Compositions and Characteristics of Strains of Streptococcus bovis

Abstract

Streptococcus bovis strains JB1, 26, 581AXY2, 21096C, and 45S1 grew on glucose, maltose, starch, sucrose, cellobiose, and lactose. None of these strains grew on xylose or ribose, but arabinose was a suitable energy source for strains 2109C and K27FF4. All strains grew at 45°C, but incubation at 50°C prevented growth. Growth was permitted in 2% sodium chloride, but 6.5% sodium chloride was inhibitory. Doubling times ranged from 24 to 27min, and final pH on glucose was approximately 4.6. None of the strains had a requirement for amino acids, and growth was rapid in media containing glucose salts and B vitamins. There was no ammonia production from arginine. All strains showed aminoendopeptidase activity, but there was considerable strain variation.Strain 7H4, reported as Streptococcus bovis, was noticeably different from the other six strains. It had a doubling time that was more than four times as long, and it grew poorly on starch or in the absence of an amino acid source. Six-and-a-half percent sodium chloride was not inhibitory, and it produced ammonia from arginine. Cell morphology was coccoid rather than ovoid. Based on these criteria, classification of strain 7H4 as Streptococcus bovis seemed doubtful.Other experiments with strain 7H4 indicated that Streptococcus bovis was devoid of diaminopimelic acid. In these experiments strain 7H4 contained significant diaminopimelic acid. The six Streptococcus bovis strains all contained diaminopimelic acid as well, but concentration varied.