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Laccase coli

Madan Kumar, Arti Mishra, Shashi Shekhar Singh, Shaili Srivastava, Indu Shekhar Thakur
In the present study, a non-blue laccase gene from previously reported lignin degrading bacterium, Pandoraea sp. ISTKB, was isolated, cloned and expressed in E. coli. Bioinformatics analysis of sequence discovered twin-arginine translocation signal sequence, copper binding motifs and presence of more random coil compare to helices and sheets in structure. The enzyme was found to be active on wide pH range and the pH optima was observed at pH 4 and 8 on substrate 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 2,6-Dimethoxyphenol respectively...
April 14, 2018: International Journal of Biological Macromolecules
Keke Zhang, Mei Huang, Jiangshan Ma, Zeyi Liu, Jiarui Zeng, Xuanming Liu, Ting Xu, Xiang Wang, Ying Liu, Zhigang Bu, Yonghua Zhu
OBJECTIVE: To identify and characterize a novel bacterial pyranose 2-oxidase (P2Ox) and investigate its potential use in lignin degradation applications. RESULTS: A new bacterial P2Ox (PaP2Ox) enzyme was identified in the lignocellulolytic bacterium Pantoea ananatis Sd-1. The PaP2Ox open reading frame was cloned, and the encoded protein was heterologously expressed in an Escherichia coli expression system. Unlike another reported bacterial P2Ox enzyme, the purified PaP2Ox exhibits a homotetrameric spatial conformation that is similar to fungal P2Oxs, with each subunit having a molecular mass of 65 kDa...
March 31, 2018: Biotechnology Letters
Rommel Santiago Granja-Travez, Rachael C Wilkinson, Gabriela Felix Persinoti, Fabio M Squina, Vilmos Fülöp, Timothy D H Bugg
The identification of enzymes responsible for oxidation of lignin in lignin-degrading bacteria is of interest for biotechnological valorization of lignin to renewable chemical products. The genome sequences of two lignin-degrading bacteria, Ochrobactrum sp., and Paenibacillus sp., contain no B-type DyP peroxidases implicated in lignin degradation in other bacteria, but contain putative multi-copper oxidase genes. Multi-copper oxidase CueO from Ochrobactrum sp. was expressed and reconstituted as a recombinant laccase-like enzyme, and kinetically characterized...
March 25, 2018: FEBS Journal
Sunil Ghatge, Youri Yang, Woo-Young Song, Tae-Young Kim, Hor-Gil Hur
In the present study, the gene encoding a multicopper oxidase, more precisely a laccase from the thermoalkaliphilic aerobic bacterium Caldalkalibacillus thermarum strain TA2.A1 (CtLac), was cloned and expressed in Escherichia coli. CtLac is a monomeric protein with a molecular weight of 57 kDa as determined by native polyacrylamide gel electrophoresis. The optimum pH and temperature for 2,6-dimethoxyphenol (2,6-DMP) oxidation were 8.0 and 70 °C, respectively. The kinetic constants Km and kcat for 2,6-DMP were of 200 μM and 23 s-1 , respectively...
March 19, 2018: Applied Microbiology and Biotechnology
Zhen Zhang, Jin Liu, Jin Fan, Zhiyong Wang, Lin Li
In this study, we report an electrochemical microbial biosensor that was made by immobilizing a bacterial laccase on the surface of Escherichia coli cells followed by adsorption of modified live cells onto a glassy-carbon electrode. Expression and surface localization of laccase on target cells were confirmed by Western blotting, flow cytometry assays and immunofluorescence microscopy observation. Increased tandem-aligned anchors with three repeats of the N-terminal domain of an ice nucleation protein were used to construct a highly active E...
June 7, 2018: Analytica Chimica Acta
Francesca Berini, Marko Verce, Luka Ausec, Elena Rosini, Fabio Tonin, Loredano Pollegioni, Ines Mandić-Mulec
Bioinformatics has revealed the presence of putative laccase genes in diverse bacteria, including extremophiles, autotrophs, and, interestingly, anaerobes. Integrity of laccase genes in anaerobes has been questioned, since laccases oxidize a variety of compounds using molecular oxygen as the electron acceptor. The genome of the anaerobe Geobacter metallireducens GS-15 contains five genes for laccase-like multicopper oxidases. In order to show whether one of the predicted genes encodes a functional laccase, the protein encoded by GMET_RS10855 was heterologously expressed in Escherichia coli cells...
