Isolation and characterization of a thermophilic lipase from bacillus thermoleovorans ID-1.
A thermophilic microorganism, Bacillus thermoleovorans ID-1, isolated from hot springs in Indonesia, showed extracellular lipase activity and high growth rates on lipid substrates at elevated temperatures. On olive oil (1.5%, w/v) as the sole carbon source, the isolate ID-1 grew very rapidly at 65 degrees C with its specific growth rate (2.50 h(-1)) and its lipase activity reached the maximum value of 520 U l(-1) during the late exponential phase and then decreased. In addition to this, isolate ID-1 could grow on a variety of lipid substrates such as oils (olive oil, soybean oil and mineral oil), triglycerides (triolein, tributyrin) and emulsifiers (Tween 20, 40). The excreted lipase of ID-1 was purified 223-fold to homogeneity by ammonium sulfate precipitation, DEAE-Sephacel ion-exchange chromatography and Sephacryl S-200 gel filtration chromatography. As a result, the relative molecular mass of the lipase was determined to be 34 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed optimal activity at 70-75 degrees C and pH 7.5 and exhibited 50% of its original activity after 1 h incubation at 60 degrees C and 30 min at 70 degrees C and its catalytic function was activated in the presence of Ca(2+) or Zn(2+).
Lee
D
D
Department of Biotechnology, Bioproducts Reasearch Center, Yonsei university, 134 Shinchon-Dong, Sudaemoon-Gu, Seoul, South Korea.
Koh
Y
Y
Kim
K
K
Kim
B
B
Choi
H
H
Kim
D
D
Suhartono
M T
MT
Pyun
Y
Y
D001407:Bacillus / Q000201:enzymology* / Q000254:growth & development; D008049:Lipase / Q000302:isolation & purification* / Q000378:metabolism
D008049:Lipase