## 1 Introduction  
Currently, the contamination of soil, water or air by toxic substances, from natural or anthropogenic sources, is considered one of the major environmental problems [1]. Anthropogenic contamination of soils is due to discharges, pesticide use, leaks, extractions, and other emissions [2, 3]. Among anthropogenic soil contaminants, hydrocarbons represent a major environmental threat because of their toxicity, bioaccumulation and persistence. In addition, their hydrophobicity renders them preferably adsorb to soil organic matter [4], which makes their removal from contaminated sites more difficult. Crude oils are extremely complex mixtures, made up mainly of hydrocarbons and to a lesser extent by metals or nitrogenous, oxygenated, or sulfur derivatives [4]. Petroleum hydrocarbons are formed mainly by carbon and hydrogen atoms and are subdivided into: saturated hydrocarbons made up of aliphatic carbon chains and aromatic hydrocarbons made up of one or more benzene rings. In soil, total petroleum hydrocarbons (TPHs) alter the physical-chemical and biological properties of the soil, such as hydrophobicity, cation exchange capacity, and electrical conductivity, preventing gas exchange with the atmosphere or modifying the autochthonous microbiota. In addition, they have toxic properties causing serious effects on human and environmental health [4]. The most frequent techniques for the recovery of contaminated soils with hydrocarbons are the extraction with solvents, washing with surfactants and thermal treatments. The first method consists of the application of an organic solvent for removing the contaminants. The washing with surfactants uses a washing solution of water and chemical additives. The contaminants are retained in this solution, whether dissolved or suspended. Finally, thermal treatments consist in applying different temperatures ranging from 90 \({}^{\circ}\)C to 600 \({}^{\circ}\)C, with the aim of volatilizing or decomposing organic contaminants [5]. All of them are ex-situ techniques that are expensive and consume a lot of energy. Although the resulting soil is clean, it remains biologically and environmentally damaged [6]. Bioremediation represents a less expensive and environmentally friendly alternative to the physico-chemical techniques previously mentioned. Bioremediation consists of the recovery of contaminated soil by the action of living organisms [7]. Enhanced contaminants biodegradation might be achieved by managing soil temperature, and moisture, and the abundance of nutrients (carbon, nitrogen, and phosphorus) among others factors [8]. There are two main strategies to bioremediate contaminants from soils, biostimulation and bioaugmentation [9]. The purpose of biostimulation is to favor the metabolism of the native microbiota of the soil to degrade contaminants by the addition of nutrients, increasing the level of oxygen and regulating the temperature and soil moisture. In bioaugmentation, specialized exogenous microorganisms, such as fungi or bacteria, are inoculated into the soil for increasing contaminants biodegradation [8]. Bioremediation is a promising technique for the amelioration of soils contaminated with TPHs. However, for the heavier hydrocarbons, the efficiency of this technique is limited due to their low bioavailability, which makes bacterial degradation difficult [10], since these organisms have to absorb the contaminant to degrade it intracellularly. To solve this problem, a new procedure known as mycoremediation has been proposed. In this approach, fungi are applied to soil for enhancing contaminants removal [5]. Fungi are very interesting organisms to decontaminate soil because their multicellular fungal mycelium can reach vast volumes of soil. Compared to bacteria, fungi are also more resistant to high concentrations of toxins and can produce many useful bioactive compounds, such as extracellular enzymes, among other advantages [11]. Fungi can degrade a wide variety of organic contaminants thanks to their non-specific metabolism [11; 12].