scholarly journals Identification and Characterization of a Halotolerant, Cold-Active Marine Endo-β-1,4-Glucanase by Using Functional Metagenomics of Seaweed-Associated Microbiota

2014 ◽  
Vol 80 (16) ◽  
pp. 4958-4967 ◽  
Author(s):  
Marjolaine Martin ◽  
Sophie Biver ◽  
Sébastien Steels ◽  
Tristan Barbeyron ◽  
Murielle Jam ◽  
...  
Keyword(s):  
Metagenomic Library ◽  
Functional Screening ◽  
Sample Collection ◽  
Prolonged Incubation ◽  
Content Type ◽  
Cold Active ◽  
Esterase Loci ◽  
Collection Period ◽  
Identification And Characterization

ABSTRACTA metagenomic library was constructed from microorganisms associated with the brown algaAscophyllum nodosum. Functional screening of this library revealed 13 novel putative esterase loci and two glycoside hydrolase loci. Sequence and gene cluster analysis showed the wide diversity of the identified enzymes and gave an idea of the microbial populations present during the sample collection period. Lastly, an endo-β-1,4-glucanase having less than 50% identity to sequences of known cellulases was purified and partially characterized, showing activity at low temperature and after prolonged incubation in concentrated salt solutions.

scholarly journals Identification and characterization of a novel carboxylesterase EstQ7 from a soil metagenomic library

2021 ◽  
Author(s):  
Zhenzhen Yan ◽  
Liping Ding ◽  
Dandan Zou ◽  
Luyao Wang ◽  
Yuzhi Tan ◽  
...  
Keyword(s):  
Metagenomic Library ◽  
Identification And Characterization

scholarly journals Functional Screening of a Metagenomic Library Reveals Operons Responsible for Enhanced Intestinal Colonization by Gut Commensal Microbes

2013 ◽  
Vol 79 (12) ◽  
pp. 3829-3838 ◽  
Author(s):  
Mi Young Yoon ◽  
Kang-Mu Lee ◽  
Yujin Yoon ◽  
Junhyeok Go ◽  
Yongjin Park ◽  
...  
Keyword(s):  
Bac Library ◽  
Metagenomic Library ◽  
Artificial Chromosome ◽  
Open Reading Frames ◽  
Functional Screening ◽  
Sequence Alignments ◽  
Protein Coding ◽  
Content Type ◽  
Usage Analysis ◽  
Functional Screens

ABSTRACTEvidence suggests that gut microbes colonize the mammalian intestine through propagation as an adhesive microbial community. A bacterial artificial chromosome (BAC) library of murine bowel microbiota DNA in the surrogate hostEscherichia coliDH10B was screened for enhanced adherence capability. Two out of 5,472 DH10B clones, 10G6 and 25G1, exhibited enhanced capabilities to adhere to inanimate surfaces in functional screens. DNA segments inserted into the 10G6 and 25G1 clones were 52 and 41 kb and included 47 and 41 protein-coding open reading frames (ORFs), respectively. DNA sequence alignments, tetranucleotide frequency, and codon usage analysis strongly suggest that these two DNA fragments are derived from species belonging to the genusBacteroides. Consistent with this finding, a large portion of the predicted gene products were highly homologous to those ofBacteroidesspp. Transposon mutagenesis and subsequent experiments that involved heterologous expression identified two operons associated with enhanced adherence.E. colistrains transformed with the 10a or 25b operon adhered to the surface of intestinal epithelium and colonized the mouse intestine more vigorously than did the control strain. This study has revealed the genetic determinants of unknown commensals (probably resemblingBacteroidesspecies) that enhance the ability of the bacteria to colonize the murine bowel.

