Effects of pfkA1 over-expression on fermentation process of streptomyces lydicus

An engineered Streptomyces lydicus strain with 6 phosphofructokinase gene (pfkA1) over-expression was constructed by recombinant DNA technology. Biomass, pH value, glucose and streptolydigin concentrations were measured and the fermentation kinetics were calculated. The cell growth and glucose consumption of the engineered strain was faster in the early period, and then slow down in the later stage during fermentation process with lowering pH, compared with the wild type strain. Streptolydigin yield were also reduced in the engineered stain. The results showed that the over-expression of pfkAl attenuates streptolydigin production and the kinetic models well describe the fermentation process.