TABLE 2.

Viable cell counts of cultures of R. sphaeroides mutant strain JZ3534 grown under different conditions

Culture conditiona	Counts of CFU/ml following culturing on plates
	Aerobic incubation	Anaerobic incubationb
Anaerobic	2 × 103	9 × 107
2% Oxygen	2 × 103	1.7 × 108
21% Oxygen	1 × 106	3.5 × 107

^aRefers to the culture conditions used prior to plating and counting the colonies.

^bPlates were incubated anaerobically in the dark, and dimethyl sulfoxide was added to the medium as an alternate electron acceptor.