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.

scholarly journals Molecular Identification and Characterization of a New Type of Bovine Enterovirus

2012 ◽  
Vol 78 (12) ◽  
pp. 4497-4500 ◽  
Author(s):  
Shahzad Shaukat ◽  
Mehar Angez ◽  
Muhammad Masroor Alam ◽  
Salmaan Sharif ◽  
Adnan Khurshid ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Phylogenetic Analyses ◽  
Pathogenic Potential ◽  
Content Type ◽  
Bovine Enterovirus ◽  
The Family ◽  
New Type ◽  
Asymptomatic Infections ◽  
Identification And Characterization

ABSTRACTBovine enteroviruses belong to the familyPicornaviridae. Little is known about their pathogenic potential; however, they cause asymptomatic infections in cattle and are excreted in feces. In the present study, viruses isolated from environmental samples were sequenced. According to phylogenetic analyses and standard picornavirus nomenclature, these isolates constitute a new type of bovine enterovirus serogroup A.

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 A Previously Uncharacterized, Nonphotosynthetic Member of the Chromatiaceae Is the Primary CO2-Fixing Constituent in a Self-Regenerating Biocathode

2014 ◽  
Vol 81 (2) ◽  
pp. 699-712 ◽  
Author(s):  
Zheng Wang ◽  
Dagmar H. Leary ◽  
Anthony P. Malanoski ◽  
Robert W. Li ◽  
W. Judson Hervey ◽  
...  
Keyword(s):  
Microbial Fuel Cells ◽  
Iron Oxidation ◽  
Extracellular Electron Transfer ◽  
Hydrogen Electrode ◽  
Content Type ◽  
Iron Oxidizing Bacteria ◽  
Distinct Cluster ◽  
The Family

ABSTRACTBiocathode extracellular electron transfer (EET) may be exploited for biotechnology applications, including microbially mediated O2reduction in microbial fuel cells and microbial electrosynthesis. However, biocathode mechanistic studies needed to improve or engineer functionality have been limited to a few select species that form sparse, homogeneous biofilms characterized by little or no growth. Attempts to cultivate isolates from biocathode environmental enrichments often fail due to a lack of some advantage provided by life in a consortium, highlighting the need to study and understand biocathode consortiain situ. Here, we present metagenomic and metaproteomic characterization of a previously described biocathode biofilm (+310 mV versus a standard hydrogen electrode [SHE]) enriched from seawater, reducing O2, and presumably fixing CO2for biomass generation. Metagenomics identified 16 distinct cluster genomes, 15 of which could be assigned at the family or genus level and whose abundance was roughly divided betweenAlpha- andGammaproteobacteria. A total of 644 proteins were identified from shotgun metaproteomics and have been deposited in the the ProteomeXchange with identifier PXD001045. Cluster genomes were used to assign the taxonomic identities of 599 proteins, withMarinobacter,Chromatiaceae, andLabrenziathe most represented. RubisCO and phosphoribulokinase, along with 9 other Calvin-Benson-Bassham cycle proteins, were identified fromChromatiaceae. In addition, proteins similar to those predicted for iron oxidation pathways of known iron-oxidizing bacteria were observed forChromatiaceae. These findings represent the first description of putative EET and CO2fixation mechanisms for a self-regenerating, self-sustaining multispecies biocathode, providing potential targets for functional engineering, as well as new insights into biocathode EET pathways using proteomics.

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 Characterization of the Genome of the Polyvalent Lytic Bacteriophage GTE2, Which Has Potential for Biocontrol of Gordonia-, Rhodococcus-, and Nocardia-Stabilized Foams in Activated Sludge Plants

2011 ◽  
Vol 77 (12) ◽  
pp. 3923-3929 ◽  
Author(s):  
Steve Petrovski ◽  
Robert J. Seviour ◽  
Daniel Tillett
Keyword(s):  
Activated Sludge ◽  
Rhodococcus Erythropolis ◽  
Lytic Bacteriophage ◽  
Content Type ◽  
Double Stranded Dna ◽  
The Family ◽  
Nocardia Otitidiscaviarum ◽  
Foam Production ◽  
Activated Sludge Systems

ABSTRACTHydrophobicActinobacteriaare commonly associated with the stabilization of foams in activated sludge systems. One possible attractive approach to control these foam-stabilizing organisms is the use of specific bacteriophages. We describe the genome characterization of a novel polyvalent DNA phage, GTE2, isolated from activated sludge. This phage is lytic forGordonia terrae,Rhodococcus globerulus,Rhodococcus erythropolis,Rhodococcus erythropolis,Nocardia otitidiscaviarum, andNocardia brasiliensis. Phage GTE2 belongs to the familySiphoviridae, possessing a characteristic icosahedral head encapsulating a double-stranded DNA linear genome (45,530 bp) having 10-bp 3′-protruding cohesive ends. The genome sequence is 98% unique at the DNA level and contains 57 putative genes. The genome can be divided into two components, where the first is modular and encodes phage structural proteins and lysis genes. The second is not modular, and the genes harbored there are involved in DNA replication, repair, and metabolism. Some have no known function. GTE2 shows promising results in controlling stable foam production by its host bacteria under laboratory conditions, suggesting that it may prove useful in the field as a biocontrol agent.

