The thermostable and organic solvent tolerant whole-cell lipase (WCL) was produced by Burkholderia sp. ZYB002 with broad spectrum organic solvent tolerance. The production medium of the WCL was primarily optimized, which resulted in the maximum activity of 22.8 U/mL and the 5.1-fold increase of the WCL yield. The optimized culture medium was as follows (% w/v or v/v): soybean meal 2, soybean oil 0.5, manganese sulfate 0.1, K(2)HPO(4) 0.1, olive oil 0.5, initial pH 6.0, inoculum density 2, liquid volume 35 mL in 250-mL Erlenmeyer flask, and incubation time 24 h. The biochemical characterization of the WCL from Burkholderia sp. ZYB002 was determined, and the results showed that the optimal pH and temperature for lipolytic activity of the WCL was 8.0 and 65°C, respectively. The WCL was stable at temperature up to 70°C for 1 h and retained 79.2% of its original activity. The WCL was highly stable in the pH range from 3.0 to 8.5 for 6 h. Ca(2+), K(+), Na(+), NO (3) (-) , etc. ions stimulated its lipolytic activity, whereas Zn(2+) ion caused inhibition effect. The WCL was also relatively stable in n-butanol at a final concentration of 50% (v/v) for 24 h. However, the WCL was strongly inhibited in Triton X-100 at a final concentration of 10% (v/v). The WCL with thermal resistance and organic solvent tolerance showed its great potential in various green industrial chemical processes.

Production and process optimization of a thermostable lipase from Burkholderia sp. ZYB002 and the application potential of this lipase for pitch control of thermomechanical pulp (TMP) has been investigated. The optimized physical and nutritional factors of Burkholderia sp. ZYB002 were found to be (all units in%, w v -1 ): 0.5 peptone, 0.025 urea, 0.5 glycerol, 0.1 NaHCO 3 , 0.2 K 2 HPO 4 , 1.5 Tween 80, 1.1 olive oil, four inoculum volume, and initial pH 8.5. The lipase production process was carried out at 308C at 250 rpm for 36 h in 250 ml Erlenmeyer flasks containing 35 ml fermentation medium and five glass beads. Under the optimized conditions, lipase activity reached 216.5 U ml -1 . In a TMP of Pinus massoniana, 39% of triglycerides were hydrolyzed by the lipase under optimized conditions wpulp concentration 6% (w v -1 ), lipase dose 20 U g -1 based on dry TMP, pulp initial pH 7.5, and 658C for 30 minx. The lipase in question displayed a great potential for pitch control of TMP.