Partial Purification and Characterization of a Thermoalkalophilic Lipase Originated from Bacillus atrophaeus FSHM2 and its Application for Ester Synthesis

Abstract

A thermoalkalophilic lipase producing bacterial strain, identified as Bacillus atrophaeus FSHM2 using 16S rDNA sequencing analysis was isolated from salty soil and its lipase was partially purified and characterized. The obtained results revealed that glucose, hazelnut oil, urea and calcium ion positively affected the lipase production by increasing the lipolytic activity to 13582.5, 6270, 4442 and 5505 U LG1, respectively compared to that of basal medium (4150 U LG1). The partially purified lipase acted optimally at pH 9 and retained 88.2% of its initial activity after 1 h of incubation at 100°C. A two fold increase in the relative activity of the partially purified lipase was obtained in the presence of 4 M of NaCl. Application of the partially purified lipase for the synthesis of ethyl and methyl valerate in the organic solvent medium (xylene) resulted in 81.6 and 62.4% esterification, respectively, after 24 h of incubation