I've never seen Legionella grow as a lawn of growth. It could be that there
is too much water in your formula (or not enough agar). Try pouring the
melted agar at a cooler temp - about 50 C.
John Gentile Rhode Island Apple Group
yjgent at home.com President
"I never make mistakes, I only have unexpected learning opportunities"
> From: in_vivo at usa.net (Patrick)
> Organization: http://groups.google.com/> Newsgroups: sci.bio.microbiology,bionet.microbiology
> Date: 25 Sep 2001 22:33:44 -0700
> Subject: weird growth on agar
>> Hi, I use "Buffered Charcoal Yeast Extract Agar" to grow Legionella
> pneumophila. I make the agar plates myself. Recently One thing happens
> very weird and interestingly that instead of growing evenly across the
> plate, the bacteria grow to form a round midsize lawn only at the
> center of my plates, for all tens of plates. Of course I'm confident
> of spreading the bacterial liquid culture evenly throughout plates.
>> My first thought was that the addition of charcoal into the agar
> somehow changes the surface tension when the agar solidify so that the
> center of the plates is lower geographically. Anybody has met similar
> problems before and any comments? Thank you.
>> Plus, how much time does a normal Legionella strain usually take to
> form a lawn on the BCYE plates? Overnight or two days or even longer,
> if I spread the bacteria with 150ul of OD600=3.0?