6-Control_of_Microorganisms_Feb7

Brock biology of microorganisms 13th edition decimal

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Unformatted text preview: ature. –  The time necessary to kill a defined fraction is independent of the initial cell concentration (90%). •  Different microorganisms have different decimal reduction times: A, mesophile; B, thermophile. Brock Biology of Microorganisms, 13th Edition. Decimal reduction time (D) 50C 70C 60C Time (min) Decimal reduction time (min) •  Heat is the most widely used method for controlling microbial growth Survival fraction (log scale) 1. Physical methods: heat B A Temperature (C) Example •  A) D = 1h, CFUT0 = 107 •  B) D = 3.3 h, CFUT0 = 107 For A, how much 4me is needed to have <1 CFU? How much 4me for B? Heat Steriliza4on •  The thermal death time is the time needed to kill all cells at a given temperature. It is dependent on the population size of the microorganism tested. Need to standardize the starting number of cells to be able to compare the sensitivity of different microorganisms. •  Endosp...
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This note was uploaded on 03/20/2014 for the course PSYC 101 taught by Professor Catone during the Spring '07 term at CSU Fullerton.

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