Characterization of esterase activity in Geobacillus sp. HBB-4

✍ Scribed by Kubilay Metin; Z. Burcu Bakir Ateslier; Gamze Basbulbul; H. Halil Biyik

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 109 KB
• Volume: 46
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.200510121

✦ Synopsis

Abstract

A thermophilic esterase producing bacterium (Bacillus sp. 4), recently isolated from Alangüllü thermal spring in Aydın (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. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)