What is microbial growth? - ANSWER-The increase in the number of cells.
What are the essential requirements for microbial growth? - ANSWER-Nutrients,
appropriate temperature, adequate moisture, appropriate pH, and oxygen tension.
What is oligotrophy? - ANSWER-The ability to grow with very low levels of nutrients.
Define heterotrophy. - ANSWER-The consumption and breakdown of organic molecules
to make new biomass.
What is autotrophy? - ANSWER-The incorporation of CO2 into organic molecules to
make new biomass.
What are macronutrients necessary for microbial growth? - ANSWER-Carbon, oxygen,
hydrogen, nitrogen, phosphorus, and sulfur.
What role do micronutrients play in microbial growth? - ANSWER-They are essential
parts of enzymes and/or cofactors.
What is the significance of the growth cycle? - ANSWER-It includes stages of growth,
growth parameters, and types of cultures (batch and continuous).
What are the types of growth media? - ANSWER-Rich (complex) media and minimal
(defined) media.
What is the function of nutrient uptake systems? - ANSWER-They facilitate the transport
of nutrients into microbial cells.
What is the role of facultative anaerobes? - ANSWER-They can grow with or without
oxygen.
What are extremophiles? - ANSWER-Microbes that can grow in conditions extremely
different from those optimal for humans.
What is the function of catalase in aerobic microbes? - ANSWER-It detoxifies toxic
forms of oxygen.
, What is the difference between strict aerobes and facultative aerobes? - ANSWER-
Strict aerobes require oxygen to grow, while facultative aerobes can survive with or
without it.
What is a common example of a mixotrophic organism? - ANSWER-
Rhodopseudomonas palustris, which can use different sources of energy and carbon.
What is the importance of understanding microbial growth physiology? - ANSWER-It
allows us to control/eliminate microbial growth in contexts like disease and food
spoilage.
What are the electron acceptors used by anaerobes? - ANSWER-NO3+, NO2+, SO4+,
Fe3+, CO2, and organic compounds.
What is the role of the Petri dish in microbiology? - ANSWER-It serves as a habitat for
microbial growth and observation.
What is batch culture? - ANSWER-A method of microbial culture where nutrients are
provided at the start and not replenished.
What is continuous culture? - ANSWER-A method of microbial culture where nutrients
are continuously supplied and waste is removed.
What is the significance of the growth parameters? - ANSWER-They include growth
rate and doubling time, which are critical for understanding microbial growth dynamics.
What is the role of siderophores in microbial growth? - ANSWER-They are molecules
that bind and transport iron into microbial cells.
What is the ΔG for butyrate in a mutualistic interaction? - ANSWER-+48.6 kJ per mole
What is the ΔG for butyrate in anaerobic conditions? - ANSWER--39.2 kJ per mole
What is the main electron acceptor for aerobes? - ANSWER-Oxygen (O2)
What defines strict (obligate) aerobes? - ANSWER-They can only grow in the presence
of oxygen.
What are microaerophilic organisms? - ANSWER-Organisms that require small
amounts of oxygen to grow.
What do anaerobes use for respiration? - ANSWER-Alternative electron acceptors such
as NO3+, NO2+, SO4+, Fe3+, CO2, and organic compounds.
What is the difference between facultative aerobes and facultative anaerobes? -
ANSWER-Facultative aerobes can survive without oxygen but do not require it, while
facultative anaerobes require oxygen but can survive without it.
What temperature range do mesophiles thrive in? - ANSWER-Growth: 10°C - 45°C;
Optimum: 20°C - 35°C.
What temperature range do thermophiles thrive in? - ANSWER-Growth: >40°C;
Optimum: 55°C - 60°C.
What pH range do neutrophiles prefer? - ANSWER-Growth: pH 5-8; Optimum: pH 7.
What is water activity (aw)? - ANSWER-A measure of how much water is available to
use, calculated as aw = ERH/100.
What is the living limit of water activity for microbes? - ANSWER-aw ≈ 0.61.
What is desiccation? - ANSWER-The process of drying or lyophilization to inhibit
microbial growth.
What is the purpose of selective growth media? - ANSWER-To support the growth of
only certain bacteria.
What is the purpose of differential growth media? - ANSWER-To identify certain
characteristics based on changes like pH or gas formation.
