TABLE 2.

Fermentation parameters^a for 24-h bioreactor batch cultures conducted under aerobic conditions in MYA medium with 30 g·liter⁻¹ glycerol as the carbon source

Parameter	Value for E. coli strain:
	K24K	K24KL
μmaxe (h−1)	0.64 ± 0.03	0.67 ± 0.02
Final CDWb concn (g·liter−1)	10.7 ± 0.8	13.9 ± 0.7
Final PHB content (% [wt/wt])	36 ± 2	44 ± 1
Specific consumption rate (mmol·g CDW−1·h−1) for:
Glycerol	1.8 ± 0.5	1.6 ± 0.3
O2	0.085 ± 0.009	0.113 ± 0.006
Specific production rate (μmol·g CDW−1·h−1) for:
Acetate	52 ± 3	61 ± 2
Formate	77 ± 4	63 ± 5
Lactate	48 ± 5	NDc
Ethanol	149 ± 1	205 ± 1
PHB	103 ± 2	178 ± 3
Ethanol-to-acetate ratio (mol·mol−1)	0.36 ± 0.08	0.64 ± 0.02
Redox ratiod ([NADH + NADPH]/[NAD+ + NADP+])	0.34 ± 0.03	0.62 ± 0.04

^aMaximum specific growth rates, as well as specific consumption and production rates, were calculated during exponential growth. Results represent the mean values ± standard deviations for duplicated measurements from at least two independent experiments.

^bCDW, cell dry weight.

^cND, not detected.

^dNucleotide content was enzymatically determined at 24 h.

^eμ_max, maximum specific growth rate.