Application and Study of X-Gal in Isolation and Counting Bifidobacterium

Majority of Bifidobacterium have Tilactase and upper enzyme activity,so add X-Gal in the improved NPNL mediu as the substrate, Bifidobacterium hydrolysis substrate and releas indole, which induces colorresponse. Bifidobacterium colony sho dark blue ,and other Bacteria generally show white or light blu X-Gal is used to compare isolation and the count of bifidobacter um in two sam ples.This m ethod can exactly indicate the count bifidobacteria in products and babies'feces. Also it can reduc workloads of bifidobacterium 'isolation and identification.