Mushroom industries produce more than 200 million tons of spent mushroom substrate (SMS) per year that is landfilled or used as fertilizers. However, considering the biological degradation of lignocelluloses by filamentous fungi during mushroom cultivation, SMS could be suitable for dry anaerobic digestion (dry-AD) to create a sustainable process by producing biogas and digestate as biofertilizers. In this study, SMS after 3-13 weeks of mushroom cultivation was treated by dry-AD to produce biogas or biomethane and also biofertilizer. The total solids (TS) used were 13% and 21%. The highest methane yield of each TS obtained for 13% TS was at 5-week SMS with 51.99 ± 1.2 mL/gVS and for 21% TS was at 9-week SMS with 92.72 ± 0.83 mL/gVS. The methane yield from untreated sawdust without fungal cultivation was lower than that of SMS with values of 38.27 ± 0.31 mL/gVS for 13% TS and 66.01 ± 0.76 mL/gVS for 21% TS in dry-AD. Digestate obtained from dry-AD was found to have a C/N ratio ranging from 16.14 to 23.04 which complies with national regulation for fertilizer.

Current food systems are highly complex, with interdependencies across regions, resources, and actors, and conventional food production is a major contributor to climate change. Transitioning to sustainable protein sources is therefore critical to meet the nutritional needs of a growing global population while reducing environmental pressures. Filamentous fungi present a promising solution by converting agro-industrial side streams into mycoproteins—nutrient-dense, sustainable proteins with a carbon footprint more than ten times lower than beef. This review evaluates the potential of mycoproteins derived from fungi cultivated on low-cost substrates, focusing on their role in advancing sustainable food systems. Evidence indicates that mycoproteins are rich in protein (13.6–71% dw), complete amino acids, fiber (4.8–25% dw), essential minerals, polyphenols, and vitamins while maintaining low fat and moderate carbohydrate content. Fermentation efficiency and product quality depend on substrate type, nutrient availability, and fungal strain, with advances in bioreactor design and AI-driven optimization enhancing scalability and traceability. Supported by emerging regulatory frameworks, mycoproteins can reduce reliance on animal-derived proteins, valorize agricultural by-products, and contribute to climate-resilient, nutritionally rich diets. Integration into innovative food products offers opportunities to meet consumer preferences while promoting environmentally sustainable, socially equitable, and economically viable food systems within planetary boundaries.

Cheese whey, a nutrient-rich dairy byproduct that requires management due to its high organic load, was valorized using an integrated biorefinery platform with the edible fungus Neurospora intermedia to simultaneously produce mycoprotein, carotenoids, and B vitamins (B1, B2, B3, B6). Initial optimization employed a one-factor-at-a-time (OFAT) approach to evaluate the effects of whey concentration, initial pH, KNO3, salt supplementation, trace elements, precursor, and pellet-inducing agents (CaCl2, glycerol, and Tween 80). Subsequent optimization via response surface methodology (RSM) revealed the limitations of OFAT analysis and identified optimal conditions for targeted outputs. Maximum biomass yield (7.8 g/L) was achieved at high whey concentration (40 g/L) and low pH (pH 4), whereas maximum nutrient yields, 249.96 µg/g carotenoids, 1.46 mg/g B1, 7.17 mg/g B2, 0.41 mg/g B3, and 1.2 mg/g B6, were attained at low whey concentration (10 g/L) and low pH (pH 4). These conditions also minimized pellet size to 2 mm, enhancing metabolite production. The process concurrently reduced whey's chemical oxygen demand by 25.8% and demonstrated high biosorption of metal ions (76.8% Ca, 69.9% Mg, 80.8% Fe, 62.5% K). CHNS mass balance analysis revealed carbon (19.8%), hydrogen (18.9%), nitrogen (40.3%), and sulfur (42.5%) transfer efficiencies from cheese whey to N. intermedia biomass, with a 2.24-fold nitrogen enrichment (from 2.69% to 6.04%) corresponding to 37.8% crude protein and atomic ratios of C/N (7.84), N/S (36.2), H/C (1.85), and C/O (≈1.15). This study demonstrates the effective biorefining of whey into valuable products using RSM. This approach allows for the targeted production of high-volume mycoprotein, nutrient-dense extracts, or specific fungal morphology.

