journal
MENU ▼
Read by QxMD icon Read
search

Enzyme and Microbial Technology

journal
https://www.readbyqxmd.com/read/28433193/regulation-of-the-catalytic-behavior-of-pullulanases-chelated-onto-nickel-ii-modified-magnetic-nanoparticles
#1
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-tagged pullulanases were chelated via nickel ions, and then studied the correlation between the MNPs surface property and the corresponding catalyst behavior...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433192/a-zymogram-technique-for-preliminary-screening-and-characterization-of-feruloyl-esterases
#2
Sakthi Kumaran Palaniswamy, Vijayalakshmi Govindaswamy
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.
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433191/enzymatic-synthesis-of-isomaltotriose-palmitate-and-evaluation-of-its-emulsifying-property
#3
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 role in the acylation of isomaltotriose...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433190/evaluation-of-the-effects-of-isolated-lignin-on-enzymatic-hydrolysis-of-cellulose
#4
Hongdan Zhang, Shubin Wu, Jun Xie
The different physical and chemical properties of lignin might have various effects on the enzymatic hydrolysis of lignocellulosic substrates. 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...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433189/synergic-regulation-of-redox-potential-and-oxygen-uptake-to-enhance-production-of-coenzyme-q10-in-rhodobacter-sphaeroides
#5
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 enhance the oxygen uptake ability of the cells, leading to 127% improvement of biomass. Subsequent coexpression of gapA-1 and vgb resulted in a CoQ10 titer of 83...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433188/metabolic-engineering-of-saccharomyces-cerevisiae-for-production-of-spermidine-under-optimal-culture-conditions
#6
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 secrete spermidine into fermentation broth, TPO1 coding for the polyamine transporter was overexpressed in an engineered S...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433187/a-study-of-co-syngas-bioconversion-by-clostridium-autoethanogenum-with-a-flexible-gas-cultivation-system
#7
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 its flexibility and excellent ability to maintain the headspace atmosphere...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433186/characterization-and-thermal-inactivation-kinetics-of-highly-thermostable-ramie-leaf-%C3%AE-amylase
#8
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 Km and kcat values for soluble potato starch of 1.1mg/mL and 7.8s(-1), respectively. The enzyme had a temperature optimum of 65°C, and its activity at 70°C was 92% of that at the optimal temperature after a 15-min incubation...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28433185/dynamic-surface-tension-measurement-for-the-screening-of-biosurfactants-produced-by-lactobacillus-plantarum-subsp-plantarum-ptcc-1896
#9
Nafiseh Bakhshi, Sabihe Soleimanian-Zad, Mahmoud Sheikh-Zeinoddin
Currently, screening of microbial biosurfactants (BSs) is based on their equilibrium surface tension values obtained using static surface tension measurement. However, a good surfactant should not only have a low equilibrium surface tension, but its dynamic surface tension (DST) should also decrease rapidly with time. 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...
June 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284314/chitosan-based-biocatalytic-nanoparticles-for-pollutant-removal-from-wastewater
#10
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. In 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 against natural microbial biodegradation were studied. The average diameter of enzymatic nanoparticles was 120nm and showed a high enzyme loading capacity...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284313/one-step-combined-focused-eppcr-and-saturation-mutagenesis-for-thermostability-evolution-of-a-new-cold-active-xylanase
#11
Juan Pablo Acevedo, Manfred T Reetz, Juan A Asenjo, Loreto P Parra
Enzymes active at low temperature are of great interest for industrial bioprocesses due to their high efficiency at a low energy cost. One of the particularities of naturally evolved cold-active enzymes is their increased enzymatic activity at low temperature, however the low thermostability presented in this type of enzymes is still a major drawback for their application in biocatalysis. Directed evolution of cold-adapted enzymes to a more thermostable version, appears as an attractive strategy to fulfill the stability and activity requirements for the industry...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284312/combined-cross-linked-enzyme-aggregates-of-horseradish-peroxidase-and-glucose-oxidase-for-catalyzing-cascade-chemical-reactions
#12
Le Truc Nguyen, Kun-Lin Yang
Cascade reactions involved unstable intermediates are often encountered in biological systems. In this study, we developed combined cross-linked enzyme aggregates (combi-CLEA) to catalyze a cascade reaction which involves unstable hydrogen peroxide as an intermediate. The combi-CLEA contains two enzymes̶ glucose oxidase (GOx) and horseradish peroxidase (HRP) which are cross-linked together as solid aggregates. The first enzyme GOx catalyzes the oxidation of glucose and produces hydrogen peroxide, which is used by the second enzyme HRP to oxidize 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284311/physico-cultural-parameters-during-agnps-biotransformation-with-bactericidal-activity-against-human-pathogens
#13
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 investigation systematically evaluates the influence of various major physico-cultural parameters including diverse growth media, concentrations of precursor salts; pH and temperature on the biotransformation of ionic silver (Ag(+)) to nanopariculate silver nanoparticles (AgNPs), utilizing the cell free extract of the bacterium, P...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284310/enzymatic-synthesis-of-phenethyl-ester-from-phenethyl-alcohol-with-acyl-donors
