dmcbbap (dmcbbap at ucl.ac.uk) wrote:
: Dear net people,
: I have been working on lag phase of bacterial growth.
: What i need is a compound or treatment that leads to extension of the
: lag phase but does NOT affect growth rate. I am not interested in
: "apparent" lag i.e. using a regime that results in cell death followed
: by outgrowth of a resistant sub-population. Compounds that lead to late
: exit from lag by all cells in a population is what i am after. I have
: already done this using an agonist/ antagonist of a particular kinase;
: the result being that i can extend and/or limit the lag phase, even in
: nutrient rich cultures. I can even induce lag in exponentially growing
: cultures. Are there reports of anything similar out there?
Siegele & Kolter have recently described a gene surB which is required by
E. coli cells to exit stationary phase. Mutants lacking surB cannot resume
aerobic growth at high temperature after glucose starvation. Analysis of the
derived amino acid sequence shows that SurB is a component of an ABC membrane
transporter and that it is identical to CydD, which is required for cyto-
chrome bd synthesis. I suppose if you could inhibit the function of SurB you
might be able to prolong lag phase. SurB is very closely related to the MDR
protein that is responsible for multi-drug resistance in human cancer cells.
The world and his wife are looking for inhibitors of this protein--check out
medline searching with the term "MDR" or "multi-drug resistance" for details.
Verapamil is one drug that I know has been shown to inhibit MDR (although
unfortunately not at clinically achievable levels). Why not try adding that
to your cultures?
Let me know if have any luck.
refs: Siegele, DA & Kolter, R Genes & Dev 7, 2629-2640
accession nos. L25859, L21749
Mark Pallen: m_pallen at v1.barts.lon.ac.uk
or mpallen at hgmp.mrc.ac.uk
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