Production of pediocin SM-1 by Pediococcus pentosaceus Mees 1934 was investigated in semi-aerobic,
pH-controlled, batch and fed-batch fermentations using a complex medium containing sucrose as the
main source of carbon. The effects of sucrose concentration were studied in fed-batch fermentations in
which a sucrose solution was added at stable feeding rates (5, 7, 9 and 10 g/l/h). The results showed that
pediocin is produced as a product of the primary metabolism and its titer could be greatly improved by
adjusting the sucrose feeding rate in fed-batch fermentation. The maximum titer of pediocin of 145AU/ml
was obtained in the fed-batch culture with 7 g/l/h feeding rate and that was 119% higher compared to the
titer obtained in batch culture. Higher feeding rates (9 and 10 g/l/h) resulted in decreased pediocin yields
while biomass levels appeared to be rather unaffected. The specific rate of pediocin formation was also
sensitive to sucrose concentration levels. A mathematical model developed on the basis of well-known
rate equations for batch and fed-batch cultures and growth associated production, described successfully
cell growth, sucrose assimilation, lactate production and pediocin production in fed-batch cultur