If a bacterium containing prophage is exposed to stressors, such as UV light, low nutrient conditions, or chemicals like mitomycin C, prophage may spontaneously extract themselves from the host genome and enter the lytic cycle in a process called induction.
Nice job! You mentioned that phages are good antibiotic because they can infect and kill bacteria, but I was wondering how we stop them from hurting our own cells?
The phage possesses a genome of linear ds DNA contained within an icosahedral head. The tail consists of a hollow core through which the DNA is injected into the host cell. The tail fibers are involved with recognition of specific viral “receptors” on the bacterial cell surface. they are really specific.
We were not really looking for a specific type of phage. we did the plaque assay numerous times, we sometimes got a lytic phage and a lysogenic phage on the same plate which prompted another phage assay until we were able to isolate one type of phage( same morphology and size).
It depends a bit on the life cycle of the specific phage you are dealing with. Turbid plaques are usually produced by lysogenic phage such as lambda. In some of the cells the phage may lysogenize instead of continuing the lytic cycle, and if this happens with high enough frequency the plaque will look ‘turbid’. Other times it is called halo plaques. The phage replication does not lyse the cell, but slows their growth noticeably enough that you can distinguish a plaque in solid medium; a typical example are filamentous phages. I wish i could show you hat it really looks like, but it kind of has like a light circle around the plaques.
Great presentation! I was wondering whether temperate or lytic phage are better for phage therapy?
Lytic phages are better for phage therapy.
Great presentation! I was wondering if temperate or lytic phage are better for phage therapy?
What type of unfavorable conditions cause a temperate phage to enter the lytic cycle?
If a bacterium containing prophage is exposed to stressors, such as UV light, low nutrient conditions, or chemicals like mitomycin C, prophage may spontaneously extract themselves from the host genome and enter the lytic cycle in a process called induction.
Nice job! You mentioned that phages are good antibiotic because they can infect and kill bacteria, but I was wondering how we stop them from hurting our own cells?
To clarify: how do we stop them from hurting our beneficial bacteria
The phage possesses a genome of linear ds DNA contained within an icosahedral head. The tail consists of a hollow core through which the DNA is injected into the host cell. The tail fibers are involved with recognition of specific viral “receptors” on the bacterial cell surface. they are really specific.
What was your expected outcome? Where you looking for a specific phage?
We were not really looking for a specific type of phage. we did the plaque assay numerous times, we sometimes got a lytic phage and a lysogenic phage on the same plate which prompted another phage assay until we were able to isolate one type of phage( same morphology and size).
What is a halo for a phage plaque and how do you know that the halo means that the phage is temperate?
It depends a bit on the life cycle of the specific phage you are dealing with. Turbid plaques are usually produced by lysogenic phage such as lambda. In some of the cells the phage may lysogenize instead of continuing the lytic cycle, and if this happens with high enough frequency the plaque will look ‘turbid’. Other times it is called halo plaques. The phage replication does not lyse the cell, but slows their growth noticeably enough that you can distinguish a plaque in solid medium; a typical example are filamentous phages. I wish i could show you hat it really looks like, but it kind of has like a light circle around the plaques.