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ARS Home » Research » Publications at this Location » Publication #82078


item Hou, Ching

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Lipases are enzymes which convert vegetable oils into more nutritionally balanced oils or health supplements and industrial chemicals. Some lipases are very selective for their reaction and also toward compounds they react with. Different industries need different type of lipases. Previously, we screened more than 1300 selected microbial strains and found many different lipases. Now, we have characterized 25 of these new yeasts lipases according to their ability to attack the oils. This information is useful for industries in developing a process to make new products from vegetable oils, thus creates new uses for American farm products.

Technical Abstract: Previously we used a simple, sensitive agar plate method to screen lipase activity from 1229 selected cultures including 508 bacteria, 479 yeasts, 230 actinomycetes and 12 fungi covering many genera and species. About 25% of the cultures tested were lipase positive. In this report, we have characterized 25 of these new yeast lipases on their positional specificity against triglycerides. Of these lipases analyzed, 19 of them showed 1,3 positional specificity and six showed random specificity. No 2 positional specific lipases were found. Among those cultures with highest lipase activity are: Candida silvicola NRRL YB 2846 (random); Candida sp. 55 (random); Candida sp. 125 (random); Pichia americana NRRL Y-2156 (1,3 specific); Pichia musicola NRRL Y 7005 (random); Pichia petersanii NRRL YB 3808 (1,3 specific); and Yarrowia lipolytica NRRL YB 423 (random). Characterization of strain 55 lipase on its substrate preference showed that this enzyme hydrolyzed soybean oil triglyceride species LLLn, LLL, LLO and LLP more readily than LOO, LOP, OOO, LOS and POO.