School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China.
School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Hunan Urban and Rural Environmental Construction Co., Ltd, Changsha, 410118, China.
Environ Res. 2022 Oct;213:113576. doi: 10.1016/j.envres.2022.113576. Epub 2022 Jun 14.
Heavy metal pollution affected the stability and function of soil ecosystem. The impact of heavy metals on soil microbial community and the interaction of microbial community has been widely studied, but little was known about the response of community assembly to the heavy metal pollution. In this study, we collected 30 soil samples from non (CON), moderately (CL) and severely (CH) contaminated fields. The prokaryotic community was studied using high-throughput Illumina sequencing of 16s rRNA gene amplicons, and community assembly were quantified using phylogenetic-bin-based null approach (iCAMP). Results showed that diversity and composition of both bacterial and archaeal community changed significantly in response to heavy metal pollution. The microbial community assembly tended to be more deterministic with the increase of heavy metal concentration. Among the assembly processes, the relative importance of homogeneous selection (deterministic process) increased significantly (increased by 16.2%), and the relative importance of drift and dispersal limitation (stochastic process) decreased significantly (decreased by 11.4% and 5.4%, respectively). The determinacy of bacterial and archaeal community assembly also increased with heavy metal stress, but the assembly models were different. The deterministic proportion of microorganisms tolerant to heavy metals, such as Thiobacillus, Euryarchaeota and Crenarchaeota (clustered in bin 32, bin59 and bin60, respectively) increased, while the stochastic proportion of microorganisms sensitive to heavy metals, such as Koribacteraceae (clustered in bin23) increased. Therefore, the heavy metal stress made the prokaryotic community be deterministic, however, the effects on the assembly process of different microbial groups differed obviously.
重金属污染影响土壤生态系统的稳定性和功能。重金属对土壤微生物群落及其相互作用的影响已得到广泛研究，但对群落组装对重金属污染的响应知之甚少。在这项研究中，我们从非（CON）、中度（CL）和重度（CH）污染区收集了 30 个土壤样本。使用高通量 Illumina 测序对 16s rRNA 基因扩增子进行了原核微生物群落研究，并使用基于系统发育 bin 的 null 方法（iCAMP）量化了群落组装。结果表明，细菌和古菌群落的多样性和组成均因重金属污染而发生显著变化。随着重金属浓度的增加，微生物群落组装趋于更加确定。在组装过程中，同质选择（确定性过程）的相对重要性显著增加（增加了 16.2%），而漂移和扩散限制（随机过程）的相对重要性显著降低（分别降低了 11.4%和 5.4%）。细菌和古菌群落组装的确定性也随着重金属胁迫而增加，但组装模型不同。对重金属具有耐受性的微生物（如硫杆菌、广古菌和泉古菌）的确定性比例增加，而对重金属敏感的微生物（如 Koribacteraceae，聚类在 bin23 中）的随机性比例增加。因此，重金属胁迫使原核微生物群落变得确定性，但对不同微生物群体的组装过程的影响明显不同。
