Screening of non-phage group II strains for antagonistic substances revealed one particular strain, D91, to excrete a substance with a wide spectrum of activity; both Gram-positive and Gram-negative bacteria were susceptible. The staphylococcin-like substance D91 produced by this strain was partially purified by column chromatography on Sephadex G-50, DEAE-cellulose, Phenyl Sepharose CL-4B and Sephadex G-200. A molecular weight of 76000 was estimated by gel filtration. The activity was heat sensitive but was not affected by hydrolytic enzymes except for pronase. The protein character of substance D91 was confirmed by gel electrophoresis and subsequent staining with Coomassie blue. The action exerted on sensitive bacteria was bacteriostatic rather than bactericidal. Biosynthesis of DNA, RNA, protein and polysaccharides were inhibited simultaneously in both and Active transport of glutamic acid was stopped in both and , whereas glucose uptake was inhibited in only. The substance induced a slow efflux of Rb from proloaded cells of and The antagonistic activity of D91 was eliminated by ethidium bromide at a rate of 47.6% suggesting that plasmids may be involved in its production.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error