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.

scholarly journals IND-6, a Highly Divergent IND-Type Metallo-β-Lactamase from Chryseobacterium indologenes Strain 597 Isolated in Burkina Faso

2009 ◽  
Vol 53 (10) ◽  
pp. 4320-4326 ◽  
Author(s):  
Boukaré Zeba ◽  
Filomena De Luca ◽  
Alain Dubus ◽  
Michael Delmarcelle ◽  
Jacques Simporé ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Posttranslational Modification ◽  
Human Pathogens ◽  
Turnover Rates ◽  
Chryseobacterium Indologenes ◽  
Sequence Identity ◽  
New Variant ◽  
The Family ◽  
Identification And Characterization

ABSTRACT The genus Chryseobacterium and other genera belonging to the family Flavobacteriaceae include organisms that can behave as human pathogens and are known to cause different kinds of infections. Several species of Flavobacteriaceae, including Chryseobacterium indologenes, are naturally resistant to β-lactam antibiotics (including carbapenems), due to the production of a resident metallo-β-lactamase. Although C. indologenes presently constitutes a limited clinical threat, the incidence of infections caused by this organism is increasing in some settings, where isolates that exhibit multidrug resistance phenotypes (including resistance to aminoglycosides and quinolones) have been detected. Here, we report the identification and characterization of a new IND-type variant from a C. indologenes isolate from Burkina Faso that is resistant to β-lactams and aminoglycosides. The levels of sequence identity of the new variant to other IND-type metallo-β-lactamases range between 72 and 90% (for IND-4 and IND-5, respectively). The purified enzyme exhibited N-terminal heterogeneity and a posttranslational modification consisting of the presence of a pyroglutamate residue at the N terminus. IND-6 shows a broad substrate profile, with overall higher turnover rates than IND-5 and higher activities than IND-2 and IND-5 against ceftazidime and cefepime.

scholarly journals Ecophysiological Characterization of Ammonia-Oxidizing Archaea and Bacteria from Freshwater

2012 ◽  
Vol 78 (16) ◽  
pp. 5773-5780 ◽  
Author(s):  
Elizabeth French ◽  
Jessica A. Kozlowski ◽  
Maitreyee Mukherjee ◽  
George Bullerjahn ◽  
Annette Bollmann
Keyword(s):  
Growth Rates ◽  
Ammonia Oxidation ◽  
Light Exposure ◽  
Enrichment Culture ◽  
Ammonia Oxidizing Bacteria ◽  
Content Type ◽  
Ammonia Oxidizing Archaea ◽  
Group I ◽  
Nitrosomonas Oligotropha

ABSTRACTAerobic biological ammonia oxidation is carried out by two groups of microorganisms, ammonia-oxidizing bacteria (AOB) and the recently discovered ammonia-oxidizing archaea (AOA). Here we present a study using cultivation-based methods to investigate the differences in growth of three AOA cultures and one AOB culture enriched from freshwater environments. The strain in the enriched AOA culture belong to thaumarchaeal group I.1a, with the strain in one enrichment culture having the highest identity with “CandidatusNitrosoarchaeum koreensis” and the strains in the other two representing a new genus of AOA. The AOB strain in the enrichment culture was also obtained from freshwater and had the highest identity to AOB from theNitrosomonas oligotrophagroup (Nitrosomonascluster 6a). We investigated the influence of ammonium, oxygen, pH, and light on the growth of AOA and AOB. The growth rates of the AOB increased with increasing ammonium concentrations, while the growth rates of the AOA decreased slightly. Increasing oxygen concentrations led to an increase in the growth rate of the AOB, while the growth rates of AOA were almost oxygen insensitive. Light exposure (white and blue wavelengths) inhibited the growth of AOA completely, and the AOA did not recover when transferred to the dark. AOB were also inhibited by blue light; however, growth recovered immediately after transfer to the dark. Our results show that the tested AOB have a competitive advantage over the tested AOA under most conditions investigated. Further experiments will elucidate the niches of AOA and AOB in more detail.

scholarly journals Gene Models, Expression Repertoire, and Immune Response of Plasmodium vivax Reticulocyte Binding Proteins

2015 ◽  
Vol 84 (3) ◽  
pp. 677-685 ◽  
Author(s):  
Jenni Hietanen ◽  
Anongruk Chim-ong ◽  
Thanprakorn Chiramanewong ◽  
Jakub Gruszczyk ◽  
Wanlapa Roobsoong ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Significant Negative Correlation ◽  
Protein Coding ◽  
Content Type ◽  
Immune Pressure ◽  
The Family ◽  
Genes Encoding ◽  
Gene Models

Members of thePlasmodium vivaxreticulocyte binding protein (PvRBP) family are believed to mediate specific invasion of reticulocytes byP. vivax. In this study, we performed molecular characterization of genes encoding members of this protein family. Through cDNA sequencing, we constructed full-length gene models and verified genes that are protein coding and those that are pseudogenes. We also used quantitative PCR to measure theirin vivotranscript abundances in clinicalP. vivaxisolates. Like genes encoding related invasion ligands ofP. falciparum,Pvrbpexpression levels vary broadly across different parasite isolates. Through antibody measurements, we found that host immune pressure may be the driving force behind the distinctly high diversity of one of the family members, PvRBP2c. Mild yet significant negative correlation was found between parasitemia and the PvRBP2b antibody level, suggesting that antibodies to the protein may interfere with invasion.

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