Identification of Bacillus sp. FTU Strain and the Study of the caa₃-Type Oxidase Homology

V. A. Grinkevich,¹ A. M. Lysenko,² M. S. Muntyan,^3,4 E. V. Skripnikova,³ and E. K. Afrikyan⁵

¹School of Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; E-mail: grin@ecol.msu.ru

²Institute of Microbiology, Russian Academy of Sciences, pr. 60-letiya Oktyabrya 7/1, Moscow, 117811 Russia; fax: (095) 135-65-30.

³Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-31-81; E-mail: mount@cytox.genebee.msu.su

⁴To whom correspondence should be addressed.

⁵Institute of Microbiology, National Academy of Sciences of Armenia, Abovian, 378510 Armenia; E-mail: microbio@pnas.sci.am

Submitted January 5, 1997; revision submitted April 7, 1997.

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The culture, morphology, and genome of alkalo- and halotolerant bacterial strain Bacillus sp. FTU were characterized; the strain is compared to other representatives of genus Bacillus. The DNA-DNA hybridization data indicate that the strains of Bacillus halodurans DSM 497 and DSM 2513 and Bacillus sp. FTU belong to the same species. Bacillus sp. FTU can be renamed to Bacillus halodurans FTU. The N-terminal amino acid fragments of the subunits I and II of the terminal caa₃-type cytochrome c oxidase of B. halodurans FTU were sequenced. The N-terminal fragments of this enzyme and of the caa₃-type oxidase of alkalophilic Bacillus firmus OF4 are highly homologous (homology of subunits I and II is over 90 and over 96%, respectively). Such high homology of the terminal oxidases of these bacteria might be due to their alkaline medium.

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KEY WORDS: Bacillus halodurans, Bacillus alcalophilus, Bacillus firmus, caa₃-type oxidase, N-terminal amino acid sequence, GC-content, halotolerance, alkalotolerance.

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