1. Sucrose and maltose behaved like dextrose, only more specifically in relation to type, in acclerating the rate of growth of lactic acid bacteria in milk. Sucrose was greatly superior to maltose but was never superior to dextrose.2. Citrate was without significant effect.3. The sterilization of yeast and dextrose in the medium produced a medium superior to milk + separately heated yeast and dextrose for Streptococcus III. For other types marked differences were not observed.4. The plant extracts used were found to fall into the following order of ability to accelerate growth: yeast autolysed for 6 days, malt = beer wort, potato, alfalfa, carrot, tomato, clover, yeast autolysed for 2 days, and bean. Malt and beer wort were superior to yeast for some group III organisms.5. Malt extract and beer wort contain growth factors for some lactic acid bacteria that are not present, or are present only to a small extent in yeast.6. Alfalfa and clover appear to contain substances specifically stimulating gas production for group III types, especially the streptococci.7. Normal variations in the content of vitamins B1 and B2 and co-carboxylase in milk do not appear to affect the rate of growth of starter organisms.
PYRIDOXAL PHOSPHATE AND PYRIDOXAMINE PHOSPHATE AS GROWTH FACTORS FOR LACTIC ACID BACTERIA
