Isolation and Characterization of a Novel Bacterium Burkholderia gladioli Bsp-1 Producing Alkaline Lipase

Active lipase-producing bacterium Burkholderia gladioli Bps-1 was rapidly isolated using a modified trypan blue and tetracycline, ampicillin plate. The electro-phoretically pure enzyme was obtained by purification using ethanol precipitation, ion-exchange chromatography, and gel filtration chromatography. The molecular weight was 34.6 kDa and the specific activity was determined to be 443.9 U/mg. The purified lipase showed the highest activity after hydrolysis with $p-NPC_{16}$ at a pH of 8.5 and $50^{\circ}C$, and the $K_m$, $k_{cat}$, and $k_{cat}/K_m$ values were 1.05 mM, $292.95s^{-1}$ and $279s^{-1}mM^{-1}$, respectively. The lipase was highly stable at $7.5{\leq}pH{\leq}10.0$. $K^+$ and $Na^+$ exerted activation effects on the lipase which had favorable tolerance to short-chain alcohols with its residual enzyme activity being 110% after being maintained in 30% ethanol for 1 h. The results demonstrated that the lipase produced by the strain B. gladioli Bps-1 has high enzyme activity and is an alkaline lipase. The lipase has promising chemical properties for a range of applications in the food-processing and detergent industries, and has particularly high potential for use in the manufacture of biodiesel.