Improvement in the bioconversion of penicillin G to deacetoxycephalosporinG by elimination of agitation and addition of decane

The bioconversion of penicillin G to deacetoxycephalosporin G (DAOG) using resting cells of Streptomyces clavuligerus could be a very valuable step in the economical production of semisynthetic cephalosporin antibiotics. The extent of the reaction, however, is very low due to inactivation of the rin g expansion enzyme deacetoxycephalosporin C synthetase ("expandase") by rea ction components. We show that elimination of agitation during the reaction lowers the rate but increases the amount of DAOG produced, presumably beca use the inactivation requires high levels of oxygen. Many additives to the medium were examined for their effect on the reaction. Clearly, the most ef fective com-pound was the organic solvent, decane.