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The Evolution of Bacteria on a “Mega-Plate” Petri Dish - Contenido educativo

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Subido el 8 de marzo de 2021 por Francisco J. M.

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So what we ended up building was basically a Petri dish, except that it's two feet by four feet. 00:00:02
And the way we set it up is that there are nine bands, and at the base of each of these bands, 00:00:07
we put a normal Petri dish thick agar with different amounts of antibiotic. 00:00:12
On the outside, there's no antibiotic. 00:00:17
Just in from that, there's barely more than the E. coli can survive. 00:00:20
Inside of that, there's 10 times as much, 100 times, 00:00:25
and then finally the middle band has 1,000 times as much antibiotic. 00:00:28
and then across the top of it, porous and thin agar 00:00:32
that bacteria can move around in. 00:00:35
The background is black because there's ink in it, 00:00:38
and the bacteria appear as white. 00:00:40
First, you see they spread in the area 00:00:46
where there's no antibiotic up until the point 00:00:49
they can no longer survive. 00:00:51
Then a mutant appears on the right. 00:00:54
It's resistant to the antibiotic. 00:00:57
It spreads until it starts to compete 00:00:58
with other mutants around it. 00:01:01
When these mutants hit the next boundary, 00:01:05
they too have to pause and develop new mutations 00:01:08
to make it into 10 times as much antibiotic. 00:01:11
And then you see the different mutants repeat this at 100. 00:01:17
And after about 11 days, they finally 00:01:28
make it into 1,000 times as much antibiotic 00:01:31
as the wild type can survive. 00:01:34
And so we can see by this process 00:01:37
of accumulating successive mutations 00:01:39
that bacteria which are normally sensitive to an antibiotic 00:01:42
can involve resistance to extremely high concentrations 00:01:46
in a short period of time. 00:01:49
Subido por:
Francisco J. M.
Licencia:
Reconocimiento - No comercial - Compartir igual
Visualizaciones:
75
Fecha:
8 de marzo de 2021 - 19:50
Visibilidad:
URL
Centro:
IES ALPAJÉS
Duración:
01′ 55″
Relación de aspecto:
1.78:1
Resolución:
1280x720 píxeles
Tamaño:
15.05 MBytes

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