colicin production?

[cloudnine]

hi all,

i am confused with the idea on colicin production.
do colcins are produced naturally?
on the agar plate, can colicins be produced?

i found somewhere that colicins are produced when the organism is under stress. is that right?

if so, what is needed to be done, to produce colicin on the agar plate?

best regards,

[Mjhavok]

Some strains of E. coli produce a substance called colicin that kills competing strains. The producing strains are immune to the action of this chemical but reproduce at a reduced rate because some of their metabolic energy is devoted to its production.

from http://www.math.cornell.edu/~durrett/survey/surve2.html

[Soares]

Also the colicin production may be due to the presence of plasmids. As Mjhavok refered there may be a cost to the bacteria, but also, the producing bacterium dies when it produces the the colicin. Velicer and Lenski (1999) made an analogy to suicide bombers. All the strain can potentially produce it, but the individuals that actually produce it, die.

H. Mendes-Soares