Lithocholic acid side-chain cleavage to produce 17-keto or 22-aldehyde steroids by Pseudomonas putida strain ST-491 grown in the presence of an organic solvent, diphenyl ether

We devised a method to screen for microorganisms capable of growing on bile acids in the presence of organic solvents and producing organic solvent-so luble derivatives. Pseudomonas putida biovar A strain ST-491 isolated in th is study produced decarboxylated derivatives from the bile acids. Strain ST -491 grown on 0.5% lithocholic acid catabolized approximately 30% of the su bstrate as a carbon source, and transiently accumulated in the medium andro sta-1,4-diene-3,17-dione in an amount of corresponding to 5% of the substra te added. When 20% (v/v) diphenyl ether was added to the medium, 60% of the substrate was converted to 17-keto steroids (androst-4-ene-3,17-dione-like steroid, androsta-1,4-diene-3,17-dione) or a 22-aldehyde steroid (pregna-1 ,4-dien-3-on-20-al). Amounts of the products were responsible for 45, 10, a nd 5% of the substrate, respectively. In the presence of the surfactant Tri ton X-100 instead of diphenyl ether, 40% of the substrate was converted exc lusively to androsta-1,4-diene-3,17-dione.