Great job! One question I have is if you could go into more detail about your web pattern plate and how that helped you make conclusions about your phage!
Thank you, Anika! Truthfully, the web pattern plate is more of a tool for creating an high titer lysate of our phage, which is useful to have when doing experiments like DNA isolation for PCR, restriction digests, and sending out samples for sequencing. The web pattern helps us to determine that we have a high enough concentration of phage on the plate that an HTL (high titer lysate) can be formed using that plate, since the web pattern appears due to so much of the bacterial lawn being replaced by plaques.
Great presentation! I did want to ask about the method of collection and maturation of your phage. Where did they come from and how did you isolate your phage?
Thank you, Nathan! Gobe was isolated from a soil sample we collected here in Boulder! The soil itself came from the garden soil of a family friend. To actually isolate our phage, we first enriched our soil samples with lsyogeny broth (LB) media and M. smeg and incubating before plating the solution on an M.smeg bacterial lawn in a plaque assay. In this environment, phages could grow, and we as the experimenters could easily identify this by finding plaques formed on the plate. We then completed a serious of dilutions from these assays to eventually isolate one phage from the many that formed in the original enrichment plate, which we could recognize by a unique, uniform plaque morphology.
Hi, Emily! That’s a really good question! Currently, I’m not entirely sure how the morphology would impact a phage’s ability to infect its host bacterium, however, I would assume it may play a role in how easily DNA is transferred from the phage into the host cell, since one of the most distinctive differences between the various morphotypes has to do with the presence of contractile/non-contractile tails– the non-contractile tails being unique to siphoviridea. That’s a really good question to look into!
Thank you, McKenzie! The cloudy halo form of the plaques is formed because our phage is temperate, meaning that it goes through both the lytic and the lysogenic lifecycle. Because of this, the cloudiness is caused by the fact that only some of the bacterial lawn was killed by the phage undergoing the lytic cycle and the rest remained intact as lysogens with prophages incorporated in their chromosomes. If Gobe had been a purely lytic phage, then the plaques would be completely clear, since every bacterium would be killed in the lawn.
Great job! One question I have is if you could go into more detail about your web pattern plate and how that helped you make conclusions about your phage!
Thank you, Anika! Truthfully, the web pattern plate is more of a tool for creating an high titer lysate of our phage, which is useful to have when doing experiments like DNA isolation for PCR, restriction digests, and sending out samples for sequencing. The web pattern helps us to determine that we have a high enough concentration of phage on the plate that an HTL (high titer lysate) can be formed using that plate, since the web pattern appears due to so much of the bacterial lawn being replaced by plaques.
Hi Ms. Felfli,
Great presentation! I did want to ask about the method of collection and maturation of your phage. Where did they come from and how did you isolate your phage?
Thank you, Nathan! Gobe was isolated from a soil sample we collected here in Boulder! The soil itself came from the garden soil of a family friend. To actually isolate our phage, we first enriched our soil samples with lsyogeny broth (LB) media and M. smeg and incubating before plating the solution on an M.smeg bacterial lawn in a plaque assay. In this environment, phages could grow, and we as the experimenters could easily identify this by finding plaques formed on the plate. We then completed a serious of dilutions from these assays to eventually isolate one phage from the many that formed in the original enrichment plate, which we could recognize by a unique, uniform plaque morphology.
What is the relevance of the siphoviridae morphology in terms of its ability to infect bacteria?
Hi, Emily! That’s a really good question! Currently, I’m not entirely sure how the morphology would impact a phage’s ability to infect its host bacterium, however, I would assume it may play a role in how easily DNA is transferred from the phage into the host cell, since one of the most distinctive differences between the various morphotypes has to do with the presence of contractile/non-contractile tails– the non-contractile tails being unique to siphoviridea. That’s a really good question to look into!
Hello! Awesome presentation, I loved it! However, I was wondering why the cloudy halo form?
Thank you, McKenzie! The cloudy halo form of the plaques is formed because our phage is temperate, meaning that it goes through both the lytic and the lysogenic lifecycle. Because of this, the cloudiness is caused by the fact that only some of the bacterial lawn was killed by the phage undergoing the lytic cycle and the rest remained intact as lysogens with prophages incorporated in their chromosomes. If Gobe had been a purely lytic phage, then the plaques would be completely clear, since every bacterium would be killed in the lawn.