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BACKGROUND: Pleurotus ostreatus, oyster mushroom, is a popular edible mushroom cultivated world-wide and it also belongs to white-rot fungi that can degrade plant cell wall lignin effectively. To develop an efficient strategy for molecular breeding in P. ostreatus, molecular genetic tools have been developed through my 30-years investigation with wonderful colleagues from domestic and foreign countries. One of the most fruitful and newest international collaborations is that with Korean researchers. In this talk, I would like to introduce some recent results of an international collaboration with Mushroom Division, NIHHS, Rural Development Administration, Republic of Korea. RESULTS: We have successfully introduced a genome editing technology into P. ostreatus using CRISPR/Cas92. To establish a non-genetically modified (non-GM) genome editing in mushroom fungi, we set sail for developing a protocol for CRISPR/Cas9 without foreign DNA integration in the edited strain. In addition, to avoid health and environmental problems caused by spores, we selected and knocked-out candidate genes essential for spore formation using CRISPR/Cas9 technique. Three new genes essential for spore formation were found and sporeless cultivars by disrupting one of these genes were isolated. CONCLUSION: The fundamental technology of non-GM molecular breeding can be used for valuable objectives including high-value-added edible mushrooms, efficient lignin-degrading strains with high potential for bioremediation and non-existent strains su

BACKGROUND: The characteristics of basidiomycete cell wall are closely related to performance of mushroom materials reported by Prof. Shin's group in 2022. From this work, we expect that it would be possible to develop superior mushroom materials with desired properties by modifying the cell wall synthesis machinery. In this talk, I would like to introduce some recent results of an international collaboration with Prof. Shin, Chosun University. Our research starts with understanding agaricomycete cell walls, then moves to modifying them. RESULTS: The cell wall structure of Pleurotus ostreatus (Basidiomycete) and Aspergillus nidulans (Ascomycete) was visualized by confocal microscopy using α-glucan and β-glucan specific fluorescent probes and calcofluor white. This imaging analysis revealed that the outermost layer of the cell wall is covered by β-glucan in P. ostreatus, although α-glucan mostly covers the outermost layer of the A. nidulans cell wall. Combining the other results, the cell wall structure of this fungus is completely different from those of Aspergilli. Therefore, we are starting to analyze cell wall polysaccharide synthases and transcription factors involved in the cell wall integrity signal transduction pathway (CWIS) in P. ostreatus1,2. In this process, important mycelial characteristics for mushroom material were successfully changed by deleting the genes involved in CWIS. CONCLUSION: Our results indicated that molecular breeding opens the door of cell wall engineering for future mushroom material improvement. We just received a new grant for an international collaboration with Prof. Shin on mycelial materials from October.

This study was aimed to investigate the dietary supplementation with the fruiting body of Lyophyllum decastes (LD) mushroom on body weight, plasma lipid profiles and histopathological changes of the liver in rats fed a high-fat and high-cholesterol diet. Five-week-old female Sprague-Dawley albino rats were divided into four groups, each consisting of eight: a normal control diet (NC group), an high-fat and hhigh-cholesterol diet (HFC group), an HFC diet supplemented with 0.03% simvastatin (HFC+SS group) and an HFC diet supplemented with 5% fruiting body powder of Lyophyllum decastes (HFC+LD group). In the HFC+LD group, plasma total cholesterol (TC), low density lipoprotein (LDL-C), and triglyceride (TG) concentrations were significantly lower than those in the HFC group. Additionally, body weight gain in the HFC+LD group was lower compared to the HFC group. No adverse effects were observed in the levels of plasma albumin, creatinine, blood urea nitrogen, uric acid, glucose, and total protein in the HFC+LD group. Enzyme activities related to liver function, such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT), were similar to those in other groups including NC, HFC, HFC+SS and HFC+LD. Feeding the rats with HFC diet supplemented with mushroom powder (HFC+LD group) increased the excretion of total lipid and total cholesterol compared to HFC group in the feces. Histopathological analysis revealed that the HFC group developed hepatic steatosis, while the HFC+DL group showed only minimal fat droplets in the liver tissues. In conclusion, the results suggested that an HFC diet supplemented with 5% fruiting body powder of LD provides health benefits to rats by acting on lowering atherogenic lipid profiles and body weights.

