While plant toxicity reduction remains the primary metric for judging the success of metal immobilization in soil, the suitability of microorganisms as universal indicators of its effectiveness in various contaminated soils remains a point of contention. This study assessed the sensitivity of microbial bioindicators in monitoring metal immobilization success in smelter-impacted soils. It compared plants and microorganisms as indicators of the efficiency of natural Fe-Mn nodules from the Gulf of Finland in immobilizing metals in soils contaminated by a Ni/Cu smelter, on the Kola Peninsula, Murmansk region, Russia. Perennial ryegrass (Lolium perenne) was grown on nodule-amended and control soils. Plant responses in the smelter-impacted soils proved to be sensitive and robust indicators of successful metal immobilization. However, microbial responses exhibited a more complex story. Despite the observed reductions in soluble metal concentrations, shoot metal contents in ryegrass, and significant improvements in plant growth, certain microbial bioindicators were unresponsive to metal immobilization success brought about by the addition of Fe-Mn nodules. Among microbial bioindicators studied, community-level physiological profiling, microbial biomass carbon, and basal respiration were sensitive indicators of metal immobilization success, whereas the number of saprotrophic, oligotrophic, and Fe-oxidizing bacteria and fungi, the biomass of bacteria and fungi, and enzymatic activity were less robust indicators. Interestingly, the correlations between different microbial responses measured were weak or even negative. Some microbial responses also exhibited negative correlations with plant biomass. These findings underscore the need for further research on comparative evaluations of plants and microorganisms as reliable indicators of metal immobilization efficacy in polluted environments.

• Klíčová slova
• Ecotoxicity, Heavy metals, Microorganisms, Phytoremediation, Phytostabilization, Phytotoxicity,
• MeSH
• Bacteria metabolismus   MeSH
• biodegradace MeSH
• biologický monitoring metody   MeSH
• houby metabolismus   MeSH
• jílek * metabolismus   MeSH
• kovy metabolismus   analýza   MeSH
• látky znečišťující půdu * analýza   metabolismus   MeSH
• monitorování životního prostředí metody   MeSH
• půda * chemie   MeSH
• půdní mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Finsko MeSH
• Rusko MeSH
• Názvy látek
• kovy MeSH
• látky znečišťující půdu * MeSH
• půda * MeSH

While zinc protects plants from copper in hydroponics, its behavior in soil remains unclear. We investigated the potential of zinc sulfate to protect ryegrass from copper toxicity in contaminated soil. Twelve soil treatments combined varying levels of copper oxide (CuO) and zinc sulfate (ZnSO4). Increasing CuO significantly stunted ryegrass, but adding ZnSO4 mitigated the effects at each CuO level. ZnSO4 had no effect in unpolluted conditions. These results, supported by the Terrestrial Biotic Ligand Model, indicate that zinc competes with copper for binding sites, reducing copper uptake by ryegrass and mitigating its toxicity. Application of zinc sulfate to copper-contaminated soils appears promising for ryegrass growth, although field studies are critical to confirm real-world efficacy.

• Klíčová slova
• Alleviating affect, Antagonism, Lolium perenne, Protective effect,
• MeSH
• jílek * MeSH
• látky znečišťující půdu * analýza   MeSH
• měď analýza   MeSH
• půda MeSH
• síran zinečnatý metabolismus   MeSH
• zinek chemie   MeSH
• znečištění životního prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• látky znečišťující půdu * MeSH
• měď MeSH
• půda MeSH
• síran zinečnatý MeSH
• zinek MeSH