Cell growth and pediocin production by Pediococcus acidilactici NRRL B-5627 were compared using batch (on MRS broth and a culture medium from mussel processing wastes (MPW)) and two fed-batch fermentations on MPW with re-alkalization cycles. This last fermentation technique yielded the highest biomass and pediocin productions as compared to batch fermentations. Mathematical models were set up to describe fed-batch production of biomass and pediocin by P. acidilactici. While cell growth was dependent on pH change, nitrogen and phosphorous availability and product inhibition (lactic acid, ethanol and butane-2,3-diol), pediocin production was dependent on both growth and the final pH reached in each re-alkalization period. The models developed offer a better fit and a more realistic description of the experimental biomass and pediocin production data than the logistic and Luedeking and Piret model. Therefore, they could be used to design feeding strategies for enhancing and controlling fed-batch pediocin production. (C) 2004 Elsevier Ltd. All rights reserved.