Bacteria - Introduction and Conditions for growth Flashcards
What are bacteria?
Microscopic unicellular microorganism
What are the two types of bacteria?
Pathogenic or non-pathogenic
Classify bacteria based on what they feed on?
Saprophytic
Parasitic
Define saprophytic bacteria
Bacteria which feed on non-living matter such as food and cause spoilage (non-pathogenic)
Give an example of a saprophytic bacteria
Lactic acid bacteria which spoils milk
Define parasitic bacteria.
Bacteria which feed on living matter such as animals or human (pathogenic)
Give an example of a parasitic bacteria.
Staphylococcus aureus which causes staph infections
Classify bacteria based on their need for oxygen.
Aerobic
Anaerobic
Facultative
Define aerobic bacteria.
Bacteria which need oxygen for growth
Define anaerobic bacteria
Bacteria which do not require oxygen for growth
Define facultative bacteria
Bacteria which can grow with or without bacteria
Give an example of an aerobic bacteria.
Mycobacterium tuberculosis
Give an example of an anaerobic bacteria.
Clostridium botulinum
Give an example of a facultative bacteria
E.coli
Classify bacteria based on their temperature preference.
Psychrophilic
Mesophilic
Thermophilic
Hyperthermophilic
Give an example of psychrophilic bacteria.
Listeria (grows in the fridge)
Give an example of mesophilic bacteria
E.coli (most prefer this temperature)
Give an example of thermophilic bacteria
Thermus aquaticus
Give an example of hyperthermophilic bacteria
Thermotoga maritima
What temperature is required to destroy bacterial endospores?
121 degrees Celsius
What aw level do bacteria require for growth?
An aw level of 0.9 or above
What type of pH environment do bacteria require for growth?
Slightly acidic or neutral (6-7)
Extreme acidic or alkaline conditions inhibit bacterial growth
How long does a bacteria require to grow?
Double every 20 minutes
