奉化江底泥碳、氮、硫转化功能基因的定量研究

Quantitative analysis on the functional genes involved in biological transformation of carbon,nitrogen and sulfur in Fenghua River sediments

采用荧光定量聚合酶链式反应(PCR)法研究了奉化江4大支流及干流下游底泥样品中碳、氮、硫元素生物地球化学循环过程中关键转化功能基因丰度的变化。结果表明,奉化江干流下游的产甲烷基因mcrA丰度显著高于上游,甲烷氧化基因pmoA的丰度在支流下游、支流汇合处、干流下游均较高;富营养区域采样点底泥中氨氧化细菌硝化基因amoA(AOB)丰度显著高于氨氧化古菌硝化基因amoA(AOA),而其他采样点的AOA丰度大于AOB;干流下游底泥样品中反硝化基因nosZ丰度显著高于上游;居民区附近采样点底泥中存在较多硫氧化菌(soxB基因)和硫酸盐还原菌(dsrB基因)。相关性分析发现,pmoA与TN极显著正相关,AOB与NO-3极显著正相关,而nosZ与总碳(TC)、TN极显著正相关。

In this study, real-time fluorescent quantitative PCR was applied to quantify the abundance of functional genes involved in biological transformation of carbon, nitrogen and sulfur in the 4 tributaries and coverage of Fenghua River sediments. The results showed that the abundances of methane-producing genes m c rA at downstream of Fenghua River were significantly higher than that at upstream,and methane oxidation gene pm oA relatively higher at downstream and confluence of tributaries as well as downstream of Fenghua River. The abundances of bacterial amoA gene （AOB） at eutrophication sites were higher than that of archaeal amo A gene （AOA） , while the other sites were inverse. The abundances of denitrification gene （nosZ） were significantly higher at downstream than that at upstream. There were relatively abundant sulfur oxidizing bacteria （sox B ） and sulfate reducing bacteria （dsrB） in the sediments near the residential area. The results of correlation analysis showed that abundance of pmo A was significantly positive correlated with TN,the abundance of AOB was significantly positive correlated with NO3 , and the abundance of nosZ was significantly positive correlated with TC and TN.