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Featured researches published by Yasuko Jojima.


International Journal of Systematic and Evolutionary Microbiology | 2002

Corynebacterium efficiens sp. nov., a glutamic-acid-producing species from soil and vegetables.

Ryosuke Fudou; Yasuko Jojima; Akira Seto; Kazuhiko Yamada; Eiichiro Kimura; Tsuyoshi Nakamatsu; Akira Hiraishi; Shigeru Yamanaka

Three glutamic-acid-producing coryneform strains were isolated from soil and vegetable samples. Chemotaxonomic investigations indicated that these strains belonged to the genus Corynebacterium. Phylogenetic studies, based on 16S rDNA analysis, demonstrated that the three strains formed a distinct cluster within the genus Corynebacterium and that their nearest relatives were Corynebacterium glutamicum and Corynebacterium callunae, also known as glutamic-acid-producing species. The data from 16S rDNA sequence and DNA-DNA relatedness studies clearly indicated that the three isolates represented a new species within the genus Corynebacterium. All of the isolates could grow at 45 degrees C and produced acid from dextrin; these were the most significant characteristics differentiating the three isolates from their neighbours. On the basis of the data presented here, it is proposed that the three glutamic-acid-producing isolates together be classified as Corynebacterium efficiens sp. nov., the type strain of which is YS-314T (= AJ 12310T = JCM 11189T = DSM 44549T).


Systematic and Applied Microbiology | 2003

Enhygromyxa salina gen. nov., sp. nov., a Slightly Halophilic Myxobacterium Isolated from the Coastal Areas of Japan

Takashi Iizuka; Yasuko Jojima; Ryosuke Fudou; Mitsunori Tokura; Akira Hiraishi; Shigeru Yamanaka

Six isolates of novel marine myxobacteria, designated strains SHK-1T, SMK-1-1, SMK-1-3, SMK-10, SKK-2, and SMP-6, were obtained from various coastal samples (mud, sands and algae) collected around Japan. All of the isolates had Gram-negative rod-shaped cells, motile by gliding and grew aerobically. They showed bacteriolytic action, fruiting body formation, and NaCl requirement for growth with an optimum concentration of 1.0-2.0% (w/v). In addition, divalent cationic components of seawater, such as Mg2+ or Ca2+, were also needed for growth. The major respiratory quinone was MK-7. The G+C content of genomic DNA ranged from 65.6 to 67.4 mol% (by HPLC). The isolates shared almost identical 16S rDNA sequences, and clustered with a recently described marine myxobacterium, Plesiocystis pacifica, as their closest relative on a phylogenetic tree (95.9-96.0% similarity). Physiological and chemotaxonomic differences between the new strains and strains of the genus Plesiocystis justify the proposal of a new genus. Therefore, we propose to classify the six isolates into a new taxon of marine myxobacteria with the name, Enhygromyxa salina gen. nov., sp. nov. The type strain is SHK-1(T) (JCM 11769(T) = DSM 15217(T) = AJ 110011(T)).


The Journal of Antibiotics | 2006

Miuraenamides A and B, Novel Antimicrobial Cyclic Depsipeptides from a New Slightly Halophilic Myxobacterium : Taxonomy, Production, and Biological Properties

Takashi Iizuka; Ryosuke Fudou; Yasuko Jojima; Sumie Ogawa; Shigeru Yamanaka; Yasutaka Inukai; Makoto Ojika

A slightly halophilic myxobacterial strain, SMH-27-4, was isolated from nearshore soil and shown to belong to a new myxobacterium genus based on phylogenetic analysis. This slowly-growing myxobacterium produced the novel antibiotic depsipeptides miuraenamides A and B. Their physico-chemical properties and molecular formulas, C34H42N3O7Br and C34H42N3O7I, were determined. Miuraenamides A exhibited potent and selective inhibition against a phytopathogenic microorganism, Phytophthora sp., and moderate inhibition against some fungi and yeasts, but was ineffective against bacteria. Both of the metabolites inhibited NADH oxidase at IC50 values of 50 μM, suggesting, like β-methoxyacrylate-type antibiotics, the electron transfer system of the mitochondrial respiratory chain as the cellular target.


