||Ishida R, Nishizawa M, Fukami K, Ko Maekawa, Takahashi T, Nishimoto T, Isolation and characterization of nobobiosin-resistant BHK cells., Sometic Cell and Molecular Genetics., 10.1007/BF02422295, 13, 1, 11-20, 1987.01, We isolated two novobiocin-resistant mutants which were stable and approximately three and four times more resistant than the parent cells to novobiocin. Both mutants (Novr A2, Novr A41) were more sensitive than the wild-type cells to nalidixic acid, and cold sensitive for cell growth. When we isolated derivatives of Novr A2 and Novr A41 cells which are resistant to nalidixic acid, those are found to be phenotypically reverted to novobiocin sensitivity like wild-type cells, thereby suggesting the relationship between the targets for novobiocin and for nalidixic acid. But the cold sensitivity did not always revert to wild type, with accompanying resistance to nalidixic acid. The DNA and RNA syntheses of Novr mutants were more resistant to novobiocin but more sensitive to nalidixic acid, than those of wild-type cells. However, in vitro assays of wild-type and Novr cell extracts were unable to demonstrate any differences in the sensitivity of topoisomerase II activity to inhibition by novobiocin. While the targets of novobiocin and nalidixic acid show a mutual interaction in vivo and play a role in DNA replication and transcription, our results suggest that these targets are probably not topoisomerase II..
||Fukami K, Ishiyama S, Yaguramaki H, Masuzawa T, Nabeta Y, Endo K, Shimoda M, Identification of distinctive volatile compounds in fish sause., J. Agric. Food Chem., 10.1021/jf020405y, 50, 19, 5412-5416, 2002.09, To make clear the distinctive odorants of fish sauce, addition tests were carried out with respect to deodorized fish sauce samples. Volatiles from the headspace gas of nontreated fish sauce and deodorized fish sauce were characterized by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Four compounds contributing to the distinctive odor of fish sauce were 2-methylpropanal, 2-methylbutanal, 2-ethylpyridine, and dimethyl trisulfide. Addition tests (quantitative descriptive analysis) with respect to the four odorants showed that contributors to the fishy aroma were 2-ethylpyridine and dimethyl trisulfide and that all four odorants contributed to the sweaty aroma. Furthermore, the fecal note of fish sauce was essential with 2-ethylpyridine and dimethyl trisulfide, and the rancid note was essential with all four odorants..
||Fukami K, Funatsu Y, Kawasaki K, Watabe S, Improvement of fish sause odor by treatment with bacteria isolated from the fish sause mush (moromi) made from frigate mackerel., Journal of food science, vol.69, 2004.12, A bacteriom, which was isolated from fish-sauce mash (moromi) of frigate mackerel and identified as Staphylococcus xylosus, could change notes of an odor in fish sauce made in Thailand. Volatile compounds of the fish sauce after incubation at 32 °C for 24 d with the cultured bacterium were analyzed by gas chromatography. Although the contents of 2-ethylpyridine and dimethyl trisulfide were reduced during the incubation. 4 volatile compounds, including 2-methylpronal, 2-methylbutanal, 2-pentanone, and 3-(methylthiolpropanal, showed no significant quantity changes. On the other hand, although 3-methyl-1-butanol and 2,6-dimethylpyrazine were markedly increased, 3-methylbutanoic acid was slightly increased. As a result of sensory evaluation, fishy, sweaty, fecal, and rancid notes of the fish sauce treated with the bacterium were all weaker than those of the nontreated fish sauce. No changes were found with respect to burnt, cheesy, meaty, and ammoniacal notes between fish sance treated with the bacterium and that without treatment. Taken together, the odor of fish sauce was much improved by treatment with the isolated bacterium..
