Growth medium for culturing probiotic bacteria for applications in vegetarian food products

Vegetarian probiotic foods by definition, must be free from all animal-derived ingredients. This not only includes tire product ingredients but the probiotic inoculum as well. Probiotic starter cultures are traditionally grown and stored in media containing milk or meat-derived ingredients. The presence of these ingredients makes the probiotic cell concentrates unsuitable for use in vegetarian products and thus creates the need for a growth medium free from animal-derived ingredients. This study investigated the growth of two strains of Lactobacillus acidophilus (MJLA1 and La-5), L. paracasei ssp. paracasei (LCSH1 and 01) and Bifidobacterium lactis (BDBB2 and Bb-12) in five media. Growth parameters such as maximum cell concentrations, lag phase and growth rate, were calculated using the growth curves generated by DModel, Institute of Food Research, U.K. Results showed that several media were suitable, with results comparable or better than the commonly used laboratory media MRS and RCM. Media containing 25 g/L soy peptone, yeast extract and glucose monohydrate gave the most desirable results with the strains examined. (C) 2002 Elsevier Science Ltd. All rights reserved.