1.3.1.86	FAD	in the absence of ferredoxin, a remarkable stimulation of crotonyl-CoA reduction by FAD is observed	
1.3.1.86	Ferredoxin	butyryl-CoA dehydrogenase from C. difficile belongs to the subfamily of bifurcating enzymes capable of coupling the exergonic reduction of crotonyl-CoA by NAD Hwith the endergonic reduction of ferredoxin by NADH	
1.3.1.86	NADH	-	
1.3.1.86	NADPH	-	
1.3.1.86	NADPH	NADPH is the sole electron donor for the reduction catalyzed by crotonyl-CoA reductase	
1.3.1.86	NADPH	the crotonyl-CoA reductase reaction requires NADPH as electron donor, but at a 20fold higher concentration NADH will substitute for NADPH with 50% Vmax