title: Effect of surfactant on the production of oxygenated unsaturated fatty acids by Bacillus megaterium ALA2.
abstract: 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.
authors.affiliation: Microbial Genomics and Bioprocessing Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604, USA.
authors.forename: Beom Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Hak-Ryul
authors.initials: HR
authors.lastname: Kim
authors.forename: Ching T
authors.initials: CT
authors.lastname: Hou
mesh_terms: 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*
chemical_list: D005231:Fatty Acids, Unsaturated; D013501:Surface-Active Agents; D013024:Soybean Oil; D019787:Linoleic Acid; D010100:Oxygen