TABLE 3.

Estimation of cell concentrations in salt marsh sediments

Target group	DNA detected (ng)	% of 200 μl of purified DNA used for dot blot	Total DNA estimated for sample (fg g of sediment−1)a	Corrected DNA cell−1 for target group (fg)b	Estimated cells g of sediment−1
General SRBc	1,130	50	1.7 × 109	5.7	3.0 × 108
	1,110	50	1.7 × 109	5.7	3.0 × 108
	1,160	50	1.8 × 109	5.7	3.2 × 108
Desulfococcus spp.c	546	50	8.3 × 108	5.6	1.5 × 107
	605	50	9.2 × 108	5.6	1.6 × 107
	628	50	9.5 × 108	5.6	1.7 × 107
General eubacteriad	14,006	4	2.7 × 1011	5.3	5.2 × 1010
General SRBd	1,019	8	9.7 × 109	5.7	1.7 × 109
Desulfovibrio spp.d	150	16	7.1 × 108	5.9	1.2 × 108
Desulfobacter spp.d	168	16	8.1 × 108	3.1	2.6 × 108
Desulfobacterium spp. d	161	16	7.6 × 108	6.5	1.2 × 108
Desulfococcus spp.d	43	16	2.0 × 108	5.6	3.5 × 107
Desulfobulbus spp.d	236	16	1.1 × 109	7.3	1.5 × 108

^aBased on extraction efficiency of 48%. 

^bValues taken from Table 2. 

^cDetected from replicate DNA preparations from one 2-g sample collected in June. 

^dDetected from one 2-g sample collected in June.