Open AccessCell cycle changes in the buoyant density of exponential-phase cells of Streptococcus faecium
Author(s) -
David T. Dicker,
M. L. Higgins
Publication year - 1987
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.169.3.1200-1204.1987
Subject(s) - percoll , biology , centrifugation , exponential growth , bacteria , streptococcaceae , doubling time , differential centrifugation , cell , streptococcus , cell cycle , buoyant density , microbiology and biotechnology , biochemistry , biophysics , genetics , dna , mathematical analysis , mathematics
Cell buoyant densities were determined by centrifugation in Percoll gradients containing exponential-phase cells of Streptococcus faecium ATCC 9790 grown at a mass doubling time of about 33 min. This bacterium showed the highest average density values (1.13 g/ml) measured to date for any eucaryotic or procaryotic organism. Fractions having the highest densities were enriched with cells that were in the process of dividing or had just divided. These high-density fractions were also enriched with cells that had newly initiated sites of cell wall growth. It appears that S. faecium shows minimum cell densities in the midportion of its cycle.