P. Upadhyay and H. Joshi Department of Biotechnology, Vigyan Bhawan, Block B, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
Two lactobacilli isolates namely Lactobacillus fermentum CM36 and Lactobacillus rhamnosus CW40 were used in present study. Both the lactobacilli isolates were grown in skimmed milk at 37°C for 24h. Fermented skimmed milk was stored at two different refrigeration temperatures, i.e. 4°C and -20°C. Viable cell count was determined in skimmed milk before storage and at an interval of 5 days during the total storage period of 20 days using standard pour plate method and the viability loss in percentage was calculated. Viable cell count of L. fermentum CM36 and L. rhamnosus CW40 was 52×109 cfu/ml and 88×109 cfu/ml, respectively in skimmed milk before storage. Viable cell count observed throughout the storage was in 109 cfu/ml range, 4°C proved to be a better storage temperature than -20°C for both the Lactobacillus isolates.
Key words: Lactobacillus fermentum, Lactobacillus rhamnosus, skim milk, viability