TABLE 2.

Estimation of cellular DNA content^a

Probe DNA	Species	Avg cell count (cells ml−1)	Avg DNA yield (fg ml−1)	DNA cell−1 (fg)
				Actual	Adjustedb
338	E. coli	1.9 × 108 (±0.1 × 108)	1.0 × 109 (±0.2 × 109)	5.3	6.9
660	D. proprionicus	7.2 × 107 (±0.8 × 107)	4.0 × 108 (±0.9 × 108)	5.6	7.3
221	D. autotrophicum	2.0 × 107 (±0.2 × 107)	1.0 × 108 (±0.4 × 108)	5.0	6.5
687	D. vulgaris	2.0 × 108 (±0.4 × 108)	9.0 × 108 (±0.5 × 108)	4.5	5.9
814	D. multivorans	4.5 × 108 (±0.5 × 108)	4.0 × 108 (±0.8 × 109)	4.3	5.6
129	D. postgatei	6.2 × 107 (±0.3 × 107)	2.0 × 108 (±0.5 × 108)	2.4	3.1

^aCell counts and DNA yields were determined with 20-ml log-phase cultures. 

^bBased on extraction efficiency of 70%.