水田土壤细菌群落对不同重金属污染水平的响应分析——以A县为例

重金属污染问题长期存在于土壤环境中,并对土壤细菌群落结构造成了较大影响,从而引起了广泛的研究.本文选取水田土壤为测试样本,通过高通量测序技术和土壤性质化验对样本进行处理,采用Spearman相关性分析等统计分析方法对不同重金属污染水平下的水田土壤细菌群落进行结构和多样性分析.结果显示,研究区内土壤样点的重金属污染水平可被划分为4个等级,其中,轻度重金属污染水平(LL)区域土壤细菌群落的多样性指数总体上显著低于其他区域,即轻度污染的环境将降低该区域的细菌群落多样性.Nitrospira和Candidatus_Solibacter等菌属在重度重金属污染水平(SL)区域中显示出较强的重金属耐受性.Proteobacteria、Firmicutes和Gemmatimonadetes等菌门在不同等级重金属污染水平区域中表现出一定的耐受性.此外,土壤含水量(SWC)、酸碱度(pH)、速效磷(AP)、有效钾(AK)、总氮(TN)、有机质(OM)、铜(Cu)、铅(Pb)、砷(As)和锌(Zn)等土壤环境因子与细菌群落结构存在显著相关性(p0.05).因此,应该尽快开发利用这些具有重金属耐性和生物修复功能的微生物,为粮食作物的健康生长提供适宜的土壤环境.

Response analysis of soil bacterial community to different heavy metal pollution levels in paddy fields: A case study of A county

The problem of heavy metal pollution has long existed in the soil environment and has a great impact on the soil bacterial community structure, which has caused extensive research. The paddy soils were selected as the test samples, and samples were processed by high-throughput sequencing technology and soil property tests, and statistical analysis methods such as Spearman correlation analysis were adopted to analyze the structure and diversity of paddy soil bacterial communities at different levels of heavy metal pollution. The results showed that the levels of heavy metal pollution in soil samples from the study area could be divided into four grades, and the diversity indexes of soil bacterial community in the light heavy metal pollution level (LL) area were generally significantly lower than other areas, namely the slightly polluted environment would reduce the diversity of bacterial communities in this area. The genus Nitrospira and Candidatus_Solibacter showed strong heavy metal tolerance in the serious heavy metal pollution level (SL) region. The bacterial phyla such as Proteobacteria, Firmicutes and Gemmatimonadetes showed a certain extent of tolerance in different levels of heavy metal pollution. In addition, soil environmental factors such as SWC, pH, AP, AK, TN, OM, Cu, Pb, As and Zn were significantly correlated with bacterial community structure (p<0.05). Therefore, the use of these microorganisms with heavy metal tolerance and bioremediation functions should be developed as soon as possible to provide a suitable soil environment for the healthy growth of food crops.