TABLE 1.

Summary of MPN results obtained using acetate as a substrate^a

Treatment	MPN contaminated	95% confidence limitb		MPN uncontaminated
		Upper	Lower
Acetate + JF-1d	2.4 × 106c	5.8 × 106	9.9 × 107	BDLd
Acetate + sulfate	1.1 × 106	3.6 × 105	3.5 × 106	BDL
Acetate + sulfate + G11d	2.1 × 106	7.9 × 105	5.6 × 106	BDL

^aThe samples used for MPN analysis were collected in 1998.

^bMPN values are per gram of sediment.

^cThe 95% upper and lower confidence values used for three tube MPN analysis (3).

^dAbbreviations: JF-1, Methanospirillum hungatei strain JF-1; G11, Desulfovibrio vulgaris strain G11; BDL, below detection limit.