Methanol extracts from 25 seed samples belonging to the family Leguminosae were subjected to an in vitro screening for their growth-promoting and inhibitory activities towards Bifidobacterium adolescentis, B. longum, B. bifidum, and Lactobacillus casei, using spectrophotometric and paper disc agar diffusion methods under O©ü-free conditions, respectively. The responses varied with both bacterial strains and plant species. Among seed extracts, extracts from Glycine max (light-green color) and Arachis hypogaea (dark-brown) enhanced the growth of lactic acid bacteria in media with or without carbon sources, suggesting that bifidus factor(s) might be involved in the phenomenon. This growth-promoting effect was most pronounced with L. casei among lactic acid bacteria used. Additionally, all seed extracts did not adversely affect the growth of the lactic acid bacteria tested.
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