Biochar modulates heavy metal toxicity and improves microbial carbon use efficiency in soil.
Biochar modulates heavy metal toxicity and improves microbial carbon use efficiency in soil.
复制标题
DOI：
10.1016/j.scitotenv.2017.11.214
复制
发表时间：
2018-04
期刊：
影响因子：
--
通讯作者：
Yilu Xu;B. Seshadri;B. Sarkar;Hailong Wang;C. Rumpel;D. Sparks;M. Farrell;Tony Hall;Xiaodong Yan
中科院分区：
文献类型：
--
作者：
Yilu Xu;B. Seshadri;B. Sarkar;Hailong Wang;C. Rumpel;D. Sparks;M. Farrell;Tony Hall;Xiaodong Yan
土壤有机碳对于提高土壤肥力和生态系统功能至关重要。土壤微生物对碳的转化和固定过程有重要贡献。然而，微生物对重金属等环境胁迫敏感。对污染土壤施用改良剂，如生物炭，可以减轻金属毒性并增加碳输入。在这项研究中，镉和铅加标的澳洲坚果壳生物炭（5% w/w）处理的土壤进行了监测，在49天的培养期。微生物磷脂脂肪酸（PLFA）提取和分析作为生物标志物，以确定微生物群落组成。土壤性质，金属的生物有效性，微生物呼吸，和微生物量碳培养期后进行了测定。微生物碳利用效率（CUE）由微生物生物量中的碳与矿化碳的比值计算得出。微生物CUE也由于金属毒性而降低。然而，生物炭的加入减轻了金属毒性，并增加了总PLFA浓度。施用生物质炭后，土壤微生物呼吸和生物量碳均增加，且生物质炭处理的土壤CUE显著高于未处理的土壤（p< 0.01）。重金属通过对CUE的负面影响降低了污染土壤中微生物固碳能力。添加生物炭提高了污染土壤中重金属的生物有效性，从而减轻了重金属对土壤微生物的毒性。
Soil organic carbon is essential to improve soil fertility and ecosystem functioning. Soil microorganisms contribute significantly to the carbon transformation and immobilisation processes. However, microorganisms are sensitive to environmental stresses such as heavy metals. Applying amendments, such as biochar, to contaminated soils can alleviate the metal toxicity and add carbon inputs. In this study, Cd and Pb spiked soils treated with macadamia nutshell biochar (5% w/w) were monitored during a 49 days incubation period. Microbial phospholipid fatty acids (PLFAs) were extracted and analysed as biomarkers in order to identify the microbial community composition. Soil properties, metal bioavailability, microbial respiration, and microbial biomass carbon were measured after the incubation period. Microbial carbon use efficiency (CUE) was calculated from the ratio of carbon incorporated into microbial biomass to the carbon mineralised.Total PLFA concentration decreased to a greater extent in metal contaminated soils than uncontaminated soils. Microbial CUE also decreased due to metal toxicity. However, biochar addition alleviated the metal toxicity, and increased total PLFA concentration. Both microbial respiration and biomass carbon increased due to biochar application, and CUE was significantly (p< 0.01) higher in biochar treated soils than untreated soils. Heavy metals reduced the microbial carbon sequestration in contaminated soils by negatively influencing the CUE. The improvement of CUE through biochar addition in the contaminated soils could be attributed to the decrease in metal bioavailability, thereby mitigating the biotoxicity to soil microorganisms.