著者

Michio Matsuhashi Alla N. Pankrushina Satoshi Takeuchi Hideyuki Ohshima Housaku Miyoi Katsura Endoh Ken Murayama Hiroshi Watanabe Shigeo Endo Mikio Tobi Yoshihiro Mano Masao Hyodo Torakichi Kobayashi Tomohiko Kaneko Sugio Otani Susumu Yoshimura Akira Harata Tsuguo Sawada

出版者

公益財団法人 応用微生物学・分子細胞生物学研究奨励会

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.44, no.1, pp.49-55, 1998 (Released:2005-08-24)

参考文献数

19

被引用文献数

9 55

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Bacterial cells enhance the proliferation of neighboring cells under stress conditions by emitting a physical signal. Continuous single sine sound waves produced by a speaker at frequencies of 6–10, 18–22, and 28–38 kHz promoted colony formation by Bacillus carboniphilus under non-permissive stress conditions of high KCl concentration and high temperature. Furthermore, sound waves emitted from cells of Bacillus subtilis at frequencies between 8 and 43 kHz with broad peaks at approximately 8.5, 19, 29, and 37 kHz were detected using a sensitive microphone system. The similarity between the frequency of the sound produced by B. subtilis and the frequencies that induced a response in B. carboniphilus and the previously observed growth-promoting effect of B. subtilis cells upon B. carboniphilus through iron barriers, suggest that the detected sound waves function as a growth-regulatory signal between cells.

著者

Miki ISODA Makoto FUKUMA Akira HARATA

出版者

The Japan Society for Analytical Chemistry

雑誌

Analytical Sciences (ISSN:09106340)

巻号頁・発行日

vol.35, no.12, pp.1311-1315, 2019-12-10 (Released:2019-12-10)

参考文献数

22

被引用文献数

3

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The first demonstration of a photothermal heterodyne interferometer (PHI) combined with micro-HPLC (high-performance liquid chromatography) is reported. A semiconductor laser (375 nm) was used for excitation, and the temperature change caused by heat released from photoexcited species was detected with a He–Ne laser (632.8 nm). The temperature-dependent refractive index change of the solvent modified the optical path of the probe beam. The phase difference between two arms of the interferometer, one passing through the heated sample and another as a reference, was sensitively detected with the PHI. The nitro-polycyclic aromatic hydrocarbon and vitamin mixture separated via micro-HPLC was successfully detected with the PHI as well as a UV detector. The detection limit of the PHI for riboflavin in the absorbance units was 77 times better than that of the commercial UV detector. The detection limit of the PHI with a small flow cell (6 nL) was the same as that with a large flow cell (18 nL) for 1-nitropyrene.