Research Note: Use of Modified Lactobacillus Selective Medium and Bifidobacterium lodoacetate Medium for Differential Enumeration of Lacttobacillus acidophilus and Bifidobacterium spp. In Powdered Nutritional Products

摘要

Modified Lactobacillus selective agar (APT agar + sodium acetate and glacial acetic acid; mLBS) was compared to selective modified Lactobacillus selective medium (LBS agar + tomato juice and acetic acid: mLSM) and nonselective de Man Rogosa Sharpe (MRS) agar for the enumeration of Lactobacillus acidophilus in probiotic-containing powdered nutritional Products. The mLBS agar was equivalent to MRS agar and superior to the mLSM agar for enumerating L. Acidophilus in Products stored in sealed cans at 22 dg. C. When samples were analyzed for L. Acidophilus concentration after high temperature Storage in sealed cans or storage in open cans at high relative humidity, the mLBS and MRS agars were highly correlated (r~2 =0.93).