[Screening and characterization of lipase from a metagenome library of dairy rumen microflora].
Using lipase segregation agar containing trioleoylglycerol, we obtained 18 lipase positive clones by screening from a metagenome library of dairy rumen microflora containing 15,360 clones. The average insert size of lipase positive clones was about 60 kb. Lipase enzyme activity analysis by p-NPP method indicated that Lipase6, Lipase7 and Lipase8 had higher lipolytic activities to substrates of p-nitrophenyl palmitate (C16), p-nitrophenyl alaurate (C12) and p-nitrophenyl palmitate (C16) respectively. The optimum pH of Lipase 6, Lipase 7 and Lipase 8 were 7.5. The halflife period of Lipase 8 with the value of 15 min in 70 degrees C decreased with the increase of temperature. In conclusion, the lipases screened in this study had different substrates specificity and good thermo stability, which laid a basis for large-scale industrial application.
State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy ofAgriculture Sciences, Beijing 100193, China.
Shengguo
S
Zhao
Jiaqi
J
Wang
Kailang
K
Liu
Yaxin
Y
Zhu
Dengpan
D
Bu
Dan
D
Li
Ping
P
Yu
D000818:Animals; D001419:Bacteria / Q000235:genetics; D002417:Cattle; D003001:Cloning, Molecular; D005260:Female; D015723:Gene Library; D008049:Lipase / Q000235:genetics* / Q000378:metabolism; D054892:Metagenome / Q000235:genetics*; D012417:Rumen / Q000382:microbiology*; D013379:Substrate Specificity; D013696:Temperature
D008049:Lipase