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Hamano R, Shoumura S, Takeda Y, Yamazaki T, Hirayama K, Hanada Y, Mayama S, Takemura M, Lin HJ, Umemura K. Sinking of Four Species of Living Diatom Cells Directly Observed by a "Tumbled" Optical Microscope. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-7. [PMID: 34294188 DOI: 10.1017/s1431927621012150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The study of the sinking phenomenon of diatom cells, which have a slightly larger specific gravity (~1.3) compared to that of water, is an important research topic for understanding photosynthetic efficiency. In this study, we successfully demonstrated the observation of the sinking behaviors of four different species of diatom using a homemade “tumbled” optical microscope. A homemade 1 mm3 microchamber was employed to decrease the effects of convection currents. In the microchamber, diatom cells were basically settled in a linear manner without floating, although some of the cells were rotated during their sinking. Sinking speeds of the four species of diatom cells, Nitzschia sp., Pheodactylum tricornutum, Navicula sp., and Odontella aurita, were 0.81 ± 5.56, 3.03 ± 10.17, 3.29 ± 7.39, and 11.22 ± 21.42 μm/s, respectively, based on the automatic tracking analysis of the centroids of each cell. Manual analysis of a vector between two longitudinal ends of the cells (two-point analysis) was effective for quantitatively characterizing the rotation phenomenon; therefore, angles and angular velocities of rotating cells were well determined as a function of time. The effects of the cell shapes on sinking velocity could be explained by simulation analysis using the modified Stokes’ law proposed by Miklasz et al.
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Affiliation(s)
- Ryo Hamano
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Shingo Shoumura
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Yuto Takeda
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Tokio Yamazaki
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Kota Hirayama
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Yasutaka Hanada
- Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori036-8561, Japan
| | - Shigeki Mayama
- Advanced Support Center for Science Teachers, Tokyo Gakugei University, 4-1-1 Nukui-kita-machi, Koganei, Tokyo184-8511, Japan
| | - Masaharu Takemura
- Laboratory of Biology, Institute of Arts and Sciences, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Han-Jia Lin
- Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung20224, Taiwan
| | - Kazuo Umemura
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
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Shoumura S, Hamano R, Hanada Y, Mayama S, Umemura K. Single cell analysis of sinking diatoms studied using a homemade ‘tumbled’ optical microscope system. J Microbiol Methods 2020; 168:105804. [DOI: 10.1016/j.mimet.2019.105804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 02/07/2023]
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Taira H, Kondo S, Kumashiro Y, Mayama S, Umemura K. Differences in dynamic behavior of single diatom cells caused by changing wavelengths. Micron 2018; 108:1-5. [PMID: 29499396 DOI: 10.1016/j.micron.2018.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/15/2018] [Accepted: 02/18/2018] [Indexed: 10/18/2022]
Abstract
We investigate a motion of diatom cells stimulated by a halogen lamp irradiation. Diatom cells are single-celled organisms which have chloroplast. Chloroplast contains photosynthetic pigment which absorbs blue light (wave length of the light is 400 nm-450 nm) and red one (650 nm-700 nm). Light intensity of the halogen lamp is fixed about 500 Lx during the experiment. We used colored films to cut the blue or red light and observed motion of diatom cells by using the optical microscope. We found that the speed of diatom cells decreases when the colored film is inserted, and it increases after ejecting the film. It is noted that the light intensity is constant during the experiment, which means that we change wave length of the irradiated light. Our results show that the average speed of diatom cells is influenced by not the light intensity but the wave length of the light.
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Affiliation(s)
- Hisao Taira
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan; Faculty of Education, Hokkaido University of Education, Sapporo, Hokkaido, 002-8502, Japan.
| | - Shunsuke Kondo
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan
| | - Yoshikazu Kumashiro
- Institute of Advanced Biomedical Engineering and Science (TWINs), Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Shigeki Mayama
- Faculty of Education, Tokyo Gakugei University, 4-1-1 Nukui-kita-machi, Koganei, Tokyo, 184-8511, Japan
| | - Kazuo Umemura
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan
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Umemura K, Miyabayashi T, Taira H, Suzuki A, Kumashiro Y, Okano T, Mayama S. Use of a microchamber for analysis of thermal variation of the gliding phenomenon of single Navicula pavillardii cells. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:113-9. [DOI: 10.1007/s00249-015-1006-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/22/2014] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
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