Bacterial Growth and Multiplication Flashcards
What are bacteria with simple needs?
Glucose/phosphate/sulphate/ammonia e.g. E. coli
What are fastidious bacteria?
Have complex nutritional needs i.e. aa, fatty acids, vitamins, nucleotides (e.g. Haemophilus)
What are usually the bacteria with unknown needs?
Intracellular parasites - unethical to grow inside host to be able to test (e.g. Rickettsia)
What are the 3 groups of bacteria defined by nutritional requirements?
Simple, fastidious, unknown
What are obligate aerobes?
Need oxygen to survive
What are microaerophilic bacteria?
Require reduced amount of oxygen (5%ish) - usually intestinal
What are facultatively anaerobic bacteria?
Can grow without oxygen but do not have to (intestinal or wounded tissue)
What are strictly anaerobic bacteria?
Can only multiply in absence of air
What are the byproducts of aerobic metabolism?
Hydrogen peroxide
Superoxide radical
How are aerobic bacteria able to deal with the byproducts of aerobic metabolism?
Catalase (deals with H2O2) Superoxide dismutase (deals with superoxide radicals)
What are the barriers to nutrient uptake?
Outer membrane and plasma membrane
What are the 3 mechanisms of nutrient uptake?
Passive diffusion, facilitated diffusion (permeases), active transport
What are the basic byproducts of fermentation?
Acids, CO2, H2, alcohols
What type of bacteria does lactic acid fermentation utilise?
Streptococcus
What type of bacteria does ethanol fermentation utilise?
Yeasts