Bioscience, Biotechnology, and Biochemistry | 2004

Rare Bacterium of New Genus Isolated with Prolonged Enrichment Culture

Akiko Hashizume; Ryosuke Fudou; Yasuko Jojima; Ryohsuke Nakai; Akira Hiraishi; Akira Tabuchi; Kikuo Sen; Hiroshiro Shibai

Dynamic change in microbial flora was monitored with an oxygen electrode. The 1st phase microorganisms, which first grew well in LB medium, were followed by the 2nd phase microorganisms, which supposedly assimilated microbial cells of the 1st phase and their metabolites. In a similar way, a change in microbial flora was observed from the 1st phase to the 4th phase in 84 hr. Based on this observation, prolonged enrichment culture was done for as long as two months to increase the ratio of existence of rare microorganisms. From these culture liquids, four slow-growing bacteria (provisionally named Shinshu-ah1, -ah2, -ah3, and -ah4), which formed scarcely visible small colonies, were isolated. Sequence analysis of their 16S rDNA showed that Shinshu-ah1 had 97% homology with Bradyrhizobium japonicum and uncultured alpha proteobacterium clone blaii 16, Shinshu-ah2 91% with Rasbo bacterium, Alpha proteobacterium 34619, Bradyrhizobium genosp. P, Afipia felis and an unidentified bacterium, Shinshu-ah3 99% with Methylobacterium mesophilicum, and Shinshu-ah4 95% with Agromyces ramosus DSM 43045. Phylogenetic study indicated that Shinshu-ah2 had a possibility to form a new family, Shinshu-ah1 a new genus, and Shinshu-ah4 a new species.


Journal of Bioscience and Bioengineering | 2005

Isolation of novel bacteria and actinomycetes using soil-extract agar medium

Takefumi Hamaki; Motomasa Suzuki; Ryosuke Fudou; Yasuko Jojima; Takayuki Kajiura; Akira Tabuchi; Kikuo Sen; Hiroshiro Shibai


International Journal of Systematic and Evolutionary Microbiology | 2004

Saccharibacter floricola gen. nov., sp. nov., a novel osmophilic acetic acid bacterium isolated from pollen

Yasuko Jojima; Yasuhiro Mihara; Sonoko Suzuki; Kenzo Yokozeki; Shigeru Yamanaka; Ryosuke Fudou


Fems Microbiology Letters | 1998

Isolation of myxobacteria from the marine environment

Takashi Iizuka; Yasuko Jojima; Ryosuke Fudou; Shigeru Yamanaka


Journal of General and Applied Microbiology | 2002

Haliangium ochraceum gen. nov., sp. nov. and Haliangium tepidum sp. nov.: novel moderately halophilic myxobacteria isolated from coastal saline environments.

Ryosuke Fudou; Yasuko Jojima; Takashi Iizuka; Shigeru Yamanaka


International Journal of Systematic and Evolutionary Microbiology | 2003

Plesiocystis pacifica gen. nov., sp. nov., a marine myxobacterium that contains dihydrogenated menaquinone, isolated from the Pacific coasts of Japan.

Takashi Iizuka; Yasuko Jojima; Ryosuke Fudou; Akira Hiraishi; Jong-Woong Ahn; Shigeru Yamanaka


International Journal of Systematic and Evolutionary Microbiology | 2013

Pseudenhygromyxa salsuginis gen. nov., sp. nov., a myxobacterium isolated from an estuarine marsh

Takashi Iizuka; Yasuko Jojima; Atsushi Hayakawa; Takayoshi Fujii; Shigeru Yamanaka; Ryosuke Fudou

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Akira Hiraishi

Toyohashi University of Technology

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