An organic-solvent-tolerant esterase from thermophilic Bacillus licheniformis S-86

TORRES SEBASTIAN,; MARIA ALEJANDRA MARTINEZ; ASHOK PANDEY; GUILLERMO R. CASTRO

BIORESOURCE TECHNOLOGY

Elsevier

Año: 2009 vol. 100 p. 896 - 902

0960-8524

A thermophile, halotolerant and organic-solvent-tolerant esterase producer Bacillus sp. S-86 strain previously isolated was found to belong to B. licheniformis species through morphological, biochemical, 16S rRNA gene sequence analyses and rDNA intergenic spacers amplification (ITSPCR). The strain can grow at 55ºC in presence of C2 to C7 alkanols (log P = -0.86 to 2.39), and NaCl concentrations up to 15% (w/v). This bacterium showed optimal growth and esterase production at 50°C. Two different molecular weight esterase activities were detected in zymographic assays. PMSF inhibited type I esterase activity, showing no inhibitory effect on type II esterase activity. B. licheniformis S-86 was able to grow in presence of hydroxylic organic  solvents like propan-2-ol, butan-1-ol and 3-methylbutan-1-ol. At a sub-lethal concentration of these solvents (392 mmol l-1 propan-2-ol; 99 mmol l-1 butan-1-ol, 37 mmol l-1 3-methylbutan-1-ol), adequate to produce 50% cell growth inhibition at 50°C, an increment between 1.9 and 2.3 times was observed in type I esterase production, and between 2.2 and 3.1 times in type II esterase production.