Fig. 4

The 4-HIL fermentation of mutant strains MK1 − MK9 in shake flasks for 144 h. SZ06 was used as a control strain. a Cell growth and glucose consumption of MK1 − MK4, b Cell growth and glucose consumption of MK5 − MK9, c 4-HIL and Lys concentration of MK1 − MK4, d 4-HIL and Lys concentration of MK5 − MK9