Nowadays, the food sector is highly concerned with environmental issues and foreseen to develop strategies to reduce waste and losses resulting from activities developed in the food system. An approach is to increment added value to the agro-industrial wastes, which might provide economic growth and environmental protection, contributing to a circular economy. Mushroom by-products represent a disposal problem, but they are also promising sources of important compounds, which may be used due to their functional and nutritional properties. Research has been developed in different fields to obtain value added solutions for the by-products generated during mushroom production and processing. Bioactive compounds have been obtained and applied in the development of nutraceutical and pharmaceutical formulations. Additionally, other applications have been explored and include animal feed, fertilizer, bioremediation, energy production, bio-based materials, cosmetics and cosmeceuticals. The main purpose of this review is to highlight the relevant composition of mushroom by-products and discuss their potential as a source of functional compounds and other applications. Future research needs to explore pilot and industrial scale extraction methods to understand the technological feasibility and the economic sustainability of the bioactive compounds extraction and valorization towards different applications.

Factors driving the expansion of particular MDR Salmonella serotypes/clones are not completely understood. We assessed if emergent MDR Salmonella serotypes/clones were more enriched in metal tolerance genes (e.g. to Cu/Ag) than other less frequent ones, as an additional feature to survive in environments contaminated with metals. Metal (Cu pco/Ag,Cu sil/Hg mer/As ars/Te ter) tolerance genes screening (PCR/sequencing), MICs of CuSO₄/AgNO₃ (aerobiosis/anaerobiosis), genetic element characterization (S1/I-CeuI PFGE) and conjugation assays were performed in a well-characterized Salmonella collection (n = 275 isolates; 2000–14; 49 serotypes/clones). The sil ± pco genes were detected in 37% of isolates from diverse serotypes, mainly in emergent Rissen/ST469 and Typhimurium/ST34 European clone (100%), which are mostly associated with pig settings where Cu is highly used. These genes were frequently co-located with merA ± terF and/or antibiotic resistance genes in plasmids (100–270 kb; IncHI2/IncHI1/IncN/IncFIIA; mostly transferable by conjugation) or in the chromosome. Most sil ± pco⁺ isolates (77%) were MDR contrasting with sil ± pco⁻ ones (48%). The sil ± pco⁺ isolates presented significantly higher MIC_CuSO4 under anaerobiosis (MIC₅₀/MIC₉₀ = 28/32 mM) and MIC_AgNO3 after previous Ag contact (MIC₅₀/MIC₉₀ > 3 mM) than sil⁻ ones (MIC₅₀/MIC₉₀ = 2/8 mM to CuSO₄; MIC₅₀/MIC₉₀ = 0.125/0.16 mM to AgNO₃). Use of these modified methodological approaches allowed the establishment of CuSO₄/AgNO₃ tolerance cut-offs to differentiate sil⁺ and sil⁻ isolates, here firstly proposed. This study demonstrates that acquisition of Cu/Ag tolerance genes (sil/pco genes) might contribute to the emergence of particular clinically relevant MDR Salmonella serotypes/clones by facilitating their survival in diverse metal-contaminated settings, particularly in pig production. Assessment of control measures for the use and/or accumulation of metals in diverse environments are needed to prevent a wider expansion of such strains or the emergence of new ones.

Mushrooms provide essential nutrients and bioactive compounds, namely glucans, protein, and phenolic compounds. In this study, two aqueous extractions were performed (M1 and M2) using Pleurotus ostreatus, Pleurotus eryngii, and Agrocybe cylindracea. In M1, a hot extraction (extract M1) (90 °C, 700 rpm, 1 h) was performed. In M2, a room-temperature extraction (extract M2A) followed by a hot extraction (extract M2B) (90 °C, 700 rpm, 1 h) of the extract M2A residue was performed. The M2B extracts showed the lowest extraction yields (12.58–21.78%), while the other yields ranged between 30.91% and 46.03%. All extracts had high protein (12.09–32.97 g/100 g of dry extract), glucan (12.69–48.57 g/100 g of dry extract), and phenolic contents (7.90–16.65 mg GAEs/g of dry extract) and high antioxidant (ABTS and ORAC assays), antimicrobial, antibiofilm, and prebiotic activities. So, they have potential to be used as functional ingredients or natural preservatives. Extracts from A. cylindracea stood out since they had higher protein content, antioxidant activity, and prebiotic activity (extract M1) and inhibited a higher number of foodborne bacteria (only extract M2A). However, unlike extracts from P. ostreatus and P. eryngii, at 40 mg/mL, they had cytotoxic effects.