CATALASE-PRODUCING STRAINS OF STREPTOCOCCI

Abstract

Two catalase-producing strains of streptococci isolated from silage fermentations conformed to the enterococcus grouping and were identified as Streptococcus faecalis var. liquefaciens. Catalase was produced on 3 media tried and was more active on low carbohydrate medium. Most of the glucose fermented by the strains was converted to lactic acid. One strain produced dextro-lactic acid and the other inactive lactic acid. The strains failed to oxidize p-phenylenediamine in the presence of a-naphthol which indicated their lack of a cytochrome system. It was suggested that when the organisms are grown under aerobic conditions, the final electron mediators to O2 are the flavoprotein systems. Detailed cultural, morphological and physiological properties of the catalase-producing strains were examined.