January 29, 2018: Applied Microbiology and Biotechnology
Zhi Zou, Diana M Mate, Kristin Rübsam, Felix Jakob, Ulrich Schwaneberg
Sortase-catalyzed ligations have emerged as powerful tools for the site-specific ligation of peptides and proteins in material science and biocatalysis. In this work, a directed sortase evolution strategy (SortEvolve) has been developed as a general high-throughput screening (HTS) platform to improve activity of sortase A (application 1) and to perform directed laccase evolution through a semipurification process in 96-well microtiter plate (MTP) (application 2). A semipurification process in polypropylene MTP (PP-MTP) is achieved through the anchor peptide LCI, which acts as adhesion promoter...
April 9, 2018: ACS Combinatorial Science
Yan Li, Xiaoguang Xu, Rui Qu, Guoqiang Zhang, Muhammad Shahid Riaz Rajoka, Dongyan Shao, Chunmei Jiang, Junling Shi
Small heat shock proteins (sHSPs) are heat shock proteins sized 12-43 kDa that can protect proteins from denaturation, particularly under high temperature; sHSPs thus increase the heat tolerance capability of an organisms enabling survival in adverse climates. sHSP20 is overexpressed in Oenococcus oeni in response to low temperatures. However, we found that overexpression of sHSP20 in Escherichia coli BL21 increased the microbial survival ratio at 50 °C by almost 2 h. Adding sHSP20 to the glutamate dehydrogenase solution significantly increased the stability of the enzyme at high temperature (especially at 60-70 °C), low pH values (especially below 6...
January 22, 2018: Cell Stress & Chaperones
Quan Luo, Yu Chen, Jing Xia, Kai-Qiang Wang, Yu-Jie Cai, Xiang-Ru Liao, Zheng-Bing Guan
Bacterial laccases are potential enzymes for biotechnological applications, such as detoxification of industrial effluents, decolorization of textile, and dimerization of phenolic acids, due to their remarkable advantages, including broad substrate spectrum, high thermostability, wide pH scope, and tolerance to alkaline environments. L386W/G417L/G57F (abbreviated as WLF), a good mutant of CotA-laccase from Bacillus pumilus W3, has been constructed and reported by our laboratory with highly improved catalytic efficiency...
February 2018: Enzyme and Microbial Technology
Shuangxin Ma, Ning Liu, Hui Jia, Dongqing Dai, Jinping Zang, Zhiyan Cao, Jingao Dong
Laccases are multicopper oxidases (E.C. that catalyze the oxidation of many phenolic compounds. In this study, a novel laccase, Stlac4, from Setosphaeria turcica was cloned and expressed in Escherichia coli by insertion into the pET-30a expression plasmid. The recombinant laccase was purified and visualized on SDS-PAGE as a single band with an apparent molecular weight of 71.5 KDa, and confirmed by Western blot. The maximum activity of the purified laccase was 127.78 U · mg-1 , the optimum temperature and pH value were 60 °C and 4...
January 2018: Journal of Basic Microbiology
Mehrnoosh Fathi-Roudsari, Mehrdad Behmanesh, Ali-Hatef Salmanian, Majid Sadeghizadeh, Khosro Khajeh
Background: Phenolic compounds, which are produced routinely by industrial and urban activities, possess dangers to live organisms and environment. Laccases are oxidoreductase enzymes with the ability of remediating a wide variety of phenolic compounds to more benign molecules. The purpose of the present research is surface display of a laccase enzyme with adhesin involved in diffuse adhesion (AIDA-I) autotransporter system on the surface of Escherichia coli cells for bioremediation of phenolic compounds...
October 28, 2017: Iranian Biomedical Journal
Arpana Kumari, Nitin Kishor, Purnananda Guptasarma
OBJECTIVE: To examine the potential for applications of TthLAC, a monomeric (~ 53 kDa) laccase encoded by the genome of Thermus thermophilus (strain HB 27) which can be produced at low cost in Escherichia coli. RESULT: Functional, thermostable and mildly alkalophilic TthLAC of high purity (> 90%) was produced through simple heating of suspended (TthLAC overexpressing) E.coli cells at 65 °C. For reactions of short duration (< 1 h) the temperature for optimal activity is ~ 90 °C...
