Abstract: Wort was chosen for the experiment. Effects of adding different nutriments in wort on the growth of Bbm Bifidobacterium bifidus were examined. The optimum enrichment medium of Bbm was screened with orthogonality test. Blm was validated in the optimum enrichment medium. The results showed that soya peptone, beef extract, yeast extract, and maize hydrolyzates in wort all promote the growth of Bbm (p<0.01), and the addition of K2HPO4 plays a role to both promote the growth and buffer the medium pH as well. The optimum enrichment media obtained by orthogonal test consist of adding soyapeptone 0.3%, beef extract 0.6%, yeast extract 0.5%, maize hydrolyzates 0.4%, K2HPO4 0.2% in 10°Brix wort, cultivated in the optimum enrichment medium for 12 hours at 37℃ with the live counts 3.84×109CFU/ml of Bbm and 3.90×109CFU/ml of Blm, increased by 8.17 and 8.14 times respectively, higher than the control. The cost decreases1000$/t compared with modified MRS medium used in lab.

Key words: Bifidobacteria, enrichment medium of wort, optimal screening