Production of pentocin 31-1 by high cell density Lactobacillus pentosus 31-1 repeated batch cell recycle fermentations

Pentocin 31-1 was produced by Lactobacillus pentosus 31-1, isolated from the traditional Chinese fermented Xuan-Wei Ham. The wide range of antimicrobial activity especially to Listeria spp showed its potential use as food preservative. The study of pentocin 31-1 production was carried out in repeated batch cell recycle fermentations in 5 L bioreactor and up to 50 L pilot bioreactor. Batch fermentation of L. pentosus 31-1 gave bacteriocin production and productivity of 1395.3 IU/mL and 66.4 IU/(mL h), respectively. The higher bacteriocin production (2186.2 and 2004.5 IU/mL, respectively) and productivity (260.7 and 237.4 IU/(mL h), respectively) was measured in repeated batch cell recycle fermentations in 5 and 50 L bioreactors. Biomass (4.8 and 5.8 g/L, respectively) were also increased with repeated batch cell recycle fermentations in 5 and 50 L bioreactors, which were equivalent to 1.48-and 1.8-fold increases compared with the biomass (3.2 g/L) obtained from batch fermentation. Fermentations were successfully scaled up from 5 to 50 L because there were no significant differences (p<0.05) in production and productivity of bacteriocin between the two volumes by using the same strain and fermentation conditions. These results suggest a reasonable solution to develop large-scale production of both pentocin 31-1 and L. pentosus 31-1 in food industry.