| abstract |
The present invention relates to a new microbial process for the preparation of compound of formula (I) from a compound of general formula (II) wherein R stands for an alkali metal or ammonium ion, by the submerged culture of a strain which is able to 6β-hydroxylate the compound of formula (II) in aerobic fermentation and by the separation and purification of the product of formula (I) formed in the course of the biocoversion. The latter comprises the cultivation of a Micromonospora strain which is able to 6β-hydroxylate a compound of general formula (II)—wherein R is as defined above—at 25-32° C. on a nutrient medium containing available carbon—and nitrogen sources and mineral salts, thereafter feeding the substrate to be transformed into the developing culture, then hydroxilating the substrate until finishing of the bioconversion, then separating the compound of formula (I) from the culture broth and, if desired, purifying the same. |