The fermentation of the batter of idli, a fermented food of India, was studied. The microorganisms responsible for the characteristic changes in the batter were isolated and identified. Although there is a sequential change in the bacterial flora, the predominant microorganism responsible for souring, as well as for gas production, was found to be Leuconostoc mesenteroides . In the later stages of fermentation, growth of Streptococcus faecalis and, still later, of Pediococcus cerevisiae becomes significant. The fermentation of idli demonstrates a leavening action caused by the activity of the heterofermentative lactic acid bacterium, L. mesenteroides . As far as is known, this is the first record of a leavening action produced exclusively by the activity of a lactic acid bacterium.

Substitution of manganese for tomato juice in the cultivation of lactic acid bacteria. Appl. MIicrobiol. 12: 165-168. 1964. Tomato juice was separated by chemical and physical methods into various active fractions, as measured by growth response and acid production by numerous lactic acid bacteria. Incineration of the treated extracts with

described a mucous fermentation of sucrose which was brought about by a lactobacillus (Lactobacillus musicus) isolated from tobacco leaves. The viscous wines discussed by Pasteur, and by others may well have been brought about by growth of lactobacilli.