Isolation and Characterization of a Moderately Halophilic Bacterium High-producing Esterase

Abstract:

A moderately halophilic bacterium strain DF-B6 capable of degrading Tween 20 was isolated from solar saltern by plate method. Based on the phenotype, physiological and biochemical characteristics, and the phylogenetic analysis of 16S rDNA sequence, strain DF-B6 was identified as Idiomarina. The substrate specificity test showed that the lipolytic enzyme from strain DF-B6 was an esterase, and not a lipase. The maximum esterase activity was observed in 8% NaCl concentration at 50°C, pH 8.0. The effect of various divalent cations was studied on the activity of esterase from Idiomarina sp. DF-B6 at the concentration of 10 mmol/L, Mg2+, Ca2+ and Mn2+enhanced the esterase activity, while Zn2+, Fe3+ and Cu2+ inhibited its activity.