Edible filamentous fungus or mycoprotein, is promising sustainable protein sources and its protein quality plays a crucial role in their nutritional value. It is hypothesized that prolonged cultivation of filamentous fungus would reduce protein content and increase cell wall thickness, thereby hampering its protein digestibility. Filaementous fungi R. oryzae was cultivated for 24, 48, and 72 hours at two aeration rates (0.3 and 1 vvm) and three pH levels (4, 5.5, and 7). Biomass was analyzed for crude protein content, amino acid composition, cell wall content, and amino acid bioaccessibility using INFOGEST in vitro gastrointestinal digestion model. Prolonged cultivation significantly reduced protein content, while the amino acid profile remained stable across treatments and was notably rich in lysine (8.5–9.4%). In addition, cell wall content increased with cultivation time, accompanied by a reduction in amino acid bioaccessibility.

Ensuring food security while reducing the environmental footprint of food production has intensified interest in fungi-based foods. This study gauges Europeans’ sentiments to such products by surveying 6004 adults in Germany, Spain and Sweden (Oct–Nov 2024), countries chosen for their contrasting food cultures, sustainability views and regulatory contexts. Many respondents already find the concept appealing, while a similarly large group is open to trying it. A group of respondents voices disinterest, and many do not know what fungi-based food is, highlighting an opportunity for awareness-building. Country effects are modest: Spain shows slightly higher rejection, Germany more uncertainty and Sweden the most trial experience. Up to one-quarter report no concerns; the remainder focus mainly on additives, processing transparency, toxicity, price and flavor or texture parity with meat, while nutritional, digestibility and sustainability worries are rarer. Younger, highly educated and animal-derived food minimizing or avoiding (e.g., flexitarian or vegetarian) persons are more receptive than older or meat-oriented cohorts. Clear labeling, sensory optimization and targeted messaging could convert the sizeable open-minded segment into early adopters, advancing the EU Farm-to-Fork vision of resilient, resource-efficient food. © 2026 The Authors. 

Fungi-based foods are gaining attention as sustainable alternatives, yet public understanding remains limited. This study quantified knowledge and perceptions in Germany, Spain, and Sweden, selected for their distinct dietary cultures and regulatory contexts. An online survey of 6,004 adults used quiz-style questions covering taxonomy, terminology, cultivation timelines, sustainability, and nutrition. Results show misconceptions. Many classified fungi as plants, were unfamiliar with mycoprotein, and underestimated the rapid cultivation of filamentous fungi. Despite these gaps, majorities in all countries endorsed fungi’s sustainability potential and nutritional parity with meat. Greater knowledge was observed among tertiary-educated, higher-income, and meat-reducing groups. These findings show that limited process-related factual knowledge exists, underscoring the need for clearer communication. Public messaging should employ accessible terminology, present fermentation as ‘grown in days,’ and emphasize nutritional properties. Addressing knowledge gaps can align perceptions with evidence, enable informed decision-making, and support integration of fungi-based foods into sustainable systems.

The presence of antinutrients remains a major challenge for sustainable protein alternatives. Fungi-based protein, commonly referred to as mycoprotein, is free of phytates and can accumulate substantial amounts of minerals from its growth environment; however, these minerals may not be bioaccessible. We hypothesized that mineral concentrations in the fungal cultivation medium play a key role in determining the mineral bioaccessibility of fungal biomass. This study investigated how cultivation media concentrations of zinc (Zn), iron (Fe), phosphorus (P), and calcium (Ca) influence fungal mineral content and in vitro gastrointestinal accessibility using a full-factorial design and the INFOGEST in vitro digestion protocol.

Fungal mineral content increased with higher concentrations of the corresponding minerals in the cultivation media. Media Zn and Fe concentrations exhibited a reciprocal positive interaction, with each enhancing uptake of the other. Low-P conditions further increased both Zn and Fe content. In addition, media phosphorus and calcium concentrations showed a positive interaction, resulting in increased P and Ca content in the fungal biomass. Fungal biomass mineral accessibility was strongly affected by media composition. Biomass cultivated in high-Zn media exhibited high zinc accessibility (19–44 %), whereas low-Zn media produced biomass with antinutritional effects on zinc. Conversely, high-Fe media yielded biomass with iron bioaccessibility up to 25 %, while low-Fe media produced biomass with Fe accessibility exceeding 100 %, likely due to siderophore-mediated chelation.

