Document Detail


Shifts in methanogen community structure and function associated with long-term manipulation of sulfate and salinity in a hypersaline microbial mat.
MedLine Citation:
PMID:  18177370     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Methanogenesis was characterized in hypersaline microbial mats from Guerrero Negro, Baja California Sur, Mexico both in situ and after long-term manipulation in a greenhouse environment. Substrate addition experiments indicate methanogenesis to occur primarily through the catabolic demethylation of non-competitive substrates, under field conditions. However, evidence for the coexistence of other metabolic guilds of methanogens was obtained during a previous manipulation of sulfate concentrations. To fully characterize methanogenesis in these mats, in the absence of competition for reducing equivalents with sulfate-reducing microorganisms, we maintained microbial mats for longer than 1 year under conditions of lowered sulfate and salinity levels. The goal of this study was to assess whether observed differences in methane production during sulfate and salinity manipulation were accompanied by shifts in the composition of methanogen communities. Culture-independent techniques targeting methyl coenzyme M reductase genes (mcrA) were used to assess the dynamics of methanogen assemblages. Clone libraries from mats sampled in situ or maintained at field-like conditions in the greenhouse were exclusively composed of sequences related to methylotrophic members of the Methanosarcinales. Increases in pore water methane concentrations under conditions of low sulfate correlated with an observed increase in the abundance of putatively hydrogenotrophic mcrA, related to Methanomicrobiales. Geochemical and molecular data provide evidence of a significant shift in the metabolic pathway of methanogenesis from a methylotroph-dominated system in high-sulfate environments to a mixed community of methylotrophic and hydrogenotrophic methanogens under low sulfate conditions.
Authors:
Jason M Smith; Stefan J Green; Cheryl A Kelley; Leslie Prufert-Bebout; Brad M Bebout
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2007-12-19
Journal Detail:
Title:  Environmental microbiology     Volume:  10     ISSN:  1462-2920     ISO Abbreviation:  Environ. Microbiol.     Publication Date:  2008 Feb 
Date Detail:
Created Date:  2008-01-17     Completed Date:  2008-02-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100883692     Medline TA:  Environ Microbiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  386-94     Citation Subset:  IM    
Affiliation:
Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, USA.
Data Bank Information
Bank Name/Acc. No.:
GENBANK/EF202615;  EF202616;  EF202617;  EF202618;  EF202619;  EF202620;  EF202621;  EF202622;  EF202623;  EF202624;  EF202625;  EF202626;  EF202627;  EF202628;  EF202629;  EF202630;  EF202631;  EF202632;  EF202633;  EF202634;  EF202635;  EF202636;  EF202637;  EF202638;  EF202639;  EF202640;  EF202641;  EF202642;  EF202643;  EF202644;  EF202645;  EF202646;  EF202647;  EF202648;  EF202649;  EF202650;  EF202651;  EF202652;  EF202653;  EF202654;  EF202655;  EF202656;  EF202657;  EF202658;  EF202659;  EF202660;  EF202661;  EF202662;  EF202663;  EF202664;  EF202665;  EF202666;  EF202667;  EF202668;  EF202669;  EF202670;  EF202671;  EF202672;  EF202673;  EF202674;  EF202675;  EF202676;  EF202677;  EF202678;  EF202679;  EF202680;  EF202681;  EF202682;  EF202683;  EF202684;  EF202685;  EF202686;  EF202687;  EF202688;  EF202689;  EF202690;  EF202691;  EF202692;  EF202693;  EF202694;  EF202695;  EF202696;  EF202697;  EF202698;  EF202699;  EF202700;  EF202701;  EF202702;  EF202703;  EF202704;  EF202705;  EF202706;  EF202707;  EF202708;  EF202709;  EF202710;  EF202711;  EF202712;  EF202713;  EF202714;  EF202715;  EF202716;  EF202717;  EF202718;  EF202719;  EF202720;  EF202721;  EF202722;  EF202723;  EF202724;  EF202725;  EF202726;  EF202727;  EF202728;  EF202729;  EF202730;  EF202731;  EF202732;  EF202733;  EF202734;  EF202735;  EF202736;  EF202737;  EF202738;  EF202739;  EF202740;  EF202741;  EF202742;  EF202743;  EF202744;  EF202745;  EF202746;  EF202747;  EF202748;  EF202749;  EF202750;  EF202751;  EF202752;  EF202753;  EF202754;  EF202755;  EF202756;  EF202757;  EF202758;  EF202759;  EF202760;  EF202761;  EF202762;  EF202763;  EF202764;  EF202765;  EF202766;  EF202767;  EF202768;  EF202769;  EF202770;  EF202771;  EF202772;  EF202773;  EF202774;  EF202775;  EF202776;  EF202777;  EF202778;  EF202779;  EF202780;  EF202781;  EF202782;  EF202783;  EF202784;  EF202785;  EF202786;  EF202787;  EF202788;  EF202789;  EF202790;  EF202791;  EF202792;  EF202793;  EF202794;  EF202795;  EF202796;  EF202797;  EF202798;  EF202799;  EF202800;  EF202801;  EF202802;  EF202803;  EF202804;  EF202805;  EF202806;  EF202807;  EF202808;  EF202809;  EF202810;  EF202811;  EF202812;  EF202813
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MeSH Terms
Descriptor/Qualifier:
Cloning, Molecular
Ecosystem*
Geologic Sediments / microbiology
Methane / metabolism*
Methanomicrobiales / classification,  enzymology,  genetics,  growth & development*
Methanosarcinales / classification,  enzymology,  genetics,  growth & development*
Mexico
Molecular Sequence Data
Oxidoreductases / genetics*
Phylogeny
Seawater / microbiology
Sequence Analysis, DNA
Sodium Chloride / metabolism*,  pharmacology
Sulfates / metabolism*,  pharmacology
Time Factors
Chemical
Reg. No./Substance:
0/Sulfates; 74-82-8/Methane; 7647-14-5/Sodium Chloride; EC 1.-/Oxidoreductases; EC 2.8.4.1/methyl coenzyme M reductase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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