Microbial Growth Flashcards
What is microbial growth
The increase in number in microbes
What is a colony
Large number of microbes usually derived from one organism (clone)
What’s a more in depth definition of binary fission
Uniceullar organisms grow in size but stop until the mother cells doubled in size and duplicates itself
One mother cells divides into 2 new daughter cells
What are the growth requirements (main 3)
- obligate vs facultative
- physical requirements
- biochemical requirements
What is obligate requirements
Must have the specific environment
What is facultative requirements
Able to adjust to fluctuations or a range of environmental factors
What is the 3 physical requirements
Ph
Temperature
Osmotic pressure
What are the 3 biochemical requirements
C and N sources ( carbon and nitrogen )
H2O and oxygen requirements
Organic growth factors & trace minerals
What are the 3 types of temperature range and give a small description of each
Psychrophiles
- cold loving
Mesophiles
- moderate temperature
Thermophiles
- heat loving
What is psychrophiles & minimum temperature ?
Cold loving
0-15C
What is psychrophiles optimum temperature
Cold loving
10-15C
What are psychrophiles mainly responsible for?
Food spoilage
What are mesophiles & minimum temperature range ?
Moderate temps
10-47C
What is mesophiles optimum temperature range
Moderate level
25-40C
What are thermophiles and their minimum temperature range
Heat loving
40-80C
What are thermophiles optimum range
Heat loving
50-60C
What are extreme thermophiles ?
Can handle more heat
What are extreme thermophiles temperature range
65-110C
What are buffers ?
Stabilizes PH of a solution
What can buffers donate or accept
Hydrogen to the solution
What is the optimum ph for most bacteria
6.5-7.5
What are neutrophils
The optimum ph for most bacteria
6.5-7.5
What are acidophils
Bacteria that can grow in low ph
Lower than 4.0
What is the ph that acidophils can grow in
Lower than 4.0
What is alkaliphiles
Bacteria that can grow in high PH
What is optimum for yeast to grow in PH
4.0-5.0
What is osmotic pressure
The force of which solvent Moves from a solution of lower solute concentration to a solution of higher solute concentration
Solvents moves from lower to higher concentration
What is hypertonic solution
Osmotic pressure
When water moves out the cell
causing cytoplasm ti shrink
10% NaCI
When does plasmolysis happen
When water leaves the cell
What is a hypotonic solution
When water moves into the cell
What happened with the cell wall is strong in a hypertonic solution
It can contain the swelling of the water going inside the cell
What happened with the cell wall isn’t strong enough for hypotonic solutions
The cell bursts ( osmotic lysis )
What is osmotic lysis
When the cells burts from having too much water move inside
What is an isotonic solution
No movement of water anywhere, stays put
What are halophiles
Salt loving
What are extreme halophiles
30% NaCI
Archaea
What are facilitative halophiles
2% NaCI
To review what are the 3 types of biochemical requirements
Carbon
Oxygen
Organic (Nitrogen ( trace elements )
What is carbon sources
Structural of backbone of all living matter
What are the two types of carbon sources ?
Heterotrophs
- carbon is derived from organic compounds ( proteins, carbohydrates)
Autotrophs
- carbon from CO2
What is heterotrophs
A carbon source
- comes from organic compounds
What are autotrophs
- carbon source
- In organic compounds
Carbon comes from co2
What are 2 types of autotrophs ?
Chemoautotrophs
Photoautotrophs
What are chemoautotrophs
Get their energy from inorganic compounds
- carbon source
- c from CO2
What are photoautotrophs
Get their energy from sunlight
- carbon source
- carbon from CO2
What does the biochemical of nitrogen use (3)
Amino acids / proteins
Nucleic acids : dna & rna
Atp
What is the biochemical nitrogen source
Breaking down of a protein containing materials
What is nitrogen fixation
The proceeds where an organism is able to N from gasesous N2
What is rhizobium
Nitrogen
- symbiotic relationship with plants
What does sulfur use
Aminos acids
What does phosphorous use
Atp, dna rna, phospholipids
Do all organism need carbon, nitrogen, sulfur, phosphorous
Yes
Do all living cells need oxygen?
No
Why is oxygen harmful?
Strong oxidizer
What are obligate aerobes
Aerobic growth
- needs oxygen
What are facultative anaerobes
Can use oxygen but not needed
- both aerobic, anaerobic growth
- greater growth if oxygen is there
What is obligate anaerobes
anerobix growth
- can’t grow if oxygen there
What is aerotolerant anaerobes
- anaerobic growth
- doesn’t use oxygen but grows if it’s there
What’s microaerophiles
- aerobic growth
- requires less oxygen
