In this study, for the first time, the potential of rose flowers and lavender straw waste biomass was studied as feeding lignocellulose substrates for the cultivation of newly isolated in Bulgaria Ganoderma resinaceum GA1M with the objective of obtaining mycelium-based bio-composites. The chemical characterization and Fourier Transform Infrared (FTIR) spectroscopy established that the proximate composition of steam distilled lavender straw (SDLS) and hexane extracted rose flowers (HERF) was a serious prerequisite supporting the self-growth of mycelium bio-materials with improved antibacterial and aromatic properties. The basic physico-mechanical properties of the developed bio-composites were determined. The apparent density of the mycelium HERF-based bio-composites (462 kg/m³) was higher than that of the SDLS-based bio-composite (347 kg/m³) and both were much denser than expanded polystyren (EPS), lighter than medium-density fiber board (MDF) and oriented strand board (OSB) and similar to hempcrete. The preliminary testing of their compressive behavior revealed that the compressive resistance of SDLS-based bio-composite was 718 kPa, while for HERF-based bio-composite it was 1029 kPa and both values are similar to the compressive strength of hempcrete with similar apparent density. Water absorbance analysis showed, that both mycelium HERF- and SDLS-based bio-composites were hydrophilic and further investigations are needed to limit the hydrophilicity of the lignocellulose fibers, to tune the density and to improve compressive resistance.

The bio-fabrication of sustainable mycelium-based composites (MBCs) from renewable plant by-products offers a promising approach to reducing resource depletion and supporting the transition to a circular economy. In this research, MBCs were obtained by cultivating Ganoderma resinaceum GA1M on essential oils and agricultural by-products: hexane-extracted rose flowers (HERF), steam-distilled lavender straw (SDLS), wheat straw (WS), and pine sawdust (PS), used as single or mixed substrates. The basic physical and mechanical properties revealed that MBCs perform comparably to high-efficiency thermal insulating and conventional construction materials. The relatively low apparent density, ranging from 110 kg/m³ for WS-based to 250 kg/m³ for HERF-based composites, results in thermal conductivity values between 0.043 W/mK and 0.054 W/mK. Compression stress (40–180 kPa at 10% deformation) also revealed the good performance of the composites. The MBCs had high water absorption due to open porosity, necessitating further optimization to reduce hydrophilicity and meet intended use requirements. An aerobic biodegradation test using respirometry indicated ongoing microbial decomposition for all tested bio-composites. Notably, composites from mixed HERF and WS (50:50) showed the most rapid degradation, achieving over 46% of theoretical oxygen consumption for complete mineralization. The practical applications of MBCs depend on achieving a balance between biodegradability and stability.

Higher basidiomycetes are recognized as functional foods due to their bioactive compound content, which exerts various beneficial effects on human health, and which have been used as sources for the development of natural medicines and nutraceuticals for centuries. The aim of this study was to evaluate and compare the biological potential of basidiocarp and mycelial biomass produced by submerged cultivation of a new regionally isolated oyster mushroom. The strain was identified with a high percentage of confidence (99.30%) as Pleurotus ostreatus and was deposited in the GenBank under accession number MW 996755. The β-glucan content in the basidiocarp and the obtained mycelial biomass was 31.66% and 12.04%, respectively. Three mycelial biomass and basidiocarp extracts were prepared, and the highest total polyphenol content (5.68 ± 0.15 mg GAE/g DW and 3.20 ± 0.04 mg GAE/g DW) was found in the water extract for both the fruiting body and the mycelium biomass. The in vitro antioxidant activity of the extracts was investigated, and it was determined that the water extracts exhibited the most potent radical scavenging activity. The potential ability of this new fungal isolate to affect the contractile activity (CA) of dissected smooth muscle preparations (SMP) was examined for the first time. It was found that oyster mushrooms likely exhibit indirect contractile effects on the gastric smooth muscle (SM) cells.

The present study is focused on a newly isolated Fomitopsis strain obtained from black pine (Pinus nigra) from the Sredna Gora Mountains, Bulgaria. Molecular identification, based on ITS1-5.8S-ITS2 region sequencing, confirmed the strain as Fomitopsis pinicola with 99.84 BLAST percent identity. Phylogenetic analysis verified that the new fungal isolate belongs to the European F. pinicola clade. The morphological analysis of the strain revealed several distinctive structures that further support its identification. The influence of culture media composition on fungal development was evaluated by analyzing the mycelial growth kinetics using both the logistic growth model and the reversible autocatalytic model. Submerged cultivation was employed to produce fungal biomass, which was subsequently lyophilized and used for the assessment of the antimicrobial potential of the fungal strain. The results demonstrated notable antimicrobial effects against all tested bacterial strains. The most significant activity was observed for the aqueous extract against Escherichia coli and the hexane extract against Salmonella enteritidis, both with a minimum inhibitory concentration of 312.5 µg/mL. These findings highlight the promising potential of the newly isolated F. pinicola strain for future applications in the medical and pharmaceutical industries, particularly in developing drugs to combat multidrug resistance, based on the promising results of its water extracts.

A significant quantity of agro-industrial waste is generated globally across various agricultural sectors and food industries. Composed primarily of cellulose, hemicellulose, and lignin—known as lignocellulosic materials—this waste holds significant potential and can be repurposed as a nutrient-rich substrate for mushroom cultivation. Therefore, mushroom cultivation can be regarded as a promising biotechnological approach for the reduction and valorization of agro-industrial waste. This investigation is the first to explore the utilization of agro-industrial waste- and by-products for the cultivation of Epicoccum nigrum for the production of extracts with valuable biological activities. The logistic curve and autocatalytic growth models were applied to study the kinetics of the growth process on wheat bran, sunflower cake, wheat straw, pine sawdust, and steam-distilled lavender straw substrates. Through mathematical modeling, the optimal composition of a nutrient medium containing the selected substrates was determined and successfully validated in experimental conditions. Biologically active water extracts were obtained after solid-state cultivation with α-amylase and cellulase activity up to 10.6 ± 0.6 U/mL and 0.52 ± 0.03 U/g, respectively. The extracts exhibited antimicrobial activity against fungal strains from six different species, and the most susceptible was the phytopathogen Sclerotinia sclerotiorum, with a minimum inhibitory concentration of 0.156–0.313 mg/mL.

In the present study, an unknown fungal strain was isolated from the fruiting body of a local Dryad’s Saddle mushroom (Polyporaceae). The molecular identification of the isolate was performed by amplification of the ITS1-5.8S-ITS2 region and the strain was identified with 100.00% confidence as Epicoccum nigrum. The morphological characteristics, including the distinctive colony pigmentation, conidiophore structure, and conidial shape, were determined to ensure comprehensive characterization of the fungus. The modeling of the kinetics of the growth process was conducted with the applying the logistic curve model and the reverse autocatalytic growth model, and the concentrations of the compounds in the nutrient medium required for the E. nigrum development were established. Controlled submerged cultivation was carried out for cultural liquid obtaining, which was further used for the evaluation of the biological activities. The untreated cultural liquid demonstrated antimicrobial activity against Sclerotinia sclerotiorum where the minimal inhibitory concentration was 1.25 mg/mL. Antimicrobial activity was also detected toward Botrytis cinerea (2.5 mg/mL) and Aspergillus flavus (2.5 mg/mL). The direct utilization of crude cultural liquid for phytopathogenic control is a sustainable approach that will provide the opportunity for the development of an environmentally friendly manufacturing process.