氮掺杂碳纳米颗粒对稻田根际土壤细菌群落的影响

氮掺杂碳纳米颗粒(N-CNPs)具有较高的农田氮肥增效潜力,但其对稻田根际土壤细菌群落结构和功能的影响尚不明确。本研究以连续3年施用低(1.2%,N-CNPs1)、中(6.7%,N-CNPs2)和高(9.3%,N-CNPs3)氮掺杂碳纳米颗粒的稻田根际土壤为研究对象,采用高通量测序技术和PICRUSt 功能预测方法研究其细菌群落组成和代谢功能变化。结果表明: 连续3年配施N-CNPs能提升稻田根际土壤细菌群落多样性,改变细菌群落功能;不同氮掺杂量水平间存在差异,其中以中氮掺杂量(N-CNPs2)碳纳米颗粒处理变化幅度最大。细菌群落分析结果指出,配施N-CNPs提升了根际土壤中变形菌门、酸杆菌门和疣微菌门的相对丰度,降低了浮霉菌门、绿弯菌门、硝化螺旋菌门和芽单胞菌门的相对丰度。PICRUSt 功能预测结果表明,在二级预测功能分类中,配施N-CNPs处理的氨基酸代谢、碳水化合物代谢和脂类代谢功能得到增强,而其他代谢功能则受到减弱。KEGG 直系同源基因簇丰度热图结果显示,N-CNPs2处理能提升根际土壤碳、氮代谢相关的细菌群落的相对丰度。

Effects of nitrogen-doped carbon nanoparticles on bacterial community in paddy rhizosphere soil

The nitrogen-doped carbon nanoparticles (N-CNPs) has a high potential of increasing nitrogen efficiency in farmland. However, little has been known about the effects of N-CNPs on soil microbial communities. In this study, paddy rhizosphere samples were collected from soils being treated with different nitrogen-doped amount of carbon nanoparticles (low, 1.2%, N-CNPs1; medium, 6.7%, N-CNPs2; high, 9.3%, N-CNPs3) for three years. We analyzed the bacterial community structure and diversity using the high-throughput sequencing. PICRUSt gene prediction analysis was used to determine soil community composition and metabolic function. Our results showed that treatment with N-CNPs changed the structure and diversity of soil microbial communities. Soil bacterial community diversity in adding medium amount of nitrogen-doped nanoparticles group (N-CNPs2) was the highest among all the treatments. Crenarchaeota, Acidobacteria and Planctomycetes were the most dominant groups in the soil microbial community. The relative abundances of Crenarchaeota, Acidobacteria and Verrucomicrobia increased, whereas Planctomycetes, Chloroflexi and Nitrospirae decreased with adding N-CNPs. Results of PICRUSt analysis revealed a wide genetic diversity of organisms involved in adding N-CNPs, such as amino acid metabolism, carbohydrate metabolism, lipid metabolism and environmental information processes. Heat map analysis of KEGG demonstrated that adding medium amount of nitrogen-doped nanoparticles (N-CNPs2) group increased the relative abundance of bacterial community associated with soil carbon and nitrogen metabolism.