Two low-molecular-weight polysaccharides (GLP-1 and GLP-2) were purified from Ganoderma leucocontextum fruiting bodies, and their physicochemical properties and antioxidant activities were investigated and compared in this study. The results showed that GLP-1 and GLP-2 were mainly composed of mannose, glucose, galactose, xylose, and arabinose, with weight-average molecular weights of 6.31 and 14.07 kDa, respectively. Additionally, GLP-1 and GLP-2 had a similar chain conformation, crystal structure, and molecular surface morphology. Moreover, GLP-1 exhibited stronger antioxidant activities than GLP-2 in five different assays: 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical, superoxide anion radical, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). The main linkage types of GLP-1 were found to be →4)-α-D-Glcp-(1→, →4)-β-D-Glcp-(1→, →3)-β-D-Glcp-(1→, →6)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and Glcp-(1→ by methylation analysis and nuclear magnetic resonance (NMR) spectroscopy. In addition, GLP-1 could protect NIH3T3 cells against tert-butyl hydroperoxide (tBHP)-induced oxidative damage by increasing catalase (CAT) and glutathione peroxidase (GSH-Px) activities, elevating the glutathione/oxidized glutathione (GSH/GSSG) ratio, and decreasing the malondialdehyde (MDA) level. These findings indicated that GLP-1 could be explored as a potential antioxidant agent for application in functional foods.

Inonotus obliquus is an edible mushroom and also a remedy against various diseases, especially metabolic syndrome. In this paper we report the actions of an ethanol extract of I. obliquus (IOE) against hyperuricemia in hyperuricemic mice, and the screen of bioactives. The extract (IOE) was prepared by extracting I. obliquus at 65 °C with ethanol, and characterized by HPLC. IOE at low, middle, and high doses reduced serum uric acid (SUA) of hyperuricemic mice (353 μmol/L) to 215, 174, and 152 μmol/L (p < 0.01), respectively, showing similar hypouricemic effectiveness to the positive controls. IOE showed a non-toxic impact on kidney and liver functions. Of note, IOE suppressed xanthine oxidase (XOD) activity in serum and liver, and also down-regulated renal uric acid transporter 1 (URAT1). Four compounds hit highly against XOD in molecular docking. Overall, the four compounds all occupied the active tunnel, which may inhibit the substrate from entering. The IC₅₀ of betulin was assayed at 121.10 ± 4.57 μM, which was near to that of allopurinol (148.10 ± 5.27 μM). Betulin may be one of the anti-hyperuricemia bioactives in I. obliquus.

Ganoderma lucidum spores (GLS), the mature germ cells ejected from the abaxial side of the pileus, have diverse pharmacological effects. However, the genetic regulation of sporulation in this fungus remains unknown. Here, samples corresponding to the abaxial side of the pileus were collected from strain YW-1 at three sequential developmental stages and were then subjected to a transcriptome assay. We identified 1598 differentially expressed genes (DEGs) and found that the genes related to carbohydrate metabolism were strongly expressed during spore morphogenesis. In particular, genes involved in trehalose and malate synthesis were upregulated, implying the accumulation of specific carbohydrates in mature G. lucidum spores. Furthermore, the expression of genes involved in triterpenoid and ergosterol biosynthesis was high in the young fruiting body but gradually decreased with sporulation. Finally, spore development-related regulatory pathways were explored by analyzing the DNA binding motifs of 24 transcription factors that are considered to participate in the control of sporulation. Our results provide a dataset of dynamic gene expression during sporulation in G. lucidum. They also shed light on genes potentially involved in transcriptional regulation of the meiotic process, metabolism pathways in energy provision, and ganoderic acids and ergosterol biosynthesis.

Russula griseocarnosa, an edible and medicinal mushroom abundant in nutrients and notable bioactivities, is predominantly grown in the broad-leaved forest with trees of the family Fagaceae in southern China. This species forms ectomycorrhizal associations with plant roots and cannot be artificially cultivated currently. Previous research indicates a strong correlation between the growth of R. griseocarnosa and factors such as the host plant, climate variables (specifically mean temperature and precipitation from June to October), and the rhizosphere microbiota of its habitat. However, comprehensive studies on the fundamental biology of this species are lacking. The interaction between R. griseocarnosa and its host plant, as well as the mechanisms underlying the microbial community dynamics within its habitat, remain ambiguous. The limited repertoire and diversity of carbohydrate-active enzymes (CAZymes) in R. griseocarnosa relative to saprophytic fungi may contribute to its recalcitrance to cultivation on synthetic media. The specific core enzyme and the substances provided by the host plant to facilitate growth are yet to be elucidated, posing a significant challenge in the artificial cultivation of R. griseocarnosa. The habitat of R. griseocarnosa harbours unique microbial communities, indicating the presence of potentially beneficial microorganisms that could be exploited for artificial propagation and conservation efforts. However, the lack of definitive functional verification experiments hinders the realization of this promising prospect. This review offers a comprehensive overview of the nutritional profile and health benefits of R. griseocarnosa, emphasizing recent developments in its isolation, molecular ecology, and artificial cultivation. Additionally, it explores prospective advancements in R. griseocarnosa research, aiming to enrich our foundational understanding for applied purposes and fostering progress in the realm of ectomycorrhizal edible mushrooms.

Ganoderma lucidum is an important medicinal mushroom widely cultured in Asian countries. Exopolysaccharides are bioactive compounds of G. lucidum with health benefits. Limited exopolysaccharide content hinders its extraction from G. lucidum. The addition of Tween80 had an enhanced effect on G. lucidum exopolysaccharide production in submerged fermentation. However, the mechanism of this effect remains unclear. In this study, we report on a high-quality assembly of G. lucidum strain yw-1-5 to lay the foundation for further transcriptome analysis. The genome sequence was 58.16 Mb and consisted of 58 scaffolds with an N50 of 4.78 Mb. A total of 13,957 protein-coding genes were annotated and Hi-C data mapped to 12 pseudo-chromosomes. Genes encoding glycosyltransferases and glycoside hydrolases were also obtained. Furthermore, RNA-seq was performed in a Tween80-treated group and control group for revealing the enhanced effect of Tween80 on exopolysaccharide production. In total, 655 genes were identified as differentially expressed, including 341 up-regulated and 314 down-regulated. Further analysis of differentially expressed genes showed that groups of MAPK, amino sugar and nucleotide sugar metabolism, autophagy, ubiquitin-mediated proteolysis, peroxisome, starch and sucrose metabolism, TCA cycle, glycolysis/gluconeogenesis KEGG pathway, glycosyltransferases and glycoside hydrolases played important roles in the enhanced effect of Tween80 on exopolysaccharide production. This work provides a valuable resource for facilitating our understanding of the synthesis of polysaccharides and accelerating the breeding of new strains with a high content of exopolysaccharides.