Fig. 2

Isoprene production of strains with key enzyme modification. a Isoprene production of strain engineered with IDI modification and the predicated T.I.R. value of IDI. b Isoprene production of strain engineered with MK modification and the predicated T.I.R. value of MK. c Isoprene production of strain engineered with IspS modification and the predicated T.I.R. value of IspS. d Isoprene production of strain engineered through combination of the three enzymes, IDI_sa, MK_mm and IspS_ib. The black column indicated the isoprene production of original strain. The white column indicated that isoprene production of strain with only enzyme substitution. The gray column indicated the isoprene production of strain with enzyme substitution and RBS sequence optimization. The dot indicated the corresponding T.I.R. values. The experiment was conducted in triplicate. Bar represents mean ± s.d