The Gas-producing Species of the Genus Lactobacillus.

In a previous study by the author (1936) of over four hundred strains of non-gas-producing lactic acid rods isolated from fermenting substances, the differences in characters observed appeared to be more varietal than specific in nature. It was concluded that twelve previously described and named species were identical in whole or in part with Lactobacillus plantarum (Orla-Jensen) Bergey et al. This work has now been supplemented by a cultural-study of several more or less authentic strains of previously described gas-producing species of lactobacilli and approximately 300 additional strains freshly isolated from a variety of sources. The study has included a determination of morphology, growth in various media, action on sugars, by-products of fermentation, inhibiting effects of various substances such as salt and acid, temperature limits of growth, and thermal death temperatures.