微生物生态学

MetaproteomiccharacterizationofasoilmicrobialcommunityfollowingcarbonamendmentMarkA.Williams*,ErinB.Taylor,HimayaP.MulaDepartmentofPlantandSoilSciences,MississippiStateUniversity,470DormanHall,MississippiState,MS39762,USAarticleinfoArticlehistory:Received18December2009Receivedinrevisedform22March2010Accepted23March2010Availableonline9April2010Keywords:SoilmetaproteomeProteinSDS-PAGESoilmicrobialcommunity16SrRNAgenesDensitygradientcentrifugationabstractMetaproteomicshasthepotentialtotransformthestudyofmicrobialcommunityfunctioninginsoil.Totestthispotential,experimentswereconductedtocharacterizethemicrobialcommunityproteomein(1.)toluene-amendedsoiland(2.)toluene-amendedsoilmicrobialinoculatedcultures.Aglucose-amendedsoilwasalsousedasacontrasttotheeffectsoftoluene.Atotalof47proteinswereidentifiedata95%confidenceinterval.Thetoluene-amendedcommunitiessharedmanyproteinsandshowedahighdegreeofsimilaritytopreviousstudiesoftolueneimpactedbacteria.Forexample,themicrobialcommunitiesinthetoluene-amendedsoilandculturesbutnottheglucoseimpactedmicrobialcommunities,showedthepresenceofglutaminesynthetase(Gln),ABCtransporters(e.g.Glt1),extra-cellularsolute-bindingproteins,andoutermembraneproteins(Omp).Theseproteinsmaybeupregu-latedforthepurposeofremovingtoluenefrombacterialcells.Toluene-amendedculturesalsoshowedthepresenceofargininedeiminase(ArcA),andcold-shockprotein(Csp),whilemicrobialproteinfromtoluene-amendedsoilshowedthepresenceofthestressproteinssuperoxidedismutase(SodB)andchaperonin(GroEL).Fattyacidmethylesteranalysisindicatedthattoluene-exposedmicroorganismsincreasedtherigidityoftheirmembranesthrougha3to12�increaseintheratioofsaturatedtomonounsaturatedfattyacids.Moreover,the16SrRNAgeneanalysisofbacterialcommunitiesinthetolueneamendedsoilshowedahighdegreeofdominance,wherebyw80%oftheOTUsweredescribedbyrepresentativesmostcloselyrelatedtogenusBacillus,Thisresearchhasshownthatproteomicstudiescanbeusedtoprovideusefuldescriptionsofmicrobialfunctioninsoil.�2010ElsevierLtd.Allrightsres