Improved Recovery of Stressed Bifidobacterium from Water and Frozen Yogurt.

A roll-tube repair-detection procedure was developed to enumerate injured and noninjured cells of Bifidobacterium species from water and food samples. This procedure combined the Virginia Polytechnic Institute and State University's anaerobic roll-tube procedure and the repair-detection technique for detecting stressed cells. Mara and Oragui's human bifid sorbitol agar medium was modified for use in the roll-tube procedure by replacing the indicator bromocresol purple with phenyl red (0.