The growth rate of Micrococcus radiodurans R1 depends on the composition of its media. It grows faster in a rich medium than in a poor medium. However, there was no difference in heat sensitivity among the cells grown in media whose compositions were different. Recently, HANSEN reported that the number of genome equivalents of DNA per call of this bacterium changed from approiximately 4 to 10 depending on the growth rates in different media and that recombination repair between intact homologous segments of multiple genomes played an imporant role in its extremely high radioresistance. However, our data indicate that the growth rate of this organism does not influence the heat sensitivity. Therefore, it is concluded here that recombination repair for DNA damage by heat is scarcely influenced by multiple genomes in a cell of M. radiodurans.
- Nippon Suisan Gakkaishi is an official journal of the Japanese Society of Fisheries Science written in Japanese only.
The society publishes an English journal, Fisheries Science, as well, which accepts submissions from non-members of the society over the world. Detailed information is available in http://jsfs.jp/en/journals/fisheries-science.