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Title: CONVERSION OF FATTY ACIDS BY BACILLUS SPHAERICUS-LIKE ORGANISMS

Author
item Kuo, Tsung Min
item Nakamura, Lawrence

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Bacillus sphaericus species are mesophilic round-spored organisms that readily utilize fatty acid-based surfactants during growth, but their ability to modify fatty acids is unknown. Among 57 B. sphaericus-like strains tested for activity in Wallen fermentation (WF) medium, ten converted oleic acid greater than 0.5% to a new product determined by GC/MS to be 10-ketostearic acid (10-KSA). Unlike most microbial hydrations of oleic acid, which produce a mixture of 10-KSA and 10- hydroxystearic acid, the bioconversion was unique in that 10-KSA was the sole reaction product. Strains NRRL BD-119 and NRRL NRS-732 were able to convert 5% and 10% oleic acid, respectively. By replacing sodium pyruvate for dextrose in WF and adjusting to pH 6.5, conversion of oleic acid to 10-KSA by strain NRRL NRS-732 was improved to greater than 60%. A few other strains also converted ricinoleic acid and linoleic acid to new products that remain to be characterized. The bioconversion using an industrial grade oleic acid as substrate is being evaluated in a stirred bioreactor for the optimum conditions of culture density, reaction pH and time, and oxygen transfer rates.