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 6-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 bioconversion. The latter comprises the cultivation of a Micromonospora
strain which is able to 6-hydroxylate a compound of general formula
(II)wherein R is as defined aboveat 25-32 C. on a nutrient
medium containing available carbonand 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.
