Transformation of Steroids by Spores of Microorganisms

Conidia ofAspergillus ochraceus convert progesterone into 11α-hydroxyprogesterone and 6β, 11α-dihydroxyprogesterone. The conversion ability does not depend on the sporulation medium. Transformation depends on the strain and on the conidia concentration. Adaptation has never been observed. Age and storage of conidia, pH, aeration-agitation, nitrogen source, metal ions, chelating agents, and metabolic activators showed no great influence within wide limits. Mercuric chloride,p -chloromercuribenzoate, NaN3 , and KCN inhibit conversion. Glucose is necessary, but can be replaced completely byd (+)-xylose, and partially by some other carbon sources. The ratio mono-/di-hydroxyprogesterone is influenced by progesterone concentration and period of incubation; also, a mutant that accumulates only monohydroxyprogesterone has been produced. Conidia ofA. ochraceus also hydroxylate a variety of steroids. Spores of certain streptomycetes, phycomycetes (mucors), ascomycetes, and deuteromycetes are active. Most reactions already observed with vegetative cells have been repeated with spores. In general, spores of a particular organism effect fewer reactions than its mycelium, and fewer products accumulate.