Farm Animal Metabolism and Nutrition

Glucose Availability and Associated Metabolism 137

Membrane Inside

HCOOH

Formate

dehydrogenase

(outer membrane)

of methanogens)

F 430

NAD(P)H,H+

FADH 2

NAD(P)+

FAD

2H+

2H+ ATP

Acrylyl-CoA

Crotonyl-CoA

Fumarate

Propionyl-CoA

Butyryl-CoA

Succinate

ADP

ADP

ATP

2H+

Reductase

2H+

Cytobox Cytobred

QH 2 Q

Fe:Sox Fe:Sred

H 2

2e–

H 2

2H+

Hydrogenase

CO 2

(Methanogens)

Outside

2H+

Fig. 6.4.Representation of anaerobic electron transport systems (putative). Not all components are found in
all microorganisms nor are all components observed in ruminal microorganisms included. Based on Erfle et
al. (1986).