Today there is an increasing amount of scientific evidence of the effects of probiotic bacteria as components of the gut microbiota on human health. Among their numerous health benefits are their antioxidant (AO) properties attracting more and more attention. Lactobacilli and bifidobacteria are the most important part of the human gut microbiome. Many in vivo and in vitro studies have demonstrated that they and their cellular components exhibit AO properties, thereby providing a certain degree of protection to the human body and contributing to the prevention of oxidative-stress-related diseases. The review discusses the AO properties of probiotic bacteria and postbiotics that are still not well known to the public. Special emphasis was put on the mechanisms of AO activity of lactobacilli and bifidobacteria, in which are involve enzymes, cell components and different metabolites as potential postbiotics. The genes encoding proteins, involved in AO activity, identified in various strains of lactobacilli and bifidobacteria were considered. The review also discusses different biotechnological methods that improve the survival rate of probiotics during processing, storage and GIT transit like microbial encapsulation that was successfully employed by many authors. Probiotic bacteria and postbiotics can be considered today as a new source of natural AO and can be used for biotechnological applications, specifically for pharmaceuticals, nutraceuticals, and cosmetic products.

The aim of this study is to characterize the bioactivity of mycelial biomass and crude exopolysaccharides (EPS) produced by Trametes versicolor NBIMCC 8939 and to reveal its nutraceutical potential. The EPS (1.58 g/L) were isolated from a culture broth. The macrofungal biomass was rich in protein, insoluble dietary fibers and glucans. The amino acid composition of the biomass was analyzed and 18 amino acids were detected. Three mycelial biomass extracts were prepared and the highest total polyphenol content (16.11 ± 0.14 mg GAE/g DW) and the total flavonoid content (5.15 ± 0.03 mg QE/g DW) were found in the water extract. The results indicated that the obtained EPS were heteropolysaccharides with glucose as the main building monosaccharide and minor amounts of mannose, xylose, galactose, fucose and glucuronic acid. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the complex structure of the crude EPS. Five probiotic lactic acid bacteria strains were used for the determination of the prebiotic effect of the crude EPS. The anti-inflammatory potential was tested in vitro using cell line HT-29. The significant decrease of IL-1 and IL-8 and increase of TGF-beta expression revealed anti-inflammatory potential of the crude exopolysaccharides from T. versicolor.

The agricultural waste with lignocellulose origin is considered to be one of the major environmental pollutants which, because of their high nutritional value, represent an extremely rich resource with significant potential for the production of value added bio-products. This review discusses the applications of higher fungi to upcycle abundant agricultural by-products into more sustainable materials and to promote the transition to a circular economy. It focuses on the main factors influencing the properties and application of mycelium composites – the feedstock, the basidiomycete species and their interaction with the feedstock. During controlled solid state cultivation on various lignocellulose substrates, the basidiomycetes of class Agaricomycetes colonize their surfaces and form a three-dimensional mycelium net. Fungal mycelium secretes enzymes that break down lignocellulose over time and are partially replaced by mycelium. The mycelium adheres to the residual undegraded substrates resulting in the formation of a high-mechanical-strength bio-material called a mycelium based bio-composite. The mycelium based bio-composites are completely natural, biodegradable and can be composted after their cycle of use is completed. The physicochemical, mechanical, and thermodynamic characteristics of mycelium based bio-composites are competitive with those of synthetic polymers and allow them to be successfully used in the construction, architecture, and other industries.

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.

Variety of microorganisms have already proven their capabilities for degradation of wide range of wastes with anthropogenic nature. These pollutants, both liquid and solids, also include so called xenobiotics like phenol and its derivatives, PAHs, dyes, pesticides, pharmaceuticals, etc. Xenobiotics as bisphenol A (BPA), chlorhexidine (CHX), octenidine (OCT), other disinfectants and antiseptics have high ecotoxicological impact. Moreover, they can also impair our quality of life and our health interfering different metabolic and hormone receptors pathways in human body. Chemical treatment of such wastes is not a viable option because of its poor socio-economics and environmental merits. Therefore, applying effective, ecofriendly and cheap treatment methods is of great importance. Basidiomycetes are extensively investigated for their abilities to degrade numerous pollutants and xenobiotics. Through their extracellular ligninolytic enzymes they are capable of reducing or completely removing wide range of hazardous compounds. These enzymes can be categorized in two groups: oxidases (laccase) and peroxidases (manganese peroxidase, lignin peroxidase, versatile peroxidase). Due to the broad substrate specificity of the secreted enzymes Basidiomycetes can be applied as a powerful tool for bioremediation of diverse xenobiotics and recalcitrant compounds.