Effect of Penicillin on Streptomycin Production by Streptomyces griseus

Abstract

The correlation between the biosynthesis of the cell wall and the formation of streptomycin (SM) in Streptomyces griseus, influenced by a specific inhibitor of cell wall synthesis, was investigated. Penicillin, in subinhibitory concentrations (1 to 5 ,ug/ml), was added to cultures of S. griseus in different stages of its life cycle. The inhibitor decreased SM production, when young cultures were treated; however, there was an increase in SM formation when penicillin was added to older cultures. The explanation for these findings is discussed in detail.The physiological role of streptomycin (SM) in the life of Streptomyces griseus has been investigated. We proved that streptidine (SD), a component of the SM molecule, is a constituent of the cell wall (2, 10). This indicates that SM or its SD component plays a role in building up the cell wall network (1,(8)(9)(10). These findings prompted us to search for correlations between cell wall synthesis and SM production in S. griseus. Use of specific inhibitors of cell wall synthesis in bacteria, such as penicillin, bacitracin, etc., seemed promising as an approach to the problem (Gy. Barabas, Folia Microbiol. 18:266, 1973). Since SD is a component of cell walls, one might expect that the inhibition of cell wall synthesis would change SM production.In this paper, we describe the effects on SM production by S. griseus cultures when penicillin is added at different stages in the S. griseus life cycle. MATERLALS AND METHODSStrains and cultivation. S. griseus LS-1 (code no. 52-1) strain was used. Its cultural and physiological characteristics, as well as the composition of the filtered soybean medium employed throughout the experiments, were previously described (8). Cultivation was carried out on a rotary shaker (250 rpm, 50-mm stroke distance) at 270C.Antibiotic assay. SM content of the fermentation liquid was determined by the agar-hole diffusion method against Bacillus subtilis ATCC 6633. The fermentation liquid was spun down, and the cellfree supernatants were diluted with 0.067 M phosphate buffer (pH 7.5) containing penicillinase (Neutrapen Riker Laboratories, Loughborough, England, in a final concentration of 100 ,ug/ml). The samples were incubated at 37°C for 1 h to inactivate penicillin. Then, four to seven replicates were pipetted in the holes of agar plates from every sample, and their mean was used for the calculation. The agar medium for antibiotic assay was prepared as follows: 5 g of meat extract, 1 g of Na2HPO4, 0.1 g of KH2PO4, and 0.5 g of peptone were dissolved in 100 ml of distilled water and boiled for 2 min. After filtration, 900 ml of distilled water was added, as well as 20 g of agar. The pH of the medium was adjusted to 7.0 after it had melted, and it was finally sterilized by autoclaving. The melted medium was inoculated with B. subtilis, poured into petri plates, and incubated at 37°C for 1 h. Samples were then pipetted into the holes. The inhibition zone of the antibiotic was measured after 20 h of incubation at 37°C. Control experiments showed ...

Biosynthesis and Mutasynthesis of Aminoglycoside Antibiotics

“…Penicillin, a well-known inhibitor of cell wall synthesis, at a subinhibitory concentration (1-5 Ilg/ml) increased streptomycin production about twofold when added to older cultures (BARABAS and SZABO 1977). However, when added to younger cultures it decreased production, so that penicillin seems not to control the utilization of D-glucosamine in young cells, but influences the permeability of the mature cell wall.…”

Possible role of streptomycin released from spore cell wall of Streptomyces griseus

“…Searching for the biological role of the aminoglycoside antibiotics, we found that streptomycin and neomycin were present in the cell wall of Streptomyces griseus and Streptomyces fradiae, respectively (2,3,14). We introduced a model to study the release of streptomycin from the spores of S. griseus strains to try to answer the question.…”

Production of a streptomycin-Park nucleotide complex by Streptomyces griseus

“…When we started to study the biological role of streptomycin, an aminoglycoside-type antibiotic, we found a correlation between cell wall synthesis and antibiotic synthesis (1-3; G. Barabas, Folia Microbiol. 18:266, 1973); various inhibitors of cell wall synthesis increased the production of streptomycin (2).Since both the cell wall and streptomycin contain significant amounts of carbohydrate, we supposed that a common precursor exists for the two biosynthetic pathways. The search for this common precursor resulted in the isolation of a molecule of unknown structure (compound X) possessing antibiotic activity.…”

“…Some of this speculation has been supported by experimental results (1,12,13); other speculations were, however, purely hypothetical in nature. When we started to study the biological role of streptomycin, an aminoglycoside-type antibiotic, we found a correlation between cell wall synthesis and antibiotic synthesis (1-3; G. Barabas, Folia Microbiol. 18:266, 1973); various inhibitors of cell wall synthesis increased the production of streptomycin (2).…”