Several studies have focused their attention on increasing the production of lactobacillus ssp. (LAB) biomass via-fermentation, in particular exploiting novel in situ product removal bioreactors that prevent accumulation of lactic acid, and therefore growth inhibition. Lactobacillus plantarum is one of the most studied species, used in nutritional supplements and in food processing. This research aimed to obtain high cell densities of L. plantarum, through fed-batch and microfiltration experiments. The latter achieved a 5-fold higher biomass density compared with batch experiments. Furthermore, the L. plantarum strain, isolated from Portoguese chorizo, was characterized for its ability to survive simulated digestion in vitro and competition potential toward certain common pathogens. Finally, the possibility of exploiting dairy liquid wastes (whey) as medium components was also explored demonstrating the strain's capability of metabolizing bovine-ovine whey. This finding might be relevant in liquid waste treatments of diary industries that are well distributed in our region. (c) 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:325-333, 2015