Improving the L-tyrosine production with application of repeated batch fermentation technology based on a novel centrifuge bioreactor

Abstract

To improve fermentation efficiency during L-tyrosine production, we established a novel method to produce L-tyrosine by repeated batch fermentation through cell recycling. According to the characteristics of the fermented broth, the cells were recovered using two dish centrifuges in series. First, L-tyrosine crystals were removed from the previous batch of fermented broth by selective centrifugation. The cells were then concentrated in another centrifuge and recycled for use in the next cycle of batch fermentation. L-tyrosine removal and cell recovery rates were 86% and 67%, respectively, in a centrifuge bioreactor. Through repeated batch fermentation, L-tyrosine productivity was increased by up to 44.1% compared with that for fed-batch fermentation, and the coupling of fermentation and separation was achieved, which is useful in reducing production costs. This study provides a rationale for the fermentation of low-solubility products by repeated batch or cell-recycle fermentation.