Molecular cloning and expression of a cold-adapted lipase gene from an antarctic deep sea psychrotrophic bacterium Pseudomonas sp. 7323
This is the author accepted manuscript. The final version is available from Springer via the DOI in this record . A psychrotrophic bacterium producing a cold-adapted lipase was isolated from the deep-sea sediment of Prydz Bay, Antarctic and identified as a Pseudomonas strain. Determination of the nu...
| Published in: | Marine Biotechnology |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Springer
2008
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10871/35890 https://doi.org/10.1007/s10126-008-9099-4 |
| Summary: | This is the author accepted manuscript. The final version is available from Springer via the DOI in this record . A psychrotrophic bacterium producing a cold-adapted lipase was isolated from the deep-sea sediment of Prydz Bay, Antarctic and identified as a Pseudomonas strain. Determination of the nucleotide sequence of the gene encoding a lipase from Pseudomonas sp. 7323 (lipA) revealed that LipA is composed of 617 amino acid residues with a calculated molecular weight of 64,466 Da. LipA has a GXSXG motif, which is conserved in lipases/esterases and generally contains the active-site serine. The lipase purified from the Escherichia coli transformant (rLipA) by metal-chelating chromatography exhibited the same electrophoretic mobility as did the wild-type lipase (wLipA) purified from strain 7323, and both enzymes were quite similar in physicochemical properties. The optimal temperature and pH value for the lipases activity were 30°C and 9.0, respectively. They were unstable at temperatures above 25°C and only retained half of their highest activity after incubation at 60°C for 5 min. These results indicated that the enzymes were typical alkaline cold-adapted enzymes. Both enzymes were particularly activated by Ca2+. Additionally, the enzymes hydrolyzed p-nitrophenyl caprate and tributyrin at the highest velocity among the other p-nitrophenyl esters and triglycerides. Hi-Tech research and development program of China |
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