Influence of selenium yeast on the growth, selenium uptake and mineral composition of Coriolus versicolor mushroom.

The ability of Coriolus versicolor medicinal mushroom to grow and accumulate selenium during submerged cultivation in a selenium-fortified medium is examined in this paper. For selenium supplementation, commercial selenium yeast was used. Control, nonenriched sample and reference cultures cultivated in the medium enriched with commercial yeast Saccharomyces cerevisiae were also prepared. The mushroom demonstrated a high ability to accumulate selenium from the added source (around 970 and 1,300 µg/g of dry mycelium weight for samples enriched with selenium in a concentration of 10 and 20 mg Se/L, respectively). The addition of selenium significantly (p ≤ .05) increased the biomass yield, whereas the addition of nonenriched yeast had no significant (p ≤ .05) impact. Furthermore, regression analysis showed statistically significant (p ≤ .05) and positive correlations between the content of Se and Fe (r = .92), Se and Cu (r = .92), Se and Mn (r = .98), and Se and Sr (r = .96), suggesting that selenium incorporation was followed by incorporation of these elements, and led to mineral enrichment of the obtained mycelium. Methanol extracts prepared from mycelium biomass demonstrated a better inhibitory effect on Gram-positive bacterial strains with minimal inhibitory concentrations between <0.3125 and 40 mg/ml. The obtained results showed that selenium yeast could be used for obtaining a potential novel food supplement: mushroom biomass with high selenium content and enhanced mineral composition.

Selenium-enriched Coriolus versicolor mushroom biomass: potential novel food supplement with improved selenium bioavailability.

BACKGROUND: The ability of Coriolus versicolor medicinal mushroom to accumulate and transform selenium from selenourea and sodium selenite into an organic form - l-selenomethionine - during growth in liquid medium is examined in this paper. Additionally, the impact of supplementation on biological activity of the selenated mushroom methanol extracts, as well as their chemical composition, is studied. RESULTS: Selenium accumulation was more efficient with sodium selenite application, but biomass yield was significantly lower (1.89 g DW L-1 ) compared to samples enriched with selenourea (4.48 g DW L-1 ). Mushroom sample obtained after growing in liquid medium with selenourea had significantly higher l-selenomethionine content compared to the sample grown in medium with sodium selenite. Selenium-enriched methanol extracts of C. versicolor mushroom showed improved antimicrobial and antioxidant activities compared to non-enriched extract. CONCLUSION: Our results suggest that C. versicolor mushroom cultivated in liquid culture enriched with selenourea can be used for the production of novel food supplements with improved selenium bioavailability. More than 30% of total accumulated selenium from selenourea is transformed into l-selenomethionine. Differences in biological activity of methanol extracts can be explained not only by different selenium content but also by the differences in chemical composition of extracts. © 2019 Society of Chemical Industry.

Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer-Ceramic Composite Material.

Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.

Green Extraction Approach for Isolation of Bioactive Compounds in Wild Thyme (Thymus serpyllum L.) Herbal Dust-Chemical Profile, Antioxidant and Antimicrobial Activity and Comparison with Conventional Techniques.

The aim of this study was to provide a chemical profile and determine the antioxidant and antimicrobial activity of the essential oil (EO) and lipid extracts of Thymus serpyllum L. herbal dust obtained via conventional (hydrodistillation (HD) and Soxhlet extraction (SOX)) and novel extraction techniques (supercritical fluid extraction (SFE)). In addition, a comparative analysis of the chemical profiles of the obtained EO and extracts was carried out, as well as the determination of antioxidant, antibacterial and antifungal activity of the lipid extracts. According to the aforementioned antioxidant and antimicrobial activities and the monoterpene yield and selectivity, SFE provided significant advantages compared to the traditional techniques. In addition, SFE extracts could be considered to have great potential in terms of their utilization in the pharmaceutical and cosmetic industries, as well as appropriate replacements for synthetic additives in the food industry.

