Weiming Cai

Species of Sanghuangporus produce abundant bioactive compounds, including flavonoids, polysaccharides, and triterpenoids, among which flavonoids exhibit prominent antioxidant activity and great development potential. Taking the peak extracellular flavonoid (EF) concentration in fermentation broth as the index, we optimized the liquid fermentation media and conditions for three Sanghuangporus strains (wild S. vaninii Z-0090, cultivar S. vaninii Z-0119, and cultivar S. baumii Z-0118) via single-factor experiments and the Box–Behnken response surface methodology. We further evaluated the antioxidant activity of the fermentation broth and analyzed its correlation with EF concentration using Pearson correlation analysis. After optimization, the EF concentrations of strains Z-0090, Z-0119 and Z-0118 were increased by 22.82%, 13.47% and 16.66%, respectively, compared with the control group. Antioxidant assays showed that strain Z-0090 had the highest hydroxyl radical scavenging rate (88.63%), strain Z-0119 presented balanced performance across all antioxidant indicators, and strain Z-0118 exhibited the strongest ABTS radical scavenging capacity (184.96 μg Trolox equivalents/mL), which was highly correlated with its EF concentration. This study provides a theoretical basis for the application of Sanghuangporus EFs in food, medicine, and industrial flavonoid production.

Stropharia rugosoannulata is a widely cultivated edible mushroom known for its nutritional value and umami flavour. Electronic tongue technology and metabolomics revealed that glutamic acid (Glu) and aspartic acid (Asp) levels were positively correlated with umami in the fruiting body developmental stages. Subsequent investigations found that overexpression of SrCS within the TCA cycle resulted in decreased levels of Glu and Asp. Integrating TF-gene-metabolite network modelling with experiments identified SrELT1 as a transcriptional regulator of SrCS. Different temperatures, cultivation substrates and genetics significantly impacted SrELT1 and SrCS expression, thereby affecting Glu and Asp synthesis. The findings suggest that increased Citrate synthase (CS) activity channelled citrate into glycolysis and oxidative phosphorylation without excessive accumulation; in contrast, decreased CS activity shifted metabolism toward the production of metabolites like Glu and Asp. This study provides insights for enhancing the umami of S. rugosoannulata, thereby substantially increasing its market competitiveness in the premium food segment.

This study integrates metagenomic and metabolomic data to systematically analyze the microbial community succession and carbon source metabolism transitions during the third fermentation cycle of Agaricus bisporus, with the aim of optimizing fermentation efficiency and lignocellulose degradation strategies. Principal Coordinate Analysis (PcoA) based on Bray–Curtis dissimilarity reveals significant microbial community separation across the stages of the first mushroom fruiting cycle. The overall pattern of “stage-specific differentiation” is consistent with the “cellulose hydrolysis” turn to the degradation of complex polysaccharides via carbohydrate-active enzymes (CAZymes). In the microbial network analysis showed that different microbe group controlled the stage-specific differentiation. These findings highlight a phase-dependent metabolic shift during the fermentation process: the early stages of fruiting rely more on cellulose-degrading microbes and their enzymatic systems, while later stages are driven by the degradation of complex polysaccharides and lignin derivatives, with Planctomycetota leading the degradation. This provides new mechanistic insights into agricultural waste resource utilization and the directional regulation of fermentation processes.

Stropharia rugosoannulata, or wine-cap Stropharia, is a well-known edible mushroom cultivated globally. The pileipellis color is a crucial quality attribute of S. rugosoannulata, exhibiting significant variation throughout its developmental stages. However, the pigment types and regulatory mechanisms behind color variation remain unclear. The metabolome analysis found that the anthocyanin biosynthesis pathway was significantly enriched and anthocyanins accumulated steadily in fruiting bodies during three developmental stages. The pileipellis pigment was extracted, and HPLC-MS confirmed the presence of anthocyanins. Notably, significant differences in anthocyanin content were observed among the various colored varieties. Thus, anthocyanins contribute to the pileipellis color of S. rugosoannulata. Through further investigation, this study elucidated, for the first time, the relationship between the "SrNFYA-SrDRF2" regulatory module and anthocyanin accumulation. Combined multiomics assays and HPLC analysis revealed that auxin functions as a signaling molecule that regulates the accumulation of anthocyanins in the pileipellis. Subsequently, the hub gene of anthranilate synthase for auxin synthesis was identified as SrTRP1, and the transcription factor SrMYB1 was verified as a regulator of SrTRP1, influencing auxin accumulation. These findings provide a valuable resource for the targeted enhancement of the quality of S. rugosoannulata.

