8 thoughts on “D9 – Simpson

    1. Well there are many possible ways that antibacterial agents can ‘attack’ the salmonella, it can target its ability to reproduce or ‘punch’ holes in its cell wall essentially killing the bacteria. In the third experiment in this case it was determined that Betulin, like Ampicillin, was bacteriostatic meaning that it prevented salmonella from reproducing which then, if taking place in a host organism, should enable the immune system to take over and kill the remaining bacteria. So in this case all that can be identified is that Betulin prevented salmonella from reproducing but further research can be undertaken to examine the particular mechanisms that Betulin targets in salmonella.

    1. The standard deviation of the negative control is important as that is how we can compare the growth or lack of bacteria in the compounds we tested. For instance 2 standard deviations below the mean absorbance of our negative control was deemed a statistcal hit meaning that there was little growth of the bacteria in the well, and this information enables us to identify in this case Betulin as a successful anitbacterial agent.

    1. That’s a great question, I don’t know specifically how or what functions Betulin has in Shiitake Mushrooms as a mere presence, it is just one of the active enzymes present in the mushroom. It is understood from other research conducted on Betulin found in Birch Trees that it can lower colesterol and prevent diet-reduced obesitey in mice so is clearly an important component that can have many health benefits.

  1. I really liked your presentation, but I had one question about the procedure. How was the absorbance of the bacteria correlated to their population? Was this direct absorbance by the bacteria or were they stained in some way? Thanks!

    1. Yes, so the well plates were loaded into a photospectrometer which used a wavelength of light of 620 as that is the wavelength that Salmonella Typhimirium absorbs, so that bacteria was not stained. Light was shone through the plate and the wells with more bacteria present absorbed more of light than those with less. So the high absorbance values directly correlate with a high population of bacteria in the well.

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