Macrorestriction analysis of Desulfurella acetivorans and Desulfurella multipotens

The genomes of the phylogenetically and physiologically unique bacteria Desulfurella acetivorans DSM 5264T and D. multipotens DSM 8415T were characterized and compared by pulsed field gel electrophoresis (PFGE). Macrorestriction patterns made of large PFGE separated DNA fragments were generated by digesting the genomic DNAs of both strains with the rare cutting restriction endonucleases ApaI, AscI, EagI, RsrII, SacII, SalI as well as with the intron encoded endonuclease I-CeuI. The sum of calculated fragment sizes from digests of the first six enzymes yielded estimates for the chromosome sizes of D. acetivorans with a mean of 1939.0 +/- 26.0 kb and for D. multipotens with a mean of 1864.0 +/- 23.0 kb. Within the patterns obtained from EagI and RsrII cleavages the apparent differences could be attributed to DNA insertion or deletion and to point mutation. The single, circular chromosomes of the two strains contain two copies of 23S rRNA genes each. Different extrachromosomal elements were detected in both strains.