Generation of a reproducible nutrient-depleted biofilm of Escherichia coli and Burkholderia cepacia.
An in vitro method of growing bacteria as a defined nutrient-depleted biofilm is proposed. The medium was defined nutritionally in terms of the quantitative composition and by the total amount of nutrient required to achieve a defined population size. Escherichia coli and Burkholderia cepacia were incubated on a filter support placed on a defined volume of solid medium. The change of biomass of the biofilm population was compared with the change in a planktonic culture. The size of the population in stationary phase was proportional to the concentration of limiting substrate up to 40 mumol cm-1 glucose for E. coli and up to 2.7 x 10(-9) mol cm-2 iron for B. cepacia. Escherichia coli growing exponentially had a growth rate of mu = 0.30 h-1 in a biofilm and mu = 0.96 h-1 in planktonic culture. The growth rate, mu, for exponentially growing B. cepacia in a biofilm was 1.12 h-1 and in planktonic culture 0.78 h-1. This method allows the limitation of the size of a biofilm population to a chosen value.
Bühler
T
T
Pharmaceutical Sciences Institute, School of Life and Health Sciences, Aston University, Birmingham, UK.
Ballestero
S
S
Desai
M
M
Brown
M R
MR
D018441:Biofilms; D016956:Burkholderia cepacia / Q000254:growth & development*; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development*; D005947:Glucose; D007501:Iron
D003470:Culture Media; D007501:Iron; D005947:Glucose