Departamento de Biología Vegetal I, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, C/ Jose Antonio Nováis, 12, Ciudad Universitaria, 28040, Madrid, Spain.
Environ Sci Pollut Res Int. 2014 May;21(9):6176-87. doi: 10.1007/s11356-014-2561-0. Epub 2014 Jan 30.
Organic matter (OM) plays a key role in microbial response to soil metal contamination, yet little is known about how the composition of the OM affects this response in Mediterranean calcareous agricultural soils. A set of Mediterranean soils, with different contents and compositions of OM and carbonate and fine mineral fractions, was spiked with a mixture of Cd, Cu, Pb, and Zn and incubated for 12 months for aging. Microbial (Biolog Ecoplates) and enzyme activities (dehydrogenase, DHA; β-galactosidase, BGAL; phosphatase, PHOS; and urease, URE) were assessed and related to metal availability and soil physicochemical parameters. All enzyme activities decreased significantly with metal contamination: 36-68 % (DHA), 24-85 % (BGAL), 22-72 % (PHOS), and 14-84 % (URE) inhibitions. Similarly, catabolic activity was negatively affected, especially phenol catabolism (∼86 % compared to 25-55 % inhibition for the rest of the substrates). Catabolic and DHA activities were negatively correlated with ethylenediaminetetraacetic acid (EDTA)-extractable Cd and Pb, but positively with CaCl2, NaNO3, and DTPA-extractable Cu and Zn. Soluble OM (water- and hot-water-soluble organic C) was positively related to enzyme and catabolic activities. Recalcitrant OM and fine mineral fractions were positively related to BGAL and PHOS. Conversely, catabolic activity was negatively related to clay and positively to silt and labile OM. Results indicate that the microbial response to metal contamination is highly affected by texture and OM composition.
有机质（OM）在微生物对土壤金属污染的响应中起着关键作用，但对于 OM 的组成如何影响地中海钙质农业土壤中的这种响应知之甚少。一组具有不同 OM 和碳酸盐以及细矿物分数含量和组成的地中海土壤，被添加 Cd、Cu、Pb 和 Zn 的混合物并培养 12 个月以进行老化。评估了微生物（Biolog Ecoplates）和酶活性（脱氢酶、DHA；β-半乳糖苷酶、BGAL；磷酸酶、PHOS；和脲酶、URE），并将其与金属的有效性和土壤物理化学参数相关联。所有酶活性都因金属污染而显著下降：DHA 下降 36-68%，BGAL 下降 24-85%，PHOS 下降 22-72%，URE 下降 14-84%。同样，代谢活性受到负面影响，特别是酚类代谢（与其余基质的抑制作用 25-55%相比，约下降 86%）。代谢和 DHA 活性与乙二胺四乙酸（EDTA）可提取 Cd 和 Pb 呈负相关，但与 CaCl2、NaNO3 和二乙基三胺五乙酸（DTPA）可提取 Cu 和 Zn 呈正相关。可溶性 OM（水和热水可溶性有机 C）与酶和代谢活性呈正相关。难降解 OM 和细矿物分数与 BGAL 和 PHOS 呈正相关。相反，代谢活性与粘土呈负相关，与粉土和易降解 OM 呈正相关。结果表明，微生物对金属污染的响应受质地和 OM 组成的高度影响。
