Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Jul 1997, 2686-2694, Vol 63, No. 7
F Joux, P Lebaron and M Troussellier
In this study, we have used different fluorescent dyes and techniques to
characterize the heterogeneity and changes of the physiological states
encountered by the marine bacterium Deleya aquamarina during a 92-day
starvation survival experiment at 20 and 5(deg)C. Changes of physiological
states were investigated on a single-cell basis by flow cytometry and
epifluorescence microscopy in conjunction with fluorescent dyes specific
for various cellular functions and constituents. Heterogeneities within
populations with regard to functions (respiration, substrate
responsiveness, enzymatic activity, and cytoplasmic membrane permeability),
constituent (DNA), and cell volume (light scatter) were compared to the
evolution of viable plate counts (CFU). At 20(deg)C, CFU changes were
divided into three stages corresponding to stability up to day 13 followed
by a rapid drop between days 13 and 42 and then by stabilization at a level
of 10 to 20% during the remaining survival period. Most of the cellular
fractions showing a metabolic activity were close to the evolution of the
culturable cells, suggesting the absence of viable but nonculturable cells.
On the other hand, cells with selective cytoplasmic membrane permeability
but without any metabolic activity were observed, and this stage was
followed by DNA alteration occurring at different rates after the loss of
membrane cytoplasmic permeability. We observed a greater maintenance of
culturability, physiological functions, DNA, and cellular volume at the
lower temperature. These results have different ecological implications
from both methodological and conceptual viewpoints.
Copyright © 1997, American Society for Microbiology
Changes in Cellular States of the Marine Bacterium Deleya aquamarina under Starvation Conditions
Observatoire Oceanologique, Universite Paris VI, Institut National des Sciences de l'Univers, URA CNRS 2071, Banyuls-sur-Mer Cedex, and Laboratoire d'Hydrobiologie Marine et Continentale, Universite de Montpellier II, UMR CNRS 5556, F-34095 Montpellier Cedex 05, France
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|