Fig. 1

Heterologous protein expression in RP deletion strains. Specific expression of two heterologous proteins (a eGFP and b Phy) in the wild-type and RP deletion strains. The wild-type strain transformed with empty vector pPICZαA was used as negative control. All strains were fermented in the liquid BMMY for 120 h by feeding 1% methanol per 24 h. Expression levels were measured by the relative fluorescence units (RFU) or enzyme activity and OD₆₀₀. Error bars represent s.d. across three biological replicates. Significance against wild type is indicated as: *p < 0.05; **p < 0.01; ***p < 0.001, t test