Fermentation process for preparing 7-chloro-6-demethyltetracycline (I) using mutant strains of Streptomyces aureofaciens which impart a colour to their whole ha

摘要

Fermentation process for preparing 7-chloro-6-demethyltetracycline (I) using mutant strains of Streptomyces aureofaciens which impart a colour to their whole harvest mashes such that either (a) a positive value of DELTA R is obtained when the values of the percent reflectance (R) of 1:200 aqs. dilution of the whole harvest mash at 460,540,560 and 660 m mu are inserted in the formula:- DELTA R = R54o+R56o-1.1R46o-0.9R66o-2.0 or (b) the colour reflectance scan of a 1:200 aqs. dilution of the whole harvest mash has the property that when the percent reflectance is plotted linearly against the wavelength, the resulting curve, between 460 m mu and 530 m mu will have one point of inflection and will have at least one point of zero slope and will be convex upward to the left of the point of inflection and concave upward to the right of the point of inflection. The mutant strains produce (I) with little other tetracyclines (less than 5% 6-demethyltetracycline).