BACTERIOCINS IN MYXOCOCCUS FULVUS

Abstract

During attempts to isolate temperate phages in Myxococcus fulvus , it was observed that three strains distinctly inhibited growth of other fulvus strains. Further investigations were carried out with Myxococcus fulvus 16 (Mxf 16) which produces larqe, clear inhibition-zones. Mxf 16 produces a bacteriocin ("fulvocin 16") which, according to the definition, is specific with respect to its action on the growth of other myxobacteria, while exerting no inhibitory effect on other bacterial genera. Maximal fulvocin 16 concentration is obtained when cultures are harvested at the end of the growth curve. Mitomycin fails to stimulate production of this bacteriocin. Ammonium sulfate precipitation, followed by column-chromatography on DEAE and Sephadex G 200 results in a ten-fold purification of this bacteriocin, is resistant to the actions of trypsin, pronase, DNase and RNase. No bacteriocin-activity is demonstrated after treatment with chloroform, while its activity gradually decreases when incubated at 100°C. It is presumed that fulvocin 16 is a bacteriocin of low molecular weight.