BIOL 2051 Lecture Notes - Lecture 2: Ionizing Radiation, Louis Pasteur, Bactericide
29 Nov 2016
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French chemist credited with processes of vaccination, microbial fermentation and pasteurization. Spontaneous generation: hypothesis that living organisms can originate from non- living matter. Pasteurization reduces microbial load while sterilization kills all microorganisms present. Heat: most widely used method, for non- heat sensitive materials. Others are used for sterilizing heat- sensitive materials: radiation, filtration, cold (gas) Some materials are heat- sensitive and would evaporate or not react as well in heat. The temperature needed for heat sterilization depends on the ______________ temperature of growth for an organism. Maximum (highest temperature that still allows growth to occur) Uses steam heat under pressure (about 121 c) Moist heat penetrated cells better than dry heat. High ph (more acidic things are easier to sterilize) High solute concentration (more water or solvent makes it easier to sterilize) Thermophile (must be heated to even higher temperatures to reach temp where microbes cannot grow)
