Denitrification and nitrification processes are the two prominent pathways of nitrogen (N) transformation in composting matrix. This study explored the dynamics of denitrifying and nitrifying bacteria at different composting stages of cow manure and corn straw using functional gene sequencing at DNA and cDNA levels. Corresponding agreement among OTUs, NMDS, mental test and network analyses revealed that functional bacteria community compositions and responses to physicochemical factors were different at DNA and cDNA levels. Specifically, some OTUs were detected at the DNA level but were not observed at cDNA level, differences were also found in the distribution patterns of nitrifying and denitrifying bacteria communities at both levels. Furthermore, co-occurrence network analysis indicated that Pseudomonas, Paracoccus and Nitrosomonas were identified as the keystone OTUs at the DNA level, while Paracoccus, Agrobacterium and Nitrosospira were keystone OTUs at the cDNA level. Mantel test revealed that TN, C/N and moisture content significantly influenced both the denitrifying bacteria and ammonia-oxidizing bacteria (AOB) communities at the DNA level. NO3--N, NH4+-N, TN, C/N, and moisture content only registered significant correlation with the nosZ-type denitrifiers and ammonia-oxidizing bacteria (AOB) communities at the cDNA level. Structural equation model (SEM) showed that TN, NH4+-N, and pH were direct and significantly influenced the gene abundance of denitrifying bacteria. Howbeit, TN, NH4+-N, and NO3--N had significant direct effects on amoA gene abundance.

中文翻译：

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牛粪堆肥中功能微生物在DNA和cDNA水平上的分布差异。

反硝化和硝化过程是堆肥基质中氮（N）转化的两个主要途径。这项研究利用DNA和cDNA水平的功能基因测序，探索了牛粪和玉米秸秆不同堆肥阶段反硝化和硝化细菌的动力学。OTU，NMDS，心理测验和网络分析之间的相应一致性表明，在DNA和cDNA水平上，功能细菌群落组成和对理化因子的反应是不同的。具体而言，在DNA水平上检测到一些OTU，而在cDNA水平上未观察到，两个水平的硝化和反硝化细菌群落的分布模式也存在差异。此外，共现网络分析表明，假单胞菌 副球菌和亚硝化单胞菌被鉴定为DNA水平的关键OTU，而副球菌，农杆菌和亚硝基螺菌则为cDNA水平的关键OTU。壁炉架测试显示，TN，C / N和水分含量在DNA水平上显着影响反硝化细菌和氨氧化细菌（AOB）群落。在cDNA水平上，NO3--N，NH4 + -N，TN，C / N和水分含量仅与nosZ型反硝化剂和氨氧化细菌（AOB）群落显着相关。结构方程模型（SEM）表明，TN，NH4 + -N和pH直接且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。农杆菌和亚硝基螺菌是cDNA水平上的关键OTU。壁炉架测试显示，TN，C / N和水分含量在DNA水平上显着影响反硝化细菌和氨氧化细菌（AOB）群落。在cDNA水平上，NO3--N，NH4 + -N，TN，C / N和水分含量仅与nosZ型反硝化剂和氨氧化细菌（AOB）群落显着相关。结构方程模型（SEM）表明，TN，NH4 + -N和pH是直接的，并且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。农杆菌和亚硝基螺菌是cDNA水平上的关键OTU。壁炉架测试显示，TN，C / N和水分含量在DNA水平上显着影响反硝化细菌和氨氧化细菌（AOB）群落。在cDNA水平上，NO3--N，NH4 + -N，TN，C / N和水分含量仅与nosZ型反硝化剂和氨氧化细菌（AOB）群落显着相关。结构方程模型（SEM）表明，TN，NH4 + -N和pH是直接的，并且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。C / N和水分含量在DNA水平上显着影响反硝化细菌和氨氧化细菌（AOB）群落。在cDNA水平上，NO3--N，NH4 + -N，TN，C / N和水分含量仅与nosZ型反硝化剂和氨氧化细菌（AOB）群落显着相关。结构方程模型（SEM）表明，TN，NH4 + -N和pH是直接的，并且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。C / N和水分含量在DNA水平上显着影响反硝化细菌和氨氧化细菌（AOB）群落。在cDNA水平上，NO3--N，NH4 + -N，TN，C / N和水分含量仅与nosZ型反硝化剂和氨氧化细菌（AOB）群落显着相关。结构方程模型（SEM）表明，TN，NH4 + -N和pH直接且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。pH值是直接的，并且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度有明显的直接影响。pH值是直接的，并且显着影响反硝化细菌的基因丰度。但是，TN，NH4 + -N和NO3--N对amoA基因的丰度具有显着的直接影响。