In this study, we investigated the occurrence of T-2 toxin-producing fungi in domestically grown corn forage. We isolated fungi, using a Fusarium-selective medium, from corn forage samples collected from eight farms or agricultural organizations in Iwate (2018) and Hokkaido (2020) prefectures. The isolated fungi were cultured on corn grits to assess T-2 toxin production. We identified 16 T-2- toxin-producing strains, among which, strains seven and nine were isolated from Hokkaido and Iwate samples, respectively. Toxin-producing fungi were isolated from grains, stem leaves, silks, and bracts. Of the four strains isolated from the grains, one was isolated from a sample exhibiting grain disease symptoms, whereas the remaining strains were isolated from grains showing no obvious disease symptoms. In Iwate samples, four and five fungal strains were identified as Fusarium sporotrichioides and Fusarium armeniacum, respectively, whereas all seven strains isolated from Hokkaido corn samples were identified as F. sporotrichioides. Although T-2 toxin has rarely been detected or detected at low concentrations in domestic feeds, our findings revealed that T-2 toxin may constitute a new threat to forage production in Japan.

  Aspergillus flavus and parasiticus agar (AFPA) medium is the most prevalent medium for the isolation of fungal strains of Aspergillus section Flavi. AFPA medium has been mainly used for the selection of the aflatoxin (AF) – producing strains of Aspergillus flavus and A. parasiticus. Recently we have developed an improved agar medium, named YES-DC-CP, for the isolation of Aspergillus section Flavi, regardless of the production of AF. In this study we adopted YES-DC-CP medium for the isolation of Aspergillus section Flavi strains from acidic tea field soils and compared the isolation efficacy with AFPA. As a result, YES-DC-CP medium was more suitable for the isolation. The isolated strains were chemically and genetically analyzed for the species identification. A. caelatus, one of the minor species of this section, was found in rather high frequencies.

  Besides being one of the most damaging pathogens of a wide range of crops, members of the Fusarium genus can produce several mycotoxins, including deoxynivalenol, fumonisins and zearalenone, which have received tremendous attention. Furthermore, the genus is a rich source of many more natural products (NPs), where polyketides is one of the most important classes. Genome analyses of 207 Fusarium species have suggested that genus has a genetic potential to produce 113 structurally distinct families of polyketide-derived NPs. However, less than 25% of the potential polyketides have been identified, which is often caused by the inability of the fungal strains to unleash their full metabolite potential under standard laboratory conditions. In this paper, we give a status on one of the best studied species of Fusarium, F. graminearum, where the products of 12 of 15 polyketide synthases (PKSs) are known. We describe the strategies that have been used to link the PKSs to their product and give some thought on how the last polyketides can be identified.

  The main players in sake making are koji mold and sake yeast, with koji mold’s main role being starch saccharification, and sake yeast’s main role being ethanol fermentation. However, there are supporting players in sake making that have been overlooked. These supporting players are kuratsuki bacteria, which change the role of sake yeast through interactions with sake yeast, thereby changing the flavor and taste of sake. While sake yeast, the main player, is used all over the country, the kuratsuki bacteria play a role in each sake brewery, and the role of each varies from brewery to brewery. We have isolated, identified, and analyzed the functions of the kuratsuki bacteria to clarify their role. Kuratsuki bacteria do not inhibit the activity of sake yeast. By considering the interactions between sake yeast and kuratsuki bacteria during sake making, it may become possible to make sake in a way that has never been seen before.

  The Japanese Society of Mycotoxicology (JSM) celebrated its 50^th anniversary in 2024. To commemorate the 50^th anniversary, the 91^st JSM Regular Meeting featured an international symposium with invited speakers from overseas and concluded successfully.