Effect of sucrose on nisin production in batch and fed-batch culture byLactococcus lactis

Abstract

The effects of sucrose on cell growth and nisin production by Lactococcus lactis were investigated in batch and pH feed-back controlled fed-batch cultures. In batch cultures, nisin titer reached its maximum, 2658 IU cm−3, at the initial sucrose concentration of 30 g dm−3. With sucrose concentrations higher than 30 g dm−3, nisin production decreased while the biomass was not influenced significantly. By using the pH feed-back controlled method, residual sucrose concentration could be controlled well in fed-batch cultures and three conditions (sucrose maintained at 2, 16, 20 g dm−3, respectively) were evaluated. Maintaining a low sucrose concentration at 2 g dm−3 during feeding favored nisin biosynthesis, and the maximum nisin titer obtained was 4961 IU cm−3 compared with 3370 IU cm−3 (16 g sucrose dm−3)and 3498 IU cm−3 (20 g sucrose dm−3), respectively. Copyright © 2005 Society of Chemical Industry