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.

Changes in glycogen and trehalose content ofStreptomyces brasiliensishyphae during growth in liquid cultures under sporulating and non-sporulating conditions

“…Supporting this finding is the observation that genes for glycogen synthesis are duplicated in streptomycetes, each copy being specific for one of the sites of glycogen deposition [3,5,6]. Accumulation of trehalose has been reported in different Streptomyces strains [1,4,7,8], and recent observations suggest that genes for trehalose metabolism might also be duplicated in streptomycetes [9]. Trehalose seems to be particularly abundant in spores and has been detected at all stages of development [1,4].…”

Polyhydroxyalkanoates in Gram-positive bacteria: insights from the genera Bacillus and Streptomyces

“…Table 2 summarizes information regarding all known PHA-producing Streptomyces spp. In Streptomyces venezuelae P(3HB) serves as a minor source of acetoacetyl-CoA for chloramphenicol biosynthesis (Ranade and Vining 1993). Also, in Streptomyces hygroscopicus, P(3HB) degradation may provide butyryl-CoA during the production of the macrolide ascomycin FK520 (Wu et al 2000).…”

Three pathways for trehalose biosynthesis in mycobacteria

“…Escherichia coli and Saccharomyces cerevisae contain little or no trehalose during exponential growth under standard culture conditions, for example, but the free sugar rapidly accumulates in response to osmotic stress or heat shock, and during the stationary phase of culture (Strom & Kaasen, 1993 ;De Virgilio et al, 1994). In Streptomyces venezuela, trehalose is absent from the mycelium in vegetative cultures, but is abundant in spores (Ranade & Vining, 1993).…”