The LysR-type transcriptional regulator, CidR, regulates stationary phase cell death inStaphylococcus aureus

ABSTRACT The relationship between a loss of viability and several morphological and physiological changes was examined with Escherichia coli strain J1 subjected to high-pressure treatment. The pressure resistance of stationary-phase cells was much higher than that of exponential-phase cells, but in both types of cell, aggregation of cytoplasmic proteins and condensation of the nucleoid occurred after treatment at 200 MPa for 8 min. Although gross changes were detected in these cellular structures, they were not related to cell death, at least for stationary-phase cells. In addition to these events, exponential-phase cells showed changes in their cell envelopes that were not seen for stationary-phase cells, namely physical perturbations of the cell envelope structure, a loss of osmotic responsiveness, and a loss of protein and RNA to the extracellular medium. Based on these observations, we propose that exponential-phase cells are inactivated under high pressure by irreversible damage to the cell membrane. In contrast, stationary-phase cells have a cytoplasmic membrane that is robust enough to withstand pressurization up to very intense treatments. The retention of an intact membrane appears to allow the stationary-phase cell to repair gross changes in other cellular structures and to remain viable at pressures that are lethal to exponential-phase cells.

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D-Amino Acids Govern Stationary Phase Cell Wall Remodeling in Bacteria

Science ◽

10.1126/science.1178123 ◽

2009 ◽

Vol 325 (5947) ◽

pp. 1552-1555 ◽

Cited By ~ 355

Author(s):

H. Lam ◽

D.-C. Oh ◽

F. Cava ◽

C. N. Takacs ◽

J. Clardy ◽

...

Keyword(s):

Amino Acids ◽

Cell Wall ◽

Stationary Phase ◽

Phase Cell ◽

Stationary Phase Cell ◽

Cell Wall Remodeling

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Poly-β-hydroxybutyrate production in eight strains of the genus Acinetobacter

Canadian Journal of Microbiology ◽

10.1139/m90-112 ◽

1990 ◽

Vol 36 (9) ◽

pp. 657-663 ◽

Cited By ~ 6

Author(s):

Matthew A. Vierkant ◽

Daniel W. Martin ◽

James R. Stewart

Keyword(s):

Stationary Phase ◽

Spectrophotometric Analysis ◽

Phase Cell ◽

Infrared Analysis ◽

Stationary Phase Cell ◽

Commercial Sample ◽

Lipid Reserve ◽

Exogenous Glucose ◽

Phb Production ◽

Lines Of Evidence

Since poly-β-hydroxybutyrate (PHB) inclusions have been reported in only a few strains of Acinetobacter grown on β-hydroxybutyrate, it was of interest to study comparatively the production of this lipid reserve in eight different acinetobacters. Three lines of evidence for PHB production were used: spectrophotometric analysis, infrared analysis, and electron microscopy. The spectrophotometric method showed that all eight strains produce PHB in stationary phase, the amounts ranging from 0.55 to 10.7 fmol/cell. PHB production was maximum after 1 h of growth in batch culture, with the amounts declining by 2 h and returning to near stationary phase cell levels in 4 h. Infrared spectra of purified PHB from the eight strains matched the spectrum of a commercial sample of PHB. In electron micrographs, the PHB reserves were visible as small electron-transparent bodies delineated by ultramembranes. PHB production in four strains (bath cultures) varied in response to exogenous glucose or xylose, with maximum production occurring over a range of 8–17 mM monosaccharide. Glucose was transported into cells by all strains in amounts that ranged from 0.5 to 1.6 fmol/cell, and 0.1–2.2% of that glucose was converted into PHB. Glucose transport was inhibited by cyanide. Key words: poly-β-hydroxybutyrate, acinetobacters.

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