Which conditions promote QS in Pseudomonas aeruginosa?

About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
Posts: 1
Joined: Fri Jan 15, 2010 10:59 am

Which conditions promote QS in Pseudomonas aeruginosa?

Post by greenbear » Fri Jan 15, 2010 11:14 am

Hi everybody,

As most of you who had experience with Pseudomonas aeruginosa know, P.a. produce two major types of AHLs: 3-oxo-C12-HSL, and C4-HSL. However, I wonder whether the bacteria would secrete these AHLs while growing as planktonic cells in LB broth (or any other kind of broth)? All that I know is that at higher cell density, bacteria produce more AHLs. But I have no idea whether this refers to bacteria growing on some kind of surface (so that they can develop biofilm at the same time).
Our future experiment requires mixing Pseudomonas with E.coli in liquid medium (such as LB broth) for QS testing. And it's necessary that Pseudomonas must produce AHLs. However, our preliminary exp seemed to show that very little AHLs were produced, if at all. I guess there must be a relation between cell density and AHL concentration, but not sure exactly.
Any suggestion on what is the optimal conditions (like OD600..) for P.a. to produce AHLs?

Any help would be appreciated!


User avatar
Posts: 146
Joined: Mon Jul 03, 2006 2:48 am
Location: Philippines

Post by mkwaje » Fri Jan 29, 2010 9:55 pm

Hi...we studied quorum sensing once. It was interesting but we didn't get to experiment on it. Here is an article about QS in Pseudomonas. Maybe you can find something useful in there.


In some cases like S. aureus, you have to reach a certain density (like 10^8 cells) for it to produce toxin. I just don't know the optimum density needed for P.a.

good luck.

Post Reply

Who is online

Users browsing this forum: No registered users and 6 guests