Construction of Library of Lipase-proudcing Strains in Extreme Enviroments and Studies of Lipase

For obtaining lipase of special quality,lipase-producing strains were directional screened from 27 samples which collected from extreme environments. Various strains constructed a library of lipase-proudcing strains.Among them,yeast L112’s lipase activity could reach 18.6u/ml at 20℃ and pH 5.0.As a reasult the characteristic of acid lipase was studied in this essay.The lipase activity could reach the highest at pH5.4 and 25～30℃,and survival 60% below 50℃ for 40min at pH4.8.Different metal ions showed adverse effects on the lipase activity.Mg~(2+) and Ca~(2+) enhanced the lipase activity,whereas Zn~(2+),Fe~(2+),Cu~(2+) and EDTA cause inhibition.The lipase-proudcing strain was certificated as Cryptococcus laurentii(Kufferath) C.E. Skinner by Institute of Microbiology,Acadmy of Sciences,Beijing,China.