BIOL 220 Lecture Notes - Lecture 4: Ecological Niche, Extremophile, Halophile
Lecture 4
BIO 220
Microbial Growth in the Environment
Growth
oMicrobes have both the fastest and the slowest growth rates of known organism
oThese differences are determined by nutrition and niche scientific physical parameters
like temperature and pH
Limits of Growth
oThe normal growth condition are
Sea level
Temperature 20C-40C
Neutral pH
0.9% salt, and ample nutrients
oAny ecological niche outside this window is called extreme and organisms initiating
them are called extremophiles
oMany of these organisms are very hard or impossible for us to culture
Adaptation to temperature
oA bacterial cell’s temperature matches that of its immediate environment
oChanges in temperature impact every aspect of microbial physiology
oEach organism has an optimum temperature as well as minimum and maximum
temperatures that define its growth limits
oMicrobes that grow at higher temperature can typically achieve higher rates of growth
oThe growth rate roughly doubles for every 10C rise in temperature
The same relationship is observed for most chemical reactions
Philes in Classifications
oA lover of or enthusiast of word proceeding it
Microbes are Classified by Temperature
oMicroorganisms can be classified by their growth temperature
Psychrophiles
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Document Summary
Microbial growth in the environment: microbes have both the fastest and the slowest growth rates of known organism, these differences are determined by nutrition and niche scientific physical parameters like temperature and ph. Limits of growth: the normal growth condition are. 0. 9% salt, and ample nutrients: any ecological niche outside this window is called extreme and organisms initiating them are called extremophiles, many of these organisms are very hard or impossible for us to culture. The same relationship is observed for most chemical reactions. Philes in classifications: a lover of or enthusiast of word proceeding it. Microbes are classified by temperature: microorganisms can be classified by their growth temperature. 65c-121c: all of these organisms have membranes and proteins best suited for their temperatures. Adaptation to pressure: barophiles or piezophiles are organism adapted to grow at very high pressures, barotolerant organisms grow well over the range of 1-50mpa, but their growth falls off thereafter.
