The Lactic Acid Fermentation of Streptococci

Abstract

Washed cells were suspended in a phosphate-buffered glucose solution; a total of 286 tests being made with 151 cultures representing the better known groups and vars. of streptococci. Similar results were obtained under strictly anaerobic conditions and without anaerobic precautions but the latter fermentations were essentially anaerobic. The average % lactic acid from glucose fermented for each var. follows. Pyogenic streptococci: Group A, 87.6; Group B, 89.7; Group C, "animal," 85.8; Group C, "human," 87.5; Group E, 87.8; Group F, 81.8; Group G, "minute," 87.1; Group G, "non-minute," 87.7; Group H, 87.6. Viridans streptococci: Streptococcus salivaiius, 93.6; Str. bovis, 91.7; "Bar-gen streptococcus," 91.9; Str. equinus, 92.3; Str. thermo-philus, 90.2. Lactic streptococci: Str. lactis, 96.6; Str. cremoris, 93.7. Enterococci (group D): Str. jecalis, 96.0; Str. liquefaciens, 91.2; Str. zymogenes, 95.8; Str. durans, 92.2; Str. uberis, 90.8. The slightly lower average efficiency of the pyogenic streptococci is of possible significance.