Introduction: Cordyceps cicadae is a traditional Chinese medicinal fungus known for its rich production of bioactive substances, particularly cyanidin, an anthocyanin commonly found in plants with notable anti-inflammatory, anti-tumor, antiviral, and antibacterial properties. This study revealed two key genes, CcDFR and CcOMT9, affecting cyanidin biosynthesis in C. cicadae.Methods: The roles of these genes in cyanidin production, growth, and development were elucidated through the gene knockout method, phenotypic analysis, transcriptomics, and metabolomics.Results: CcDFR deletion led to reduced cyanidin-3-O-glucoside (C3G), suppressed expression of cyanidin biosynthesis genes, impaired synnemata formation, decreased polysaccharide and adenosine content, and diminished chitinase activity. Meanwhile, the ΔCcOMT9 mutant exhibited an increase in C3G production, promoted expression of cyanidin biosynthesis genes and rising bioactive compounds, suppressed RNA methylation, and led to phenylalanine accumulation with no effect on fruiting body formation.Discussion: We revealed a distinct anthocyanin biosynthesis pathway in C. cicadae and identified two genes with opposite functions, laying the foundation for future genetic modification of cyanidin-producing strains using modern biological techniques. This will shorten the production period of this valuable compound, facilitating the industrial-scale production of cyanidin.

Agaricus bisporus growth alters the lignocellulosic composition and structure of compost. However, it is difficult to differentiate the enzyme activities of A. bisporus mycelia from the wider microbial community owing to the complication of completely speareting the mycelia from compost cultures. Macrogenomics analysis was employed in this study to examine the fermentation substrate of A. bisporus before and after mycelial growth, and the molecular mechanism of substrate utilization by A. bisporus mycelia was elucidated from the perspective of microbial communities and CAZymes in the substrate. The results showed that the relative abundance of A. bisporus mycelia increased by 77.57-fold after mycelial colonization, the laccase content was significantly increased and the lignin content was significantly decreased. Analysis of the CAZymes showed that AA10 family was extremely differentiated. Laccase-producing strains associated with AA10 family were mostly bacteria belonging to Thermobifida and Thermostaphylospora, suggesting that these bacteria may play a synergistic role in lignin decomposition along with A. bisporus mycelia. These findings provide preliminary evidence for the molecular mechanism of compost utilization by A. bisporus mycelia and offer a reference for the development and utilization of strains related to lignocellulose degradation.

Isaria cicadae is a famous edible and medicinal fungus in China and Asia. The molecular basis of morphogenesis and synnemal formation needs to be understood in more detail because this is the main source of biomass production in I. cicadae. In the present study, a fruiting body formation-related gene with a glycosylphosphatidylinositol (GPI) anchoring protein (GPI-Ap) gene homolog IcFBR1 was identified by screening random insertion mutants. Targeted deletion of IcFBR1 resulted in abnormal formation of synnemata, impairing aerial hyphae growth and sporulation. The IcFBR1 mutants were defective in the utilization of carbon sources with reduced polysaccharide contents and the regulation of amylase and protease activities. Transcriptome analysis of ΔIcfbr1 showed that IcFBR1 deletion influenced 49 gene ontology terms, including 23 biological processes, 9 molecular functions, and 14 cellular components. IcFBR1 is therefore necessary for regulating synnemal development, secondary metabolism, and nutrient utilization in this important edible and medicinal fungus. This is the first report illustrating that the function of IcFBR1 is associated with the synnemata in I. cicadae.

Sanghuangporus sanghuang (SS) is a rare medicinal polypore fungus that grows solely on Morus trees. In this study, seven grains (oats, barley, millet, rice, buckwheat, corn, and coix seed) were used as solid substrates for SS fermentation and characterized in their nutrition, functional composition, and antioxidant activities. After fermentation, the nutrient compositions of crude protein (F_1,41 = 111.1, P < 0.01), soluble protein (F_1,41 = 595.7, P < 0.01), soluble sugar (F_1,41 = 51.4, P < 0.01) and ash (F_1,41 = 227.3, P < 0.01) increased significantly. Oats were one of the best grains for SS fermentation, SS-Oat produced 6.23 mg QE/g polyphenols, 21.8 mg rutin/g flavonoids, and 2.3% triterpene. In addition, the antioxidant capacities of the seven grains all increased. Principal component analysis analysis shows that the antioxidant properties of the grains were similar after SS fermentation. The changes of antioxidant activity due to SS fermentation were corrected with corresponding grain and remarked as ΔT-AOC/ABTS⁺/DPPH/DNAp, that was correlated to part of changes in polyphenol, carotenoid, triterpenoids, and flavonoid contents. In summary, oats have the greatest potential for use as a fermentation substrate for health food development.