Lipolytic activity from Halobacteria: Screening and hydrolase production

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• 作者：Bhatnagar ; Tej ; Boutaiba ; Saad ; Hacene ; Hocine ; Cayol ; Jean-Luc ; Fardeau ; Marie-Laure ; Ollivier ; Bernard ; et. al.
• 关键词：Halobacteria ; Screening ; Lipolytic activity ; p-Nitrophenyl esters ; Archaeon ; Natronococcus
• 刊名：FEMS Microbiology Letters
• 出版年：2005
• 出版时间：July 15, 2005
• 年：2005
• 卷：248
• 期：2
• 页码：133-140
• 全文大小：190 K

文摘

Strains of Halobacteria from an Algerian culture collection were screened for their lipolytic activity against p-nitrophenyl butyrate (PNPB) and p-nitrophenyl palmitate (PNPP). Most strains were active on both esters and 12 % hydrolyzed olive oil. A strain identified as Natronococcus sp. was further studied. It grew optimally at 3.5 M NaCl, pH 8 and 40 °C. An increase in temperature shifted the optimum salt concentration range for growth from a wider range of 2–4 M, obtained at 25–30 °C, to a narrower range of 3.5–4 M, obtained at 35–40 °C. At 45 °C the optimum salt concentration was 2 M. These results show a clear correlation between salt and temperature requirement. The optimum conditions for the production of hydrolytic activity during growth were: 3.5 M NaCl and pH 8 for PNPB hydrolytic activity and 4 M NaCl and pH 7.5 for PNPP hydrolytic activity; both at 40 °C. The clear supernatant of cells grown at 4 M NaCl showed olive oil hydrolysis activity (in presence of 4 M NaCl) demonstrating the occurrence of a lipase activity in this strain. To our knowledge, this is the first report of a lipase activity at such high salt concentration.