||Fukami K, Satimi M, Funatsu Y, Kawasaki K, Watabe S, Characterization and distribution of Staphylococcus sp. Implicated for improvement of fish sause odor., Fisheries Science, 10.1111/j.1444-2906.2004.00887.x, 70, 5, 916-923, 2004.10, The two Staphylococcus strains that had been isolated from fish sauce mush (moromi) made from frigate mackerel in Japan and proved to improve fish sauce odor, were examined for their taxonomic positions. The sequence analysis based on 16S rRNA and rpoB showed that the two strains, R4Nu and R5G, had an identical sequence with sequence identities of 99.5% and 99.0% to the above two genes from the closest species of S. nepalensis, respectively. A DNA hybridization test of the two strains showed more than 80% DNA similarity with S. nepalensis, thus confirming the above-mentioned species identification. Polymerase chain reaction primers specific to the strain isolated from fish sauce mush were designed from rpoB and examined for the distribution of this species to various fish sauces made in Asian countries as well as to fish sauce starter (malt) made from soy beans and barley in Toyama Prefecture, Japan. The amplified DNA fragment bearing the S. nepalensis gene was detected in the enriched culture of the malt, although no positive reaction was shown with fish sauce samples. These results suggest that S. nepalensis indebted to improve fish sauce odor was originated from the fish sauce starter malt..
||Yamaguchi H, Nakaya M, Kaneko G, Yoneda C, Mochizuki T, Fukami K, Ushio H, Watabe S, Comparison in taste and extractive components of boiled dorsal muscle and broth from half-smooth golden puffer Lagocephalus spadiceus caught in Japan with those of the same fish imported, Fisheries Science, 10.1007/s12562-012-0585-2, Volume 79, Issue 2 , pp 327-334 , 2013.03.
||Tran Hai Bang, Hiroto Suhara, Katsumi Doi, Hiroya Ishikawa, Katsuya Fukami, Gopal Prasad Parajuli, Yoshinori Katakura, Shuntaro Yamashita, Kazuo Watanabe, Mahesh Kumar Adhikari, Hira Kaji Manandhar, Ryuichiro Kondo, Kuniyoshi Shimizu, Wild Mushroom in Nepal: Some potential Candidates as Antioxidant and ACE Inhibition Sources, Evidence-Based Complementary and Alternative Medicine, 2014.01, Twenty-nine mushrooms collected in the mountainous areas of Nepal were analyzed for antioxidant activity by different methods, including Folin-Ciocalteu, ORAC, ABTS, and DPPH assays. Intracellular H2O2-scavenging activity was also performed on HaCaT cells. The results showed that phenolic compounds are the main antioxidant of the mushrooms. Among studied samples, Inonotus andersonii, and Phellinus gilvus exhibited very high antioxidant activity with the phenolic contents up to 310.8 and 258.7 mg GAE/g extracts, respectively. The H2O2-scavenging assay on cells also revealed the potential of these mushrooms in the prevention of oxidative stress. In term of ACE-inhibition, results showed that Phlebia tremellosa would be a novel and promising candidate for antihypertensive studies. This mushroom exhibited even higher in vitro ACE-inhibition activity than Ganoderma lingzhi, with the IC50 values of the two mushrooms being 32 μg/mL and 2 μg/mL, respectively. This is the first time biological activities of mushrooms collected in Nepal were reported. Information from this study should be a valuable reference for future studies on antioxidant and ACE-inhibitory activities of mushrooms..
||Fukami K, Sumikawa A, Suetsugu Y, Hanada Y, Materials and MTAs Management Tool for Universities, UIIN Good Practice Series, 144-153, 2014.08.
||Chisato Inoue, Tomomi Kozaki, Yukiko Morita, Bungo Shirouchi, Katsuya Fukami, Kuniyoshi Shimizu, Masao Sato, Yoshinori Katakura, Kibizu concentrated liquid suppresses the accumulation of lipid droplets in 3T3-L1 cells, Cytotechnology, Vol 67, p 721-725, 2015.08, Adipocyte size is closely related to the occurrence of diabetes, metabolic syndrome, and insulin resistance. Thus, researchers are searching for active substances that function to reduce adipocyte size. In the present study, we focused on sugar cane vinegar, Kibizu, and evaluated the function of Kibizu to reduce adipocyte size by using an in vitro model system, because people in Amami Oshima famous for longevity regularly consume Kibizu. Results showed that Kibizu treatment significantly reduced the size and number of lipid droplets in 3T3-L1 cells, relative to treatment with Kurozu, another traditional vinegar. Results of an extraction experiment suggest that the active components in Kibizu are lipophilic and hydrophobic. In addition, an in vivo experiment on rats treated with Kibizu showed that the active components were contained in large vein blood. Results of an additional in vivo experiment suggest that metabolites generated by Kibizu-treated rats are primarily contained or modified specifically in the large vein blood. .