Medium-based optimization of an organic solvent-tolerant extracellular lipase from the isolated halophilic Alkalibacillus salilacus

• DOI: 10.1007/s00792-015-0769-7
• Publication Date: 2015-07-21T07:56:08Z
• Authors: Amene Samaei-Nour...; Shahla Rezaei; Nika Khoshnevis; Mahmoud Doosti; Reza Hajihoseini; Mohammad Reza Kho...; Mohammad Ali Fara...
• Keywords: 0106 biological sciences; Fatty Acids; Cobalt; Lipase; Salt Tolerance; 01 natural sciences; Substrate Specificity; Nitrophenols; Bacterial Proteins; Alcohols; Enzyme Stability; Bacillaceae; Aluminum

A haloalkaliphilic solvent-tolerant lipase was produced from Alkalibacillus salilacus within 48 h of growth in liquid medium. An overall 4.9-fold enhanced production was achieved over unoptimized media after medium optimization by statistical approaches. Plackett-Burman screening suggested lipase production maximally influenced by olive oil, KH2PO4, NaCl, and glucose; and response surface methodology predicted the appropriate levels of each parameter. Produced lipase was highly active and stable over broad ranges of temperature (15-65 °C), pH (4.0-11.0), and NaCl concentration (0-30 %) showing excellent thermostable, pH-stable, and halophilic properties. The enzyme was optimally active at pH 8.0 and 40 °C. Majority of cations, except some like Co(2+) and Al(3+) were positive signals for lipase activity. In addition, the presence of chemical agents and organic solvents with different log P ow was well tolerated by the enzyme. Finally, efficacy of lipase-mediated esterification of various alcohols with oleic acid in organic solvents was studied.