title: Characterization of esterase activity in Geobacillus sp. HBB-4.
abstract: A thermophilic esterase producing bacterium (Bacillus sp. 4), recently isolated from Alangüllü thermal spring in Aydin (Turkey), was analyzed using 16S rRNA and classified as Geobacillus sp. HBB-4, most closely related to Bacillus sp. BGSC W9A59 (0.70% sequence divergence) which belongs to the newly described genus Geobacillus. The effects of several chemicals on the activity of thermostable esterase from Geobacillus sp. HBB-4 were examined. Among the various metal ions tested, esterase activity was enhanced by Mn(+2) and Ni(+2), but was inhibited by Hg(+2) and Cu(+2), whereas Ca(+2), Mg(+2) and Co(+2) had no effect. In addition, other metal ions studied have caused a slight inhibition on the esterase activity. EDTA partially inhibited the HBB-4 esterase. The activator metal ions, Mn(+2) and Ni(+2) have restored partial inhibition of EDTA. The activity of HBB-4 esterase was inhibited by ionic detergents while non-ionic detergents activated the enzyme. However, a zwitterionic detergent, CHAPS, has caused a slight inhibition in the enzyme activity. HBB-4 esterase activity was inhibited at the high concentrations of all the organic solvents tested in the present study. However, 50% final concentration of DMSO increased the enzyme activity about 7%. The HBB-4 esterase has shown more than about 50% of activity in the presence of ethanol and methanol solutions. These characteristics of the enzyme along with its significant thermostability make the Geobacillus sp. HBB-4 esterase a potent candidate for future industrial applications.
authors.affiliation: Department of Biology, Faculty of Science and Literature, Adnan Menderes University, 09010 Aydin, Turkey. kmetin@adu.edu.tr
authors.forename: Kubilay
authors.initials: K
authors.lastname: Metin
authors.forename: Z
authors.initials: Z
authors.lastname: Burcu Bakir Ateslier
authors.forename: Gamze
authors.initials: G
authors.lastname: Basbulbul
authors.forename: H
authors.initials: H
authors.lastname: Halil Biyik
mesh_terms: D001406:Bacillaceae / Q000145:classification / Q000201:enzymology*; D004275:DNA, Ribosomal / Q000235:genetics; D003902:Detergents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004950:Esterases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D008670:Metals / Q000494:pharmacology; D009930:Organic Chemicals / Q000494:pharmacology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012997:Solvents / Q000494:pharmacology; D013696:Temperature
chemical_list: D004275:DNA, Ribosomal; D003902:Detergents; D008670:Metals; D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D012997:Solvents; D004492:Edetic Acid; D004950:Esterases