Microbial Growth and Ecology
Unit 2, SJRState, Kempke, Micro
What are three physical factors affecting bacterial growth?
Temperature, pH, and Osmotic pressure
Psychrophiles thrive at which temperatures?
Mesophiles thrive at which temperatures?
Thermophiles thrive at which temperatures?
Psychrotrophs thrive at which temperatures?
An example of a psychrotroph is:
Most bacteria thrive at in a narrow pH range near __________.
Acidophiles thrive at which pH?
Alkaliphiles thrive at which pH?
Neutrophiles thrive at which pH?
An example of an acidophile is:
An example of a mesophiles is:
E. coli, Salmonella
Most human pathogens are:
Hyperthermophiles thrive at which temperatures?
An example of a hyperthermophile is:
An example of a hypoacidophile is:
can adapt to
Osmotic pressures have to do with which compound?
Define facultative halophile:
an organism that can adapt to higher salt concentrations
Halophiles thrive in which environment:
An example of a facultative halophile is:
Which of the properties can be used to differentiate bacteria?
Halophile or not
Do the cells of halophiles shrink when placed in an osmotic solution?
shrinkage of the cell membrane due to high osmolarity
Define obligate halophile:
must have salt to live
What type of agar is best suited for S. aureus?
What is the carbon source for autotrophs?
An example of a photo-autotroph is:
What is the energy source of chemo-heterotrophs and chemo-autotrophs?
What is the carbon source of heterotrophs?
What is the energy source of photo-heterotrophs and photo-autotrophs?
Most bacteria have which energy/carbon source combination?
Most humans have which energy/carbon source combination?
T or F Carbon is a chemical requirement for growth
T or F Sodium is a chemical requirement for growth
T or F Nitrogen is a chemical requirement for growth
T or F Hydrogen is a chemical requirement for growth
T or F Oxygen is a chemical requirement for growth
T or F Sulfur and Phosphorus can be chemical requirements for growth
What is a component of proteins, nucleic acids, coenzymes, and cell walls?
Nitrogen accounts for 12-15% of ___________ of a bacterial cell
Bacteria obtain Nitrogen from inorganic/organic/both sources?
Define Nitrogen fixation
the conversion of Nitrogen to a usable form
What is an important component of amino acids?
What type of sulfur is used directly by bacteria?
What is an important component of nucleic acids and phospholipids?
What type of phosphorus is used directly by bacteria?
Normal molecular oxygen that has been boosted into a higher energy state:
Toxic to cellular components, need SOD to neutralize it:
Superoxide free radical
Toxic to cells, need catalase to neutralize it:
No known enzymatic system to deal with this, but has a very short half-life:
In obligate aerobes oxygen is:
In facultative aerobes oxygen is:
In micoraerophiles oxygen is:
required but at levels lower than in atmosphere
In obligate anaerobes oxygen is:
Enzymes used by obligate aerobes:
SOD+, Catalase +
Enzymes used by facultative aerobes:
SOD+, Catalase +
Enzymes used by micoraerophiles:
SOD-, Catalase -
Enzymes used by obligate anaerobes:
SOD-, Catalase -
An example of an obligate aerobe:
An example of a facultative aerobe:
An example of a microaerophile:
An example of an obligate anaerobe:
A complex polysaccharide derived from red algae:
Can Agar be degraded by microorganisms?
At what temp does Agar liquefy?
At what temp should a water bath be for Agar?
The highest incubation temperature for Agar:
A medium whose exact chemical composition is known is called a:
chemically defined medium
Chemically defined mediums are good for organisms that require:
many growth factors
Define fastidious organism:
An organism that has complex nutritional requirements
An example of a fastidious organism:
You should culture fastidious organisms on which type of medium?
In what type of media are the requirements for energy, carbon, nitrogen, and sulfur primarily provided by protein?
small, soluble protein fragments that can be digested by most bacteria
A nutrient broth is an example of what type of media?
What is a nutrient broth called if you add agar to it?
T or F Nutrient broth and Nutrient Agar are the same thing?
T or F Many bacteria have never been grown successfully on laboratory media?
Two examples of bacteria that have never been grown successfully in the lab?
M. leprae and T. pallidum
Which types of bacteria have not been grown successfully on laboratory media?
What do capnophiles require for growth?
Higher concentrations of CO2
This media inhibits the growth of one type of bacteria while permitting the growth of another.
