Pediocin PA-1 production during repeated-cycle batch culture of immobilized Pediococcus acidilactici UL5 cells

Abstract

Pediocin PA-1 production by Pediococcus acidilactici UL5 cells immobilized in κ-carrageenan/locust bean gum gel beads was studied during repeated-cycle batch (RCB) culture with pH control in Man Rogosa and Sharpe (MRS) broth supplemented with 1% glucose and whey permeate (SWP) medium. The pediocin PA-1 production by free P. acidilactici cells pH-controlled batch culture has reached 2048 and 4096 AU ml-1 after 11 and 12 h of incubation, with volumetric productivities of 187 and 342 AU ml-1 h-1 in SWP and MRS media, respectively. In RCB culture, immobilized cells reached a maximum concentration of 7.3±0.2×1010 and 4.3±0.9×1010 cfu g-1 of beads in MRS and SWP media, respectively. The maximum pediocin PA-1 activity obtained during RCB fermentation was 4096 AU ml-1; it was attained after only 0.75 and 2 h of incubation in MRS and SWP media, respectively. The corresponding volumetric productivities were 5461 and 2048 AU ml-1 h-1. Pediocin PA-1 production in the RCB culture was highly stable over 12 fermentation cycles carried out over 3 d in SWP media. © 2008 The Society for Biotechnology, Japan.