Bacterial Pigmentation - (Oct/13/2005 )
Dear memebrs, Im a newbie.While cultivating P.aeruginosa in peptone rich medium i find bluish-green pigmentation sometimes only. It is absent on many times even there is no contamination, as we used the same medium incubating at same physical conditions. This we observe in both solid agar and liquid broth mediums.What is resason? Thanks
how long are you incubating? I used to grow those guys in the public health lab all the time, and sometimes it took a little longer for the pigment to show up, but it should always be there. pigment production is one of the hallmarks of that species and genera and one of the identifying characteristics
I incubated for 24hrs time. I waited upto 48hrs also. sometimes pigmentation is observed well over agar slants, but the colonies were very light and no streak line is observed. We are using Himedia Nutrient agar(MM 012). But in culture bank they are cultivating on Nutrient agar but with different grade(MM002). I found there is no much difference in their composition.
The pigment is pyocyanin if I remember. I think it also glows under UV light. I wouldn't be surprised if it's under quorum sensing control. A whole host of characteristics in Pseudomonas are.
In liquid culture, shaking (ie. oxygen availablity) was important for pyocyanin production. Also, some mediums enhance its production. It could be the medium you are using that is making pyocyanin production inconsistant.
Thanks for all of your responses. Actually i'm putting in shaking conditons only.Sometimes i'm observing pigmentation, but not often. It's observed in both liquid and solid medium too