Effects of cadmium pollution on soil bacterial structure and diversity in riparian wetland of mountain reservoir
[Objective]The present paper aimed to study the effects of cadmium pollution on soil bacterial structure and diversity in riparian wetlands of mountain reservoir,and to find out the cadmium-resistant bacteria which were beneficial to the remediation of cadmium pollution.[Method]The high throughput sequencing method of Illumina Miseq was used to analyze the effects of cadmium stress on bacterial community and diversity in rhizosphere soils of Taxodium distichum planting in riparian wetlands of Changtan reservoir,Zhejiang province.The concen-trations of cadmium were set at0,100,400 mg/kg,respectively,and were marked as Cd0,Cd100,Cd400,correspondingly.[Result]The cadmium stress could cause changes in both bacterial diversity and community structure.There were 34 phyla,96 classes,202 orders,313 families,and 502 genera in the rhizosphere soil of T.distichum planting in riparian wetlands of Changtan reservoir under different gradients of cadmium pollution.Low cadmium stress might raise the Chao1 index and Shannon index of soil bacterial community and high cadmium stress might reduce the Chao1 index and Shannon index of soil bacterial community.With the increase of Cd stress,the relative abundance of Actinobacteri and Planctornyces in the soil of riparian wetland showed a downward trend all the time,while the relative abundance of Bacteroidetes and Gemmatimonadetes were on the increase all the time.The relative abundance of soil Proteobacteria and Patescibacteria de-creased first and then increased.The relative abundances of Acidobacteria,Rokubacteria,Errucomicrobia,Nitrospirae and Firmicutes in soil increased first and then decreased.Proteobacteria,Bacteroidetes,Patescibacteria and Gemmatimonadetes were the dominant groups in high Cd concentration stress.With the increase of Cd stress,the relative abundance of Pseudarthrobacter,Muciaginibacter and Rhodopseudomonas in the soil of riparian wetland showed a downward trend all the time,while the relative abundance of Flavobacterium was on the increase all the time.The relative abundance of soil Rhodanobacter decreased first and then increased.The relative abundances of Sphingomonas in soil increased first and then decreased.This indicated that low cadmium stress might stimulate the growth and eproduction of cadmium-sensitive bacteria,which made the community structure more complex.High concentration of cadmium significantly inhibited bacteria,resulting in the extinction of some species and the decrease of diversity.High cadmium pollution could induce cadmium-resistant bacteria such as Rho-danobacter to become dominant groups,and the community structure tended to be stable and single.The bacterial community structure had obvious response characteristics to different cadmium pollution stresses and could be used as a sensitive index for soil quality evaluation of cadmium contaminated wetlands.[Conclusion]There are a large number of Rhodanobacter,Gemmatimonadaceae-unclassified,Massilia,Can-didate-Adlerbacteria-unclassified,Chitinophagaceae-unclassified,Alphaproteobacteria-unclassified,Flavobacterium and Duganella in the Cd400 group,which can be used as a reference for microbial remediation of cadmium contaminated riparian wetland of montain reservoir in southern China.
CadmiumRiparian wetlandBacterial community structureHigh throughput sequencingTaxodium distichum
NETL
NSTL
万方数据
维普
