Fig. 1

The sequence of the inulinase promoter and signal sequence, with mutations annotated. a Map of inulinase promoter and signal sequence. Mutants that improved expression of the reporter gene are in red. b Relative Est1E activity expressed by the WT or mutant promoter. The expression of a reporter gene, Est1E, was driven by WT or the mutant promoter on a plasmid. The activity of Est1E expressed from the WT promoter was designated as unit 1. Values in (b) and below represent mean ± S.D. from four parallel cultures. (*p < 0.05, **p < 0.01, ***p < 0.001). c Relative Est1E activity expressed by the inulinase promoter containing point mutation. d Relative Est1E activity expressed by double or triple mutant