講演・口頭発表等 - 本多 大輔
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Examination of the condition of CARD-FISH for specific detection of the aplanochytrid cells
Haruka Nakamura, Runa Mori, Yoko Hamamoto, Takanori Shono, Akira Kuwata, and Daiske Honda
First International Conference on Labyrinthulean Protists (Konan University) ICoLP 2019 Secretariat
開催年月日: 2019年8月
The labyrinthuleans have been detected as ubiquitous and abundant heterotrophs in the marine and brackish water. Recent studies suggested that each phylogenetic group has different ecological roles such as decomposers and predators, so that the catalyzed reporter deposition – fluorescence in situ hybridization (CARD-FISH) method is effective to stain each phylogenetic group of labyrinthuleans specifically. In this study, we focused on the phylogenetic group including the genus Aplanochytrium because the aplanochytrids is one of the major groups in the marine environment by the metagenomic studies and it was revealed that the aplanochytrid cells intake the nutrients from the important primary producer diatoms. Initially specific fluorescence of aplanochytrids was not confirmed, but non-specific fluorescence was observed in microalgae and zooplankton. After the examination of the condition of the hybridization temperature and endogenous peroxidase inactivation, specific fluorescence of the aplanochytrids was successively confirmed. The observation of the environmental samples with this method will be provide the important information for understanding the role and impact of the aplanochytrids in the marine ecosystem.
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Haruka Umazume, Yohei Ishibashi, Makoto Ito, Yasuhiko Hayakawa, and Daiske Honda
First International Conference on Labyrinthulean Protists (Konan University) ICoLP 2019 Secretariat
開催年月日: 2019年8月
The strains of genus Aurantiochytrium have been used in applied molecular biology and industrial production of PUFAs, carotenoids and so on because of their high growth ability and high gene transfer efficiency by electroporation or Agrobacterium-mediated plant transformation. While, Parietichytrium is also important for high PUFA productivity by the different synthetic pathway of the fatty acids, but the gene transfer has been not successful except particle bombardment method with relatively low efficiency. In this study, we examined the condition in the gene transfer into Parietichytrium cells by electroporation. First, we attempted gene transfer with multiple pulses that square electric poring pulses for forming pores in cell membrane were applied, followed by multiple transferring pulses, for delivering the target molecules into cells. In general, it is known that transformation efficiency tends to increase under pulse condition that survival rate decrease rapidly. Then as the result of examination of the survival rates under the wide voltage condition (300–2,400 V), the survival rates in Parietichytrium cells decrease rapidly at relatively low voltage conditions. However, no transformants have obtained in this condition yet. It has continued the examination of conditions in low-voltage conditions such as using the pulses with voltage decay.
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Characterization of novel eicosapentaenoic acid producing thraustochytrid
Yui Takeuchi, Ayako Matsuda, Daiske Honda, Takayoshi Sekiguchi, Li Han, and Masahiro Hayashi
First International Conference on Labyrinthulean Protists (Konan University) ICoLP 2019 Secretariat
開催年月日: 2019年8月
Thraustochytrids are known as marine heterotrophic unicellular protists that remarkably accumulate lipids in the cells. Their lipids are rich in polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA). On the other and, although their lipids contain DHA and n-6 docosapentaenoic acid as PUFA, only trace amount of eicosapentaenoic acid (EPA) is contained. Actually EPA is purified from sardine oil and has been utilize as a medicine for arteriosclerosis and hyperlipidemia. In the present study, a novel thraustochytrid producing EPA was isolated and its characterization was investigated. The novel thraustochytrids were isolated by a pine pollen bating method. After isolation of novel thraustochytrids, their fatty acid compositions and contents were determined by GC analysis of their total lipids. The phylogenic analyses based on the 18S rRNA gene sequences were also carried out for an identification of the isolates.
As a result of screening, only the strain SEK704 contained significant amount of EPA. This thraustochytrid can grow only on the medium containing glycerol as a carbon source. The growth and productivity of the strain was greatly affected by the condition of the culture such as agitation or aeration. The finding of the EPA producing thraustochytrid and its characterization would be quite profitable for microbial production of EPA. -
Examination of quantitative PCR to quantify the abundance of oblongichytrids in marine environment
Tomi Morimoto, Yoko Hamamoto, Mayumi Ueda and Daiske Honda
First International Conference on Labyrinthulean Protists (Konan University) ICoLP 2019 Secretariat
開催年月日: 2019年8月
The labyrinthuleans have been recognized as ubiquitous and abundant heterotrophs in the marine and brackish water. Recent studies suggested that each phylogenetic group has different ecological roles such as decomposers and predators, so that the quantitative PCR (qPCR) method is suitable for quantifying the abundance of each phylogenetic group of labyrinthuleans. In this study, we focused on the phylogenetic group including the genus Oblongichytrium because the oblongichytrids and aplanochytrids are shown as the major groups of labyrinthuleans in the marine environment by the metagenomic studies (e.g., TARA ocean project) and monitoring study by the culturing method. For establishment of the method for quantifying the abundance of oblongichytrids by qPCR, we continue to work on the design for the specific primers of oblongichytrids, preparation for the standard samples of calibration curve, and estimation of the copy number of 18S rDNA gene sequence per a cell. By combining this study with the already established qPCR method for measuring aplanochytrids, it should be possible to understand the ecological impact of the labyrinthuleans.
