Ganoderma lucidum is used widely in oriental medicine to treat obesity and metabolic diseases. Bioactive substances extracted from G. lucidum have been shown to ameliorate dyslipidemia, insulin resistance, and type 2 diabetes in mice via multiple 5′ AMP-activated protein kinase (AMPK)-mediated mechanisms; however, further studies are required to elucidate the anti-obesity effects of G. lucidum in vivo. In this study, we demonstrated that 3% G. lucidum extract powder (GEP) can be used to prevent obesity and insulin resistance in a mouse model. C57BL/6 mice were provided with a normal diet (ND) or a high-fat diet (HFD) supplemented with 1, 3, or 5% GEP for 12 weeks and the effect of GEP on body weight, liver, adipose tissue, adipokines, insulin and glucose tolerance (ITT and GTT), glucose uptake, glucose-metabolism related proteins, and lipogenesis related genes was examined. GEP administration was found to reduce weight gain in the liver and fat tissues of the mice. In addition, serum parameters were significantly lower in the 3% and 5% GEP mice groups than in those fed a HFD alone, whereas adiponectin levels were significantly higher. We also observed that GEP improved glucose metabolism, reduced lipid accumulation in the liver, and reduced adipocyte size. These effects may have been mediated by enhanced AMPK activation, which attenuated the transcription and translation of lipogenic genes such as fatty acid synthase (FAS), stearoyl-CoA desaturase 1 (SCD1), and sterol regulatory element-binding protein-1c (SREBP1c). Moreover, AMP-activated protein kinase (AMPK) activation increased acetyl-CoA carboxylase (ACC), insulin receptor (IR), IR substrate 1 (IRS1), and Akt protein expression and activation, as well as glucose transporter type 1/4 (GLUT1/4) protein production, thereby improving insulin sensitivity and glucose metabolism. Together, these findings demonstrate that G. lucidum may effectively prevent obesity and suppress obesity-induced insulin resistance via AMPK activation.

Mycotherapy has been shown to improve the overall response rate during cancer treatment and reduce some chemotherapy-related adverse events. Ganoderma lucidum is a traditional mushroom used for pharmaceutical purposes. G. lucidum extracts (GLE) showed potential antitumor activities against several cancers. These tumor inhibitory effects of GLE were attributed to the suppression of the proliferation and metastasis of cancer cells. Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is defined as the monoclonal proliferation of carcinoma cells with latent EBV infection. The inhibitory effects of GLE against EBVaGC are questionable. The aim of this study was to investigate GLE as potential antitumor agents and a counterpart of quercetin (QCT) for the cotreatment in suppressing EBVaGC development. Therefore, this study conducted antitumor assays using a EBVaGC xenograft mice model and found that GLE could suppress tumor development. These inhibitory effects were significantly augmented by the low concentration of the quercetin (QCT) cotreatment in the xenograft mice. The addition of GLE in low concentrations synergistically reinforced QCT-induced apoptosis and EBV lytic reactivation. GLE contains various polysaccharides and triterpenes, such as ganoderic acid. Interestingly, the addition of ganoderic acid A (GAA) could produce similar bioactive effects like GLE in QCT-mediated antitumor activity. The GAA addition in low concentrations synergistically reinforced QCT-induced apoptosis and EBV lytic reactivation. GAA was sufficiently effective as much as GLE. Therefore, our results suggested that QCT-supplemented GLE could be a potential food adjunct for the prevention of EBVaGC development.

Tricholoma matsutake is an ectomycorrhizal fungus that has obligate symbiotic relationships with Pinus densiflora. Its fruiting body has a distinctive flavor and is traded at a high price. Thus, it has been a significant source of income for rural communities in Korea. We hypothesized that biotic factors considerably influence the formation of the T. matsutake mushroom, and the soils producing T. matsutake share similar microbial characteristics. Therefore, the present study aimed to detect the specific fungal and bacterial groups in T. matsutake production soils (shiro+) and nonproduction soils (shiro−) of the Bonghwa and Yanyang regions via next-generation sequencing. In a total of 15 phyla, 36 classes, 234 genera of bacteria, six phyla, 29 classes, and 164 genera of fungi were detected from four samples at both sites. The species diversity of shiro+ soils was lower than the shiro− samples in both the fungal and bacterial groups. In addition, we did not find high similarities in the microbial communities between the shiro+ soils of the two regions. However, in the resulting differences between the fungal communities categorized by their trophic assembly, we found a distinguishable compositional pattern in the fungal communities from the shiro+ soils and the shiro− soils of the two sites. Thus, the similarity among the microbial communities in the forest soils may be due to the fact that the microbial communities in the T. matsutake dominant soils are closely associated with biotic factors and abiotic factors such as soil properties.

Greasiness in apple skin reduces its quality, and its level varies depending on the variety. In this study, low-temperature (1 ± 0.5 °C) stored ‘Hongro’ and ‘Fuji’, which had differences in the occurrence of greasiness, were moved to room temperature (20 °C) and untargeted metabolite and fatty acids for skin and flesh along with quality changes due to greasiness occurrence were compared. Ethylene production differed noticeably between the two varieties and increased rapidly in ‘Hongro’ until 9 d of room-temperature storage. The ethylene production did not differ significantly between the two varieties on day 20 when greasiness occurred. According to the PLS-DA score plot, while ‘Hongro’ had similar amounts of unsaturated and saturated fatty acids, ‘Fuji’ had approximately twice as much unsaturated-fatty-acid content. ‘Hongro’, after 50 d of low-temperature (1 ± 0.5 °C) storage, produced excessive ethylene during room-temperature storage, which was directly related to greasiness development. As a result, the primary wax components of greasy ‘Hongro’ were nonacosane and nonacosan-10-ol. As the room-temperature storage period elapsed, pentyl linoleate and α-farnesene contents increased significantly. Furthermore, these greasiness-triggering characteristics of ‘Hongro’ may have been genetically influenced by the paternal parent used during breeding.

Shin-Hye Kim, Hye-Lim Shin, Tae Hyun Son, Dongsoo Kim, Hwan-Gyu Kim, Jae-Han Cho, and Sik-Won Choi. J. Microbiol. Biotechnol. 2024;34:1-10. https://doi.org/10.4014/jmb.2408.08055

Flammulina velutipes is the most widely consumed edible mushroom in Korea, with a unique flavor and texture that support its popularity domestically and internationally. Korea produces approximately 26,000 tons of F. velutipes annually, accounting for 17% of its total mushroom production and generating export revenues of about 126 million USD. However, recent detection of Listeria monocytogenes in F. velutipes has led to product recalls and import restrictions in major markets, including the United States, thereby threatening export competitiveness. L. monocytogenes is a psychrotrophic foodborne pathogen capable of surviving and proliferating at low temperatures, causing severe diseases such as meningitis and sepsis in immunocompromised individuals, and miscarriage or fetal death in pregnant women. This study evaluated the antibacterial efficacy of peracetic acid (PAA) among several disinfectants for controlling Listeria contamination. Treatment with 80 ppm PAA once daily or once every two days effectively inhibited Listeria growth on F. velutipes surfaces without affecting mushroom fresh weight or marketability. Furthermore, PAA treatment suppressed not only Listeria but also other pathogenic microorganisms, suggesting improved overall microbial safety. PAA decomposes into water and oxygen, producing no harmful residues, and is approved for organic food production. Its ease of field application further enhances practicality. These findings indicate that PAA is an effective, eco-friendly method for controlling L. monocytogenes contamination in F. velutipes, and its implementation could strengthen the microbiological safety and export stability of Korean mushrooms in global markets.