Table 2.

Growth conditions for methanogenic cultures, pH values adjusted according to literature (Neil and James, 1980; Huser et al., 1982; Neil et al., 1982; Touzel et al., 1988).

	Substrate	Gas phase	pH
Methanosarcina barkeri	185 mmol L−1 methanol, 10 mmol L−1 acetate	N2:H2 ~ (97:3, v/v)	7.1
Methanobacterium formicicum	50 mmol L−1 formate, H2:CO2 (50:50, v/v)	H2:CO2 (50:50, v/v)	7.5
Methanothrix soehngenii	40 mmol L−1 acetate	N2:CO2 (50:50, v/v)	7.6