Davies K J, Lloyd D, Boddy L
Department of Microbiology, University College, Cardiff, UK.
J Gen Microbiol. 1989 Sep;135(9):2445-51. doi: 10.1099/00221287-135-9-2445.
Denitrification by Paracoccus denitrificans and Pseudomonas aeruginosa was studied using quadrupole membrane-inlet mass spectrometry to measure simultaneously and continuously dissolved gases. Evidence was provided for aerobic denitrification by both species: in the presence of O2, N2O production increased in Pa. denitrificans, while that of N2 decreased; with Ps. aeruginosa, the concentrations of both N2 and N2O increased on introducing O2 into the gas phase. Disappearance of NO-3 was monitored in anaerobically and aerobically grown cells which were maintained either anaerobically or aerobically: the rate and extent of NO-3 utilization by both species depended on growth and maintenance conditions. The initial rate of disappearance was most rapid under completely anaerobic conditions, and lowest rates occurred when cells were grown anaerobically and maintained aerobically. In nitrogen balance experiments both species converted over 87% of the added NO-3 to N2 and N2O under both anaerobic and aerobic maintenance conditions.
利用四极杆膜进样质谱法同时连续测量溶解气体，研究了反硝化副球菌和铜绿假单胞菌的反硝化作用。这两种菌都有好氧反硝化的证据：在有O2存在时，反硝化副球菌中N2O的产生增加，而N2的产生减少；对于铜绿假单胞菌，将O2引入气相后，N2和N2O的浓度都增加。在厌氧或好氧条件下维持生长的厌氧和好氧细胞中监测了NO-3的消失情况：两种菌利用NO-3的速率和程度取决于生长和维持条件。在完全厌氧条件下，NO-3消失的初始速率最快，而当细胞在厌氧条件下生长并在好氧条件下维持时，速率最低。在氮平衡实验中，在厌氧和好氧维持条件下，两种菌都将超过87%的添加NO-3转化为N2和N2O。
