Systems Microbiolog8

Systems Microbiolog8 - If youre sterilizing something very...

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Systems Microbiology ° Microbial growth control o Physical antimicrobial control o Chemicals that are used externally o Antimicrobial agents used internally o Antimicrobial drug resistance and discovery of new drugs ° Physical antimicrobial control o Anything that you’d expect is injurious to your cells is likely injurious to bacterial cells as well o Heat – the most common means of controlling bacterial populations o Radiation o Filtration – removes the bacteria, rather than killing them ° Heat o Measuring heat sterilization ° Graph: survival fraction vs. time ° Death time (10-fold reduction at a given temperature) ° Thermal death time – easier to determine o Autoclave ° Steam at very high pressures – a giant pressure cooker ° Steam at 121 degrees Celsius ° Sterilizes things that can survive that high temperature
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Unformatted text preview: If youre sterilizing something very large, like a large vat of liquid, its difficult for the steam to penetrate If youre autoclaving something like surgical instruments, you wrap them in a porous material first, so that microbes dont get back onto them after theyre autoclaved o Pasteurization At the time that this was invented at the turn of the last century, there were huge problems with pathogens transmitted through milk, such as tuberculosis You need to very carefully control both the absolute temperature and the flow of the milk through the machine Flash pasteurization is 71 degrees Celsius for 15 seconds There is always the possibility today of picking up pathogens like Listeria, Salmonella, and E. coli if you consume non-pasteurized dairy...
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