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.

Background: Gerhardtia and Ossicaulis are two genera within the family Lyophyllaceae, which show an apparently poor species diversity worldwide. During the field investigation on wild macrofungi, six interesting collections within Gerhardtia and Ossicaulis genera are discovered in the northeastern China.Methods: To identify whether these collections of Gerhardtia and Ossicaulis are novel species, we performed phylogenetic analyzes using the following DNA regions: the internal transcribed spacer (ITS) region and the large subunit nuclear ribosomal RNA (nrLSU) region. Moreover, a traditional morphological method also be conducted based on both the macro-morphological and micro-morphological features.Results: The results indicated that these collections tested formed two independent lineages in each genus with a high support. In addition, they can easily be separated from all other taxa of the two genera in morphology. Based on the combination of morphological and molecular data, Gerhardtia tomentosa and Ossicaulis borealis, are confirmed as two new species to science.Discussions: This study provided a theoretical basis is for the two lyophylloid genera and indicated that the biodiversity resources of northeastern China might be underestimated.