Effect of surfactant on the production of oxygenated unsaturated fatty acids by Bacillus megaterium ALA2.
Bacillus megaterium ALA2 NRRL B-21660 has been well studied for the production of many oxygenated unsaturated fatty acids from linoleic acid. Its major product, 12,13,17-trihydroxy-9(Z)-octadecenoic acid (12,13,17-THOA), inhibited the growth of many plant pathogenic fungi. However, we have been unable, until now, to demonstrate 12,13,17-THOA production in a fermentor. Here, we have investigated the effect of surfactants on 12,13,17-THOA production. Surfactant types (SO-25, Tween-80 and Triton X-100) at various concentrations were evaluated for their effects on cell growth and production of 12,13,17-THOA. Triton X-100 decreased cell growth and 12,13,17-THOA production while 1% Tween-80 increased 12,13,17-THOA production more than twofold over control. In a pH and dissolved oxygen (DO) controlled fermentor and with 1.0% Tween-80, both 12,13,17-THOA production and productivity increased to 553 mg/L and 24.0mg/L/hour, respectively. We further conducted THOA production in a fermentor without the control of pH and DO, but with aeration through medium surface rather than by Spurger, and with various amounts of Tween-80 to compare with the results obtained in flask runs. Both additions with 0.1% and 0.5% Tween-80 and the control runs produced poor amounts of product 12,13,17-THOA. The maximum 12,13,17-THOA production was observed at 1.0% Tween-80 at a yield of 650 mg/L. Thus fermentor production of 12,13,17-THOA was successfully demonstrated.
Kim
Beom Soo
BS
Microbial Genomics and Bioprocessing Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604, USA.
Kim
Hak-Ryul
HR
Hou
Ching T
CT
D001410:Bacillus megaterium / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000737:chemistry; D005285:Fermentation; D019787:Linoleic Acid / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D013024:Soybean Oil / Q000737:chemistry; D013501:Surface-Active Agents / Q000378:metabolism*
D005231:Fatty Acids, Unsaturated; D013501:Surface-Active Agents; D013024:Soybean Oil; D019787:Linoleic Acid; D010100:Oxygen