【摘要】 实验室分离纯化出一株具有反硝化功能的兼性厌氧菌,16S rDNA序列分析其为柠檬酸杆菌属,命名为Citrobacter sp. ZY630.对菌株利用Fe（Ⅱ）还原NO^-₃过程进行探究,结果表明,在无外加有机物的情况下,菌株ZY630可以以Fe²⁺为电子供体还原NO^-₃,经过120 h反应,Fe²⁺+菌组约1.1 mmol/L的NO^-₃完全降解,产物包含NO^-₂、N₂和N₂O.通过对照分析,发现体系中NO^-₃-NO^-₂的转化是由生物作用主导.同时发现6 mmol/L Fe²⁺+菌组较3 mmol/L Fe²⁺+菌组反硝化程度进行更彻底,表明Fe²⁺有助于促进该体系反硝化过程.进一步探究菌株ZY630利用Fe²⁺降解NO^-₂过程,发现120 h后,加菌加Fe²⁺体系的Fe²⁺氧化总量与NO^-₂还原总量的摩尔比约为2.22,较只加Fe²⁺体系的摩尔比略高,表明NO^-₂和Fe²⁺之间化学反应占优.所以,菌株ZY630厌氧亚铁氧化硝酸盐还原是一个生物化学耦合过程.更多还原

【Abstract】 A facultative anaerobe with denitrification function is isolated and purified, which is found to belong to the genus Citrobacter by 16 S rDNA sequence analysis and named as Citrobacter sp. ZY630. The strain is probed for its ability to reduce nitrate by Fe（Ⅱ）, and the results show that the strain ZY630 can reduce NO^-₃ with Fe²⁺ as the electron donor in the absence of additional organic matter. After 120 h of reaction, about 1.1 mmol/L of NO^-₃ in the Fe²⁺+ bacterias group is completely degraded, and the products include NO^-₂, N₂ and N₂O. The control analysis reveals that the conversion of nitrate to nitrite in the system is dominated by biological action. It is also found that the 6 mmol/L Fe²⁺+ bacterias group carries out denitrification more completely than the 3 mmol/L Fe²⁺+ bacterias group, indicating that Fe²⁺ helps to promote the denitrification process in this system. Further studies are conducted on the biological and chemical pathways in the NO^-₂ degradation process by strain ZY630 using Fe²⁺. It is found that the molar ratio of total amount of Fe²⁺oxidation to total amount of NO^-₂reduction is about 2.22 after 120 h, which is slightly higher than that of the system with only Fe²⁺, indicating that the chemical reaction between NO^-₂and Fe²⁺ is dominant. The anaerobic ferrous oxidative nitrate reduction by strain ZY630 is a biochemically coupled process.更多还原