BACKGROUND: The tiger milk mushroom has been extolled for centuries due to its medicinal properties. In Malaysia, the major species Lignosus rhinocerus is recorded by ethnomycological writings to have therapeutic values. Prior to its successful cultivation in 2009, there were no records of scientific studies due to unavailability of sufficient samples. A patented solid state fermentation method successfully cultivated TM02®; followed by the development of ACE Technology to produce its extract xLr® are the first of its kind in the world and can produce a consistent supply of both the TM02® sclerotia and its extract, xLr®. Thorough study which encompassed chronic1, subacute2, and acute toxicity, genotoxicity, antifertility, and teratogenic effects was conducted to enable mass commercialization. Rigorous scientific investigations have been done to validate its traditional use and to investigate its biochemical and biopharmacological properties. RESULTS: TM02® and xLr® contain Rhinoprolycan3 fraction as its active component which could play possible role in rendering significant therapeutic properties such as antiinflammatory4, immuno-modulatory3, anti-proliferative5, anti-oxidative6, neurite outgrowth stimulation and anti-AGE7. It is proven to be effective in supporting the lung and respiratory health, immune health, maintenance of joint health (caused by inflammation), improving vitality and stamina and improving the quality of life for cancer patients. The revelation of the genome, transcriptome, proteome of L. rhinocerus has provided valuable insights into the biomolecule discovery and provided the foundation for future research and exploitation in pharmacological and functional food applications. The most recent pandemic accelerated the visibility of tiger milk mushroom for use to overcome chronic cough and severity of the infection8. CONCLUSION: It is a listed traditional medicine active ingredient list under the Malaysian National Pharmaceutical Control Bureau and the TM02® cultivar has also been filed under the New Plant Variety Protection (NPVP) of Malaysia. This is the first medicinal mushroom species that has experienced the bench to bedside framework – having had successfully completed 4 clinical trials to date with one more ongoing.

BACKGROUND: Biomass-based materials have gained attention as next-generation materials due to their renewable and eco-friendly characteristics. Among these, mycelium materials, utilizing mushroom mycelium, are being actively researched and developed worldwide. The current mainstream technology involves a bottom-up process of cultivating mycelium to form objects. However, in Japan, where mushroom production is high, we considered the possibility of competition between mycelium cultivation and food production. Therefore, we focused on a "scrap-and-build" approach, which allows for the use of inedible mushrooms and by-products. This study aims to create novel fibrous materials by breaking down mushroom mycelium. Specifically, we prepare mycelium pulp using Ganoderma lucidum (Reishi), an inedible and tough mushroom, as well as hot-water extraction residues of Flammulina velutipes (Enokitake) by-products. This presentation will discuss the concept of this technology and the properties of the materials. RESULTS: Through chemical treatment with sodium hydroxide solution and hydrogen peroxide, as well as UV irradiation, the fruiting bodies were effectively bleached, and ultrasonic processing produced a slurry-like substance with dispersed micrometer-sized mycelium. In the obtained samples, the mycelium maintained its structure, with thick, linear mycelium measuring 8.0 ± 3.4 μm in width observed in F. velutipes and fine, branched mycelium measuring 2.3 ± 0.6 μm in width observed in G. lucidum. FT-IR spectral analysis indicated no significant changes in the chemical composition of the mycelium pulp after bleaching and fibrillation treatments, suggesting the presence of various polysaccharides. The mycelium pulp could be molded into yarn-like, film-like, or sponge-like forms. CONCLUSION: These findings confirmed that, unlike conventional fruiting body-derived materials, the mycelium pulp retained its mycelial structure. This study successfully created mycelium pulp, a novel mushroom-derived material. Mycelium pulp holds diverse potential applications as a sustainable material and is expected to contribute to the circular bioeconomy.