Abstract: A procedure for the preparation of pseudomonic acid A comprising submerged cultivation of a Pseudomonas bacterium strain capable of biosynthesis of the substantially pure pseudomonic acid A in aerated conditions via fermentation; and isolation of the desired compound is disclosed. In particular, the procedure of the present invention comprises cultivation of the Pseudomonas sp. bacterium strain No. 19/26 deposited under accession No. NCAIM(P)B 001235 in the National Collection of the Agricultural and Industrial Microorganisms, Budapest, Hungary, or its pseudomonic acid A-producing mutant or variant, on a medium at a temperature of between about 20° C. and 30° C. containing organic nitrogen and carbon sources and, optionally, mineral salts.

Abstract: A procedure for the preparation of pseudomonic acid A comprising submerged cultivation of a Pseudomonas bacterium strain capable of biosynthesis of the substantially pure pseudomonic acid A in aerated conditions via fermentation; and isolation of the desired compound is disclosed. In particular, the procedure of the present invention comprises cultivation of the Pseudomonas sp. bacterium strain No. 19/26 deposited under accession No. NCAIM(P)B 001235 in the National Collection of the Agricultural and Industrial Microorganisms, Budapest, Hungary, or its pseudomonic acid A-producing mutant or variant, on a medium at a temperature of between about 20° C. and 30° C.

Abstract: A procedure for the preparation of pseudomonic acid A comprising submerged cultivation of a Pseudomonas bacterium strain capable of biosynthesis of the substantially pure pseudomonic acid A in aerated conditions via fermentation; and isolation of the desired compound is disclosed. In particular, the procedure of the present invention comprises cultivation of the Pseudomonas sp. bacterium strain No. 19/26 deposited under accession No. NCAIM(P)B 001235 in the National Collection of the Agricultural and Industrial Microorganisms, Budapest, Hungary, or its pseudomonic acid A-producing mutant or variant, on a medium at a temperature of between about 20° C. and 30° C. containing organic nitrogen and carbon sources and, optionally, mineral salts.

Abstract: A procedure for the preparation of pseudomonic acid A comprising submerged cultivation of a Pseudomonas bacterium strain capable of biosynthesis of the substantially pure pseudomonic acid A in aerated conditions via fermentation; and isolation of the desired compound is disclosed. In particular, the procedure of the present invention comprises cultivation of the Pseudomonas sp. bacterium strain No. 19/26 deposited under accession No. NCAIM(P)B 001235 in the National Collection of the Agricultural and Industrial Microorganisms, Budapest, Hungary, or its pseudomonic acid A-producing mutant or variant, on a medium at a temperature of between about 20° C. and 30° C. containing organic nitrogen and carbon sources and, optionally, mineral salts.

Abstract: A procedure for the preparation of pseudomonic acid A comprising submerged cultivation of a Pseudomonas bacterium strain capable of biosynthesis of the substantially pure pseudomonic acid A in aerated conditions via fermentation; and isolation of the desired compound is disclosed. In particular, the procedure of the present invention comprises cultivation of the Pseudomonas sp. bacterium strain No. 19/26 deposited under accession No. NCAIM(P)B 001235 in the National Collection of the Agricultural and Industrial Microorganisms, Budapest, Hungary, or its pseudomonic acid A-producing mutant or variant, on a medium at a temperature of between about 20° C. and 30° C. containing organic nitrogen and carbon sources and, optionally, mineral salts.

Abstract: The invention refers to a new microbial process for preparing .beta.,.delta.-dihydroxy-7-[1,2,6,7,8,8a-hexahydro-2.6-dimethyl-8-(2-methy l-butyryloxy)-naphthalen-1-yl]-heptanoic acid .delta.-lactone of formula (I) and .beta.,.delta.-dihydroxy-7-[1,2,6,7,8,8a-hexahydro-2.6-dimethyl-8-(2-methy lbutyryloxy)-naphtalen-1-yl]-heptanoic acid of formula (II), ##STR1## by the aerobic fermentation of the submerged culture of an imperfect fungus strain biosynthesizing the above compounds, in a nutrient medium containing utilizable carbon and nitrogen sources as well as mineral salts, and by isolating the product of formula (I), which comprises cultivating a strain of the new Aspergillus obscurus fungus species producing the above compound(s) of formulas (I) and/or (II), in a temperature range of 25.degree. to 30.degree. C. and, if desired, separating the product(s) formed from the fermentation broth, then isolating it in the lactone form of formula (I) and, if desired, purifying the same.

Abstract: The invention relates to a process for the production of 9.alpha.-hydroxy-4-androstene-3,17-dione from natural sterols of plant or animal origin or from mixtures thereof by the submerged aerobic fermentation of an enzyme-deficient, sterol-de-grading microorganism in a nutrient medium containing utilizable carbon and nitrogen sources as well as mineral salts, and by isolating the product formed, which comprises transforming the sterol or sterol mixture with the culture of a 1,2-steroid-dehydrogenase deficient strain of new Mycobacterium roseum species which is able to degrade the side-chain of natural sterols, preferably with Mycobacterium roseum sp. nov. 1108/1 deposited at the National Collection of Agricultural and Industrial Microorganisms, Budapest, Hungary under the number NCAIM B (P) 000339, and by isolating and purifying the 9.alpha.-hydroxy-4-androstene-3,17-dione obtained.