Published online by Cambridge University Press: 01 June 2009
The pH ranges of growth of streptococci and lactobacilli in dextrose yeast casein digest broth have been studied. Nearly all the group I and II streptococci grew at pH 8·8, but only the enterococci grew at pH 4·8; all group III types (heterofermentative) grew at pH 4·4. Only a few lactobacilli grew at pH. 8·8 but most were able to grow at pH 4 if other conditions were favourable. The enterococci, Str. lactis and Str. cremoris could be differentiated by the alkaline limits of growth.