Fermentation characteristics of novel Coriolus versicolor and Lentinus edodes kombucha beverages and immunomodulatory potential of their polysaccharide extracts.

Medicinal mushrooms, Coriolus versicolor and Lentinus edodes are extremely attractive as nutraceuticals. Here we used fruiting bodies to prepare novel kombucha beverage. Microbiological, physicochemical and chemical properties were monitored for eleven days, while the immunological properties of kombucha polysaccharide extracts were determined in peripheral blood mononuclear cell (PBMC) cultures. FTIR analysis of polysaccharide extracts showed dominant presence of polysaccharides, in addition to phenols, lipids and proteins. C. versicolor kombucha extract displayed more complex polysaccharides, and a higher content of total polysaccharides, phenols and flavonoids compared to L. edodes kombucha extract. The extracts were not cytotoxic for PBMC in vitro up to 500 µg/ml, while immunomodulatory effects depended on their chemical compositions. The most prominent effect was on the reduction of Th2 cytokines and IL-10 in PBMC cultures. Based on these results, novel kombucha products could be recommended as functional beverages or nutraceuticals with potentially beneficial immunomodulatory effects in allergies.

Turkey Tail Medicinal Mushroom, Trametes versicolor (Agaricomycetes), Crude Exopolysaccharides with Antioxidative Activity.

Crude Trametes versicolor exopolysaccharides (cEPS) were used for antioxidative activity testing. Obtained results revealed high ability of cEPS for DPPH free radical scavenging and high chelating ability at the highest tested concentration (20 mg/mL), while the reducing power was significantly lower. However, based on the EC50 values, antioxidative activities of the cEPS decreased in the following order: reducing power > DPPH scavenging ability > chelating ability. Due to the high carbohydrate and ß-glucan content it is assumed that they are the main carriers of cEPS antioxidative activities. D-glucose was the main monosaccharide (87.18 ± 0.27%) while the dominant amino acids were L-lysine (L-glutamic and L-aspartic acid), which are amino acids with taste similar to the monosodium glutamate. In addition, content of sweet tasting amino acids compared with the group of bitter tasting amino acid was 2.1 times higher, indicating favorable composition of cEPS protein fraction for food industry applying.

Novel Kombucha Beverage from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum, with Antibacterial and Antioxidant Effects.

Kombucha is a nonalcoholic beverage traditionally made by fermenting black tea using a combination of yeast and acetic acid bacteria (AAB) cultures. Ganoderma lucidum hot water extract (HWE) was used-to our knowledge for the first time-to prepare a novel, health-promoting kombucha product. During the 11-day fermentation, pH, total acidity, and the numbers of yeasts and AAB were monitored. It was found that sweetened G. lucidum HWE was a good medium for yeast and AAB growth. The desired acidity for the beverage was reached on the second day (3 g/L) of the fermentation process; the maximum established acidity was 22.8 ± 0.42 g/L. Fourier transform infrared analysis revealed that the vacuum-dried beverage is a mixture of various compounds such as polysaccharides, phenols, proteins, and lipids. Total phenolic content of the liquid sample was 4.91 ± 0.2338 mg gallic acid equivalents/g, whereas the vacuum-dried sample had a smaller amount of phenolics (2.107 ± 0.228 mg gallic acid equivalents/g). Established half-maximal effective concentrations for DPPH scavenging activity and reducing power were 22.8 ± 0.17 and 10.61 ± 0.34 mg/mL, respectively. The antibacterial testing revealed that activity does not originate solely from synthesized acetic acid. The liquid G. lucidum beverage was the most effective against the tested bacteria, with the lowest minimum inhibitory concentration (0.04 mg/mL) against Staphylococcus epidermidis and Rhodococcus equi, and a minimum bactericidal concentration (0.16 mg/mL) against Bacillus spizizenii, B. cereus, and R. equi. The vacuum-dried sample was less effective, with the lowest minimum bactericidal concentration against the Gram-positive bacteria R. equi (1.875 mg/mL) and against the Gram-negative bacteria Proteus hauseri (30 mg/mL).