Identification and characterization of a novel bifunctional cellulase/hemicellulase from a soil metagenomic library

2020 ◽  
Vol 104 (17) ◽  
pp. 7563-7572 ◽  
Author(s):  
Shumao Chai ◽  
Xueliang Zhang ◽  
Zhenyu Jia ◽  
Xiaofei Xu ◽  
Yanfen Zhang ◽  
...  
Keyword(s):  
Metagenomic Library ◽  
Bifunctional Cellulase ◽  
Identification And Characterization

scholarly journals Tannin Degradation by a Novel Tannase Enzyme Present in Some Lactobacillus plantarum Strains

2014 ◽  
Vol 80 (10) ◽  
pp. 2991-2997 ◽  
Author(s):  
Natalia Jiménez ◽  
María Esteban-Torres ◽  
José Miguel Mancheño ◽  
Blanca de las Rivas ◽  
Rosario Muñoz
Keyword(s):  
Lactobacillus Plantarum ◽  
Tannic Acid ◽  
Plant Material ◽  
Aliphatic Alcohol ◽  
Methyl Gallate ◽  
Content Type ◽  
Sequence Identity ◽  
Tannin Degradation ◽  
Identification And Characterization

ABSTRACTLactobacillus plantarumis frequently isolated from the fermentation of plant material where tannins are abundant.L. plantarumstrains possess tannase activity to degrade plant tannins. AnL. plantarumtannase (TanBLp, formerly called TanLp1) was previously identified and biochemically characterized. In this study, we report the identification and characterization of a novel tannase (TanALp). While all 29L. plantarumstrains analyzed in the study possess thetanBLpgene, the genetanALpwas present in only four strains. Upon methyl gallate exposure, the expression oftanBLpwas induced, whereastanALpexpression was not affected. TanALpshowed only 27% sequence identity to TanBLp, but the residues involved in tannase activity are conserved. Optimum activity for TanALpwas observed at 30°C and pH 6 in the presence of Ca2+ions. TanALpwas able to hydrolyze gallate and protocatechuate esters with a short aliphatic alcohol substituent. Moreover, TanALpwas able to fully hydrolyze complex gallotannins, such as tannic acid. The presence of the extracellular TanALptannase in someL. plantarumstrains provides them an advantage for the initial degradation of complex tannins present in plant environments.

scholarly journals Identification and Characterization of Mycobacterium tuberculosis Beijing Genotype Strain SBH163, Isolated in Sabah, Malaysia

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Jaeyres Jani ◽  
Siti Fatimah Abu Bakar ◽  
Zainal Arifin Mustapha ◽  
Chin Kai Ling ◽  
Roddy Teo ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Whole Genome Sequence ◽  
Beijing Genotype ◽  
Molecular Characteristics ◽  
Whole Genome ◽  
Content Type ◽  
Identification And Characterization ◽  
Insight Into ◽  
Malaysian Borneo

This is a report on the whole-genome sequence of Mycobacterium tuberculosis strain SBH163, which was isolated from a patient in the Malaysian Borneo state of Sabah. This report provides insight into the molecular characteristics of an M. tuberculosis Beijing genotype strain related to strains from Russia and South Africa.

scholarly journals Construction and Application of a Functional Library of Cytochrome P450 Monooxygenases from the Filamentous Fungus Aspergillus oryzae

2011 ◽  
Vol 77 (9) ◽  
pp. 3147-3150 ◽  
Author(s):  
K. H. M. Nazmul Hussain Nazir ◽  
Hirofumi Ichinose ◽  
Hiroyuki Wariishi
Keyword(s):  
Cytochrome P450 ◽  
Aspergillus Oryzae ◽  
Cytochrome P450 Monooxygenases ◽  
Functional Screening ◽  
Content Type ◽  
P450 Monooxygenases ◽  
Rapid Characterization ◽  
Catalytic Functions ◽  
First Time

ABSTRACTA functional library of cytochrome P450 monooxygenases fromAspergillus oryzae(AoCYPs) was constructed in which 121 isoforms were coexpressed with yeast NADPH-cytochrome P450 oxidoreductase inSaccharomyces cerevisiae. Using this functional library, novel catalytic functions of AoCYPs, such as catalytic potentials of CYP57B3 against genistein, were elucidated for the first time. Comprehensive functional screening promises rapid characterization of catalytic potentials and utility of AoCYPs.

scholarly journals Malonic Semialdehyde Reductase from the Archaeon Nitrosopumilus maritimus Is Involved in the Autotrophic 3-Hydroxypropionate/4-Hydroxybutyrate Cycle

2014 ◽  
Vol 81 (5) ◽  
pp. 1700-1707 ◽  
Author(s):  
Julia Otte ◽  
Achim Mall ◽  
Daniel M. Schubert ◽  
Martin Könneke ◽  
Ivan A. Berg
Keyword(s):  
Succinic Semialdehyde ◽  
Alcohol Dehydrogenases ◽  
Content Type ◽  
Metallosphaera Sedula ◽  
Ammonia Oxidizing Archaea ◽  
The Family ◽  
Terrestrial Environments ◽  
Identification And Characterization ◽  
Low Activity

