Characterization of thermostable lipase from thermophilic Geobacillus sp. TW1.
A novel lipase-producing thermophilic strain TW1, assigned to Geobacillus sp. TW1 based on 16S rRNA sequence, was isolated from a hot spring in China. Based on this strain, a lipase gene encoding 417 amino acids was cloned. Subsequently, the lipase gene was expressed in Escherichia coli and purified as a fusion protein with glutathione S-transferase. The results showed that the recombinant lipase had an activity optimum at 40 degrees C and pH at 7.0-8.0. It was active up to 90 degrees C at pH 7.5, and stable over a wide pH ranging from 6.0 to 9.0. The recombinant lipase was stable in 1 mM enzyme inhibitors (EDTA, 2-ME, SDS, PMSF or DTT), as well as in 0.1% detergents (Tween 20, Chaps or Triton X-100). Its catalytic function was enhanced in the presence of Ca(2+), Mg(2+), Zn(2+), Fe(2+) or Fe(3+), but inhibited by Cu(2+), Mn(2+), and Li(+). By comparison with the crude lipase, the recombinant lipase had similar properties and was characteristic of thermostable enzymes. Our study presented a rapid overexpression and purification of the lipase gene from thermophile, aimed at improving the enzyme yield for industrial applications.
Li
Hebin
H
School of Life Sciences, Xiamen University, People's Republic of China.
Zhang
Xiaobo
X
D000595:Amino Acid Sequence; D001406:Bacillaceae / Q000201:enzymology* / Q000235:genetics; D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003902:Detergents / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D002413:Cations, Divalent; D004269:DNA, Bacterial; D003902:Detergents; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D008049:Lipase