Lipase activity and gene cloning of Acinetobacter calcoaceticus LP009

The Journal of General and Applied Microbiology

Gunjana Theeragool¹  Jaturong Pratuangdejkul³  Saovanee Dharmsthiti²  Sudaporn Luchai² 

[1] Department of Microbiology, Faculty of Science, Kasetsart University;Center for Biotechnology, Institute for Research and Development in Science and Technology, Mahidol University;Department of Biotechnology, Faculty of Science, Mahidol University

关键词: Acinetobacter calcoaceticus;    heterogeneous expression;    lipase;    lipase gene cloning;   

DOI  :  10.2323/jgam.44.139

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

The production of lipase from Acinetobacter calcoaceticus LP009, a bacterium isolated from raw milk, was found to be best induced by Tween-80 at 1.0% concentration. It was efficiently secreted, and only a minute amount of activity was detected at the cell surface and intracellularly. A. calcoaceticus LP009 lipase exhibited maximum activity at pH 7.0 and 50°C, and was relatively stable upon storage at pH 5.0 to 7.0 and at 4, 30, or 37°C. The enzyme was found to be inactivated by EDTA suggesting that it was a metalloenzyme. Its activity was reduced by less than 20% with the addition of various ions to reaction mixtures, but long storage with them caused approximately 50% reduction in subsequent reactions under standard conditions. By contrast, the addition of Fe3+ enhanced activity. The enzyme was highly stable upon storage with 0.1% of Triton X-100, Tween-80 or Tween-20, but highly unstable with various organic solvents tested. PMSF, a serine enzyme inhibitor, and 2-mercaptoethanol, a reducing agent, did not affect enzyme activity. After extraction and transfer, the lipase gene was efficiently expressed in recombinant Aeromonas sobria. This recombinant strain was shown to have increased hydrolyzing efficiency and have high potential for lipid-rich wastewater treatment.

【 授权许可】

Unknown