STEREOSPECIFIC OXIDATION OF 3-BETA-HYDROXYSTEROIDS BY PERSOLVENT FERMENTATION WITH PSEUDOMONAS SP ST-200

Pseudomonas sp, strain ST-200 isolated from a humus soil effectively o xidizes cholesterol dissolved in organic solvents but not that suspend ed in the growth medium, The organism does not assimilate cholesterol, This organism oxidized a variety of 5 alpha- or 5-ene-sterols dissolv ed in organic solvent, First, tile 3 beta-OH group was oxidized to a k etone group, The 3 alpha-OH group was scarcely oxidized. Successively, C-6 position of 5-ene-steroids was hydroxylated, and a double bond of 5-ene-steroids was transferred from Delta(5) to Delta(4), Then, the 6 -OH group was oxidized to a ketone group, Persolvent fermentation with ST-200 would provide an effective, convenient, and stereospecific met hod to oxidize the C-3 and C-6 positions of steroids.