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 (TB-TA) 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-NPC₁₆ at a pH of 8.5 and 50°C, and the K_m, k_cat, and k_cat/K_m values were 1.05, 292.95 s^-1 and 279 s^-1mM^-1, respectively. The lipase was highly stable at 7.5 ≤ pH ≤ 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.