Microbiology 175 Discussion Guide Microbial Ecology
Discuss the different challenges that the environment places on life, making sure to use the
appropriate terminology.
-Give special consideration to temperature and oxygen.
Some environmental factors include: temperature, oxygen, pressure, food, and acidity
Temperature can affect structure and function of biological molecules —> cold slows
down chemical reactions
heat speeds up
chemical reactions to the point where they’re out of control and my denature proteins
Cardinal temperature = range within which a particular organism can live and is
adapted to
minimal, optimal, maximum temperatures
Psychrophile —> live in cold temperatures
Psychrotroph —> live in cool temperatures
Mesophile —> live in moderate temperatures (humans)
Thermophile —> live in hot temperatures
Extreme Thermophile —> live in extremes
Oxygen is reactive and may damage biological molecules
Superoxide —> component of oxygen radicals, aerobic organisms can break
superoxide down into a lesser form of oxygen and water through enzymes called superoxide
dismutase and catalase
(Anaerobes found a way to bind oxygen —> hemoglobin originally neutralized
built up oxygen but is now involved in oxygen transport)
Strict (obligate) anaerobes = organisms that cannot live in the presence of oxygen
Aerotolerant anaerobes = anaerobes that can grow in the presence of oxygen but
do better without it
Facultative anaerobes = aerobes that can grow without oxygen
Aerobes = organisms that need oxygen
Microaerophiles = organisms that need little oxygen, but too much will kill them
Capnophiles = cells that grow best in higher carbon dioxide concentrations
What kinds of microbes would you find at the surface of the ocean? Two miles below the
surface of the ocean? How would these microbes differ from those in Lake Michigan?
Aerotolerant anaerobes on the surface of the ocean
Strict anaerobes two miles below the surface
Microbes in the ocean would be osmophiles, osmotolerant, or halophiles because of the oceans’
higher salt concentration
Microbes in Lake Michigan would most likely be isotonic to their environment (the water
Discuss the different challenges that the environment places on life, making sure to use the
appropriate terminology.
-Give special consideration to temperature and oxygen.
Some environmental factors include: temperature, oxygen, pressure, food, and acidity
Temperature can affect structure and function of biological molecules —> cold slows
down chemical reactions
heat speeds up
chemical reactions to the point where they’re out of control and my denature proteins
Cardinal temperature = range within which a particular organism can live and is
adapted to
minimal, optimal, maximum temperatures
Psychrophile —> live in cold temperatures
Psychrotroph —> live in cool temperatures
Mesophile —> live in moderate temperatures (humans)
Thermophile —> live in hot temperatures
Extreme Thermophile —> live in extremes
Oxygen is reactive and may damage biological molecules
Superoxide —> component of oxygen radicals, aerobic organisms can break
superoxide down into a lesser form of oxygen and water through enzymes called superoxide
dismutase and catalase
(Anaerobes found a way to bind oxygen —> hemoglobin originally neutralized
built up oxygen but is now involved in oxygen transport)
Strict (obligate) anaerobes = organisms that cannot live in the presence of oxygen
Aerotolerant anaerobes = anaerobes that can grow in the presence of oxygen but
do better without it
Facultative anaerobes = aerobes that can grow without oxygen
Aerobes = organisms that need oxygen
Microaerophiles = organisms that need little oxygen, but too much will kill them
Capnophiles = cells that grow best in higher carbon dioxide concentrations
What kinds of microbes would you find at the surface of the ocean? Two miles below the
surface of the ocean? How would these microbes differ from those in Lake Michigan?
Aerotolerant anaerobes on the surface of the ocean
Strict anaerobes two miles below the surface
Microbes in the ocean would be osmophiles, osmotolerant, or halophiles because of the oceans’
higher salt concentration
Microbes in Lake Michigan would most likely be isotonic to their environment (the water
