To use nitrate as electron donor in the electron transport chain during respiration. 利用硝酸盐作为呼吸作用中，电子传递链之电子提供者。
D. To use nitrate as electron acceptor in the electron transport chain during respiration. 利用硝酸盐作为呼吸作用中，电子传递链之电子接受者。
Denitrifying bacteria such as Pseudomonas, Micrococcus, and Clostridium use nitrate as the terminal electron acceptor in anaerobic respiration. 反硝化细菌有假单胞菌，微球菌以及梭菌。