[Fermentation conditions for production of glutathione by recombinant Escherichia coli]

The fermentation conditions for production of glutathione by recombinant E. coli were investigated, the addition of certain materials, such as yeast extract, precusor amino acids and ATP were mainly focused on. The results showed that the addition of precusor amino acids and ATP could promote intracellular GSH accumulation. DCW and intracellular GSH content would be 24% and 1.4 times higher than that of fermentation without additions when 2.0 g/L ATP and 9 mmol/L precusor amino acids were added at the begining and 12 h of fermentation, respectively. By using the optimized combination of additives obtained from orthogonal experiments, the maximal DCW and total GSH in broth could be improved 10% and 26% higher than the best results in orthogonal experiments, respectively. Based on the analysis of glucose utilizing ability of this strain, an exponential fed-batch culture process was conducted. DCW and total GSH in broth culd be 8.3 and 4.6 times higher than that of shaking flask culture and finally reached 80 g/L and 880 mg/L, respectively.