Determination and characterization of thermostable esterolytic activity from a novel thermophilic bacterium Anoxybacillus gonensis A4

Faiz O., Colak A., Saglam N., Canakci S., Belduez A. O.

JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY, vol.40, no.4, pp.588-594, 2007 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 4
  • Publication Date: 2007
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.588-594
  • Keywords: Anoxybacillus, esterase, lipase, thermophile, thermostability, CULTURE-CONDITIONS, CARBOXYL ESTERASE, LIPASE, CLONING, PURIFICATION, EXPRESSION, RESOLUTION
  • Karadeniz Technical University Affiliated: Yes


A novel hot spring thermophile, Anoxybacillus gonensis A4 (A. gonensis A4) was investigated in terms of capability of tributyrin degradation and characterization of its thermostable esterase activity by the hydrolysis of p-nitrophenyl butyrate (PNPB). It was observed that A. gonensis A4 has an esterase with a molecular weight of 62 kDa. The extracellular crude preparation was characterized in terms of substrate specificity, pH and temperature optima and stability, kinetic parameters and inhibition/activation behaviour towards some chemicals and metal ions. Tributyrin agar assay showed that A. gonensis A4 secreted an esterase and V-max and K-m values of its activity were found to be 800 U/L and 176.5 mu M, respectively in the presence of PNPB substrate. The optimum temperature and pH, for A. gonensis A4 esterase was 60-800 degrees C and 5.5, respectively. Although the enzyme activity was not significantly changed by incubating crude extract solution at 30-70 degrees C for 1 h, the enzyme activity was fully lost at 80 degrees C for same incubation period. The pH-stability profile showed that original crude esterase activity increased nearly 2-fold at pH 6.0. The effect of some chemicals on crude esterase activity indicated that A. gonensis A4 produce an esterase having serine residue in active site and -SH groups were essential for its activity.