Fig. 2

Identification of the mutants with improved acetic acid tolerance. A Insertion positions (red arrows) of the LEU2-UT8 fragment in the mutant strains. B, C Growth curves of the Y. lipolytica control strain Po1f and the mutant strains without B and with C the addition of 50 mM acetic acid. D Relative transcription levels of NIP1. E, F Spot assay E and growth curves F of Po1f and the mutant strains under 90 mM acetic acid. G Spot assay of Po1f and the mutant strains under low pH. H, I Growth curves of Po1f and the mutant strains under high temperature H and 10% NaCl I. R-NIP1: UT8 promoter-driven NIP1 overexpression strain