October 23, 2017: Biotechnology Letters
Baozhong Chai, Yunqian Qiao, He Wang, Xiaoming Zhang, Jiao Wang, Choushi Wang, Ping Zhou, Xiangdong Chen
Pyomelanin is the major constituent of pigment in melanogenic Aeromonas strains of bacteria. However, eumelanin, synthesized from tyrosine via L-DOPA and polyphenol oxidases (PPOs), may also be present in this genus since L-DOPA is frequently detected in culture fluids of several species. To address this question, we used a deletion mutant of Aeromonas media strain WS, in which pyomelanin synthesis is completely blocked under normal culture conditions. When tyrosine was supplied to the medium, we observed residual melanin accumulation, which we interpret as evidence for existence of the DOPA-melanin pathway...
2017: Frontiers in Microbiology
Sara Callejón, Ramón Sendra, Sergi Ferrer, Isabel Pardo
Biogenic amines degradation by bacterial laccases is little known, so we have cloned and heterologously expressed, in E. coli, a new laccase from Pediococcus acidilactici CECT 5930 (Lpa5930), a lactic acid bacterium commonly found in foods able to degrade tyramine. The recombinant enzyme has been characterized by physical and biochemical assays. Here we report the optimization of expression and purification procedures of this laccase. DNA encoding sequence of laccase from P. acidilactici was amplified by PCR and cloned into the expression plasmid pET28a for induction by isopropyl-β-D-thiogalactoipyranoside...
2017: PloS One
Xiuyan Zhao, Fei Chang, Zemin Fang, Yinliang Zhang, Yazhong Xiao
Laccase is a widely-used environment-friendly copper-containing oxidase found in many plants, insects and fungi. Recently, more and more laccases are also found in bacteria. Myxobacteria are an important bacteria resource. However, myxobacteria are much more difficult to isolate and purify than other bacteria. We used bioinformatic approach to screen myxobacteria proteomes available in NCBI. Based on conserved sequences of four copper binding sites in multicopper oxidase, 30 potential laccase sequences were obtained...
April 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Haipeng Guo, Bingsong Zheng, Dean Jiang, Wensheng Qin
Laccases from bacteria have been widely studied in the past 2 decades due to the higher growth rate of bacteria and their excellent thermal and alkaline pH stability. In this study, a novel laccase gene was cloned from Bacillus sp., analyzed, and functionally expressed in Escherichia coli. The laccase was highly induced in the E. coli expression system with a maximum intracellular activity of 16 U mg-1 protein. The optimal temperature and pH of the purified laccase were 40°C and 4.6, respectively, when ABTS (2,2'-azino-bis[3-ethylbenzothiazoline-6-sulfonate]) was used as the substrate...
2017: Journal of Molecular Microbiology and Biotechnology
Luka Ausec, Francesca Berini, Carmine Casciello, Mariana Silvia Cretoiu, Jan Dirk van Elsas, Flavia Marinelli, Ines Mandic-Mulec
Metagenomics is a powerful tool that allows identifying enzymes with novel properties from the unculturable component of microbiomes. However, thus far only a limited number of laccase or laccase -like enzymes identified through metagenomics has been subsequently biochemically characterized. This work describes the successful bio-mining of bacterial laccase-like enzymes in an acidic bog soil metagenome and the characterization of the first acidobacterial laccase-like multicopper oxidase (LMCO). LMCOs have hitherto been mostly studied in fungi and some have already found applications in diverse industries...
June 6, 2017: Applied Microbiology and Biotechnology
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
Sushil Kumar Singh, Robinka Khajuria, Loveleen Kaur
Unrestricted and reckless use of antibiotics has resulted in their accumulation in environment. This, in turn, has led to the emergence of multiple drug-resistant microbes. The present study focuses on degradation of ciprofloxacin (CIP) by an edible white rot fungus Pleurotus ostreatus. Effect of CIP was determined on radial growth and biomass of P. ostreatus. Titrimetric and spectrophotometric assays were carried out to assess the degrading potential of P. ostreatus towards CIP. It was found that CIP has a stimulatory effect on growth and enzyme activity of P...
May 2017: 3 Biotech
Selin Ece, Camilla Lambertz, Rainer Fischer, Ulrich Commandeur
Laccases are used for the conversion of biomass into fermentable sugars but it is difficult to produce high yields of active laccases in heterologous expression systems. We overcame this challenge by expressing Streptomyces cyaneus CECT 3335 laccase in Escherichia coli (ScLac) and we achieved a yield of up to 104 mg L(-1) following purification by one-step affinity chromatography. Stability and activity assays using simple lignin model substrates showed that the purified enzyme preparation was active over a broad pH range and at high temperatures, suggesting it would be suitable for biomass degradation...
December 2017: AMB Express
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