Competition between oxygen and nitrate respirations in continuous culture of Pseudomonas aeruginosa performing aerobic denitrification
Competition between oxygen and nitrate respirations in continuous culture of Pseudomonas aeruginosa performing aerobic denitrification
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DOI：
10.1002/bit.20812
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发表时间：
2006-04-20
影响因子：
3.8
通讯作者：
Ju, LK
中科院分区：
文献类型：
--
作者：
Chen, F;Xia, Q;Ju, LK
采用含硝酸盐的培养基，在稀释率（D）为0.026、0.06和0.13/h，溶解氧（DO）为0 ~ 2.2 mg/L的条件下，对铜绿假单胞菌进行连续培养。在所有研究的系统中，该细菌都进行了厌氧O（2）和硝酸盐呼吸。对于每个D，来自葡萄糖的（表观）细胞产率（Y-X/S）在零DO下较低，但在非零DO下基本上没有变化。在非零DO系统中，Y-X/S随D的增加而增加，用考虑细胞死亡的模型拟合，得到最大细胞产量Y-X/S（m）= 0.49，维持系数M-S = 0.029（/h），细胞衰减常数k（d）= 0.014/h。相同的模型未能描述零DO系统的行为，其中葡萄糖和硝酸盐都不是限制性的，并且限制因素仍然未知。然而，在所有系统中，细胞接受电子的产率（Y-X/e）相对恒定，通过反硝化作用接受的每个电子的能量产率估计为通过O-2呼吸的69%。进一步的研究表明，增加DO仅在极低DO时才能增强O-2呼吸（
Continuous culture of P. aeruginosa was conducted with nitrate-containing media under the dilution rates (D) of 0.026, 0.06, and 0.13/h and the dissolved oxygen concentrations (DO) of 0-2.2 mg/L. The bacterium performed simultaneousO(2) and nitrate respiration in all of the systems studied. For each D, the (apparent) cell yield from glucose (Y-X/S) was lower at zero DO, but did not change substantially with non-zero DO. In non-zero DO systems, Y-X/S increased with increasing D, and when fit with a model considering cell death, gave the following parameters: maximum cell yield Y-X/S(m) = 0.49, maintenance coefficient M-S = 0.029 (/h), and cell decay constant k(d) = 0.014/h. The same model failed to describe the behaviors of zero-DO systems, where neither glucose nor nitrate was limiting and the limiting factor(s) remained unknown. The cell yield from accepted electron (Y-X/e) was however relatively constant in all systems, and the energy yield per electron accepted via denitrification was estimated at similar to 69% of that via O-2 respiration. A closer examination revealed that increasing DO enhanced O-2 respiration only at extremely low DO (