Phenotypic Recovery of a Heterobasidion Isolate Infected by a Debilitation-Associated Virus Is Related to Altered Host Gene Expression and Reduced Virus Titer

The fungal genus Heterobasidion includes forest pathogenic species hosting a diverse group of partitiviruses. They include the host debilitating Heterobasidion partitivirus 13 strain an1 (HetPV13-an1), which was originally observed in a slowly growing H. annosum strain 94233. In this study, a relatively fast-growing sector strain 94233-RC3 was isolated from a highly debilitated mycelial culture of 94233, and its gene expression and virus transcript quantities as well as the genomic sequence of HetPV13-an1 were examined. The sequence of HetPV13-an1 genome in 94233-RC3 was identical to that in the original 94233, and thus not the reason for the partial phenotypic recovery. According to RNA-seq analysis, the HetPV13-an1 infected 94233-RC3 transcribed eight genes differently from the partitivirus-free 94233-32D. Three of these genes were downregulated and five upregulated. The number of differentially expressed genes was considerably lower and the changes in their expression were small compared to those of the highly debilitated original strain 94233 with the exception of the most highly upregulated ones, and therefore viral effects on the host transcriptome correlated with the degree of the virus-caused debilitation. The amounts of RdRp and CP transcripts of HetPV13-an1 were considerably lower in 94233-RC3 and also in 94233 strain infected by a closely related mildly debilitating virus HetPV13-an2, suggesting that the virus titer would have a role in determining the effect of HetPV13 viruses on their hosts.

Identification of the Primary Structure of Selenium-Containing Polysaccharides Selectively Inhibiting T-Cell Proliferation

We previously described the biosynthesis, isolation, and immunosuppressive activity of the selenium-containing polysaccharide fraction isolated from the mycelial culture of Lentinula edodes. Structural studies have shown that the fraction was a protein-containing mixture of high molar mass polysaccharides α- and β-glucans. However, which of the components of the complex fraction is responsible for the immunosuppressive activity non-typical for polysaccharides of fungal origin has not been explained. In the current study, we defined four-polysaccharide components of the Se-containing polysaccharide fraction determined their primary structure and examined the effect on T- and B-cell proliferation. The isolated Se-polysaccharides, α-1,4-glucan (Mw 2.25 × 106 g/mol), unbranched β-1,6-d-glucan, unbranched β-1,3-d-glucan and β-1,3-branched β-1,6-d-glucan (Mw 1.10 × 105 g/mol), are not typical as components of the cell wall of L. edodes. All are biologically active, but the inhibitory effect of the isolated polysaccharides on lymphocyte proliferation was weaker, though more selective than that of the crude fraction.

