洪泽湖湿地不同植物作用下沉积物细菌群落结构

为研究植物类型对水体沉积物细菌群落结构的影响,以洪泽湖湿地荷花、茭草和芦苇3种植物区沉积物样品为研究对象,采用高通量测序技术分析其细菌群落组成。结果显示:3种植物区的沉积物样品分别获得1494、1503、1600个Operational Taxonomic Unit(OTU)。门的水平上,主要有变形菌门(Proteobacteria),绿弯菌门(Chloroflexi),酸杆菌门(Acidobacteria),硝化螺旋菌门(Nitrospirae),拟杆菌门(Bacteroidetes),厚壁菌门(Firmicutes)。属的水平上,硝化螺旋菌属(Nitrospira),亚硝化单胞菌属(Nitrosomonadaceae)为优势菌属,它们具有硝化作用。芦苇区和茭草区沉积物细菌群落结构较为相似。荷花区沉积物总有机碳和总氮的含量明显低于芦苇区和茭草区,细菌群落组成也存在较大的差异,其中具有较强反硝化能力的嗜甲基菌(Methylotenera)、芽孢杆菌(Bacillus)、假单胞菌(Pseudomonas)、乳球菌(Lactococcus)相对丰度高出芦苇区和茭草区的10倍以上。研究表明,植物类型影响沉积物有机碳和氮的含量,继而影响沉积物细菌群落结构。与芦苇或茭草相比,荷花区沉积物具有更强的反硝化潜力,有利于降低水体富营养化风险。

Bacterial community structures in sediments are affected by different plants in Hongze Lake wetlands

To study the effects of plant species on sediment bacterial community structure, we collected samples from three different wetlands dominated by Nelumbo nucifera, Zizania caduciflora, and Phragmites australis in the Hongze Lake area and analyzed the samples using the high-throughput sequencing technique. The results showed that the number of Operational Taxonomic Units(OTUs) for each sample from the three wetlands were 1494, 1503, and 1600, respectively. At the phylum level, the dominant phyla in the sediments were Proteobacteria, Chloroflexi, Acidobacteria, Nitrospirae, Bacteroidetes, and Firmicutes. At the genus level, high abundances of Nitrospira and Nitrosomonadaceae, which are mainly involved in nitrification, were observed in all sediment samples. The results also showed that the bacterial community structure at the Phragmites australis site was similar to that at the Zizania caduciflora site. The TOC and TN contents at the Nelumbo nucifera site were significantly lower than at the Phragmites australis and Zizania caduciflora sites. Furthermore, significant differences in bacterial community structure were observed between the Nelumbo nucifera site and the Phragmites australis or Zizania caduciflora sites. The relative abundances of Methylo tenera, Bacillus, Pseudomonas, and Lactococcus, with their high nitrification capacities, meant that nitrification at the Nelumbo nucifera site was over 10 times higher than at the Phragmites australis or Zizania caduciflora sites. This indicated that the plant species had a significant influence on the C/N contents and bacterial community structure in the wetland sediments. Furthermore, Nelumbo nucifera has a greater potential for denitrification compared to Zizania caduciflora and Phragmites australis, which means that this plant can reduce the risk of eutrophication.