Liu Ping, Song Yan, Wei Jie, Mao Wei, Ju Jing, Zheng Shengyang, Zhao Haitao
College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Key Laboratory of Cultivated Land Quality Monitoring and Evaluation, Yangzhou University, Ministry of Agriculture and Rural Affairs, Yangzhou 225127, China.
Biology (Basel). 2023 Jun 8;12(6):831. doi: 10.3390/biology12060831.
Soil heavy metal pollution has become one of the major environmental issues of global concern and solving this problem is a major scientific and technological need for today's socio-economic development. Environmentally friendly bioremediation methods are currently the most commonly used for soil heavy metal pollution remediation. Via controlled experiments, the removal characteristics of chromium from contaminated soil were studied using earthworms ( and ) and plants (ryegrass and maize) at different chromium concentrations (15 mg/kg and 50 mg/kg) in acidic and alkaline soils. The effects of chromium contamination on biomass, chromium bioaccumulation, and earthworm gut microbial communities were also analyzed. The results showed that had a relatively stronger ability to remove chromium from acidic and alkaline soil than , and ryegrass had a significantly better ability to remove chromium from acidic and alkaline soil than maize. The combined use of and ryegrass showed the best effect of removing chromium from contaminated soils, wih the highest removal rate (63.23%) in acidic soil at low Cr concentrations. After soil ingestion by earthworms, the content of stable chromium (residual and oxidizable forms) in the soil decreased significantly, while the content of active chromium (acid-extractable and reducible forms) increased significantly, thus promoting the enrichment of chromium in plants. The diversity in gut bacterial communities in earthworms decreased significantly following the ingestion of chromium-polluted soil, and their composition differences were significantly correlated with soil acidity and alkalinity. , , and may have strong abilities to resist chromium and enhance chromium activity in acidic and alkaline soils. There was also a significant correlation between changes in enzyme activity in earthworms and their gut bacterial communities. The bacterial communities, including and , were closely related to the bioavailability of chromium in soil and the degree of chromium stress in earthworms. This study provides insights into the differences in bioremediation for chromium-contaminated soils with different properties and its biological responses.
土壤重金属污染已成为全球关注的主要环境问题之一，解决这一问题是当今社会经济发展的一项重大科技需求。环境友好型生物修复方法是目前土壤重金属污染修复最常用的方法。通过对照实验，研究了在酸性和碱性土壤中，蚯蚓（和）以及植物（黑麦草和玉米）对不同铬浓度（15毫克/千克和50毫克/千克）污染土壤中铬的去除特性。还分析了铬污染对生物量、铬生物积累和蚯蚓肠道微生物群落的影响。结果表明，在酸性和碱性土壤中去除铬的能力相对比更强，黑麦草在酸性和碱性土壤中去除铬的能力明显比玉米更好。蚯蚓和黑麦草联合使用对污染土壤中铬的去除效果最佳，在低铬浓度的酸性土壤中去除率最高（63.23%）。蚯蚓摄食土壤后，土壤中稳定铬（残留和可氧化态）含量显著降低，而活性铬（酸可提取和可还原态）含量显著增加，从而促进了植物对铬的富集。摄食铬污染土壤后，蚯蚓肠道细菌群落的多样性显著降低，其组成差异与土壤酸碱度显著相关。、和在酸性和碱性土壤中可能具有较强的抗铬能力并能增强铬的活性。蚯蚓体内酶活性的变化与其肠道细菌群落之间也存在显著相关性。包括和在内的细菌群落与土壤中铬的生物有效性以及蚯蚓的铬胁迫程度密切相关。本研究为不同性质的铬污染土壤生物修复差异及其生物学响应提供了见解。
