Fig. 5

Co-feed of xylose and methanol for FFA production in strain FD09. A Schematic diagram of xylose and methanol metabolism in O. polymorpha. Supplemented xylose will increase Xu5P supply via xylose metabolism for both cell growth and FFA production. B Growth curves of strain FD09 in different carbon sources. 10 M: 10 g/L methanol, 10X: 10 g/L xylose, 10 M/5 M/2 M + 10X: 10 / 5 / 2 g/L methanol and 10 g/L xylose, 5 M + 5 M + 10X: Initial adding 5 g/L methanol and 10 g/L xylose and then supplementing 5 g/L methanol at 48 h. C FFA titers of strains cultivated in minimal media containing above substrates. Red asterisks indicate statistical significance as determined by paired t test (*P < 0.05; **P < 0.01). D Specific FFA production rate of strains cultivated in minimal media containing above substrates. E Methanol concentration. F Xylose concentration. Data are presented as mean ± s.e.m. (n = 4 biologically independent samples)