Concerning the model for the role of "MCF" and NMCF" cells in the ecology
of C. testosteroni proposed by Peter Bossier: I have several questions
=46irstly, in the experiments conducted to demonstrate the effect of stress
on switching between MCF and NMCF types, under what conditions was stress
introduced (sublethal?, lethal for planktonic cells?, duration? applied to
cells already in biofilms?)
Secondly, what is the time necessary for a stress to induce switching
between MCF and NMCF forms of C. testosteroni ? If there is a short delay,
do the NMCF forms risk liberating themselves into an environment where
stress factors (hydrogen peroxide, etc. as listed by P.B.) are intense ?
Are the NMCF forms capable of surviving the stress? If so, what role does
the biofilm play in protecting bacterial cells from stress? I would be
interested in hearing about ideas concerning why it might be advantageous
for a bacterium to be liberated into a potentially hostile environment.
Concerning another topic, please note that "Plant & Soils, Bulletin N=B0 2"
is forthcoming. We are trying to solicit more response from leaf surface
ecologists before we write up the second bulletin.
Cindy E. Morris
INRA, Centre de Recherches d'Avignon
Station de Pathologie V=E9g=E9tale
84143 Montfavet cedex
e-mail: morris at avignon.inra.fr