What are the essential requirements for microbial growth? - ANSWER-Nutrients,
appropriate temperature, adequate moisture, appropriate pH, and oxygen tension.
What is oligotrophy? - ANSWER-The ability to grow with very low levels of nutrients.
Define heterotrophy. - ANSWER-The consumption and breakdown of organic molecules
to make new biomass.
What is autotrophy? - ANSWER-The incorporation of CO2 into organic molecules to
make new biomass.
What are macronutrients necessary for microbial growth? - ANSWER-Carbon, oxygen,
hydrogen, nitrogen, phosphorus, and sulfur.
What role do micronutrients play in microbial growth? - ANSWER-They are essential
parts of enzymes and/or cofactors.
What is the significance of the growth cycle? - ANSWER-It includes stages of growth,
growth parameters, and types of cultures (batch and continuous).
What are the types of growth media? - ANSWER-Rich (complex) media and minimal
(defined) media.
What is the function of nutrient uptake systems? - ANSWER-They facilitate the transport
of nutrients into microbial cells.
What is the role of facultative anaerobes? - ANSWER-They can grow with or without
oxygen.
What are extremophiles? - ANSWER-Microbes that can grow in conditions extremely
different from those optimal for humans.
What is the function of catalase in aerobic microbes? - ANSWER-It detoxifies toxic
forms of oxygen.
, What is the difference between strict aerobes and facultative aerobes? - ANSWER-
Strict aerobes require oxygen to grow, while facultative aerobes can survive with or
without it.
What is a common example of a mixotrophic organism? - ANSWER-
Rhodopseudomonas palustris, which can use different sources of energy and carbon.
What is the importance of understanding microbial growth physiology? - ANSWER-It
allows us to control/eliminate microbial growth in contexts like disease and food
spoilage.
What are the electron acceptors used by anaerobes? - ANSWER-NO3+, NO2+, SO4+,
Fe3+, CO2, and organic compounds.
What is the role of the Petri dish in microbiology? - ANSWER-It serves as a habitat for
microbial growth and observation.
What is batch culture? - ANSWER-A method of microbial culture where nutrients are
provided at the start and not replenished.
What is continuous culture? - ANSWER-A method of microbial culture where nutrients
are continuously supplied and waste is removed.
What is the significance of the growth parameters? - ANSWER-They include growth
rate and doubling time, which are critical for understanding microbial growth dynamics.
What is the role of siderophores in microbial growth? - ANSWER-They are molecules
that bind and transport iron into microbial cells.
What is the ΔG for butyrate in a mutualistic interaction? - ANSWER-+48.6 kJ per mole
What is the ΔG for butyrate in anaerobic conditions? - ANSWER--39.2 kJ per mole
What is the main electron acceptor for aerobes? - ANSWER-Oxygen (O2)
What defines strict (obligate) aerobes? - ANSWER-They can only grow in the presence
of oxygen.
What are microaerophilic organisms? - ANSWER-Organisms that require small
amounts of oxygen to grow.
What do anaerobes use for respiration? - ANSWER-Alternative electron acceptors such
as NO3+, NO2+, SO4+, Fe3+, CO2, and organic compounds.
What is the difference between facultative aerobes and facultative anaerobes? -
ANSWER-Facultative aerobes can survive without oxygen but do not require it, while
facultative anaerobes require oxygen but can survive without it.
What temperature range do mesophiles thrive in? - ANSWER-Growth: 10°C - 45°C;
Optimum: 20°C - 35°C.
What temperature range do thermophiles thrive in? - ANSWER-Growth: >40°C;
Optimum: 55°C - 60°C.
What pH range do neutrophiles prefer? - ANSWER-Growth: pH 5-8; Optimum: pH 7.
What is water activity (aw)? - ANSWER-A measure of how much water is available to
use, calculated as aw = ERH/100.
What is the living limit of water activity for microbes? - ANSWER-aw ≈ 0.61.
What is desiccation? - ANSWER-The process of drying or lyophilization to inhibit
microbial growth.
What is the purpose of selective growth media? - ANSWER-To support the growth of
only certain bacteria.
What is the purpose of differential growth media? - ANSWER-To identify certain
characteristics based on changes like pH or gas formation.
