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:从中国福建沿海某一污染滩涂的沉积物中筛选到一株具有较强拮抗水产病原菌的生防细菌LHB02。采用通用引物,对LHB02的16SrRNA片段进行扩增,获得1511bp的DNA系列,基于该DNA系列,结合细菌形态学、生理生化特征,鉴定LHB02为一株枯草芽孢杆菌。对LHB02进行了抗菌试验、抗菌谱检测和发酵条件优化研究,结果表明,LHB02对哈维氏弧菌、溶藻弧菌、鳗弧菌等有很强的拮抗作用,其优化后的发酵条件为:KB培养基(蛋白胨20g,丙三醇10mL,K2HPO41.5g,MgSO4.7H2O1.5g,H2O1000mL);温度28°C,pH值7.0,培养时间36h,接种量1.5%。