Hey, Kiana! If the phage belonged to a different cluster then it would have had different enzyme cuts and a different plaque and phage morphology. The ramifications of that result wouldn’t really change, but it would have been nice to isolate a rarer phage(Cluster A is one of the largest clusters). The cluster really comes into play in the second part of the class when it comes to gene sequencing and similarity with other clusters(which could tell us about our phage’s possible host range)
Thanks for the great question! The soil was combined in a flask with the bacteria we wanted it to infect(M. smegmatis) and a LB media solution(1L total volume,10g tryptone,5g yeast extract,10g NaCl) and then we let it incubate for 48 hours. After that we centrifuged the sample and used a syringe to push it through a microfilter to make a pure phage lysate solution. That lysate was poured on the plate with bacteria and then we were able to extract a single phage species from the resulting plaques!
That’s a great question! Phage in the lysogenic lifecycle would leave behind cloudy plaques, sometimes described as turbid or having a “halo” like appearance. A lysogenic result wouldn’t be as desirable for medical applications or phage therapy research because it wouldn’t be killing the target bacteria, just integrating with it.
If the phage belonged to a different cluster, other than A, what would the analyses look like?
Hey, Kiana! If the phage belonged to a different cluster then it would have had different enzyme cuts and a different plaque and phage morphology. The ramifications of that result wouldn’t really change, but it would have been nice to isolate a rarer phage(Cluster A is one of the largest clusters). The cluster really comes into play in the second part of the class when it comes to gene sequencing and similarity with other clusters(which could tell us about our phage’s possible host range)
Thank you for a great presentation! Could you explain the process of isolating the phage from the soil?
Thanks for the great question! The soil was combined in a flask with the bacteria we wanted it to infect(M. smegmatis) and a LB media solution(1L total volume,10g tryptone,5g yeast extract,10g NaCl) and then we let it incubate for 48 hours. After that we centrifuged the sample and used a syringe to push it through a microfilter to make a pure phage lysate solution. That lysate was poured on the plate with bacteria and then we were able to extract a single phage species from the resulting plaques!
Wow, that is super interesting. Thank you!
What would the phage have looked like if it was lysogenic and what would be the significance of that result?
That’s a great question! Phage in the lysogenic lifecycle would leave behind cloudy plaques, sometimes described as turbid or having a “halo” like appearance. A lysogenic result wouldn’t be as desirable for medical applications or phage therapy research because it wouldn’t be killing the target bacteria, just integrating with it.
Are there benefits to the lytic vs lysogenic lifecycle for a phage?