Microbial Growth and The Control of Microbial Growth (Chapter 6 & 7) Lecture Materials for Amy Warenda Czura, Ph.D. Suffolk County Community College Eastern Campus Primary Source for figures and content: Tortora, G.J. Microbiology An Introduction 8th, 9th, 10th ed. San Francisco: Pearson Benjamin Cummings, 2004, 2007, 2010. Amy Warenda Czura, Ph.D. 1 SCCC BIO244 Chapter 6 & 7 Lecture Slides
16
Embed
Microbial Growth and The Control of Microbial Growth (Chapter 6 ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Microbial Growthand
The Control of Microbial Growth(Chapter 6 & 7)
Lecture Materials
for
Amy Warenda Czura, Ph.D.
Suffolk County Community College
Eastern Campus
Primary Source for figures and content:
Tortora, G.J. Microbiology An Introduction 8th, 9th, 10th ed. San Francisco: PearsonBenjamin Cummings, 2004, 2007, 2010.
For methods that involve heat:Thermal Death Point (TDP) = lowest temp at
which all microbes in liquid suspensionwill be killed in 10 min
Thermal Death Time (TDT)= minimal lengthof time for all microbes in liquidsuspension to be killed at given temp
*Both are different for different species due tomicrobial variation in heat tolerance
Concept of equivalent treatments:With any heat treatment, the higher thetemperature used the shorter the exposuretime needed to achieve the same effect
Moist heat will always kill faster than dry heatat the same temperature
Chemical Methods of Microbial Control-used to “disinfect” surfaces and peopleChemical antimicrobial agents should:1. be effective against wide range of microbes2. be effective in presence of organic material3. be toxic to microbe but non-toxic to people
and non-corrosive to surfaces-hard to find all in one agent: usually have to
select best agent based on use application-most chemical agents that are “safe” do not
sterilize: they reduce microbe levels, but only if used at the correct concentration