Lipase from Pseudomonas aeruginosa LP602: biochemical properties and application for wastewater treatment

Lipase from Pseudomonas aeruginosa LP602, a bacterial strain isolated from a domestic wastewater sample, was preliminarily characterized. The enzyme exhibited maximum lipolytic activity at pH 8.0 where it was also stably maintained. At 55 degrees C, the lipase had the highest activity but not stability. The enzyme was insensitive to EDTA and to many ions tested except Zn2+. It was sensitive to SDS but not to Tween-20, Tween-80 or Triton X-100, The enzyme was active towards a number of commercial food grade fats and oils. A suitable medium formula for lipase production was MMP containing 6.25% whey as a carbon source, 1% soybean oil as inducer and 0.5% yeast extract supplement. The culture was fed with glucose to a final concentration of 0.1% at the 15th hour of incubation. Lipase production under this condition was 3.5 U ml(-1). Both P. aeruginosa LP602 cells and the lipase were shown to be usable for lipid-rich wastewater treatment.