Diversity and functional characterization of microflora isolated from traditional fermented food idli

Abstract

Idli is a traditional fermented food made from rice and black mung bean consumed for its taste, flavor, nutrients, and easy digestibility. The present work was undertaken to enumerate the bacterial diversity of idli batter during fermentation and to characterize the potential functional properties of selected isolates. Ten household fresh idli batter samples were analyzed during various fermentation time intervals and isolated 300 pure colonies, and characterized by morphological and biochemical methods. Out of the 300 colonies isolated, 40 strains were characterised and identified as Leuconostoc spp, Weissella spp, Pediococcus spp, Lactococcus spp, and Bacillus spp. Among the 40 strains, 10 strains were randomly selected and screened for potential probiotic properties in vitro. Results revealed maximum acid tolerance of 97 ± 0.822 % and maximum bile tolerance of 91.6 ± 4.2 %. Preliminary screening of phytase activity showed maximum zone of 15 mm and phytase assay showed highest 109.5 ± 3.47 μM liberation of inorganic orthophosphate. Screening of BSH activity showed maximum zone of 13 mm and cholesterol assimilation highest of 78.2 ± 3.1 %. Three different strains (KC834380, KC834386, and KC117496) showed effective adherence to HT-29 colon cell lines. This paper outlines the microbial diversity of idli batter and also highlights the significant functional properties of obtained microflora can be used as potential probiotic candidates for the food industry.