#14
Hyunah Kim, Chulhwan Park
Phenethyl ester is an important contributors to food, drinks, cosmetics and perfumery. Phenethyl acetate was synthesized enzymatically from phenethyl alcohol with acyl donors catalyzed by Novozym 435 from Candida antarctica lipase B. Through acyl donor screening, acetic anhydride and vinyl acetate were found to be the optimal acyl donors for the reaction. The effects of the molar ratio, temperature and solvents were investigated. The maximum conversion of phenethyl acetate were 99.12%, and 98.44%, using acetic anhydride and vinyl acetate as the acyl donors, respectively...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284309/alleviation-of-metabolic-bottleneck-by-combinatorial-engineering-enhanced-astaxanthin-synthesis-in-saccharomyces-cerevisiae
#15
Pingping Zhou, Wenping Xie, Aipeng Li, Fan Wang, Zhen Yao, Qi Bian, Yongqiang Zhu, Hongwei Yu, Lidan Ye
Highly efficient biosynthesis of the commercially valuable carotenoid astaxanthin by microbial cells is an attractive alternative to chemical synthesis and microalgae extraction. With the goal of enhancing heterologous astaxanthin production in Saccharomyces cerevisiae, metabolic engineering and protein engineering were integrated to improve both the expression and activity of rate-limiting enzymes. Firstly, to increase the supply of β-carotene as a key precursor for astaxanthin, a positive mutant of GGPP synthase (CrtE03M) was overexpressed together with three other rate-limiting enzymes tHMG1, CrtI and CrtYB...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284308/enzymatic-biosensor-based-on-entrapment-of-d-amino-acid-oxidase-on-gold-nanofilm-mwcnts-nanocomposite-modified-glassy-carbon-electrode-by-sol-gel-network-analytical-applications-for-d-alanine-in-human-serum
#16
Yalda Shoja, Amir Abbas Rafati, Javad Ghodsi
Sensing and determination of d-alanine is studied by using an enzymatic biosensor which was constructed on the basis of d-amino acid oxidase (DAAO) immobilization by sol-gel film onto glassy carbon electrode surface modified with nanocomposite of gold nanofilm (Au-NF) and multiwalled carbon nanotubes (MWCNTs). The Au-NF/MWCNT nanocomposite was prepared by applying the potentiostatic technique for electrodeposition of Au-NF on the MWCNT immobilized on glassy carbon electrode surface. The modified electrode is investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), linear sweep voltammetry (LSV) and cyclic voltammetry(CV) techniques...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284307/changing-the-electron-donor-improves-azoreductase-dye-degrading-activity-at-neutral-ph
#17
Jingxian Qi, Caroline E Paul, Frank Hollmann, Dirk Tischler
The oxygen-insensitive azoreductase AzoRo originating from Rhodococcus opacus 1CP was found to be most active at low pH (ca. 4) and high temperature (ca. 50°C). AzoRo is not an efficient biocatalyst when used at low pH due to stability problems. To overcome this issue, we discovered that AzoRo accepts an alternative electron donor, 1-benzyl-1,4-dihydronicotinamide (BNAH), which allows fast turnover at neutral pH. In order to screen this nicotinamide coenzyme mimic as a source of electrons, AzoRo-catalysed reactions were run under neutral conditions, under which typically slow rates are observed with NADH...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284306/an-improved-amperometric-triglyceride-biosensor-based-on-co-immobilization-of-nanoparticles-of-lipase-glycerol-kinase-and-glycerol-3-phosphate-oxidase-onto-pencil-graphite-electrode
#18
Vinay Narwal, C S Pundir
Nanoparticles (NPs) of commercial lipase from Candida rugosa, of glycerol kinase (GK) from Cellulomonas species, of glycerol-3- phosphate oxidase (GPO) from Aerococcus viridans were prepared, characterized and co-immobilized onto a pencil graphite (PG) electrode. The morphological and electrochemical characterization of PG electrode was performed by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) before and after co-immobilization of enzyme nanoparticles (ENPs)...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28284305/autodisplay-of-the-la-ssb-protein-on-lps-free-e-coli-for-the-diagnosis-of-sj%C3%A3-gren-s-syndrome
#19
Gu Yoo, Carina Dilkaute, Ji-Hong Bong, Hyun-Woo Song, Misu Lee, Min-Jung Kang, Joachim Jose, Jae-Chul Pyun
The objective of this study was to present an immunoassay for the diagnosis of Sjögren's syndrome based on the autodisplayed La/SSB protein on the outer membrane of intact E. coli (strain UT-5600) and LPS-free E. coli (ClearColi™). As the first step, an autodisplay vector (pCK002) was transfected into intact E. coli and LPS-free E. coli for comparison of efficiency of autdisplay of La/SSB. The maximal level of La/SSB expression was estimated to be similar for LPS-free E. coli and intact E. coli at different optimal induction periods...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28193334/glutamate-dehydrogenase-rocg-in-bacillus-licheniformis-wx-02-enzymatic-properties-and-specific-functions-in-glutamic-acid-synthesis-for-poly-%C3%AE-glutamic-acid-production
#20
Guangming Tian, Qin Wang, Xuetuan Wei, Xin Ma, Shouwen Chen
Poly-γ-glutamic acid (γ-PGA), a natural biopolymer, is widely used in cosmetics, medicine, food, water treatment, and agriculture owing to its features of moisture sequestration, cation chelation, non-toxicity and biodegradability. Intracellular glutamic acid, the substrate of γ-PGA, is a limiting factor for high yield in γ-PGA production. Bacillus subtilis and Bacillus licheniformis are both important γ-PGA producing strains, and B. subtilis synthesizes glutamic acid in vivo using the unique GOGAT/GS pathway...
April 2017: Enzyme and Microbial Technology
journal
journal
27896
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"