Table 4.

Methanogenic substrate consumption and corresponding methane accumulation.

Treatment	Methanogenic substrate	Well	Bottle	Substrate consumed inμmol	Measured methane	MCR
No substrate	Methanol	A3-11	1	725 (±40)	407	1.8
			2	712 (±70)	341	2.1
		C1-12	1	130 (±11)	86	1.5
			2	60 (±5)	40	1.5
Methanol	Methanol	A3-11	1	3392 (±133)	1858	1.8
			2	3174 (±130)	1361	2.3
		B1-12	1	1620 (±165)	418	3.9
			2	4140 (±240)	377	11.0
TMA*	TMA	A3-11	1	150 (±19)	383	0.39
			2	190 (±13.5)	404	0.47
		B1-12	1	181 (±5.1)	365	0.50
			2	144 (±15.4)	409	0.35
Yeast extract*	Hydrogen	B1-12	1	15	39	0.38
			2	16	45	0.36
		C1-12	1	32	22	1.45
			2	34	37	0.92
Formate*	Hydrogen	B1-12	1	211	74	2.90
			2	311	85	3.66

^*Methane yields corrected for methane derived from methylotrophic methanogens after subtraction of the “no substrate” background. See Supplementary Figures S5, S6 for comparison. No MCR_MeOH could be calculated for the B1-12 ”no substrate” and C1-12 “methanol” experiments. The low initial methanol concentration in the B1-12 well reached the detection limit at the time of sampling in the incubation experiment. The C1-12 well water incubated with methanol addition did not reach a methane plateau at the end of the experiments (see Figure 4). Error for the methane measurement was on average between 1.1 and 2.7 μmol and for hydrogen measurements 0.1 and 1.4 μmol in all incubations.