Purification and characterization of extracellular lipases from Pseudomonas monteilii TKU009 by the use of soybeans as the substrate

San-Lang Wang,¹ Yu-Ting Lin,¹ Tzu-Wen Liang,¹ Sau-Hua Chio,¹ Li-June Ming,^2,3 Pei-Chen Wu¹

[1] Graduate Institute of Life Sciences, Tamkang University, Tamsui 251, Taiwan

[2] Department of Chemistry, University of South Florida, Tampa, FL 33620, USA

[3] visiting professor at Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan

Abstract A lipase-producing bacterium was isolated and identiWed as Pseudomonas monteilii TKU009. A lipase (F2) and lipase-like materials (F1) were puriWed from the culture supernatant of P. monteilii TKU009 with soybean powder as the sole carbon/nitrogen source. The molecular mass of F1 and F2 was estimated to be 44 kDa by SDSPAGE and gel Wltration. The optimum pH, optimum temperature, and pH and thermal stabilities of F2 were 7, 40 °C, 8–11, and 50°C; and of F1 were 6, 40 °C, 6–7, and 50 °C, respectively. F2 was completely inhibited by EDTA and slightly by Mg²⁺, Fe²⁺, Mn²⁺, and SDS. F1 was completely inhibited by EDTA and Fe²⁺ and strongly by Zn²⁺, Mn²⁺, Ca²⁺, Mg²⁺, and SDS. The activities of both the enzymes were enhanced by the addition of non-ionic surfactants Triton X–100 and Tween 40, especially for F1. F2 preferably acted on substrates with a long chain (C10–C18) of fatty acids, while F1 showed a broad spectrum on those with chain length of C4–C18. The marked activity of F2 in organic solvents makes it an ideal choice for application in a water-restricted medium including organic synthesis.

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