TABLE 1.

Specific growth rates, biomass yields, and metabolic fluxes in aerobic and anaerobic cultures of Z. bailii, C. utilis, and S. cerevisiae^a

Medium	Conditions	Organism	Specific growth rate (h−1)	Biomass yield (g of biomass · g of glucose−1)	Metabolic fluxes (mmol · g of biomass−1 · h−1)
					Glucose	Ethanol	Glycerol
Defined	Aerobic	Z. bailii	0.25 ± 0.02	0.29 ± 0.01	4.7 ± 0.1	3.5 ± 0.1	0.10 ± 0.01
		C. utilis	0.53 ± 0.02	0.53 ± 0.01	5.5 ± 0.1	<0.01	<0.01
		S. cerevisiae	0.29 ± 0.01	0.12 ± 0.01	13 ± 1	19 ± 4	0.09 ± 0.06
	Anaerobic	Z. bailii	0.03–0.08b	0.07	1.9–6.4	2.6–9.4	0.3–1.1
		C. utilis	0.01–0.03b	0.05	1.1–3.3	1.6–4.6	0.2–0.6
		S. cerevisiae	0.27 ± 0.01	0.10 ± 0.01	15 ± 1	24 ± 1	2.7 ± 0.3
Complex YPD	Anaerobic	Z. bailii	0.09 ± 0.01	0.09 ± 0.01	5.6 ± 0.2	9.5 ± 0.9
		S. cerevisiae	0.17 ± 0.01	0.07 ± 0.004	13 ± 1	22 ± 1

^aCells were grown on 20 g of glucose per liter in defined and complex YPD media in pH-controlled fermentors (pH 3.0). The data for aerobic Z. bailii and S. cerevisiae cultures are from the respirofermentative parts of the growth curves. Unless indicated otherwise, data are averages ± standard deviations based on duplicate independent experiments. 

^bRange calculated along the linear growth curve (μ = dx/xdt, where μ is the specific growth rate and dx/dt is constant). Data obtained in three independent experiments differed by less than 10%.