Pleurotus eryngii is a tasty and low-calorie mushroom containing abundant high-quality protein. This study aims to improve the digestibility of P. eryngii protein (PEP) and hence to facilitate its development as a healthy alternative protein. The extracted PEP was pretreated with 1000–5000 U of papain, neutral protease and alkaline protease. The Chyme collected from in vitro simulated gastrointestinal digestion was analyzed by fluorescence microscopy and protein particle analyzer, and the endpoint profiles of peptides and amino acids were determined by UHPLC-MS/MS and NanoLC-MS/MS. The particle size curve and fluorescence microscopy images jointly supported that protease hydrolysis improved decomposition and dispersion of PEP during digestion, particularly in the gastric phase. The impact on Zeta potential was minimal. Proteases effectively increased the abundance of amino acids after digestion, particularly L-isomer Lys and Arg Maximum release was achieved when pretreated with 5000 U of alkaline protease, reaching 7.54 times that of control. Pretreatments by proteases also notably increased digestive yields of 16,736–19,870 peptides, with the maximum reaching 1.70 times that of the control, which mainly consisted of small peptides composed of 7–15 amino acids with molecular weight below 800 Da. The findings indicated that protease hydrolysis, especially pretreatment with 5000 U of alkaline protease, effectively enhanced the digestibility of PEP, which shed light on providing enzymatic approaches for improving bioavailability and developing healthy fungal proteins.

Introduction: Low temperature is the most common method used to maintain the freshness of Phlebopus portentosus during long-distance transportation. However, there is no information regarding the nutritional changes that occur in P. portentosus preserved postharvest in low temperature.Methods: In this study, the changes in flavor quality and bioactive components in fruiting bodies stored at 4 °C for different storage periods were determined through LC/MS and GC/MS analyses. Sampling was performed at 0, 3, 5, 7, and 13 days storage.Results and Discussion: Based on the results, the metabolites present in caps and stipes were different at the same period and significantly different after 7 days of storage. A total of 583 and 500 different metabolites were detected in caps and stipes, respectively, and were mainly lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds and others. Except for prenol lipids and nucleotides, the expression levels of most metabolites increased with longer storage time. In addition, geosmin was identified as the major contributor to earthy-musty odors, and the level of geosmin was increased when the storage time was short.Conclusion: The variations in these metabolites might cause changes in flavor quality and bioactive components in P. portentosus. Variations in these metabolites were thoroughly analyzed, and the results revealed how storage processes affect the postharvest quality of P. portentosus for the first time.

Phlebopus portentosus (Berk. and Broome) Boedijn is an attractive edible mushroom and is considered the only bolete for which artificial cultivation in vitro has been achieved. Gene expression analysis has become widely used in research on edible fungi and is important for elucidating the functions of genes involved in complex biological processes. Selecting appropriate reference genes is crucial to ensuring reliable RT‒qPCR gene expression analysis results. In our study, a total of 12 candidate control genes were selected from 25 traditional housekeeping genes based on their expression stability in 9 transcriptomes of 3 developmental stages. These genes were further evaluated using geNorm, NormFinder, and RefFinder under different conditions and developmental stages. The results revealed that MSF1 domain-containing protein (MSF1), synaptobrevin (SYB), mitogen-activated protein kinase genes (MAPK), TATA-binding protein 1 (TBP1), and SPRY domain protein (SPRY) were the most stable reference genes in all sample treatments, while elongation factor 1-alpha (EF1), actin and ubiquitin-conjugating enzyme (UBCE) were the most unstably expressed. The gene SYB was selected based on the transcriptome results and was identified as a novel reference gene in P. portentosus. This is the first detailed study on the identification of reference genes in this fungus and may provide new insights into selecting genes and quantifying gene expression.

A new species, Leucoagaricus purpurascens, collected from a subtropical region in China, is described based on morphological and molecular data. Leucoagaricus purpurascens is characterized by its small basidiomata with purple discolouration when dried, the pileus with distinct umbo, the amygdaliform, ellipsoidal to oblong basidiospores, and the absence of cheilocystidia. A detailed morphological description, line drawings, colour photographs, and a phylogenetic tree showing the phylogenetic placement of the new species are provided.

Ophiocordyceps sinensis is one of the best-known traditional Chinese medicines with distribution confined to the Tibetan Plateau and its surrounding regions. Harvesting the fungus contributes greatly to the livelihood of local communities. The quality and price varies amongst different production regions, usually resulting in an intentional mix-up of its production locality during trading processes, which leads to a demand of developing a reliable way that can trace the geographical origin of this fungus. In the present study, a DNA barcoding-based method applying two universal DNA barcodes for identifying fungal and insect, respectively i.e. the nuclear ribosomal internal transcribed spacer (ITS) and the mitochondrial cytochrome oxidase I (COI), was evaluated and used for geographical origin authentication of O. sinensis. A total of 24 ITS and 78 COI haplotypes were recognised from 215 individuals collected from 75 different geographic localities (county level). Ninety-nine haplotypes were defined using the combination of ITS and COI, discriminating the 75 investigated production counties into 99 distinct regions. A “core” production region was recognised which covers areas of Nagqu and Qamdo in Xizang, Yushu and Guoluo in Qinghai, Gannan (Maqu and Xiahe) in Gansu and certain regions in Nyingch (Bomi and Zayü) and Lhasa (Damxung) in Xizang and Garzê (Sêrxü) in Sichuan Province. Haplotype analyses using the combined barcodes of ITS and COI showed an excellent performance in the geographical origin authentication of O. sinensis and the definition of “core” and “non-core” production region.