Gene analysis, optimized production and property of marine lipase from Bacillus pumilus B106 associated with South China Sea sponge Halichondria rugosa

Gene cloning, optimized production and property of marine lipase from Bacillus pumilus B106 associated with South China Sea sponge Halichondria rugosa were investigated in this paper. A lipase gene with whole ORF encoding 215 amino acids was obtained by PCR, protein domain prediction suggested that the deduced lipase belongs to alpha/beta hydrolases family. Based on single factor Seriatim-Factorial test and Plackett-Burman experimental design, the optimal medium consisted of (per l) 12.5 ml maize oil, 5.0 g beef extract, 2.0 g PO4 (3-) (0.6 g KH2PO4, 1.4 g K2HPO4), 17.15 g Mg2+, 5.0 g yeast extract, 2.282 g CaCl2 and 5.0 ml Tween80 with artificial sea water. Using this optimum medium, lipase activity and cell concentration were increased by 3.54- and 1.31-fold over that of the basal medium, respectively. This lipase showed tolerance to high salinity, pH and temperature. About 10-20% methanol exhibited a stimulatory effect on the lipase activity, while activity was inhibited by 30-40% methanol, 2-propanol, DMSO, and ethanol. This study provides a valuable resource for marine lipase production and extends our understanding of the possible role of sponge-associated bacteria in the biotransformation of chemical compounds for the sponge host.