Production of oxygenated fatty acids from vegetable oils by Flavobacterium sp. strain DS5

Flavobacterium sp. strain DS5 (NRRL B-14859) was used to convert two vegetable oils, olive oil and soybean oil, directly to oxygenated fatty acids such as 10-ketostearic acid (10-KSA) and 10-hydroxystearic acid (10-HSA). Lipase addition to the culture was required because strain DS5 did not induce lipase activity to release free fatty acids from vegetable oils. 10-KSA production was higher from olive oil than from soybean oil because olive oil contains more oleic acid, the precursor of 10-KSA. The optimum amounts of olive oil and lipase addition for 10-KSA production were determined as 0.3ml and 1mg (specific activity=700units/mg) per 50ml culture medium, respectively. At these conditions, 2.8g/L of 10-KSA and 0.40g/L of 10-HSA were obtained from olive oil as a substrate.