A differential medium for lactic acid-producing bacteria in a mixed culture.
OBJECTIVE
Modified deMan-Rogosa Sharpe agar containing bromophenol blue (mMRS-BPB) was tested as a medium for counting and differentiation of each lactic acid-producing bacterium (LAB), especially in a mixed culture.


RESULTS
Type strains of 10 LAB species (Lactobacillus acidophilus, L. brevis, L. bulgaricus, L. gasseri, L. paracasei, L. plantarum, L. reuteri, Weissella confusa, Bifidobacterium bifidum and B. infantis) and five commercial yogurts were inoculated on plate count agar with bromocresol purple, mMRS, and mMRS-BPB. Each type strain showed more clearly formed colonies on the three media under anaerobic conditions than under aerobic conditions. Especially each type strain produced colonies with specific characteristics of each species on mMRS-BPB. Commercial yogurts produced the largest number of colonies with various shapes and colours on mMRS-BPB.


CONCLUSIONS
Modified deMan-Rogosa Sharpe agar containing bromophenol blue under anaerobic conditions is appropriate for counting and differentiating each LAB in a mixed culture.


CONCLUSIONS
Modified deMan-Rogosa Sharpe agar containing bromophenol blue will be useful in isolation and enumeration of each LAB from fermented foods as well as intestinal microflora.
Lee
H M
HM
Culture Collection of Antimicrobial Resistant Microbes, Department of Biology, Seoul Women's University, Seoul, Korea.
Lee
Y
Y
D001431:Bacteriological Techniques; D001644:Bifidobacterium / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D005516:Food Microbiology; D019344:Lactic Acid / Q000096:biosynthesis*; D007778:Lactobacillus / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D015014:Yogurt / Q000382:microbiology
D003470:Culture Media; D019344:Lactic Acid