Ligninolytic basidiomycetes as promising organisms for the mycoremediation of PAH-contaminated Environments

Endophytic, extremophilic and entomophilic fungi strains biodegrade anthracene showing potential for bioremediation

Anthropogenic activities have been increasing Polycyclic Aromatic Hydrocarbons (PAHs) release, promoting an urgent need for decontamination methods. Therefore, anthracene biodegradation by endophytic, extremophilic, and entomophilic fungi was studied. Moreover, a salting-out extraction methodology with the renewable solvent ethanol and the innocuous salt K₂HPO₄ was employed. Nine of the ten employed strains biodegraded anthracene in liquid medium (19-56% biodegradation) after 14 days at 30 °C, 130 rpm, and 100 mg L^-1. The most efficient strain Didymellaceae sp. LaBioMMi 155, an entomophilic strain, was employed for optimized biodegradation, aiming at a better understanding of how factors like pollutant initial concentration, pH, and temperature affected this process. Biodegradation reached 90 ± 11% at 22 °C, pH 9.0, and 50 mg L^-1. Futhermore, 8 different PAHs were biodegraded and metabolites were identified. Then, experiments with anthracene in soil ex situ were performed and bioaugmentation with Didymellaceae sp. LaBioMMi 155 presented better results than natural attenuation by the native microbiome and biostimulation by the addition of liquid nutrient medium into soil. Therefore, an expanded knowledge about PAHs biodegradation processes was achieved with emphasis to the action of Didymellaceae sp. LaBioMMi 155, which can be further employed for in situ biodegradation (after strain security test), or for enzyme identification and isolation aiming at oxygenases with optimal activity under alkaline conditions.

Impact of lignocellulosic waste-immobilised white-rot fungi on enhancing the development of 14C-phenanthrene catabolism in soil

In this study, an investigation was carried out to explore the the impact of white-rot fungi (WRF) on enhancing the development of phenanthrene catabolism in soil over time (1, 25, 50, 75 and 100 d). The WRF were immobilised on spent brewery grains (SBG) prior to inoculation to the soil. The results showed that SBG-immobilised WRF-amended soils reduced the lag phases and increased the extents of ¹⁴C-phenanthrene mineralisation. Greater reductions in the lag phases and increases in the rates of mineralisation were observed in immobilised Trametes versicolor-amended soil compared to the other WRF-amendments. However, the presence of Pleurotus ostreatus and Phanerochaete chrysosporium influenced biodegradation more strongly than the other fungal species. In addition, fungal enzyme activities increased in the amended soils and positively correlated with the extents of ¹⁴C-phenanthrene mineralisation in all soil amendments. Maximum ligninolytic enzyme activities were observed in P. ostreatus-amended soil. Microbial populations increased in all amended soils while PAH-degrading fungal numbers increased with increased soil-PAH contact time and strongly positively correlated with fastest rates of mineralisation. The findings presented in this study demonstrate that inoculating the soil with these immobilised WRFs generally enhanced the mineralisation of the ¹⁴C-phenanthrene in soil. This has the potential to be used to stimulate or enhance PAH catabolism in field-contaminated soils.

Construction, renovation and demolition (CRD) wastes contaminated by gypsum residues: Characterization, treatment and valorization

Management of wastes resulting from construction, renovation and demolition (CRD) activities has become an important challenge for scientists. The recovery of gypsum residues from CRD waste is one of the solutions to minimize the impact of CRD operations on the environment. This review discusses the characteristics of CRD waste, different treatment and valorization methods for both CRD waste and extracted gypsum residues. Pre-treatment based on particle size separation is the most fundamental step in the process of extracting gypsum residues from CRD fine tailings. The subsequent application of a physical, chemical or biological decontamination approach on the gypsum residues could significantly improve its quality as compared to natural gypsum. The quality of the gypsum obtained affects its valorization potential in different sectors such as cement manufacturing, the sequestration of carbon dioxide and nutrients. The valorization strategy could help reducing emissions of greenhouse gases while producing by-products that can be reused in agriculture. As such, this review may provide guidance for more sustainable management of CRD and gypsum residues in the future.

Climatic and Socioeconomic Aspects of Mushrooms: The Case of Spain

Fungi are some of the most diverse organisms on earth and since prehistoric times have played an important role in human society. In recent years they have become a strategic asset not only in the conservation and management of ecosystems but also as a resource for halting the exodus from rural areas in peripheral Mediterranean regions, such as inland eastern Spain. In view of this important ecological and socioeconomic role, in this paper we present a geographical analysis of edible fungi, paying particular attention to the Spanish case. To this end we carried out a bibliographic review of the climatic factors affecting the fruiting of these fungi and the socioeconomic aspects of their commercial exploitation. We also performed an online search for mycotourism-related activities and explored the statistical data on the cultivation of edible mushrooms and its economic impact. Our main findings include a synthesis of the international research on the effects of climatic variability on the natural production of macrofungi, and an assessment of the economic viability and the social importance of mushrooms in Spain, in particular in relation to the current and future potential of mushroom cultivation and the multifunctional management and use of forests.