Table 1. Specific enzyme activities (U per mg protein) in Pelobacter species. If not mentioned otherwise, all enzyme assays were done with the P. carbinolicus/M. hungatei strain M1h coculture. (DCPIP  =  2,6-dichlorophenolindophenol, n. ac.  =  non-acetylating, BV  =  benzyl viologen, MV  =  methyl viologen, M. arb.  =  Methanobrevibacter arboriphilus, n. d. =  not determined).

Species	P. acetylenicus	P. carbinolicus	P. carbinolicus	P. carbinolicus
Culture	Syntrophic	Syntrophic	Pure	Pure
Substrate	Ethanol	Ethanol	Acetaldehyde	Acetoin
Extract	Cell-free extract	Cytoplasmic fraction	Cytoplasmic fraction	Cytoplasmic fraction
Acetoin: DCPIP oxidoreductase	n. d.	0.0027±0	0.006±0.002	1.3±0.28
Alcohol dehydrogenase, NAD+ (oxidative) pH 7.5	0.12±0.01	0.019±0	0.033±0.001	0.24±0.04
Alcohol dehydrogenase, NAD+ (oxidative) pH 9.0	0.70±0.13	0.26±0	n. d.	2.78±0.54
Alcohol dehydrogenase, NADH (reductive) pH 7.5	1.12±0.06	0.027±0	n. d.	0.60±0.08
Acetaldehyde dehydrogenase, acetylating	0.08±0.01	1.54±0.49	0.008±0.001	4.21±1.0
Phosphotransacetylase	18.84±3.07	37.8±3.8	n. d.	17.0 [7]
Acetate kinase	2.21±0.19	6.4±0.4	n. d.	12.6 [7]
Acetaldehyde dehydrogenase, n. ac., NAD+	0	0	n. d.	0
Acetaldehyde dehydrogenase, n. ac., BV	4.86±1.64	3.65±0.6	0.77±0.08	0.25±0.07
Acetaldehyde dehydrogenase, n. ac., MV	2.33±0.278	0.43±0.11	n. d.	n. d.
Formate dehydrogenase, NAD+	0.07±0.01	0.96±0.66	n. d.	n. d.
Formate dehydrogenase, BV	4.09±0.43	23.2±1.8	0.083±0.037	n. d.
Formate dehydrogenase, MV	2.14±0	6.2±0.7	n. d.	n. d.
Formate dehydrogenase, NAD+, M. arb.-Coculture	n. d.	0.0032±0	n. d.	n. d.
Formate dehydrogenase, BV, M. arb.-Coculture	n. d.	0.20±0.02	n. d.	n. d.
Formate dehydrogenase, MV, M. arb.-Coculture	n. d.	0.08±0.01	n. d.	n. d.
Hydrogenase, NAD+	0	0	n. d.	0
Hydrogenase, BV	136±36	75±15	16.0±2.0	0.81±0.07
Hydrogenase, MV	385±109	91±11	n. d.	n. d.