Title: Effect of Surfactants on Production of Oxygenated Unsaturated Fatty Acids by Bacillus megaterium ALA2 Authors
Submitted to: UJNR Food & Agricultural Panel Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 10, 2009
Publication Date: October 9, 2009
Citation: Hou, C.T., Kim, B., Kim, H., Ray, K.J. 2009. Effect of surfactants on production of oxygenated unsaturated fatty acids by Bacillus megaterium ALA2. United States-Japan Natural Resources, Food & Agricultural Panel. p. 168-171. Technical Abstract: Bacillus megaterium ALA2 (NRRL B-21660) produces many oxygenated unsaturated fatty acids from linoleic acid. Its major product, 12,13,17-trihydroxy-9(Z)-octadecenoic acid (12,13,17-THOA), inhibits the growth of some plant pathogenic fungi. Because hydrophobic fatty acids need to be evenly dispersed in culture for effective contact with microbial cells, we investigated the effect of surfactants on the production of 12,13,17-THOA. Surfactant type (SO-25, Tween-80 and Triton X-100) with concentrations from 0.01, to 1% were used to evaluate their effects on cell growth and production of 12,13,17-THOA. Among three surfactants tested, Triton X-100 decreased cell growth and 12,13,17-THOA production while Tween-80 at 0.5% nearly doubled 12,13,17-THOA production over the control. When the concentration of substrate was changed with a fixed concentration of Tween-80 (0.5 %), maximum 12,13,17-THOA production was achieved at 1% of substrate. When different concentrations of Tween-80 were tested in a dissolved oxygen controlled fermentor, 12,13,17-THOA production reached maximum at 0.5% of surfactant with THOA production at 620 mg/L.