Marutomo (Japan)

Fermented katsuobushi, a traditional Japanese seasoning, is produced from skipjack tuna through smoking, drying and fermentation by xerophilic Aspergillus molds, primarily Aspergillus chevalieri and Aspergillus pseudoglaucus. In this study, we characterized lipolytic enzymes (cLip_1 to cLip_5 and pLip_1 to pLip_3) to clarify their roles in lipid hydrolysis during katsuobushi production under low water activity. The enzymes showed significant diversity in their activity, stability and substrate specificity, and in the hydrolysis profiles of their reactions with fish oil. Phylogenetic analyses revealed that cLip_5 showed a high identity with pLip_2 (94%) and these enzymes formed a phylogenetic cluster with filamentous fungal lipases. Purified recombinant enzymes (rcLip_1, rcLip_2, rcLip_4 and rcLip_5) and wild-type enzymes (cLip_3 and pLip_3) showed varying substrate preferences toward p-nitrophenyl esters. The addition of glycerol to reduce the water activity in the reaction mixture led to increased activities of rcLip_1 and rcLip_4, but it did not affect the activity of the other three enzymes. Among the tested six enzymes, cLip_5 showed the highest hydrolytic activity toward fish oil. The cLip_5 and pLip_2 gene transcript levels were moderately high in strains MK86 and MK88, respectively. cLip_5 and its homolog pLip_2 were identified as the most promising enzymes for katsuobushi fermentation, because of their high hydrolytic activities toward fish oil and adaptability to low water activity conditions. These findings support the selection of optimal Aspergillus strains as starter cultures to potentially shorten the fermentation time and improve the quality and shelf life of katsuobushi. © 2025 Society of Chemical Industry.

We have previously demonstrated that collagen from jellyfish simulated immunoglobulin and cytokine production by human-human hybridoma line HB4C5 cells and by human peripheral blood lymphocytes (hPBL). The mode of action of the collagen as an immunostimulatory factor was investigated. The expression levels of immunoglobulin mRNAs in HB4C5 cells, and those of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and transforming growth factor (TGF)-beta in hPBL were up-regulated by jellyfish collagen. In addition, this collagen activated IgM production by transcription-suppressed HB4C5 cells that had been treated with actinomycin D. This collagen also enhanced IgM production by translation-suppressed HB4C5 cells that had been treated with sodium fluoride, but was ineffective in accelerating IgM production by HB4C5 cells treated with cycloheximide. Moreover, the intracellular IgM level in HB4C5 cells treated with the post-translation inhibitor, monensin, was increased by this collagen. These results suggest that collagen from jellyfish stimulated not only the transcription activity, but also the translation activity for enhanced immunoglobulin and cytokine production.

The effect of smoke-dried bonito undigested fraction remaining after microbial protease treatment (SDBR) on a spontaneously occurring mouse model of atopic dermatitis was studied in male 5-wk-old, NC/Nga mice. Smoke-dried bonito, Katsuobushi, is a traditional Japanese food. SDBR contains 2 major components: bonito oil and protease-undigested proteins. Mice were fed a casein diet containing corn oil (C diet) or a diet containing SDBR (SDBR diet) for 18 wk. In comparison with the C diet, the SDBR diet alleviated the increase in skin severity score and plasma IgE concentration in a time-dependent manner, and lowered leucotriene B(4) (LTB(4))-releasing ability upon calcium ionophore A23187 stimulation. The SDBR diet did not affect scratching time. These results demonstrate that SDBR diet alleviates atopic dermatitis-like skin lesions in NC/Nga mice.

Journal Article Microbial Degradation of BHA in Niboshi (Boiled and Dried Anchovy) by Aspergillus Species Get access Mikiharu Doi, Mikiharu Doi Marutomo Co., Ltd., 1696 Kominato, Iyo, Ehime 799–31, Japan Search for other works by this author on: Oxford Academic Google Scholar Hajime Yamauchi, Hajime Yamauchi Marutomo Co., Ltd., 1696 Kominato, Iyo, Ehime 799–31, Japan Search for other works by this author on: Oxford Academic Google Scholar Muneaki Matsui, Muneaki Matsui Marutomo Co., Ltd., 1696 Kominato, Iyo, Ehime 799–31, Japan Search for other works by this author on: Oxford Academic Google Scholar Yoshihiro Shuto, Yoshihiro Shuto Department of Agricultural Chemistry, Faculty of Agriculture, Ehime University, Matsuyama 790, Japan Search for other works by this author on: Oxford Academic Google Scholar Yoshiro Kinoshita Yoshiro Kinoshita Department of Agricultural Chemistry, Faculty of Agriculture, Ehime University, Matsuyama 790, Japan Search for other works by this author on: Oxford Academic Google Scholar Agricultural and Biological Chemistry, Volume 55, Issue 4, 1 April 1991, Pages 1095–1098, https://doi.org/10.1080/00021369.1991.10870725 Published: 01 April 1991 Article history Received: 31 October 1990 Published: 01 April 1991

Eleven strains of Aspergillus species, isolated from dried bonito (Katsuobushi), were grown in a liquid medium containing the individual phenolic compounds, in order to determine the fate of phenols during the molding process in Katsuobushi production. Of the 10 phenols studied, guaiacol, creosol and 2,6-dimethoxyphenol were O-methylated by 5 strains of Aspergillus species, and the others were degraded by some strains studied. Similar changes in the phenols were presumed to occur also during the molding process in Katsuobushi production. It was concluded that the pungent smoky flavor became milder mainly through biological degradation or O-methylation of phenols during the molding process.