This media does not inhibit one type of bacteria over another but allows different bacteria to display different characteristics
An example of a differential media is
An example of a selective and differential media at the same time is:
Mannitol is selective for
A differential medium that differentiates lipase producing bacteria
Spirit Blue Agar
This selective and differential media is selective to gram negative coliforms:
This selective and differential media is used to differentiate lactose vs. sucrose fermentation:
Which bacteria is negative on Spirit blue (non-lipase producing)?
Which bacteria is positive on Spirit blue (lipase-producing)?
Is Mannitol selective, differential, or both?
Mannitol is selective for:
Mannitol is differential for:
An example of a non-Mannitol fermenter:
An example of a Mannitol fermenter is:
Is Spirit Blue Agar selective, differential, or both?
Spirit Blue is differential for:
lipase producing bacteria
An example of a lipase producing bacteria:
An example of a non-lipase producing bacteria:
Is EMB selective, differential, or both?
EMB is selective for:
gram - microbes
EMB is differential for:
lactose vs. sucrose fermentation
Lactose fermenters form _____ colonies on EMB.
Non-lactose fermenters form ______ colonies on EMB.
Is MacConkey Agar selective, differential, or both?
MacConkey is selective for:
gram - enterics
MacConkey is differential for:
lactose vs. non-lactose fermenting
What in MacConkey agar inhibits the growth of gram + bacteria?
Crystal violet and bile salts
What is the pH indicator in MacConkey?
Strong lactic acid colonies form what on MacConkey?
A pink halo
If a bacterium produces lactic acid what color is it on MacConkey?
An example of a lactic acid producer via MacConkey:
This type of culture is designed to increase very small numbers of desired organisms to detectable amounts.
An example of substances to be tested using enrichment cultures include:
soil or fecal samples, drinking water txt facilities
An increase in bacterial numbers is called:
A simple splitting of a parent cell into two daughter cells is called:
When a cell forms a small initial outgrowth that enlarges until its size approaches that of the parent cell, and then separates is called:
The time required for a bacterial cell to divide is called:
What is the relative generation time for most bacteria?
30 - 60 minutes
Do pathogens generally have a short or long doubling time?
Which pathogen has a generation time of 10 - 30 days?
Bacteria in a free-floating state are said to be:
The phase in which there is little to no cell division and the microbial population is undergoing intense metabolic activity:
The phase in which exponential growth occurs and cellular reproduction is most active:
The phase in which the number of deaths equals the number of new cells:
The phase in which the number of deaths exceeds the number of new cells:
Microbes are most sensitive to antibiotics during which phase?
Bacterial growth can be measured either ___________ or __________.
Tell whether the following is an indirect or direct measure: Serial dilution and standard plate counts.
Tell whether the following is an indirect or direct measure: Direct microscopic counts.
Tell whether the following is an indirect or direct measure: Most probable number.
Tell whether the following is an indirect or direct measure: Filtration.
Tell whether the following is an indirect or direct measure: Turbidity
Tell whether the following is an indirect or direct measure: Spectrophotometry
Tell whether the following is an indirect or direct measure: Metabolic Activity
Tell whether the following is an indirect or direct measure: Dry Weight
How many colonies fall constitute a "countable" range?
What measures the number of viable cells?
What is done to ensure that colony counts are in a countable range?
A series of small dilutions is called
Which type of count requires no incubation time?
Direct Microscopic Count
Which type of count requires the use of a microscope and slides?
Direct Microscopic Count
Which type of count incorporates statistical estimating?
Which type of count is used when microbes will not grow on solid media?
Which type of count is used when the quantity of bacteria is extremely small?
Which type of count estimates bacterial numbers by measuring a population's metabolic activity?
These microbes carry out complete lysis of red blood cells when grown on blood agar:
A facultative anaerobe:
A relationship in which both partners benefit:
Requires oxygen, but at lower levels than those found in the atmosphere:
Neutralizes free radicals
Requires higher concentration of Co2 for growth:
Nitrogen fixing bacterium
Breaks down hydrogen peroxide
Conversion of atmospheric Nitrogen to a usable form:
Microbe that grows on Mannitol Salt Agar:
Medium that inhibits the growth of one type of bacteria but permits the growth of another:
Uses carbon dioxide as its carbon source:
An acid loving microbe:
A differential medium:
A fastidious microbe:
Optimum temperature for growth is 25C:
A photosynthetic bacteria: