TABLE 2.

Summary of fermentation results for the C. saccharoperbutylacetonicum mutants compared to the wild-type strain N1-4

Characteristic	Result (mean ± SD) in medium:
	P2				MP2
	N1-4	deltpta	deltbuk	deltptabuk	N1-4	deltpta	deltbuk	deltptabuk
Growth rate (/h)	0.42 ± 0.01	0.38 ± 0.02	0.36 ± 0.03	0.29 ± 0.01	0.66 ± 0.01	0.41 ± 0.01	0.56 ± 0.03	0.35 ± 0.02
Maximum OD600	14.6 ± 0.2	13.2 ± 0.2	13.8 ± 0.5	12.5 ± 0.3	16.0 ± 0.2	14.7 ± 0.15	13.8 ± 0.4	11.8 ± 0.2
Peak acetate (g/liter)a	2.1 ± 0.03	1.9 ± 0.04	2.4 ± 0.01	2.0 ± 0.01	0.69 ± 0.01	0.59 ± 0.02	1.9 ± 0.01	0.67 ± 0.02
Peak butyrate (g/liter)	2.7 ± 0.02	3.1 ± 0.04	2.5 ± 0.02	2.9 ± 0.01	2.5 ± 0.05	3.8 ± 0.05	2.0 ± 0.03	3.6 ± 0.05
Peak lactate (g/liter)	1.6 ± 0.05	1.7 ± 0.03	1.7 ± 0.01	1.9 ± 0.01	1.2 ± 0.05	2.2 ± 0.15	1.5 ± 0.05	1.3 ± 0.1
Butanol (g/liter)b	17.7 ± 0.1	17.7 ± 0.2	17.9 ± 0.2	19 ± 0.1	18.4 ± 0.02	18.7 ± 0.05	17.7 ± 0.1	18.8 ± 0.15
Butanol yield (g/g)	0.24 ± 0.01	0.24 ± 0.01	0.25 ± 0.01	0.25 ± 0.01	0.23 ± 0.01	0.26 ± 0.02	0.24 ± 0.02	0.26 ± 0.01
Acetone (g/liter)	7.7 ± 0.05	7.5 ± 0.1	6.8 ± 0.05	6.5 ± 0.05	7.7 ± 0.02	4.4 ± 0.05	6.8 ± 0.05	4.7 ± 0.1
Ethanol (g/liter)	0.72 ± 0.02	0.78 ± 0.01	0.6 ± 0.04	0.87 ± 0.02	0.72 ± 0.01	0.61 ± 0.01	0.73 ± 0.02	0.44 ± 0.01
Total ABE (g/liter)	25.9 ± 0.16	25.8 ± 0.06	25.2 ± 0.08	26.3 ± 0.03	26.8 ± 0.02	23.6 ± 0.11	25.2 ± 0.17	23.8 ± 0.22
Butanol selectivityc (g/g, %)	68.2 ± 0.05	68.3 ± 0.05	71.3 ± 0.01	72.4 ± 0.25	68.5 ± 0.1	79 ± 0.2	70.3 ± 0.1	78.7 ± 0.1

^aThere was approximately 1.7 g/liter of acetate preadded in the P2 medium.

^bThe reported titers were the maximum values after the solvent production reached a plateau.

^cRatio of butanol to total ABE.