Fig. 4

Sorbitol consumption by anaerobic chemostat cultures of S. cerevisiae strains IMX2506 (optimized PRK-RuBisCO bypass and gpd2∆ mutation, overexpression cassettes for HXT15 and SOR2) (A) and IMX1489 (optimized PRK-RuBisCO bypass and gpd2∆ mutation [26]) (B). Chemostat cultures were grown at a dilution rate of 0.025 h⁻¹ on 10 g L⁻¹ of glucose and 10 g L⁻¹ of sorbitol. A Average residual sorbitol concentration ± standard deviation in four chemostat cultures of strain IMX2506. After 400 h, the CO₂ content of the inlet gas was reduced to zero in two of the four cultures. The dotted line represents expected wash-in kinetics of sorbitol in the absence of sorbitol consumption: c(t) = c_in-((c_in-c₄₀₀)*e^(−D*t)) with c = residual sorbitol concentration, c₄₀₀ = sorbitol concentration at 400 h, \( \hbox{c}_{{\rm in}}\) = sorbitol concentration in medium feed and D = dilution rate. B: Average sorbitol concentration ± standard deviation in two chemostats of strain IMX1489. CO₂ supplementation was stopped at 700 h