TABLE 7.

Growth rates of S. cerevisiae CEN.PK 113-7D and mutant strains^a

Genotype	Avg specific growth rate (h−1)
	500 mM lactic acid	750 mM lactic acid
Reference	0.25	0.19
haa1Δ	0.16	No growthb
tpo2Δ	0.22	0.17
tpo2Δ tpo3Δ	0.25	0.17
yro2Δ	0.24	0.19
ygp1Δ	0.23	0.20

^aSpecific growth rates of S. cerevisiae CEN.PK 113-7D (reference strain) and those of strains carrying deletions in the HAA1 gene or in the genes belonging to the Haa1p regulon that were most strongly upregulated in response to lactic acid (Table 6). Each strain was grown at pH 3 in anaerobic batch cultures in the presence of the indicated concentration of lactic acid. Specific growth rates (h⁻¹) are averages of two independent experiments for each concentration of lactic acid. Data for replicate growth experiments differed by less than 15%.

^bNo change in CO₂ concentrations were measured in the off gas after nearly 200 h.