A novel broad-temperature active and solvent stable esterase from a newly isolated Bacillus aerophilus

This study reported a newly isolated Bacillus aerophilus from hot spring soil samples produces a broad temperature-active esterase. Maximum esterase activity of the culture medium was obtained after 12 h at 35 °C and pH 9.0, 300 rpm. The enzyme was purified to homogeneity with molecular mass of 28 kDa. The enzyme was active over a broad range of temperature (5-50 °C), displayed the optimal activity at pH 8.0 and 37 °C, and being stable at alkali pHs from 8.0 to 10.0 for 12 h. In addition, it was highly active and stable in hydrophobic solvents for 24 h. Metal ions like Li+, Mg2+ and Ca2+ could not interfere the enzyme activities whereas detergents strongly inhibited the activity. Enzyme showed preferred specificity with short-chain substrates and displayed an optimum activity against butyrate ester. This new vigorous enzyme with remarkable properties provides us a promising candidate to meet the needs of some harsh industrial processes.