ε-Poly-L-lysine Production from Precursor L-lysine by Streptomyces sp. M-Z18

To investigate the process of e-poly-L-lysine(e-PL) production from precursor L-lysine under different culture conditions of Streptomyces sp.M-Z18,it has developed conversion of precursor L-lysine for e-PL production,combined with two-stage culture method,and with fermentation from glycerol,respectively.The results of experiment showed that two-stage culture method was used for conversion L-lysine to e-PL and attained at 15 g/L with biotransformation of 3 g/L L-lysine;Furthermore,e-PL production from glycerol fermentation coupled with L-lysine conversion achieved 33.76 g/L e-PL and enhanced e-PL productivity at 37.8%,compared with L-lysine-free fermentation.It was demonstrated that e-PL production could be derived from precursor L-lysine,however,the efficiency of this conversion is needed further improved.It has indicated that the limit of e-PL production is the biosynthesis of L-lysine in primary metabolism.Meanwhile,the results presented here provide a guidance for the e-PL-producing strains primary metabolism improvement by metabolic engineering,and an efficient approach to enhancement of e-PL production in scale fermentation.