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Morels ( Morchella spp.) are valuable and rare edible mushrooms with unique flavors and high nutritional value. White mold disease occurring during cultivation has seriously affected the quality and yield of morels in China. In this study, the fungus causing white mold disease in morels was isolated, purified, and identified as Pseudodiploöspora longispora by morphology and molecular biology. In addition, research has shown that P. longispora infection causes wrinkled and rupturing asci, loosened cell walls, and obvious membrane breakage accompanied by severe cytoplasmic leakage in M. sextelata . Interestingly, research has shown that infection with P. longispora can induce the production of an unknown substance in the cells of M. sextelata , which accumulates on the cell membrane, leading to membrane breakage. Furthermore, integrated transcriptomics-proteomics analysis revealed the response mechanism of M. sextelata to P. longispora infection. The results indicate that DEGs and DEPs can be significantly enriched in pathways involved in oxidoreductase activity; peroxisomes, lipid transport, and metabolism; cell wall assembly; and integral components of membranes. Further electron microscopy analysis clarified the important role of changes in the cell membrane and cell wall in the response of mycelia to biological stress. This study clarified the response mechanism of M. sextelata to P. longispora , laying a foundation for further clarifying the infection mechanism of P. longispora .

Morchella importuna polysaccharide (MIP) has been proven to have obvious hypoglycemic effects on mice with type 2 diabetes (T2DM). This study looked at the functional and rheological characteristics of MIP, and investigated the effects of MIP on the human fecal microbiota through in vitro fermentation experiments. The outcomes demonstrate the excellent oil-holding capacity, emulsifying, foaming, and rheological characteristics of MIP. After salivary gastrointestinal digestion, the Mw of MIP decreased from 398.2 kDa and 21.5 kDa to 21.9 kDa and 11.7 kDa. By 16S rRNA sequencing of bacteria fermented in vitro, it was found that MIP did not improve the richness and diversity of intestinal microorganisms, but it may exert an anti-T2DM function by significantly increasing the relative abundance of Firmicutes and promoting Ruminococcaceae_UCG_014 , Bacteroides , and Blautia proliferation. Escherichia-Shigella could also be inhibited to improve the intestinal microenvironment. In addition, the fermentation of MIP increased the total short-chain fatty acid (SCFA) concentration from 3.23 mmol/L to 39.12 mmol/L, and the propionic acid content increased significantly. In summary, MIP has excellent processing performance and is expected to exert potential anti-T2DM activity through the human intestinal microbiota, which has broad market prospects.

Anaerobic fungi, though low in abundance in rumen, play an important role in the degradation of forage for herbivores. When only anaerobic fungi exist in the fermentation system, the continuous accumulation of metabolites (e.g., hydrogen (H 2 ) and formate) generated from their special metabolic organelles-the hydrogenosome-inhibits the enzymatic reactions in the hydrogenosome and reduces the activity of the anaerobic fungi. However, due to interspecific H 2 transfer, H 2 produced by the hydrogenosome can be used by other microorganisms to form valued bioproducts. This symbiotic interaction between anaerobic fungi and other microorganisms can be used to improve the nutritional value of animal feeds and produce value-added products that are normally in low concentrations in the fermentation system. Because of the important role in the generation and further utilization of H 2 , the study of the hydrogensome is increasingly becoming an important part of the development of anaerobic fungi as model organisms that can effectively improve the utilization value of roughage. Here, we summarize and discuss the classification and the process of biomass degradation of anaerobic fungi and the metabolism and function of anaerobic fungal hydrogensome, with a focus on the potential role of the hydrogensome in the efficient utilization of biomass.