Selective enumeration of Lactobacillus casei from yogurts and fermented milk drinks |
| |
| Authors: | Ramakanth R Ravula Nagendra P Shah |
| |
| Institution: | (1) School of Life Sciences and Technology, Victoria University of Technology, Werribee Campus, Melbourne City Mail Centre Victoria, Australia |
| |
| Abstract: | A selective medium (LC agar) was developed for enumeration of Lactobacillus casei populations from commercial yogurts and fermented milk drinks that may contain strains of yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), probiotic bacteria (Lactobacillus acidophilus and bifidobacteria) and L. casei. Appropriate dilutions were pour-plated in specially formulated LC agar acidified to pH 5.1 and the plates incubated at 27°C for 72 to 96 h under anaerobic conditions. Growth of S. thermophilus was prevented by adjusting pH to 5.1. L. delbrueckii ssp. bulgaricus did not ferment ribose as the carbon source, as a result the organisms did not form colonies. L. acidophilus formed colonies on MRS-ribose agar; however, this organism did not grow in the specially formulated LC agar containing ribose. Similarly, Bifidobacterium spp. did not form colonies in LC agar. L. casei formed colonies on LC agar. © Rapid Science Ltd. 1998 |
| |
| Keywords: | Selective enumeration ribose L casei fermented milk drinks |
| 本文献已被 SpringerLink 等数据库收录！ |
