Lecture 3 - Cultivation of Bacteria Flashcards
What are the five major environmental factors that affect bacterial growth?
Temperature pH Oxygen Carbon Dioxide Water avalibility / Osmotic pressure
What are obligate growth factors?
These growth factors are restricted aka these conditions are a must for the bacteria to grow
What are Facultative growth factors?
These growth conditions have a little more give to them when it comes to conditions the bacteria will grow in
What most pathogenic bacteria when it comes to temperature?
Mesophiles
What conditions are optimal for mesophiles?
37 degrees C
What is special about 37 degrees C?
Body temp
What is the pH that is optimal for most bacteria?
6.5 to 7.5
What are most pathogenic bacteria when it comes to pH?
Neutrophiles
What are transport + culture media buffered at most of the time?
pH of 7.0
What are two factors that are taken into consideration when deciding if a bacteria can handle oxygen or not?
Do they grow in oxygen or not
– and –
Can they handle ROS
Describe obligate aerobes?
Oxygen require + ROS enzymes present
Describe microaerophiles.
Oxygen required at low levels + ROS enzymes present
Describe facultative anaerobes.
Oxygen not require but will growth if present + ROS enzymes present
Describe aerotolerant anaerobe.
No preference for oxygen + Some ROS enzymes
Describe obligate anaerobes.
Oxygen kills + NO ROZ enzymes
What methods are used to grow obligate anaerobes?
Anaerobic transport media
Reducing media
Anaerobic jars/bags/chambers
What are capnophiles?
Require 5 to 10% CO2 for optimal growth
What kind of bacteria tend to be capnophiles?
Microaerophiles
What methods are used to increase CO2 levels?
Candle jar
CO2 packet
CO2 incubator
What are halotolerant bacteria?
Bacteria do not need NaCl but can grow in higher concentrations
What does increased NaCl cause?
Increased osmotic pressure
What are halophiles?
Grow best under saline conditions
In regards to bacterial nutrition, what are most bacteria?
Chemoheterotrophs
What are chemoheterotrophs?
Bacteria that need organic compounds for energy and carbon