scholarly journals Characterization of a Highly Enriched Dehalococcoides-Containing Culture That Grows on Vinyl Chloride and Trichloroethene

2004 ◽  
Vol 70 (9) ◽  
pp. 5538-5545 ◽  
Author(s):  
Melanie Duhamel ◽  
Kaiguo Mo ◽  
Elizabeth A. Edwards
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Vinyl Chloride ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Enrichment Culture ◽  
Phylogenetic Analyses ◽  
Rrna Gene ◽  
Sufficient Information ◽  
Gene Copies ◽  
Gradient Gel Electrophoresis

ABSTRACT A highly enriched culture that reductively dechlorinates trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC) to ethene without methanogenesis is described. The Dehalococcoides strain in this enrichment culture had a yield of (5.6 ± 1.4) × 108 16S rRNA gene copies/μmol of Cl− when grown on VC and hydrogen. Unlike the other VC-degrading cultures described in the literature, strains VS and BAV1, this culture maintained the ability to grow on TCE with a yield of (3.6 ± 1.3) × 108 16S rRNA gene copies/μmol of Cl−. The yields on an electron-equivalent basis measured for the culture grown on TCE and on VC were not significantly different, indicating that both substrates supported growth equally well. PCR followed by denaturing gradient gel electrophoresis, cloning, and phylogenetic analyses revealed that this culture contained one Dehalococcoides 16S rRNA gene sequence, designated KB-1/VC, that was identical (over 1,386 bp) to the sequences of previously described organisms FL2 and CBDB1. A second Dehalococcoides sequence found in separate KB-1 enrichment cultures maintained on cDCE, TCE, and tetrachloroethene was no longer present in the VC-H2 enrichment culture. This second Dehalococcoides sequence was identical to that of BAV1. As neither FL2 nor CBDB1 can dechlorinate VC to ethene in a growth-related fashion, it is clear that current 16S rRNA gene-based analyses do not provide sufficient information to distinguish between metabolically diverse members of the Dehalococcoides group.

scholarly journals Characterization of a Culturable Alphaproteobacterial Symbiont Common to Many Marine Sponges and Evidence for Vertical Transmission via Sponge Larvae

2006 ◽  
Vol 72 (5) ◽  
pp. 3724-3732 ◽  
Author(s):  
Julie J. Enticknap ◽  
Michelle Kelly ◽  
Olivier Peraud ◽  
Russell T. Hill
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Marine Sponges ◽  
Rrna Gene ◽  
Surrounding Water ◽  
Axinella Corrugata ◽  
Gradient Gel Electrophoresis ◽  
Related Group

ABSTRACT A closely related group of alphaproteobacteria were found to be present in seven genera of marine sponges from several locations and were shown to be transferred between sponge generations through the larvae in one of these sponges. Isolates of the alphaproteobacterium were cultured from the sponges Axinella corrugata, Mycale laxissima, Monanchora unguifera, and Niphates digitalis from Key Largo, Florida; Didiscus oxeata and Monanchora unguifera from Discovery Bay, Jamaica; an Acanthostronglyophora sp. from Manado, Indonesia; and Microciona prolifera from the Cheasapeake Bay in Maryland. Isolates were very similar to each other on the basis of 16S rRNA gene sequence (>99% identity) and are closely related to Pseudovibrio denitrificans. The bacterium was never isolated from surrounding water samples and was cultured from larvae of M. laxissima, indicating that it is a vertically transmitted symbiont in this sponge. Denaturing gradient gel electrophoresis, 16S rRNA gene clone library analysis, and fluorescent in situ hybridization with probes specific to the alphaproteobacterium confirmed the presence of this bacterium in the M. laxissima larvae. The alphaproteobacterium was densely associated with the larvae rather than being evenly distributed throughout the mesohyl. This is the first report of the successful culture of a bacterial symbiont of a sponge that is transferred through the gametes.

scholarly journals Combined Phospholipid Biomarker-16S rRNA Gene Denaturing Gradient Gel Electrophoresis Analysis of Bacterial Diversity and Physiological Status in an Intertidal Microbial Mat

2004 ◽  
Vol 70 (11) ◽  
pp. 6920-6926 ◽  
Author(s):  
Laura Villanueva ◽  
Antoni Navarrete ◽  
Jordi Urmeneta ◽  
David C. White ◽  
Ricardo Guerrero
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Microbial Mat ◽  
Physiological Status ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Lipid Biomarker ◽  
Gradient Gel Electrophoresis

ABSTRACT A combined lipid biomarker-16S rRNA gene denaturing gradient gel electrophoresis analysis was used to monitor changes in the physiological status, biomass, and microbial composition of a microbial mat. In the morning hours, an increase in the biomass of layers containing a high density of phototrophs and a decrease in the growth rate in the deep layers were observed. The combined approach also revealed differences in major groups of microorganisms, including green nonsulfur, gram-positive, and heterotrophic bacteria.

Denaturing Gradient Gel Electrophoresis Detects Bacterial and Cyaonbacterial Diversities in Biological Soil Crusts in a Semiarid Desert, China

2013 ◽  
Vol 726-731 ◽  
pp. 3680-3684
Author(s):  
Ying Zhang ◽  
Cheng You Cao ◽  
Peng Zhang
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Biological Soil Crusts ◽  
Rrna Gene ◽  
Sandy Land ◽  
Specific Primers ◽  
Soil Crusts ◽  
Gradient Gel Electrophoresis

The purpose of this study is to assess the application of denaturing gradient gel electrophoresis (DGGE) for analyzing the bacterial and cyanobacterial diversities of biological soil crusts (BSCs) in sandy land. Soil microbial DNA was extracted from BSCs under different plantations in Horqin Sandy Land of Northeast China. 16S rRNA gene fragments from bacteria and cyanobacteria were amplified by universal bacterial and cyanobacteria-specific primers. Fourteen and six prominent bands were detected in the bacterial and cyanobacterial DGGE profiles, respectively. These bands were excised, cloned and sequenced. Phylogenetic analysis classified the bacterial sequences into the following main groups:Escherichia,Bacillus,Paenibacillus,Shigella, andPseudomonas. The cyanobacterial sequences were classified asMicrocoleus,LeptolyngbyaandHaslea. Our study suggests that DGGE is a useful technique for detecting dominant species compositions of bacterial and cyanobacterial communities in biological soil crusts, and specific primers are recommended for PCR of 16S rRNA gene fragments.

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