1.7.2.1	nitrite reductase (NO-forming)	nitrate reduction I (denitrification)	-	
1.7.2.4	nitrous-oxide reductase	nitrate reduction I (denitrification)	-	
1.7.2.5	nitric oxide reductase (cytochrome c)	nitrate reduction I (denitrification)	-	
1.7.5.1	nitrate reductase (quinone)	nitrate reduction I (denitrification)	-