Role of Leuconostoc mesenteroides in Leavening the Batter of Idli, a Fermented Food of India

Abstract

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.