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Search for nutrients required for growth of the strains of “difficult-to-culture” aplanochytrids
Toshiki Miyaoka, Ryosuke Nakai, and Daiske Honda
First International Conference on Labyrinthulean Protists (Konan University) ICoLP 2019 Secretariat
開催年月日: 2019年8月
Many of the thraustochytrids, especially Aurantiochytrium strains, grow well in standard media for heterotrophs including glucose and yeast extract. However, the most strains of genus Aplanochytrium are hard to grow in these media. Recently, it was reported that Aplanochytrium cells grew well by obtaining nutrients from living diatoms in two-membered culture examination. This result suggests that Aplanochytrium cells potentially have the ability of well-growth but they cannot grow in the standard media because the unknown materials obtaining from living diatoms is the limiting factor. In this study, we searched for essential nutrients required for growth of the strains of Aplanochytrium. First, the proliferation test was examined using PM plates (BIOLOG, Hayward, USA) containing nutrients such as sugars, amino acids, nucleoside, and vitamins in 96-well plates. The Aplanochytrium cells appeared to be proliferating, for example, in the wells of PM plates containing nicotinic acid and quinolinic acid, but re-examination on a larger culture scale did not show particularly greater growth. While, it was investigated whether there was anything in the food that could enhance the growth of the cells. The highest cell growth was observed in the culture with the medium including the glucose, yeast extract, minerals and a liquid prepared by soaking the dried shrimps in Milli-Q water. It has been reported that the aplanochytrids detected in the guts of the copepods and the other zooplankton. Enhancing the cell growth by adding crustacean extracts may be related to the association of aplanochytrids with crustaceans found in marine environments.
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ラビリンチュラ類Aplanochytrium が栄養源とする藻類の検討と物質転送
茂木 大地,浜本 洋子,今井 博之,本多 大輔
日本藻類学会第43回大会
開催年月日: 2019年3月
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ラビリンチュラ類の生態学的役割とその影響
浜本 洋子,庄野 孝範,中井 亮佑,上田 真由美,長井 敏,本多 大輔
日本藻類学会第43回大会
開催年月日: 2019年3月
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ラビリンチュラ類Aplanochytrium属株の外質ネットを用いた珪藻からの栄養摂取
髙橋 遼,本多 大輔
日本藻類学会第43回大会
開催年月日: 2019年3月
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Aplanochytriumが栄養摂取の対象とする藻類の検討
茂木大地, 浜本洋子,本多大輔
第5回 ラビリンチュラ シンポジウム
開催年月日: 2018年9月
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Aplanochytrium属群の現存量から推定された海洋生態系における影響力
浜本 洋子, 庄野 孝範, 中井 亮佑, 上田 真由美, 本多 大輔
第5回 ラビリンチュラ シンポジウム
開催年月日: 2018年9月
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ラビリンチュラ類の属間におけるセルラーゼ活性の比較
田中 美穂,本多大輔
第5回 ラビリンチュラ シンポジウム
開催年月日: 2018年9月
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原生生物ラビリンチュラ類の現存量から推定された海洋生態系における影響力
浜本 洋子,庄野 孝範,中井 亮佑,上田 真由美,本多 大輔
日本微生物生態学会第32回大会
開催年月日: 2018年7月
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真核微生物ラビリンチュラ類が海洋生態系で果たす役割 — 魚のDHAは何に由来するのか —
本多大輔
第13回オートアナライザーシンポジウム (大手町サンケイプラザ) オートアナライザーシンポジウム開催事務局
開催年月日: 2018年6月
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ラビリンチュラ類の現存量の把握に向けたアプローチ
浜本 洋子,庄野 孝範,中井 亮佑,上田 真由美,本多 大輔
日本藻類学会第42 回大会 (東北大学青葉山新キャンパス) 日本藻類学会
開催年月日: 2018年3月
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Parietichytrium 属(ラビリンチュラ類)の核相変化の解明に向けた検討
佐藤 正和,石橋 真由,武田 鋼二郎,本多 大輔
日本藻類学会第42 回大会 (東北大学青葉山新キャンパス) 日本藻類学会
開催年月日: 2018年3月
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多様なラビリンチュラ類へのアグロバクテリウムを用いた形質転換の試み
秋山 達哉,小田切 正人,守屋 繁春,伊東 信,本多 大輔
日本藻類学会第42 回大会 (東北大学青葉山新キャンパス) 日本藻類学会
開催年月日: 2018年3月
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水産餌料へのラビリンチュラ類の活用
本多大輔
新たな生物資源の活用を考える 海洋生物「ラビリンチュラ」講演会 (清掃⼯場大会議室) さが藻類バイオマス協議会事務局
開催年月日: 2017年12月
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Ultrafine structure and molecular phylogeny of living radiolarians—with a view to clarifying the fossil phylogeny—
Yasuhide NAKAMURA, Izumi IWATA, Rei SOMIYA, Daiske HONDA, Akihiro TUJI, Noritoshi SUZUKI, Rie S. HORI, Hiroaki OHFUJI
15th Meeting of the International Association of Radiolarists (Niigata University, Japan) The Organizing Committee for InterRad XV in Niigata 2017
開催年月日: 2017年10月
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ラビリンチュラ類の外質ネットによる栄養摂取
本多大輔,浜本洋子,岩田いづみ
第55 回日本生物物理学会年会 (熊本大学 黒髪北地区) 日本生物物理学会
開催年月日: 2017年9月
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Genetic transformation of thraustochytrid strains (Labyrinthulea) by Agrobacterium tumefaciens
Tatsuya Akiyama, Masato Otagiri, Shigeharu Moriya, Makoto Ito, Daiske Honda
15th International Congress of Protistology (Prague, Czech Republic) International Society of Protistologists
開催年月日: 2017年7月 - 2017年8月