title: Purification and Characterization of an Alkali-Thermostable Lipase from Thermophilic Anoxybacillus flavithermus HBB 134.
abstract: An intracellular lipase from Anoxybacillus flavithermus HBB 134 was purified to 7.4-fold. The molecular mass of the enzyme was found to be about 64 kDa. The maximum activity of the enzyme was at pH 9.0 and 50°C. The enzyme was stable between pH 6.0 and 11.0 at 25°C, 40°C, and 50°C for 24 h. The Km and Vmax of the enzyme for pNPL substrate were determined as 0.084 mM and 500 U/mg, respectively. Glycerol, sorbitol, and mannitol enhanced the enzyme thermostability. The enzyme was found to be highly stable against acetone, ethyl acetate, and diethyl ether. The presence of PMSF, NBS, DTT and β-mercaptoethanol inhibited the enzyme activity. Hg(2+), Fe(3+), Pb(2+), Al(3+), and Zn(2+) strongly inhibited the enzyme whereas Li(+), Na(+), K(+), and NH4(+) slightly activated it. At least 60% of the enzyme activity and stability were retained against sodium deoxycholate, sodium taurocholate, n-octyl-β-D-glucopyranoside, and CHAPS. The presence of 1% Triton X-100 caused about 34% increase in the enzyme activity. The enzyme is thought to be a true lipase since it has preferred the long-chain triacylglycerols. The lipase of HBB 134 cleaved triolein at the 1- or 3-position.
authors.affiliation: Department of Biology, Faculty of Science and Arts, Adnan Menderes University, 09010 Aydn, Turkey.
authors.forename: Zehra Burcu
authors.initials: ZB
authors.lastname: Bakir
authors.affiliation: Department of Biology, Faculty of Science and Arts, Adnan Menderes University, 09010 Aydn, Turkey.
authors.forename: Kubilay
authors.initials: K
authors.lastname: Metin
mesh_terms: D000468:Alkalies / Q000494:pharmacology; D058677:Anoxybacillus / Q000201:enzymology* / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005990:Glycerol / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism; D008623:Mercaptoethanol / Q000494:pharmacology; D008970:Molecular Weight; D013012:Sorbitol / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000468:Alkalies; D001426:Bacterial Proteins; D008353:Mannitol; D013012:Sorbitol; D008623:Mercaptoethanol; D008049:Lipase; C428386:thermostable lipase; D005990:Glycerol
keywords: Anoxybacillus; characterization; lipase; purification; thermophilic