6-Control_of_Microorganisms_Feb7

At 15 psi poundsquare inch steam reaches 121c

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Unformatted text preview: ores survive heat that would rapidly kill vegetative cells. A higher temperature is needed to kill endospores. Endospores can resist boiling for a long time: 5 min for a decimal reduction. •  The autoclave is a sealed device that uses steam under pressure: –  Allows temperature of water to get above 100°C. –  At 15 psi (pound/square inch), steam reaches 121°C, sterilization is achieved in 10-15 min. –  The object being sterilized will reach this temperature. Not suitable for heatsensitive object/liquid. –  It is not the pressure that kills microorganisms, but the high temperature. Chamber pressure gauge Steam exhaust Steam exhaust valve Door Jacket chamber Thermometer and valve Air exits through vent Steam supply valve Steam enters here Temperature (C) Autoclave time Stop steam Begin pressure Flowing steam Sterilization time Temperature of object being sterilized Temperature of autoclave Total cycle time (min) Brock Biology of Microorganisms, 13th Edition. 1. Physical methods: pasteuriza4on •  Pasteurization is the process of using precisely controlled heat to...
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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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