The brown film (BF) of Lentinula edodes mycelium has been reported to exert biological activities during mushroom cultivation; however, to date, there is limited information on its chemical composition. In this study, untargeted metabolomics analysis was performed via liquid chromatography–mass spectrometry (LC–MS), and the results were used to screen the antimicrobial compounds. A total of 236 differential metabolites were found among the BF stages compared with the white hyphal stage. Among them, five important antimicrobial metabolites related to antimicrobial activities, namely, 6-deoxyerythronolide B, tanikolide, hydroxyanthraquinone, benzylideneacetone, and 9-OxooTrE, were present at high levels in the BF samples. The score plots of the principal component analysis indicated that the samples from four time points could be classified into two groups. This study provided a comprehensive profile of the antimicrobial compounds produced during BF formation and partly clarified the antibacterial and antifungal mechanism of the BF of L. edodes mycelium.

• UPLC-MS/MS and GC × GC-TOF/MS based metabolomics was applied to morel. • 253 non-VOCs and 87 VOCs were differentially accumulated between two cultivars of morel. • Variations in lipids, carbohydrates, amino acids, alcohols and ketones cause flavor difference. • Morchella importuna showed more mushroom flavor and sweeter flavor than Morchella sextelata.

Casein is a commonly used protein in the food industry, with its related products such as beverages and desserts. However, the further application of casein is limited by its solubility and stability. This study aimed to improve the functional of casein through protein-glutaminase (PG) deamination. The deamination of casein using PG was optimized through central composite design experiments, and its impact on the structure, solubility, and stability of casein was investigated. The results demonstrate that the optimal conditions for PG deamidation were determined at pH 6.0, E/S 15 U/g, and a temperature of 45 °C. The deamidation process alters the secondary structure of casein, resulting in a decrease in α-helix structure and an increase in β-sheet structure. The modification of casein improved emulsifying activity at pH 8.0 and 10.0, respectively, while significantly enhancing the solubility from 5.0 to 6.0. Furthermore, the deamidation of casein caused an increase in zeta potential and a decrease in particle size, resulting in improved stability of the protein solution due to reduced particle aggregation. The 3% deamidated casein-based beverage with carrageenan exhibited reduced precipitation rates compared to the control after sterilization at 121 °C for 15 min. In summary, PG deamidation offers a promising method for the modification and enhancement of the functional properties, including solubility, stability, and emulsifying activity of casein, thereby expanding its use of casein in the food industry.

Mycelial BF formation and postripening of L. edodes affects the quality and quantity of its edible fruiting bodies. In this study, we explored the role of protein KAC in this biological process, with the aim of optimizing the cultivation and yield of L. edodes .

Sparassis latifolia is an edible and medicinal mushroom with significant economic value, now commercially cultivated on a large scale in China. However, current cultivars face challenges, including an extended mycelial growth period and unstable fruiting body yields. Advances in molecular breeding and functional genomics for this species are hindered by the absence of a reliable genetic transformation system. In this study, we first determined that S. latifolia is highly sensitive to carboxin and hygromycin, two selective agents commonly used in fungal genetics. We subsequently constructed a novel binary vector, pCbxHyg, harboring a carboxin resistance cassette driven by its native Pleurotus eryngii promoter and a hygromycin resistance cassette under the control of the P. eryngii Glycerol 3-phosphate dehydrogenase (GPD) gene promoter. Initial transformation attempts using Agrobacterium-mediated transformation of liquid-cultured mycelial pellets were unsuccessful. During microscopic examination, we discovered that S. latifolia mycelia produce abundant asexual chlamydospores. Using these chlamydospores as recipient material, we efficiently and reproducibly obtained transformants with the pCbxHyg vector under both carboxin and hygromycin selection. This method highlights the advantage of using asexual spores of Basidiomycetes as recipients for genetic transformation. PCR analysis confirmed the stable integration of the exogenous resistance genes into the fungal genome. The functionality of the system was further validated by transforming chlamydospores with a vector carrying a β-glucuronidase (GUS) reporter gene, whose expression was confirmed via histochemical staining of the resulting transformant mycelia. This work establishes the first successful Agrobacterium-mediated genetic transformation system for S. latifolia, providing a foundational platform for future gene function studies and molecular breeding efforts.

Following the elucidation of the fungal bioluminescence pathway (FBP), it was quickly adopted as a reporter system in plants; however, no such application has been documented in fungi to date. In this study, we established for the first time a luminescent reporter in the commercially important mushroom Hypsizygus marmoreus by expressing the luciferase gene from the luminous fungus Neonothopanus nambi. Using an established Agrobacterium-mediated transformation method, we separately introduced the wild-type luciferase gene nnLuz and the previously reported optimized variant nnLuz-v4 that can enhance bioluminescence expression into H. marmoreus arthroconidia. Both genes were stably integrated into the genome and expressed under the control of the H. marmoreus Glycerol 3-phosphate dehydrogenase (GPD) gene promoter. Upon addition of exogenous luciferin, transformants carrying the wild-type nnLuz produced clear, readily detectable bioluminescence signals, whereas no luminescence was observed in untransformed controls. Unexpectedly, the wild-type luciferase consistently exhibited substantially higher luminescence intensity than the optimized nnLuz-v4 variant. This finding suggests that codon optimization may be unnecessary or even detrimental when the donor and host are phylogenetically close basidiomycetes. The successful deployment of the fungal luciferase gene in H. marmoreus provides a sensitive and non-invasive genetic tool that does not require external excitation. This system opens new avenues for promoter characterization, real-time gene expression monitoring during mushroom development, and molecular breeding efforts aimed at improving agronomically important traits.