Burdová Hana, Polanská Nebeská Diana, Marková Kristýna, Říha Jakub, Trubač Jakub, Kříženecká Sylvie, Kwoczynski Zdenka, Baka Michal, Sevcu Alena, Trögl Josef
Faculty of Mechanical Engineering, Jan Evangelista Purkyně University in Ústí nad Labem, Pasteurova 7, 40096, Ústí nad Labem, Czech Republic.
Faculty of Environment, Jan Evangelista Purkyně University in Ústí nad Labem, Pasteurova 15, 40096, Ústí nad Labem, Czech Republic.
J Environ Manage. 2025 May;381:125208. doi: 10.1016/j.jenvman.2025.125208. Epub 2025 Apr 9.
Miscanthus × giganteus, a high-yielding perennial grass, has recently shown promise for phytomanagement of petroleum hydrocarbons (PHC) contaminated sites, however the mechanisms of plant-soil interactions are not clear. This study followed the second growing season of miscanthus cultivation on soil spiked with representatives of the most common PHC pollutants: diesel (dominantly aliphatic hydrocarbons), pyrene + phenanthrene (polycyclic aromatic hydrocarbons; PAH) and their mixture. Miscanthus demonstrated tolerance to PHC-contaminated soils, although high diesel concentrations significantly reduced biomass, limiting the overall benefits of cultivation. This was evident in reduced carbon sequestration, plant-induced soil respiration and root exudate content in diesel-treated soils. Despite comparable PHC levels in planted and unplanted soils after two seasons, several indicators of ongoing rhizodegradation were observed. These included increased root exudates production, a higher fungal-to-bacterial ratio and, at lower diesel levels, increased abundance of actinobacteria, i.e. shifts towards biodegraders capable of biodegradation of more recalcitrant components of petroleum. A comprehensive analysis revealed significant PHC impacts on soil microbial communities. While biomass and respiration increased, bacterial diversity decreased with increasing diesel concentrations. The microbial community shifted towards potentially PHC-degrading microorganisms, such as fungi and specific bacterial genera (e.g., AlkB gene abundance increased 100-fold). PAH contamination primarily affected the abundance of the pahGP marker, but its overall impact was limited due to low residual PAH levels in the second season. These findings show changing role of M. × giganteus in PHC bioremediation from the support of biodegradation in the first year to stabilization and enrichment of soil in the second.
芒草（Miscanthus × giganteus）是一种高产的多年生草本植物，最近在石油烃（PHC）污染场地的植物修复方面展现出了潜力，然而植物与土壤相互作用的机制尚不清楚。本研究跟踪了芒草在添加了最常见的PHC污染物代表的土壤上种植的第二个生长季节，这些污染物包括柴油（主要是脂肪烃）、芘+菲（多环芳烃；PAH）及其混合物。芒草对PHC污染土壤表现出耐受性，尽管高浓度柴油显著降低了生物量，限制了种植的总体效益。这在柴油处理土壤中碳固存减少、植物诱导的土壤呼吸和根系分泌物含量降低方面表现明显。尽管两个季节后种植土壤和未种植土壤中的PHC水平相当，但仍观察到了一些正在进行的根际降解指标。这些指标包括根系分泌物产量增加、真菌与细菌比例升高，以及在较低柴油水平下放线菌丰度增加，即向能够生物降解石油中更难降解成分的生物降解菌转变。综合分析表明，PHC对土壤微生物群落有显著影响。虽然生物量和呼吸作用增加，但细菌多样性随着柴油浓度的增加而降低。微生物群落向潜在的PHC降解微生物转变，如真菌和特定细菌属（例如，AlkB基因丰度增加了100倍）。PAH污染主要影响pahGP标记物的丰度，但由于第二季残留PAH水平较低，其总体影响有限。这些发现表明，芒草在PHC生物修复中的作用从第一年支持生物降解转变为第二年稳定和富集土壤。
