Screening of biosurfactant-producing ability of three Lactobacillus strains was performed,
being shown that, for all the tested strains, biosurfactant production is occurring mainly in
the first 7 hours. All strains reduced 8 mN/m the surface tension of the fermentation broth at
the end of fermentation and lysed blood agar with scores ranging between (++)
corresponding to complete hemolysis with a diameter < 1 cm. Time courses of lactose,
biomass and biosurfactant were modeled according to reported models, assuming product
inhibition. Using optimized MRS broth as culture medium, the values estimated by the
modeling of biosurfactant were P_max = 1.4 g of biosurfactant/L and rp/X = 0.137g/L.hˉ¹ for
Lactobacillus casei CECT-5275, P_max = 1.5 g/L and rp/X = 0.145g/L.hˉ¹ for Lactobacillus
rhamnosus CECT-288 and P_max = 1.5 g/L and rp/X = 0.089 g/L.hˉ¹ for Lactobacillus pentosus
CECT-4023. Using whey as production medium, the values obtained for Lactobacillus
rhamnosus CECT-288 were P_max = 1.3 g of biosurfactant/L and rp/X = 0.078 g/L.hˉ¹. In
conclusion, the results obtained showed that whey can be used as an alternative medium for
biosurfactant production by Lactobacillus strains
