Accumulation of intracellular carbon reserves in relation to chloramphenicol biosynthesis by Streptomyces venezuelae

Abstract

Two chloramphenicol-producing strains of Streptomyces venezuelae accumulated small amounts of polyhydroxybutyrate during exponential growth; the compound disappeared from the mycelium as the cultures entered stationary phase. Depletion of polyhydroxybutyrate coincided with chloramphenicol production but the amount of polymer stored in the mycelium was insufficient to supply the precursor requirement for biosynthesis of the antibiotic. Accumulation of polyhydroxybutyrate in the S. venezuelae strains was appreciably lower than in two other streptomycetes examined. Glycogen and lipids accumulated in the mycelium of S. venezuelae 13s during the stationary phase, after nitrogen depletion; under the culture conditions used, they were the principal storage compounds in S. venezuelae. Trehalose was absent from the mycelium in vegetative cultures grown under nonsporulating conditions but it was abundant in spores obtained from submerged and surface cultures. Glycogen and polyhydroxybutyrate were absent from spores.Key words: storage compounds, biosynthesis, polyhydroxybutyrate, glycogen, trehalose, lipid.