Microbial Nutrition & Growth Pt.1 Flashcards
Autotroph
Producer
Heterotroph
Consumer
Categorize organisms according to their nutritional pattern
Photo-Autotroph
Carbon Source: CO2
Energy Source: Light
Chemo-Autotroph
Carbon Source: CO2
Energy Source: Inorganic Compounds
Photo-Heterotroph
Carbon Source: Organic Compounds
Energy Source: Light
Chemo-Heterotroph
Carbon Source: Organic Compounds
Energy Source: Organic Compounds
Classify Microbes according to temperature preference
Psychrohiles: Cold Loving
Thermophiles: Heat Loving
Mesophiles: Moderate-temp Loving
Hypermophiles: Extreme temp Loving
too low = slow metabolism
too high = enzymes are denatured + shuts down ability to grow
Identify Microbes according to pH and osmotic pressure preference
pH:
Neutrophils- pH 6.5-7.5
Acidophiles: pH less than 2
Osmotic Pressure:
Obligate halophiles: requires high osmotic pressure
Facultative Halophiles: tolerate high osmotic pressure but, do not require it
Physical Requirements for Growth
- Temperature
- pH
- Osmotic pressure
Chemical Requirements
Major Elements:
- Carbon
- Nitrogen
- Phosphorus
- Oxygen
Osmotic Pressure
pressure required to stop water from diffusing through membrane by osmosis
Hypotonic Environment
low solute=low pressure
water in –> Swelling –> bursting the cell (lysis)
Hypertonic Environment
High solute = high osmotic pressure
water out –> Shriveling
Describe the role of major, and trace, elements in microbial growth
Major Elements:
Carbon- needed for organic macromolecules
- proteins, carbohydrates, lipids, nucleic acid
Nitrogen- Nucleic Acids (DNA), Proteins
Phosphorus- Nucleic Acid, phospholipids
Oxygen- Aerobic respiration
Trace elements are needed in small amounts
- Ions: iron, copper, and Zinc
-Enzyme inorganic cofactors
Classify organisms based on their oxygen requirements
Obligate aerobe: needs oxygen
Obligate anaerobe: no oxygen (anaerobic respiration)
Facultative anaerobe: prefers oxygen
Micro-aerophile: low oxygen
Aerotolerant anaerobe: Tolerates oxygen (fermentation)
Identify enzymes involved with microbes avoiding damage by oxygen free radicles
Superoxide dismutase (SOD): produces hydrogen peroxide (H2O2)
Catalase/Peroxidase (Px): Neutralizes toxic (H2O2), Catalase (H2O2 –> H2O + O2), Peroxidase (H2O2 –> H2O)
Oxygen free radicals
produced in the presence of oxygen
highly reactive –> seeks e-s to stabilize
oxidative molecules –> cell damage
Changes in ph and Growth
risk denaturing the macromolecules
- Destroying structures