Overall, these findings indicate that cultivation media mineral composition affects mineral content and bioaccessibility in R. oligosporus fungal biomass, supporting its use as a sustainable iron and zinc source.

Vinasse, a high-strength byproduct of the sugar–ethanol industry, was simultaneously valorized and remediated using the edible filamentous fungus Neurospora intermedia. Optimal cultivation conditions (6°Brix vinasse, pH 7, 0.5 g/L KNO₃, 1% inoculum, and 1 g/L diammonium citrate) produced 14.9 g/L fungal biomass enriched with carotenoids (76.38 μg/g) and vitamins B1, B2, B3, and B6. The process reduced vinasse COD by 63% and enabled substantial minerals bioaccumulation, removing up to ∼65% of Mn and Ca. FTIR analysis confirmed melanoidin adsorption, while SEM revealed thinner, highly branched hyphae under vinasse stress. Post-treatment with activated carbon or Purolite A502PS resin achieved >94% decolorization. This integrated system converts a problematic effluent into nutrient-rich biomass while improving wastewater quality, offering a practical circular-bioeconomy strategy for the sugar–ethanol sector.

The increasing global population and evolving dietary preferences demand sustainable and innovative food solutions. Edible filamentous fungi offer a promising protein source and are emerging as key ingredients in meat alternatives. This study investigates the quality and safety of Neurospora intermedia biomass (NIB), produced in a demo-scale bubble column reactor using grape marc (GM) and wine lees (WL) as cultivation media, and synthetic glucose medium (SYN) as a control. For submerged fermentation, GM and WL were used at 4% w/v and 50% v/v, respectively, whereas 1.5% w/v glucose was used for SYN. The NIB exhibited a complete amino acid profile, with notable levels of lysine (9.25-9.46%) and leucine (8.69-9.04%), and its lipid fraction was rich in unsaturated fatty acids-oleic (41.0-59.8%) and linoleic (19.7-33.9%), along with phosphorus (1097-2747 mg/100 g) and polyphenols (5.48-7.89 mg GAE/g). Overall, the proteomic analysis allowed the identification of more than 3000 proteins. Bioinformatic predictions identified potential allergens, which together accounted for only a minor fraction of the total protein mass. This study underscores NIBs grown on GM and WL as a functional and nutritious ingredient that has a rich and diverse protein profile with potentially low allergenicity. Additionally, it offers an innovative strategy that adds economic value to oenological by-products, reduces environmental impact, and promotes a circular bioeconomy. 

Purpose of Review

The rapid expansion of agricultural and agri-food production has generated substantial volumes of byproducts and side-streams rich in organic matter. Despite their potential, these residues remain largely underutilized, contributing to environmental pressures and constraining the economic sustainability of food systems. Filamentous fungi, with a long history of assimilating agri-food side-streams (AFS), offer a promising solution by enabling the conversion of organic-rich side-streams into nutrient-dense fungal biomass suitable for novel food and feed applications. This review synthesizes recent advances in the use of filamentous fungi to valorize AFS into value-added, bio-based products and compounds relevant to food and feed sectors. 

Recent Findings

A comprehensive analysis of 268 peer-reviewed research articles was conducted to identify prevailing trends, technological developments, and key factors influencing the bioconversion of AFS. Emphasis is placed on bioprocessing strategies for tproducing commercially relevant fungal-derived ingredients, including proteins, enzymes, polysaccharides, lipids, and bioactive compounds. Innovative approaches aimed at improving production efficiency and addressing industrial-scale challenges, including fungal biomass recovery, downstream processing, and functional compound extraction, are also discussed. 

Summary

The review highlights significant opportunities for innovation in upcycling AFS through integrated fungal biorefinery platforms. Advancements in fungal bioprocessing support the development of sustainable, cost-effective, and environmentally friendly food and feed products within a circular bioeconomy framework, emphasizing both ecological and economic benefits.