| Title: | Protozoal ciliate promotes bacterial autoinducer-2 accumulation in mixed culture with Escherichia coli |
| Authors: | Oguri, Satoshi Browse this author |
| Hanawa, Tomoko Browse this author |
| Matsuo, Junji Browse this author →KAKEN DB |
| Ishida, Kasumi Browse this author |
| Yamazaki, Tomohiro Browse this author |
| Nakamura, Shinji Browse this author →KAKEN DB |
| Okubo, Torahiko Browse this author |
| Fukumoto, Tatsuya Browse this author |
| Akizawa, Kouzi Browse this author |
| Shimizu, Chikara Browse this author →KAKEN DB |
| Kamiya, Shigeru Browse this author |
| Yamaguchi, Hiroyuki Browse this author →KAKEN DB |
| Keywords: | autoinducer-2 |
| ciliates |
| Escherichia coli |
| luxS |
| quorum sensing |
| Tetrahymena thermophila |
| vacuole |
| ydgG |
| Issue Date: | 2015 |
| Publisher: | 応用微生物学・分子細胞生物学研究奨励会 |
| Journal Title: | The Journal of General and Applied Microbiology |
| Volume: | 61 |
| Issue: | 5 |
| Start Page: | 203 |
| End Page: | 210 |
| Publisher DOI: | 10.2323/jgam.61.203 |
| PMID: | 26582290 |
| Abstract: | We have previously demonstrated conjugation of Escherichia coli into vacuoles of the protozoal ciliate (Tetrahymena thermophila). This indicated a possible role of ciliates in evoking bacterial quorum sensing, directly connecting bacterial survival via accumulation in the ciliate vacuoles. We therefore assessed if ciliates promoted bacterial autoinducer (AI)-2 accumulation with vacuole formation, which controls quorum sensing. E. coli AI-2 accumulation was significantly enhanced in the supernatants of a mixed culture of ciliates and bacteria, likely depending on ciliate density rather than bacterial concentration. As expected, AI-2 production was significantly correlated with vacuole formation. The experiment with E. coli luxS mutants showed that ciliates failed to enhance bacterial AI-2 accumulation, denying a nonspecific phenomenon. Fluorescence microscopy revealed accumulation of fragmented bacteria in ciliate vacuoles, and, more importantly, expulsion of the vacuoles containing disrupted bacteria into the culture supernatant. There was no increase in the expression of luxS (encoding AI-2) or ydgG (a transporter for controlling bacterial export of AI-2). We conclude that ciliates promote bacterial AI-2 accumulation in a mixed culture, via accumulation of disrupted bacteria in ciliate vacuoles followed by expulsion of the vacuoles, independently of luxS or ydgG gene induction. This is believed to be the first demonstration of a relationship between E. coli AI-2 dynamics and ciliates. In the natural environment, ciliate biotopes may provide a survival advantage to bacteria inhabiting such biotopes, via evoking quorum sensing. |
| Rights: | ©2015 Applied Microbiology, Molecular and Cellular Biosciences Research Foundation |
| Type: | article |
| URI: | http://hdl.handle.net/2115/60277 |
| Appears in Collections: | 保健科学院・保健科学研究院 (Graduate School of Health Sciences / Faculty of Health Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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