Efficient utilization of cassava pulp for succinate production by metabolically engineered Escherichia coli KJ122

A metabolically engineered Escherichia coli KJ122 was efficiently utilized for succinate production from cassava pulp during batch separate hydrolysis and fermentation (SHF) under simple anaerobic conditions. Succinate concentration of 41.46 ± 0.05 g/L with yield and productivity of 82.33 ± 0.14 g/100 g dry pulp and 0.84 ± 0.02 g/L/h was obtained. In batch simultaneous saccharification and fermentation (SSF), hydrolysis of 12 % (w/v) cassava pulp with an enzyme loading of 2 % AMG + 3 % Cel (v/w) at pH 6.5 was optimized at 39 °C. Succinate concentration of 80.86 ± 0.49 g/L with a yield of 70.34 ± 0.37 g/100 g dry pulp and a productivity of 0.84 ± 0.01 g/L/h was attained using E. coli KJ122. Fed-batch SSF significantly enhanced succinate concentration to 98.63 ± 0.12 g/L at yield and productivity of 71.64 ± 0.97 g/100 g dry pulp and 1.03 ± 0.01 g/L/h. This result indicated an efficient and economical succinate production from cassava pulp using SHF and SSF by the use of E. coli KJ122.