Abstract
Bifidobacterium growth promoting activity of defatted rice bran hydrolyzed by Aspergillus oryzae (rice bran koji extract) was tested. It was effective as much as yeast extracts known as a Bifidobacterium growth promoting factor. It was found that defatted rice bran was more effective than wheat bran and hatomugi bran as koji material to produce the factor. We isolated the active substances from rice bran koji extract. The active fractions, having stimulants on the growth of Bifidobacterium were separated by ion-exchange chromatography, and those fractions were found to promote the growth of B. longum, B. bifidum, B. infantis, B. adolescentis and B. breve. Low molecular weight peptides in these fractions were suggested to play significant roles as Bifidobacterium growth promoting factor.
