Hello everyone,
I've encountered an unexpected issue while attempting to multiply bacteriophages from soil samples that were previously isolated. During the double-plate assay, I observed the formation of bubbles. Initially, I assumed they were typical bubbles caused by improper preparation of the culture medium. However, these bubbles exhibited an inhibition halo against Pseudomonas syringae, and over the course of three days, they have grown, burst, and given rise to new ones.
I hypothesize that this could be a contamination from a fermentative bacteria or possibly the bacteriophages themselves being carried by the bubbles. However, I'm not entirely certain. Any suggestions or insights into this phenomenon would be greatly appreciated.
Hello,
is this hallow after the burst , was totally clear and transparent or turbid inside the hallow?
Hello, it depended on the bubble, as in some cases it was completely clear inside, and in others, it only had a small clear halo, with the rest being turbid."
I guess if it’s clear and (Transparent ) this hallow must be made by the bacteriophage, if u don’t have a mind u could mention the type of the host bacteria and we can investigate why it adopts such behavior to form bubbles and you can grow it alone in same conditions it without inoculation of the bacteriophage to check if it’s caused by the growth process itself or caused by the interaction between the bacteria and it’s specific bacteriophage
and remember that the one type of bacteriophage causes same size and same shape of plaques with one specific host
maybe The phage has some genes induces fermentation characteristics of host bacteria
and it may be a lysogenic bacteriophage which doesn’t show plaques but shows changes in genotypic traits of the host bacteria
and it’s very hot area of research u can take Alejandro Caldera
The bacteria in which I cultured it is Pseudomonas syringae. I conducted an investigation on my own to see if it produces these types of bubbles on its own under the conditions in which I grew it, but I found nothing. I have also grown it alone several times, and it has never exhibited this behavior. In fact, in the same experiment where the bubbles appeared, the blank sample without phage inoculation did not show them. Therefore, I have the theory that they are phages or some type of contamination present in the filtered phage sample. Either way, I am currently conducting experiments to determine if these bubbles are repeatable and to rule out any type of contamination.
Hello
I think the air bubbles main cause originated from the phage source. So
I think there are some probabilities:
1- as the plaques are not Ideal plaques I mean ( not totally circular and transparent) and also not the same in shape and size , so this means it’s not necessary a lyric bacteriophage. It maybe a lysogenic bacteriophage which interferes the genetic material of the host and represents itself without lysis of its specific host. So it might be a lysogenic phage induces more gas production for its specific host.
2- it might be a contamination originated from phage stock , to be sure about this, as u said. You can first add 1:10 from chloroform to phage stock and centrifuge for 13 min to release all bacteriophage inside bacterial cell (in case if it’s lytic phage) then take supernatant and filter via .22 um filter syringe and ALSO
Perform the plaque assay on MacConky agar selective media to ensure that no contamination and in this time make a normal agar plate as control with phage and bacteria inside and observe if there are any difference
If the air bubbles appear on agar only and no macconky so it must be caused by gram positive bacteria contamination or
And if both show air bubbles it must be caused by some character of the phage and in this case, I guess it’s a lysogenic phage
Let me know when u get the result . And all best wishes !
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