TABLE 3.

MPNs of various freshwater sediments determined with anaerobic media amended with a mixture of methanol, TMA, and DMS, with DMS alone, and with only syringate

Sediment origin	MPN (no. of bacteria/ml of sediment slurry) on substratea:
	MeOH + TMA + DMS	DMS	Syringate
Zegveld I	4.0 × 105	4.0 × 104	9.0 × 103
Zegveld II	9.0 × 104	2.3 × 105	4.0 × 103
Hatertse Vennen	2.3 × 101	0.4 × 101	2.3 × 101
Bruuk I	9.0 × 103	9.0 × 103	4.0 × 102
Bruuk II	2.3 × 104	2.3 × 103	4.0 × 103
Dekkerswald	4.0 × 105	4.0 × 104	2.3 × 105
Breukelen	9.0 × 105	1.5 × 105	4.0 × 104
Tienhoven I	2.3 × 103	9.0 × 102	4.0 × 102
Tienhoven II	9.0 × 103	2.3 × 103	4.0 × 103
Maarssen	9.0 × 104	9.0 × 103	9.0 × 103

^aMethylotrophic methanogens were targeted with methanol (MeOH), DMS, and TMA, while MT and DMS producers were targeted by addition of syringate.