简介:BacteriaofthegenusFlammeovirgacandigestcomplexpolysaccharides(CPs),butnodetailshavebeenreportedregardingtheCPdepolymerasesofthesebacteria.MY04,anagarolyticmarinebacteriumisolatedfromcoastalsediments,hasbeenidentifiedasanewmemberofthegenusFlammeovirga.TheMY04strainisabletoutilizemultipleCPsasasolecarbonsourceandgrowswellonagarose,mannan,orxylan.Thisstrainproduceshighconcentrationsofextracellularproteins(490mgL-1±18.2mgL-1liquidculture)thatexhibitefficientandextensivedegradationactivitiesonvariouspolysaccharides,especiallyagarose.Theseproteinshaveanactivityof310Umg-1±9.6Umg-1proteins.Theextracellularagarasesystem(EAS)inthecrudeextracellularenzymescontainsatleastfouragarosedepolymerases,whicharewithmolecularmassesofapproximately30-70kDa.TheEASisstableatawiderangeofpHvalues(6.0-11.0),temperatures(0-50℃),andsodiumchloride(NaCl)concentrations(0-0.9molL-1).TwomajordegradationproductsgeneratedfromagarosebytheEASareidentifiedtobeneoagarotetraoseandneoagarohexaose,suggestingthatβ-agarasesarethemajorconstituentsoftheMY04EAS.TheseresultssuggestthattheFlammeovirgastrainMY04anditspolysac-charide-degradationsystemholdgreatpromiseinindustrialapplications.
简介:ToanalyzethegenomicmolecularstructureandgenotypeofhumanastrovirusisolatedfrominfantinGuangzhouofChina,theprimersweredesignedbasedonthegenomicsequenceofastrovirusfromtheGenBankandthetargetsequencewereamplifiedbyRT-PCR.ThenthePCR-productswereclonedtoTvectorandsequenced.ThegenomicnucleotidesequenceswereanalyzedbytheprogramsCLUSTALWandDNASTAR.ItwasfoundthatthefullgenomiclengthofHASTVgz01strainwas6721bpandtheORFswere6558bp.The5'and3'UTRwere82and81nucleotides.Thegenomeincluded3openreadingframes(ORFs):ORF1a,ORF1bandORF2.The5'-terminalORF1astartedatnucleotide83andextendedtonucleotide2845.ORFlb(nt2785tont4332)overlapedORFlaby61nucleotides.The3'-terminalORF2beganatnucleotide4325andterminatedatnucleotide6640.ORF2had2316nucleotides.ComparedwithotherastrovirussequencesinGenBank,thehomologyoftheaminoacidsequenceofORF2ofHASTVgz01strainwiththatofserotype4was93%.Homologywithotherserotypesrangedfrom61%to70%.ThecompletenucleotidesequenceofastrovirusHASTVgz01strainisolatedfromGuangzhouinChinawas6721bpinlength,GenBankaccessionNO.DQ344027.ComparingtheORF2ofastrovirusHASTVgz01withtheknownsequencesoftypes1-8thehighesthomologywasserotype4(93%).ComparativesequenceanalysisoftheHASTVgz01ORF2withthereportedhumanastrovirussequencesrevealedthattheisolatedastrovirusbelongstogenotype(serotype)4.