A proposal of “core enzyme” bioindicator in long-term Pb-Zn ore pollution areas based on topsoil property analysis

Abstract

To study the effects of long-term mining activities on the agricultural soil quality of Mengnuo town in Yunnan province, China, the heavy metal and soil enzyme activities of soil samples from 47 sites were examined. The results showed that long-term mining processes led to point source heavy metal pollution and Pb, Cd, Zn and As were the primary metal pollutants. Polyphenoloxidase was found the most sensitive soil enzyme activity and significantly correlated with almost all the metals (P < 0.05). Amylase (for C cycling), acid phosphatase (for P cycling) and catalase (for redox reaction) activities showed significantly positive correlations (P < 0.05) with Pb, Cd, Zn and As contents. The correlations between soil enzymes activities and Cd, Pb and Zn contents were verified in microcosm experiments, it was found that catalase activity had significant correlations (P < 0.05) with these three metals in short-term experiments using different soils under different conditions. Based on both field investigation and microcosm simulation analysis, oxidoreductases activities (rather than a specific enzyme activity) were suggested to be used as "core enzyme", which could simply and universally indicate the heavy metal pollution degrees of different environments. And hydrolases (for C, N, P and S recycling) could be used as a supplement to improve correlation accuracy for heavy metal indication in various polluted environments.

Soil Quality and Heavy Metal Pollution Assessment of Iron Ore Mines in Nizna Slana (Slovakia)

“…Currently, no quantitative standard of soil enzyme activity has been set to assess the level of heavy metal soil pollution. Generally, high enzyme activity represents good soil quality, while low activity may be related to the toxicity of pollutants to biological processes [8,54]. The urease enzyme (URE) plays an important role in the N cycle [55], it is loosely present in soil and is more often bound to soil organic matter or clay particles.…”

Removal of Heavy Metals Zinc, Lead, and Cadmium by Biomineralization of Urease-Producing Bacteria Isolated from Iranian Mine Calcareous Soils

“…In recent years, heavy metal contamination of soils has become a serious issue not only to agricultural production, but also to the ecosystem health. The non-biodegradable nature of heavy metals, undoubtedly, leads to their accumulation of toxic levels which have resulted in several destructive effects on human health as well as the environment (Xiao et al 2017;Yang et al 2016). It is reported that globally, there are more than 5 million contaminated sites covering 20 million hectares of land in which the soils are contaminated by the heavy metal(loid)s As, Cd, Pb, Co, Cr, Hg, Cu, Ni, Zn, and Se with the present soil concentrations higher than the geo-baseline or regulatory levels (He et al 2015;Wuana and Okieimen 2011).…”

Heavy metal remediation in soil with chemical amendments and its impact on activity of antioxidant enzymes in Lettuce (Lactuca sativa) and soil enzymes

“…This result can be interpreted that much higher Pb concentration compared to Cd in soil inhibits microbial activity, resulting in reduced phosphatase activity, while impact of soluble Cd on inhibition of microbial activity was minimal. In addition, phosphatase activity could be more sensitive than β-glucosidase activity when soil is polluted with heavy metals [29,57]. Yang et al [29] tested two different soil enzymes, oxidoreductase and hydrolase, to select the bio-indicator for evaluating heavy metal pollution in soil.…”

“…In addition, phosphatase activity could be more sensitive than β-glucosidase activity when soil is polluted with heavy metals [29,57]. Yang et al [29] tested two different soil enzymes, oxidoreductase and hydrolase, to select the bio-indicator for evaluating heavy metal pollution in soil. This study revealed that amylase (for C cycling), acid phosphatase (for P cycling), and catalase (for redox reaction) was sensitive to heavy metal pollution showing significantly positive correlation (p < 0.05) with Pb, Cd, Zn concentration.…”

“…Soil enzyme activity is also a good indicator of heavy metal toxicity in soil [29]. Common soil enzymes may be categorized into oxidoreductases (polyphenoloxidase (PPO) and catalase for redox control) and hydrolases (amylase, acetylglucosaminidase (NAG), β-glucosidase (BG), cellulose, invertase, protease, urease, and acid phosphatase for soil nutrients cycling control) [30].…”