title: Medium-based optimization of an organic solvent-tolerant extracellular lipase from the isolated halophilic Alkalibacillus salilacus.
abstract: 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.
authors.affiliation: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, P.O. Box 14155-6451, 1417614411, Tehran, Iran.
authors.forename: Amene
authors.initials: A
authors.lastname: Samaei-Nouroozi
authors.forename: Shahla
authors.initials: S
authors.lastname: Rezaei
authors.forename: Nika
authors.initials: N
authors.lastname: Khoshnevis
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Doosti
authors.forename: Reza
authors.initials: R
authors.lastname: Hajihoseini
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Khoshayand
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Faramarzi
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000535:Aluminum / Q000737:chemistry; D001406:Bacillaceae / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003035:Cobalt / Q000737:chemistry; D004795:Enzyme Stability; D005227:Fatty Acids / Q000737:chemistry; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D009596:Nitrophenols / Q000737:chemistry; D055049:Salt Tolerance; D013379:Substrate Specificity
chemical_list: D000438:Alcohols; D001426:Bacterial Proteins; D005227:Fatty Acids; D009596:Nitrophenols; D003035:Cobalt; D000535:Aluminum; D008049:Lipase