[Nonactin biosynthesis. The incorporation of precursors into the antibiotic molecule]

It was shown that 14C-glucose and 14C-acetate are incorporated with the mycelial suspension of Streptomyces chrysomallus var. macrotetrolidi into the macromolecular compounds of the biomass and into nonactin, an antibiotic of the macrotetrolide group. The dependence of the incorporation on the time of the mycelium incubation with the 14C-substrate was similar for both compounds. Incorporation of 14C-acetate into nonactin was observed at earlier incubation periods, while intensive incorporation of 14C-glucose started after 60-90 minutes of incubation. The culture was shown to have two pathways of glucose metabolism, i. e. glycolysis and pentosophosphate pathway. Under the experimental conditions glycolysis was more important for both the biomass construction and the antibiotic synthesis. Inhibition of various areas of the tricarbonic acid cycle had a significant effect on incorporation of 14C-acetate into nonactin. The character of the effect depended on the site of the inhibitor action: inhibition of aconitase by trifluoroacetate lowered the level of the antibiotic synthesis by 2-4 times and inhibition of succinate dehydrogenase by malonate increased it by 2 times.