- 著者
- Ryo Matsuzaki Yusuke Takashima Iwane Suzuki Masanobu Kawachi Hisayoshi Nozaki Seiichi Nohara Yousuke Degawa
- 出版者
- Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
- 雑誌
- Microbes and Environments (ISSN:13426311)
- 巻号頁・発行日
- vol.36, no.2, pp.ME21011, 2021 (Released:2021-06-16)
- 参考文献数
- 31
- 被引用文献数
- 1
Chionaster nivalis is frequently detected in thawing snowpacks and glaciers. However, the taxonomic position of this species above the genus level remains unclear. We herein conducted molecular analyses of C. nivalis using the ribosomal RNA operon sequences obtained from more than 200 cells of this species isolated from a field-collected material. Our molecular phylogenetic analyses revealed that C. nivalis is a sister to Bartheletia paradoxa, which is an orphan basal lineage of Agaricomycotina. We also showed that C. nivalis sequences were contained in several previously examined meta-amplicon sequence datasets from snowpacks and glaciers in the Northern Hemisphere and Antarctica.
- 著者
- Shuhei Ota Shigeshi Fuchida Haruyo Yamaguchi Takahiro Yamagishi Hiroshi Yamamoto Hiroshi Koshikawa Masanobu Kawachi
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.87, no.2, pp.177-187, 2022-06-25 (Released:2022-06-25)
- 参考文献数
- 41
- 被引用文献数
- 2
Seafloor resource development in the future is expected to be accompanied by the mining of metal ores, as these sulfide ores contain valuable metals. However, the mining process is detrimental to marine oceanic environments. As a precautionary approach, innovations in the collection of environmental baseline data and new onboard assessment methods for marine environmental impacts are required. Due to the low cell density in open ocean water, techniques for rapid impact assessment of seawater without sample concentration are required. The purpose of this study was to establish a heavy metal impact assessment system for seawater samples of marine microbes using a portable flow cytometer, On-chip Sort. We established a protocol for detecting heavy metal-induced damage to cells via propidium iodide (PI) staining using algal culture strains (Bathycoccus prasinos NIES-2670, Synechococcus sp. NIES-969, Prochlorococcus sp. NIES-2885, and Cyanobium sp. NIES-981) obtained from the marine environment maintained at the Microbial Culture Collection of the National Institute for Environmental Studies, Tsukuba, Japan. Results showed that PI staining could detect the effects of heavy metals on cells. The proportion of PI-positive cells increased with an increase in the concentration of heavy metal mixture or copper exposure. Compared to cyanobacteria, damaged cells of eukaryotic algae were detected. Therefore, the effects of heavy metals on both eukaryotic and prokaryotic algae can be rapidly assessed via PI-based flow cytometry using samples containing low cell densities.
- 著者
- Maki Yamamoto Shinji Handa Masanobu Kawachi Shinichi Miyamura Tamotsu Nagumo Aiko Hirata Shigeyuki Kawano
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.81, no.1, pp.35-39, 2016-03-25 (Released:2016-04-11)
- 参考文献数
- 9
- 被引用文献数
- 4 6
Stichococcus Nägeli is a unicellular green algal species that belongs to the Trebouxiophyceae. Stichococcus bacillaris Nägeli NIES-3639 propagates by binary fission, but can form a filament without separating into two daughter cells. Transmission electron microscopy showed that cytokinesis starts according to invagination of the plasma membrane at the plane of division. Synthesis of the daughter cell wall occurs on the surface of invaginating plasma membrane during the protoplast division phase. The mother cell wall may cleave after protoplast division in either the single-cell or filament state. Field emission scanning electron microscopy revealed scars of cleaved mother cell walls from the single-cell state, two-cell state after cell division, and four-cell state during filament formation. Because the mother cell wall was cleaved, the delay of the daughter cell separation may have caused filament formation. Since this cell division cycle repeats rapidly, it may begin before the separation of the daughter cells yielded by the former cell cycle.