Ahmed, Yusuf Akhter
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 brevicompactum (TB) and Trichoderma arundinaceum (TA). The last step in the pathway involves the conversion of trichodermol into trichodermin or HA alternatively, which is catalyzed by 4-O-acetyltransferase (encoded by tri3 gene)...
September 2017: Enzyme and Microbial Technology
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 range, and demonstrated better performance in alkaline condition compared to other characterized GH115 α-glucuronidases, which generally show optimal activity in acidic conditions...
September 2017: Enzyme and Microbial Technology
Shafaq Parveen, Biqiang Chen, Luo Liu, Tianwei Tan
Mannose-6-phosphate is an important phosphor-sugar, which is involved in many physiological functions and it is used to treat many diseases. Its production is however expensive since it requires costly substrate ATP as phosphorylation agent. 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...
September 2017: Enzyme and Microbial Technology
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 conjugation between FA-oxidation products and pectin was confirmed using FTIR, UV-Vis and LC-MS analyses...
September 2017: Enzyme and Microbial Technology
Songhee Han, Thi Thanh Hanh Nguyen, Jaewon Hur, Nahyun M Kim, Seong-Bo Kim, Kyeong-Hwan Hwang, Young-Hwan Moon, Choongil Kang, Byoungsang Chung, Young-Min Kim, Tae Sung Kim, Jun-Seong Park, Doman Kim
Astragalin (kaempferol-3-O-β-d-glucopyranoside, Ast) is a kind of flavonoid known to have anti-oxidant, anti-HIV, anti-allergic, and anti-inflammatory effects. It has low solubility in water. 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...
August 2017: Enzyme and Microbial Technology
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. Therefore, genetic control of Mgat expression is an effective method to increase sialic acid contents by enhancing glycan antennarity...
August 2017: Enzyme and Microbial Technology
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 solvothermal method. Then, SiO2 shell was coated on the Fe3O4 nanoparticle surface by a sol-gel reaction...
August 2017: Enzyme and Microbial Technology
Xiaojian Ma, Lu Liu, Qingqing Li, Yunyun Liu, Li Yi, Lixin Ma, Chao Zhai
Laccases are oxidoreductase catalyze the oxidation of a wide range of substrates with oxygen as the electron acceptor. This report was aimed to the high-level expression of a laccase, CueO from Escherichia coli K12 in Pichia pastoris GS115 and its application on 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...
August 2017: Enzyme and Microbial Technology
Akiho Maruta, Mirei Yamane, Midori Matsubara, Shiho Suzuki, Masami Nakazawa, Mitsuhiro Ueda, Tatsuji Sakamoto
We previously reported that Fusarium oxysporum 12S produces two bifunctional proteins, FoAP1 and FoAP2, with α-d-galactopyranosidase (GPase) and β-l-arabinopyranosidase (APase) activities. The aim of this paper was to purify a third GPase, FoGP1, from culture supernatant of F. oxysporum 12S, to characterize it, and to determine its mode of action towards gum arabic. A cDNA encoding FoGP1 was cloned and the protein was overexpressed in Escherichia coli. Module sequence analysis revealed the presence of a GH27 domain in FoGP1...
August 2017: Enzyme and Microbial Technology
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 was at 200-300MPa at 55.0 and 58.6°C, and at 250-300MPa at 62.3-70.0°C. The stability of XOx increased 9.5 times at 300MPa and 70.0°C compared to atmospheric pressure at the same temperature...
August 2017: Enzyme and Microbial Technology
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). Electroporation-mediated overexpression of the genes resulted in two transformants, HSF33-1 and HSF33-2, with 9- and 20-fold increases in hlyB and mdh transcript levels...
August 2017: Enzyme and Microbial Technology
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 also lower protein loadings in these reactions. However, many factors affect the synergism that occurs between these lignocellulolytic enzymes, such as enzyme ratios, substrate characteristics, substrate loadings, enzyme loadings and time...
August 2017: Enzyme and Microbial Technology
Ke Zhang, Limei Chen, Jianmin Liu, Feng Gao, Ronglin He, Wuxi Chen, Wei Guo, Shulin Chen, Demao Li
Schizochytrium is a microalgae-like fungus and is widely used for producing docosahexaenoic acid (DHA). It is also a promising source of squalene and carotenoids. However, few fermentation strategies are available in enhancing squalene and carotenoid content in Schizochytrium. 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...
July 2017: Enzyme and Microbial Technology
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 transformed into Komagatella (Pichia) pastoris X33. The engineering strain X4, which had much higher copy number and could secretively express HBscFv-IFNγ, was screened from transformed X33 by qPCR...
July 2017: Enzyme and Microbial Technology
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 purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase...
July 2017: Enzyme and Microbial Technology
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