ABSTRACTThe recently described ammonia-oxidizing archaea of the phylumThaumarchaeotaare highly abundant in marine, geothermal, and terrestrial environments. All characterized representatives of this phylum are aerobic chemolithoautotrophic ammonia oxidizers assimilating inorganic carbon via a recently described thaumarchaeal version of the 3-hydroxypropionate/4-hydroxybutyrate cycle. Although some genes coding for the enzymes of this cycle have been identified in the genomes ofThaumarchaeota, many other genes of the cycle are not homologous to the characterized enzymes from other species and can therefore not be identified bioinformatically. Here we report the identification and characterization of malonic semialdehyde reductase Nmar_1110 in the cultured marine thaumarchaeonNitrosopumilus maritimus. This enzyme, which catalyzes the reduction of malonic semialdehyde with NAD(P)H to 3-hydroxypropionate, belongs to the family of iron-containing alcohol dehydrogenases and is not homologous to malonic semialdehyde reductases fromChloroflexus aurantiacusandMetallosphaera sedula. It is highly specific to malonic semialdehyde (Km, 0.11 mM;Vmax, 86.9 μmol min−1mg−1of protein) and exhibits only low activity with succinic semialdehyde (Km, 4.26 mM;Vmax, 18.5 μmol min−1mg−1of protein). Homologues ofN. maritimusmalonic semialdehyde reductase can be found in the genomes of allThaumarchaeotasequenced so far and form a well-defined cluster in the phylogenetic tree of iron-containing alcohol dehydrogenases. We conclude that malonic semialdehyde reductase can be regarded as a characteristic enzyme for the thaumarchaeal version of the 3-hydroxypropionate/4-hydroxybutyrate cycle.

Identification and characterization of a novel methionine γ-lyase gene from deep-sea sediment metagenomic library

2011 ◽  
Vol 27 (11) ◽  
pp. 2729-2736 ◽  
Author(s):  
Huixian Li ◽  
Yali Huang ◽  
Jiong Zhang ◽  
Jikun Du ◽  
Hongming Tan ◽  
...  
Keyword(s):  
Deep Sea ◽  
Metagenomic Library ◽  
Deep Sea Sediment ◽  
Identification And Characterization

scholarly journals Two Zinc Uptake Systems Contribute to the Full Virulence of Listeria monocytogenes during GrowthIn VitroandIn Vivo

2011 ◽  
Vol 80 (1) ◽  
pp. 14-21 ◽  
Author(s):  
David Corbett ◽  
Jiahui Wang ◽  
Stephanie Schuler ◽  
Gloria Lopez-Castejon ◽  
Sarah Glenn ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Zinc Uptake ◽  
Detectable Effect ◽  
Intracellular Growth ◽  
Content Type ◽  
Zinc Sensing ◽  
Identification And Characterization ◽  
Cell Deletion

ABSTRACTWe report here the identification and characterization of two zinc uptake systems, ZurAM and ZinABC, in the intracellular pathogenListeria monocytogenes. Transcription of both operons was zinc responsive and regulated by the zinc-sensing repressor Zur. Deletion of eitherzurAMorzinAhad no detectable effect on growth in defined media, but a doublezurAM zinAmutant was unable to grow in the absence of zinc supplementation. Deletion ofzinAhad no detectable effect on intracellular growth in HeLa epithelial cells. In contrast, growth of thezurAMmutant was significantly impaired in these cells, indicating the importance of the ZurAM system during intracellular growth. Notably, the deletion of bothzinAandzurAMseverely attenuated intracellular growth, with the double mutant being defective in actin-based motility and unable to spread from cell to cell. Deletion of eitherzurAMorzinAhad a significant effect on virulence in an oral mouse model, indicating that both zinc uptake systems are importantin vivoand establishing the importance of zinc acquisition during infection byL. monocytogenes. The presence of two zinc uptake systems may offer a mechanism by whichL. monocytogenescan respond to zinc deficiency within a variety of environments and during different stages of infection, with each system making distinct contributions under different stress conditions.

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