Table 1 Yields of biomass and ethanol on glucose, sorbitol consumption, stoichiometric relationships between glycerol production and biomass formation and specific growth rates in anaerobic bioreactor batch cultures of S. cerevisiae strains IME324 (reference strain), IME611 (overexpression cassettes for HXT15 and SOR2), IMX1489 (optimized PRK-RuBisCO bypass and gpd2∆ mutation, [26]) and IMX2506 (optimized PRK-RuBisCO bypass and gpd2∆ mutation, overexpression cassettes for HXT15 and SOR2)

HXT15 and SOR2 cassettes

no

yes

no

yes

PRK-RuBisCO bypass and gpd2∆

no

no

yes

yes

Specific growth rate (⁻¹)

0.31 ± 0.01

0.31 ± 0.00

0.30 ± 0.00

0.27 ± 0.00

Biomass yield on glucose (g_x mol⁻¹)^a

16.2 ± 0.3

16.0 ± 0.2

16.3 ± 0.9

17.4 ± 0.5

Ethanol yield on glucose (mol mol⁻¹)^a

1.47 ± 0.02

1.51 ± 0.01

1.64 ± 0.04

1.80 ± 0.05

Ethanol yield on substrates (mol mol⁻¹)

1.47 ± 0.02

1.42 ± 0.01

1.64 ± 0.04

1.65 ± 0.05

Glycerol produced (mmol (g_x⁻¹))

11.8 ± 0.2

16.3 ± 0.2

3.1 ± 0.1

3.5 ± 0.0

Sorbitol consumed (mmol (g_x⁻¹))

 < 0.3

4.3 ± 0.1

 < 0.3

5.4 ± 0.2

Degree of reduction recovery (%)

100–102

100–101

100–104

95–99