Stress Response of Miscanthus Plants and Soil Microbial Communities: A Case Study in Metals and Hydrocarbons Contaminated Soils

Abstract

Second-generation biofuel crop miscanthus is one of the most promising plants tested for phytomanagement of contaminated sites. In this preliminary pot case study, the most used hybrid Miscanthus x giganteus was cultivated in three different real contaminated soils: agricultural soil contaminated with Cd; post-military soil slightly contaminated with Zn, Pb and Cd; and soil contaminated by petroleum industry with metals and hydrocarbons. The stress response of plants and soil microbial communities was monitored to receive data that are important for successful phytomanagement application. With metals only, the plant grew well, and chlorophyll fluorescence measurement proved their good vitality. Changes in leaf anatomy (leaf thickness and sclerenchyma cells area) were additionally determined in post-military soil compared to agricultural. On the contrary, in petroleum-contaminated soil, the biomass yield was too reduced and also physiological parameters were significantly decreased. The response of microbial communities also differed. In agricultural soil, no microbial stress was determined. In post-military soil, it became reduced during the experiment, and in petroleum contamination, it increased year-on-year. It could be concluded that miscanthus is suitable for cultivation in metals contaminated soils with potential for microbial communities support, but in soil contaminated by the petroleum industry, its application did not seem meaningful.

Dynamic of Morphological and Physiological Parameters and Variation of Soil Characteristics during Miscanthus × giganteus Cultivation in the Diesel-Contaminated Land

“…A growing number of studies have described the crop's successful application for phytoremediation of the trace elements (TEs) contaminated soil [19] and soil health improvement during vegetation [20]. However, few publications introduced the plant's successful application to remediate organic's contaminated lands [12], including the petroleum hydrocarbons contaminated soils [6,21,22]. Nevertheless, such lands are among the most prevalent polluted areas in the environment [23,24].…”

Microbiological Study in Petrol-Spiked Soil

“…The microbiological degradation of petroleum hydrocarbons in the soil is a natural process, owing to which organic pollutants can be mineralized by autochthonous microorganisms [ 41 , 84 ]. The cultivation of cocksfoot enhanced their activities as a result of the stimulating effect of root secretions on their development [ 42 , 60 ].…”

“…Cocksfoot significantly intensified the degradation of all PAHs, except for IP, because plant roots improve the physical [ 35 , 36 , 37 ] and chemical [ 75 ] properties of soil, thereby creating more favourable conditions for the proliferation of microorganisms, including the hydrocarbon-degrading ones [ 87 ]. These abilities of plants are particularly important in the soils polluted with petroleum products [ 41 , 85 ], especially that plant roots create a specific habitat for rhizospheric microbial communities, which can be used for rhizoremediation [ 42 , 60 ]. The cultivation of cocksfoot on the petrol-polluted soil had an especially beneficial effect on the bacteria belonging to the phylum Proteobacteria , mainly those from the genus Ramlibacter and the class β - Proteobacteria , those from the genus Pseudoxanthomonas and the class γ - Proteobacteria , as well as those from Mycoplana and Sphingobium genera from the class α - Proteobacteria.…”

“…Soil pollution with diesel oil reduced the counts of all bacterial taxa except for species, while soil pollution with petrol decreased the bacterial diversity only at the class, order, and family level. The composition of soil microbiota in the soil polluted with petrol hydrocarbons evolves [ 53 , 60 ]. The soils exposed to the pressure of PAHs are mainly predominated by representatives of β -, γ - Proteobacteria , Actinobacteria , and Bacteroidia [ 61 , 62 , 63 ].…”

Optimization of the Micromycete Cultivation Process � Basics of Growth Regulators and Biotesting Their Growth- Stimulating Activity Concerning to Miscanthus Giganteus

“…Ефективність процесів фіторемедіації з використанням M. × giganteus на сильно забруднених металами ґрунтах визначена в модельних лабораторних експериментах (Chaney et al, 2014). Питанням впливу застосування M. × giganteus на мікробіоту забрудненого металами ґрунту в лабораторному модельному експерименті, аналізу потенційної токсичної концентрації металів на мікробну активність та фосфоліпідно-жирні кислоти (PLFA) присвячена низка робіт учених європейських країн (Nebeská et al, 2018;Nebeská et al, 2021). Виявлено позитивні зміни у структурі мікробної спільноти за впливу M. × giganteus.…”