Low-cost fermentative medium for biosurfactant production by probiotic bacteria

Potential use of alternative fermentative medium for biosurfactant production by Lactococcus lactis 53 and Streptococcus thermophilus A was studied. Suitable models were established to describe the response of the experiments pertaining to glucose, lactose or sucrose consumption, cell growth and biosurfactant production. Synthetic media MRS and M17 broth were used as control experiments. When the synthetic media were replaced by cheaper alternative media, as cheese whey and molasses, fermentations were carried out effectively with high yields and productivities of biosurfactant. An increase about 1.2-1.5 times in the mass of produced biosurfactant per gram cell dry weight and 60-80% medium preparation costs reduction were achieved, for both strains. In conclusion, the results obtained showed that supplemented cheese whey and molasses media can be used as a relatively inexpensive and economical alternative to synthetic media for biosurfactant production by probiotic bacteria, thus an attractive alternative as many of the potential applications for biosurfactants depend on whether they can be produced economically. (c) 2006 Elsevier B.V. All rights reserved.