Table_2_Fungal Community, Metabolic Diversity, and Glomalin-Related Soil Proteins (GRSP) Content in Soil Contaminated With Crude Oil After Long-Term Natural Bioremediation.XLSX

Fungi have increased tolerance to environmental stress (also related to the access of pollutants, e.g., trace elements and polycyclic aromatic hydrocarbons PAHs). The aim of the study was to evaluate the mycobiome and functional diversity of fungi in long-term crude-oil contaminated soils as the potential bioremediators of oil contaminated sites. Samples were taken from three historical oil wells (over a century old) at two distances: within a 0.5 m radius of the oil wells (OWP1, OWP2, and OWP3) and within a 3 m radius from the oil wells as the controls (OW1, OW2, and OW3). Next generation sequencing (for the ITS region) was accompanied with determination of the functional fungal community based on Biolog FFPlates, glomalin related soil protein (GRSP) content, trace element and PAHs concentration. The research hypothesis assumed that long-term natural bioremediation of crude oil contaminated soils can contribute to intensive development of a unique fungal community adapted to the contamination conditions. The identification of such fungi can be of particular importance in soil bioremediation. There were significant differences in the fungal community and functional diversity between the soil samples. The soils collected directly from the oil wells were characterized by higher biological activity and higher diversity of PAH-degrading fungal candidates compared to the soils collected within 3 m of the oil wells. The total glomalin-related soil proteins (T-GRSP) and easily-extractable glomalin-related soil proteins (EE-GRSP) contents were lower in soil samples taken directly from the crude oil well. The control soil (OW) subjected to a long-term natural remediation may already have sufficient conditions for the growth and development of mycorrhizal fungi. The mycobiome of the soils collected directly from the oil wells (OWP1, OWP2, and OWP3) was characterized by a 35% share of PAH-degrading candidates, compared to the soil collected at the 3 m distance from the oil wells (OW1, OW2, and OW3) at < 5%. The main PAH-degrading fungal candidates belong to genera Ilyonectria, Chaetomium, Gibberella, Paraphoma, Schizothecium, Pseudorobillarda, Tetracladium, Ganoderma, Cadophora, Exophiala, Knufia, Mycoleptodiscus, Cyphellophora, Fusicolla, Devriesia, Didymella, Plenodomus, Pyrenochaetopsis, Symbiotaphrina, Phallus, Coprinellus, Plectosphaerella, Septoriella, and Hypholoma. The share of three- and four-ringed PAHs in soil was higher as the distance from the oil well increased. These results may indicate that more effective degradation processes occur closer to the oil wells.

真菌对环境胁迫（亦与污染物接触相关，例如微量元素与多环芳烃（polycyclic aromatic hydrocarbons, PAHs））的耐受能力有所提升。本研究旨在评估长期受原油污染土壤中的真菌群落（mycobiome）与真菌功能多样性，以明确其作为石油污染场地潜在生物修复剂的应用潜力。研究样本采自3口具有百年历史的老式油井，设置两种采样距离：分别为油井周边0.5米半径范围内（记为OWP1、OWP2、OWP3），以及油井周边3米半径范围内作为对照组（记为OW1、OW2、OW3）。本研究采用针对ITS区（internal transcribed spacer）的二代测序（next generation sequencing）技术，并结合基于Biolog FF平板（Biolog FFPlates）的真菌功能群落测定、球囊霉素相关土壤蛋白（glomalin related soil protein, GRSP）含量检测，以及微量元素与PAHs浓度测定。本研究的假说认为，长期自然生物修复作用可促使原油污染土壤中形成适应污染环境的独特真菌群落并实现其快速增殖。此类功能真菌的筛选鉴定，对土壤生物修复工作具有重要应用价值。不同土壤样本间的真菌群落组成与功能多样性存在显著差异。直接采自油井的土壤样本，相较于油井周边3米范围内的对照土壤，其生物活性与PAHs降解候选真菌的多样性均更高。直接采自原油井的土壤样本中，总球囊霉素相关土壤蛋白（total glomalin-related soil proteins, T-GRSP）与易提取球囊霉素相关土壤蛋白（easily-extractable glomalin-related soil proteins, EE-GRSP）的含量均更低。经长期自然修复的对照土壤（OW），或已具备足够的条件支持菌根真菌（mycorrhizal fungi）的生长与繁殖。直接采自油井的土壤（OWP1、OWP2、OWP3）的真菌群落中，PAHs降解候选真菌占比达35%；而油井周边3米范围内的对照土壤（OW1、OW2、OW3）中该占比不足5%。主要的PAHs降解候选真菌隶属于以下菌属：Ilyonectria、Chaetomium、Gibberella、Paraphoma、Schizothecium、Pseudorobillarda、Tetracladium、Ganoderma、Cadophora、Exophiala、Knufia、Mycoleptodiscus、Cyphellophora、Fusicolla、Devriesia、Didymella、Plenodomus、Pyrenochaetopsis、Symbiotaphrina、Phallus、Coprinellus、Plectosphaerella、Septoriella以及Hypholoma。土壤中三环与四环PAHs的占比，随采样点与油井距离的增加而升高。上述结果表明，油井周边区域的降解过程更为高效。