Lab 4 Flashcards
Ideal temp at which an organism can grow is called?
lowest temp at which an organism can grow is called?
Highest temp at which an organism can grow is called?
Optimum
Minimum
Maximum
What is the range of temps bacteria can grow?
0 celcius to over 110
Turgor pressure
Water activity
Osmosis
Turgor pressure - how hard a cell pushes out into its environment
*higher turgor pressure = bloated cell
Water activity - the amount of water available for metabolic use
Osmosis - movement of water across a membrane
Plasmolysis
Plasmolysis - membrane will pull away from the cell wall
Anaerobic
Reactive oxygen species
Anaerobic - no oxygen present
Reactive oxygen species - forms of oxygen that can damage cellular components
Classifications for oxygen requirements
Strict aerobes -
Facultative Anaerobes -
Aerotolerant -
Microaerophilic -
Strict anaerobes -
Strict aerobes - Microbes that solely rely on oxygen as a final electron acceptor for cellular respiration to produce ATP
Facultative Anaerobes - Microbes that can use oxygen but don’t require it
Aerotolerant - Microbes that can tolerate the presence of oxygen but dont use it to make ATP
Microaerophilic - Microbes that require oxygen to grow but cant tolerate high concentrations of oxygen
Strict anaerobes - Microbes that cannot grow in the presence of oxygen at all. Rely on fermentation and/or anaerobic respiration to make ATP
Acid-fast stain -
Mycolic acids -
Virulence factor -
Acid-fast stain - a differential stain that detects the presence or absence of mycolic acids in bacterial cell wall
Mycolic acids - waxy materials composed of fatty acids and fatty alcohols and are found in cell walls of bacteria from genera, Mycobacterium and Nocardia
Virulence factor - aids in the pathogenesis, causes bacteria to clump together, helps them survive phagocytosis, resistant to disinfectant and antimicrobial therapy
Kinyoun method -
Carbolfuchsin-
Fushia pink complex -
Kinyoun method - cold acid-fast stain method that uses phenolic compound, carbolfushsin, as primary dye
Carbolfuchsin- lipid-soluble, concentrated stain. Able to penetrate a waxy mycolic acid layer
Fushia pink complex - acid fast positive / BLUE negative
Microbes that can only grow below 20 celsius
Pyschrophiles
Microbes that grow at cold temps but can survive up to 35 celcius
*found in fridge
Psychrotrophs
Adapted to temps of 15-45 Celcius
*human body 35-40
Mesophiles
Grow at 45 celcius
*hot springs, compost
Thermophiles
Can survive temps from 80-100 celcius
*deep ocean thermal vents
Extreme thermophiles
Mesophiles that are able to survive at high temps for short times
*can survive pasteurization
Thermoduric
CAn only survive very low salt concentrations
Non-tolerant
0-5%
Microbes can grow in the moderate range of salt
Halotolerant
0-11%
Microbes that will only grow in high salt concentrations
MIcrobes can only grow in high salt environments
Extreme halophiles 15-30%
Dead Sea nd Great salt lake
Microbes that can tolerate very high sugar concentrations
Osmophiles
Microbes that solely rely on oxygen to produce ATP
Strict aerobes
Microbes that use oxygen but do not require it
Facultative anaerobes
Microbes that can tolerate the presence of oxygen but do not use to create ATP
Aerotolerant
Microbes that require oxygen to grow but cannot tolerate a high concentration
Microaerophilic
Microbes that cannot grow in presence of oxygen and rely on fermentation and anaerobic respiration
Strict anaerobes
Mycolic acids are found in bacteria from the genre
mycobacterium and nocardia
What is a virulence factor
Virulence is described as an ability of an organism to infect the host and cause a disease.
Causes this bacteria to clump together, survive phagocytosis, and resist disinfectants and microbial therapy
Examples are toxins, surface coats that inhibit phagocytosis, and surface receptors that bind to host cells
acid-fast postive is what color
negative?
positive - fuchsia-pink
Negative - blue
What is the cellular target of acid-fast stain?
mycolic acids
What are 2 diseases caused by acid fast bacteria
Tuberculosis, Leprosy
Explain how the acid fast property of the bacterium is a virulence factor?
The myolic acid of myobacterium clump the cells together. it is a virulence factor that allow them to survive in phagocytes and make them resistant to disinfectants & antimicrobial therapy.
Explain a screening test and a more definitive test for diagnosis of tuberculosis
skin testing (screens people with high risk for tuberculosis but may have false results even if it test positive)
Chest X-Ray
Direct identification of myobacterium tuberculosis in sputum.
Cultural isolation & identification
Do animals get tuberculosis
yes
Explain the meaning of tb as a re-emerging infection?
diseases that once were major health problems globally or in a particular country, and then declined dramatically, but are again becoming health problems for a significant proportion of the population
emergence of multidrug resistance and the interaction between TB and HIV infection are responsible for this surge.
Turbidity is measured by
absorbance using a spectrophotometer.
what are some examples of psyrotrophs
Mold and some bacteria such as Pseudomonas and are pathogens
Why are thermoduric bacteria important to consider after pasteurization
Thermoduric bacteria are “heat resistant” and able to survive at pasteurization temperature, and have the potential to cause loss of quality and shelf life in foods.
what is an example of a hypotonic environment
pure water
give examples of where you would find a
halophilic
halotolerant
osmophilic
halophilic - great salt lake, dead sea
halotolerant- hypersaline lakes
osmophilic - jelly jars
What is the final electron acceptor for fermination?
for anerobic respiration
Fermination - organic compound - carbohydrates, fats (lipids), proteins, and nucleic acids,
Anaerobic respiration - sulfate (SO42-), nitrate (NO3–), or sulfur (S)
what are diseases caused by strict anaerobes
appendicitis
abscess
