RT Journal Article SR Electronic(1) A1 Gilbert, E. Jane A1 Drozd, Jan W. A1 Jones, Colin W.YR 1991 T1 Physiological regulation and optimization of lipase activity in Pseudomonas aeruginosa EF2 JF Microbiology, VO 137 IS 9 SP 2215 OP 2221 DO https://doi.org/10.1099/00221287-137-9-2215 PB Microbiology Society, SN 1465-2080, AB Summary: Physiological regulation of extracellular lipase activity by a newly-isolated, thermotolerant strain of Pseudomonas aeruginosa (strain EF2) was investigated by growing the organism under various conditions in batch, fed-batch and continuous culture. Lipase activity, measured as the rate of olive oil (predominantly triolein) hydrolysis, was weakly induced by general carbon and/or energy limitation, strongly induced by a wide range of fatty acyl esters including triglycerides, Spans and Tweens, and repressed by long-chain fatty acids including oleic acid. The highest lipase activities were observed during the stationary phase of batch cultures grown on Tween 80, and with Tween 80-limited fed-batch and continuous cultures grown at low specific growth rates. The lipase activity of Tween 80-limited continuous cultures was optimized with respect to pH and temperature using response surface analysis; maximum activity occurred during growth at pH 6·5, 35·5 †C, at a dilution rate of 0·04 h−1. Under these conditions the culture exhibited a lipase activity of 39 LU (mg cells)−1and a specific rate of lipase production (q Lipase) of 1·56 LU (mg cells)−1h−1(1 LU equalled 1 μmol fatty acid released min−1). Esterase activity, measured with p-nitrophenyl acetate as substrate, varied approximately in parallel with lipase activity under all growth conditions, suggesting that a single enzyme may catalyse both activities., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-137-9-2215