College of Resources and Environmental Science, Northeast Agricultural University, Harbin, 150030, China.
College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China.
Environ Sci Pollut Res Int. 2020 May;27(14):16326-16338. doi: 10.1007/s11356-020-08122-7. Epub 2020 Mar 2.
Soil cadmium (Cd) pollution has received increasing attention from scholars. In the field of Cd pollution remediation, there is an urgent need to study the combined bioremediation technology of earthworms and microbes. In this paper, a short-term stress test and a long-term stress test were conducted. Eisenia fetida were inoculated into artificial soil that was contaminated with Cd. After different Cd stress times, the regulation process between the microbial communities in the earthworms and in the soil was studied. Canonical correlation analysis and the TOPSIS method were combined to establish a mathematical model for data analysis, and the changes in the carbon source utilization intensity by microbes were analysed. The results showed that in the short-term stress tests, the regulation process could be divided into five stages. Specifically, after 1-3 days of stress, the microbial community in the earthworms regulated the soil microbial community, but on the 3rd day, the regulation was weakened. On the 4th day, the soil microbial community was affected not only by the microbes in the earthworms but also by the increasing intensity of Cd stress. After 5 days of stress, the microbial communities in the earthworms and the soil were both greatly affected by Cd poisoning, and the microbes transitioned from stable to declining. At 6-7 days, the microbes in the earthworms gained control over those in the soil once again, and the Cd-tolerant microbes began to appear and proliferate. At 8-10 days, the regulation of the soil microbes by the earthworm microbes weakened, while the Cd-tolerant population in the soil microbial communities gradually evolved at this stage to adapt to the increasing Cd stress. The long-term stress tests showed that the difference between the microbial communities in the soil and in the earthworms increased, and there was almost no regulation between them.
土壤镉（Cd）污染受到学者们的日益关注。在 Cd 污染修复领域，迫切需要研究蚯蚓和微生物的联合生物修复技术。本文进行了短期胁迫试验和长期胁迫试验。将赤子爱胜蚓接种到受 Cd 污染的人工土壤中。在不同的 Cd 胁迫时间后，研究了蚯蚓和土壤中微生物群落之间的调节过程。结合典范对应分析和 TOPSIS 方法建立了数据分析的数学模型，并分析了微生物利用碳源强度的变化。结果表明，在短期胁迫试验中，调节过程可以分为五个阶段。具体来说，在应激的 1-3 天内，蚯蚓体内的微生物群落调节了土壤微生物群落，但在第 3 天，调节作用减弱。第 4 天，土壤微生物群落不仅受到蚯蚓体内微生物的影响，还受到 Cd 胁迫强度增加的影响。应激 5 天后，蚯蚓和土壤中的微生物群落都受到 Cd 中毒的极大影响，微生物从稳定状态过渡到衰退状态。在 6-7 天，蚯蚓体内的微生物再次对土壤中的微生物产生控制，Cd 耐受微生物开始出现并增殖。在 8-10 天，蚯蚓体内微生物对土壤微生物群落的调节作用减弱，而土壤微生物群落中的 Cd 耐受种群在此阶段逐渐进化以适应不断增加的 Cd 胁迫。长期胁迫试验表明，土壤微生物群落和蚯蚓体内微生物群落之间的差异增大，它们之间几乎没有调节作用。
