Isolation Screening And Identification Of Lipase-producing Trichoderma Spp. And Studies On Enzymatic Characteristics

114 strains of Trichoderma spp. were isolated from 23 soil samples collected from Beijing,Renqiu,Baoding and Zhangjiakou of Hebei Province,Xinjiang,Yunnan,Menggu.Four strains of lipase-producing Trichoderma were screened.They were identified as T.harzianum,T. longibrachiatum,T.harzianum,T. longibrachiatum by observation of colony morphology and microscope,determination of ITSrDNA sequence and named as 153-1,13-2,30425,Xi1-1. The lipase activity were 4.79 U/ml,2.41 U/ml,5.32 U/ml,3.30 U/ml.The enzymatic characteristics of lipase showed that,the optimum temperature and pH of lipase produced by 153-1 for the enzymatic reaction was 45℃and 9.5.The lipase activity was stimulated by Fe²⁺,Ba²⁺,Li²⁺,but was inhibited by Ca²⁺,Mg²⁺,Cu²⁺,Pb²⁺ .The optimum temperature and pH of lipase produced by 13-2 for the enzymatic reaction was 40℃and 10.0.The lipase activity was stimulated by K⁺,Fe²⁺,Ba²⁺,but was inhibited by Mn²⁺,Cu²⁺. The optimum temperature and pH of lipase produced by 30425 for the enzymatic reaction was 20℃and 7.5.The lipase activity was stimulated by K⁺,Ca²⁺,Mg²⁺,but was inhibited by Li²⁺,Mn²⁺,Cu²⁺. The optimum temperature and pH of lipase produced by Xi1-1 for the enzymatic reaction was 20℃and 9.5.The lipase activity was stimulated by K⁺,Ba²⁺,but was inhibited by Ca²⁺,Cu²⁺,Pb²⁺.The lipase of four strains were purified by centrifuge enrichment,ammonium sulfate precipitation,ion-exchange chromatography on HiPrep DEAE Fast Flow or Resource Q and Superose12 gel-chromatography.The lipase produced by 153-1 got single component,and the lipase produced by 13-2 got two components,but the lipase produced by 30425 and Xi1-1 abtained no active components though purification.It need further test to analysis.Low temperature lipase from two strains of Trichoderma 30425 and Xi1-1,and alkaline lipase from three strains of Trichoderma 153-1,13-2,Xi1-1were got in this study.The strain of Xi1-1 was low temperature alkaline lipase,it have prospective development.