MYCELIAL AMYLASE AND CELLULASE CHARACTERIZATION AS WELL AS BASIDIOMA PHYSICOCHEMICAL ANALYSIS OF LINGZHI MUSHROOM

Karakterisasi Amilase dan Selulase Miselial Serta Analisis Fisikokimia Basidioma Jamur Lingzhi (Ganoderma lucidum) Lingzi mushroom (Ganoderma lucidum) synthesizes enzymes which have anti-hyperglycemic and anti-diabetic activities. This preliminary study aims to characterize the amylase and cellulase activities of mycelial culture, and to analyze the physicochemical compounds in the basidioma of G. lucidum InaCC F11 and G. lucidum InaCC F106. The enzymes were characterized spectrophotometrically using DNS method, and the basidioma was subjected to proximate and high performance liquid chromatography (HPLC) analysis, as well as microstructural observation using scanning electron microscope. Results showed both strains demonstrated amylase activity, but not cellulase activity. The optimum activity of amylase in G. lucidum InaCC F11 mycelial cultures was achieved on the 3rd incubation day, at pH 5.5, 35 ºC temperature, and 1.5% substrate concentration, whereas that of G. lucidum InaCC F106 on the 7th incubation day, at pH 5, 40 ºC temperature, and 1.75% substrate concentration. Dried basidioma of G. lucidum InaCC F11 contained 93.72% carbohydrates, 3.06% protein, 0.85% fat, 0.768% crude fiber, 0.54% ash, and 1.83% moisture. In addition, HPLC detected the presence of phenols (0.036%), steroids (0.014 mg 100 mL-1), and active triterpenoid compounds. Jamur lingzi (Ganoderma lucidum) mensintesis enzim yang memiliki aktivitas anti-hiperglikemik dan anti-diabetes. Studi pendahuluan ini bertujuan mengkarakterisasi aktivitas amilase dan selulase kultur miselium, serta menganalisis senyawa fisikokimia pada basidioma G. lucidum InaCC F11 dan G. lucidum InaCC F106. Enzim dikarakterisasi secara spektrofotometri menggunakan metode DNS. Basidioma dianalisis secara proksimat, menggunakan kromatografi cair kinerja tinggi (KCKT), serta diamati mikrostrukturnya menggunakan mikroskop elektron. Hasil menunjukkan kedua strain tersebut memiliki aktivitas amilase, dan tidak ada aktivitas selulase. Aktivitas amilase optimum pada kultur miselium G. lucidum InaCC F11 dicapai pada inkubasi hari ke-3, pH 5,5, suhu 35 ºC, dan konsentrasi substrat 1,5%, sedangkan pada kultur miselium G. lucidum InaCC F106 dicapai pada inkubasi hari ke-7, pH 5, suhu 40 ºC, dan konsentrasi substrat 1,75%. Basidioma kering G. lucidum InaCC F11 mengandung karbohidrat 93,72%, protein 3,06%, lemak 0,85%, serat kasar 0,768%, abu 0,54%, dan kadar air 1,83%. Selain itu, KCKT mendeteksi adanya fenol (0,036%), steroid (0,014 mg 100 mL-1), dan senyawa triterpenoid aktif.

Mycelial culture extracts of selected wood-decay mushrooms as a source of skin-protecting factors

Objectives This study analyzed the content of substances with cosmetologic properties in the extracts obtained from the mycelial cultures of Ganoderma applanatum, Laetiporus sulphureus, and Trametes versicolor. The effect of these extracts on the inhibition of tyrosinase and hyaluronidase was determined, and their values of sun protection factor (SPF) were calculated. Results The total amount of phenolic acids in the extracts ranged from 2.69 (G. applanatum) to 10.30 mg/100 g dry weight (T. versicolor). The total amount of sterols was estimated at 48.40 (T. versicolor) to 201.04 mg/100 g dry weight (L. sulphureus), and that of indoles at 2.90 (G. applanatum) to 16.74 mg/100 dry weight (L. sulphureus). Kojic acid was determined in the extracts of L. sulphureus and G. applanatum. It was observed that L. sulphureus extract caused dose-dependent inhibition of hyaluronidase, while all the extracts inhibited tyrosinase. The extract of G. applanatum exhibited an SPF value of ~ 9. Conclusions The results showed that the mycelial cultures of the studied species may be used as an alternative source of substances used in cosmetology.

Discovery of Antifungal and Biofilm Preventative Compounds from Mycelial Cultures of a Unique North American Hericium sp. Fungus

Edible mushrooms are an important source of nutraceuticals and for the discovery of bioactive metabolites as pharmaceuticals. In this work, the OSMAC (One Strain, Many Active Compounds) approach was used to isolate two new compounds (1 and 2) along with seven known compounds (3–9) from a mycelial culture of a unique North American edible mushroom Hericium sp. The fruiting body was collected in Marine on St. Croix, Minnesota (USA), and mycelial cultures were grown on four different solid and liquid media. Extracts from the mycelial cultures were screened for antimicrobial activity and only the extract from the Cheerios substrate culture exhibited antifungal activity. Bioassay guided fractionation and HPLC analysis were used to isolate nine pure compounds and the structures of the known compounds were established by analysis of the NMR and mass spectrometry data and comparison to published reports. Compound 1 is a new erinacerin alkaloid and 2 is an aldehyde derivative of 4-hydroxy chroman. Four chlorinated orcinol derivatives (3–6), a pyran (7), erinaceolactone (8), and erinacine (9) were identified. Compound 4 showed antifungal activity against C. albicans and C. neoformans (MIC = 31.3–62.5 μg/mL, respectively). Compound 4 also inhibited biofilm formation of C. albicans and C. neoformans at 7.8 μg/mL. These results suggest that mycelial cultures of edible fungi may provide useful, bioactive compounds.

A 90-day subchronic toxicity study of submerged mycelial culture of Cordyceps militaris in rats

Cordyceps militaris (C. militaris) is a parasitic fungus that grows on the larvae of Lepidoptera.