07: Microbial Nutrition, Ecology and Growth Flashcards
1
Q
Bioelements
A
basic requirements for life
- carbon
- hydrogen
- oxygen
- phosphorus
- potassium
- nitrogen
- sulfur
- calcium
- iron
- sodium
- chlorine
- magnesium
2
Q
Essential Nutrients
A
substance an organism must get from a source outside its cells
3
Q
Macronutrients
A
- required in large quantities
- play principal roles in cell structure and metabolism
- proteins
- carbohydrates
4
Q
Micronutrients
A
- required in small amounts
- involved in enzyme function
- maintenance of protein structure
- manganese
- zinc
- nickel
5
Q
Organic Nutrients
A
- contain carbon and hydrogen atoms
- usually the products of living things
- Methane (CH4)
- carbohydrates
- lipids
- proteins
- nucleic acids
6
Q
Inorganic Nutrients
A
- atom or molecule that contains a combination of atoms other than carbon and hydrogen
- Metals and their salts
- magnesium sulfate
- ferric nitrate
- sodium phosphate
- gases
- oxygen
- carbon dioxide
- water
- Metals and their salts
7
Q
Micronutrient Examples
A
- Elements/Nutrients Forms Found in Nature
- copper
- cobalt
- nickel
- molybdenum
- manganese
- iodine
- Sources/Reservoirs of Compounds:
- Geologic sediments
- soil
8
Q
Heterotroph
A
- must obtain carbon in an organic form
- proteins
- carbohydrates
- lipids
- nucleic acids made by other living organisms
9
Q
Autotroph
A
- an organism that uses CO2, an inorganic gas, as its carbon source
- Not nutritionally dependent on other living things
10
Q
Essential Organic Nutrients
A
- Organic compounds that cannot be synthesized by an organism
- lack the genetic and metabolic mechanisms to synthesize them
- Growth factors must be provided as a nutrient for survival
- Essential amino acids
- vitamins
11
Q
Classification of Nutritional Source
A
- Carbon source
- Heterotroph
- from other organisms
- Autotroph
- uses CO2
- Heterotroph
- Energy source
- Chemotroph
- gain energy from chemical compounds
- Phototrophs
- gain energy through photosynthesis
- Chemotroph
12
Q
Nutritional Categories
A
13
Q
Photoautotrophs:
Oxygenic Photosynthesis
A
- Produce oxygen
- use chlorophyll as the primary pigment
- plants
- algae
- cyanobacteria
14
Q
Photoautotrophs:
Anoxygenic Photosynthesis
A
- no oxygen
- sulfur production
- use bacteriochlorophyll as pigment
- purple and green sulfur bacteria
15
Q
Chemoautotrophs
A
- lithoautotrophs
- survive totally on inorganic substances
16
Q
Methanogens
A
- chemoautotroph
- produce methane gas under anaerobic conditions
17
Q
Chemoorganotrophs
A
- Derive carbon and energy from organic compounds
- aerobic respiration
18
Q
Saprobes
A
- Category of Chemoorganotrophs
- free-living microorganisms that feed on organic detritus from dead organisms
- Opportunistic pathogen
- Facultative parasite
19
Q
Parasites
A
- Category of Chemoorganotrophs
- derive nutrients from host
- Pathogens
- obligate parasites
20
Q
Q: If an organism is degrading large organic molecules to get both carbon and energy, it would be best described as a:
A
Chemoorganotroph
21
Q
Passive Transport
A
- does not require energy
- substances exist in a gradient and move from areas of higher concentration toward areas of lower concentration
- Diffusion
- Osmosis
- diffusion of water
- Facilitated diffusion
- solutes that require a carrier
22
Q
Active Transport
A
- requires energy
- carrier proteins
- gradient independent
- Carrier-mediated active transport
- Group translocation
- transported molecule chemically altered
- Bulk transport
- endocytosis
- exocytosis
- pinocytosis
23
Q
Isotonic Solution
A
- Water concentration is equal inside and outside the cell
- thus rates of diffusion are equal in both directions.
24
Q
Hypotonic Solution
A
- Net diffusion of water is into the cell
- swells the protoplast
- pushes it tightly against the wall
- Wall usually prevents cell from bursting
- swells the protoplast
25
Hypertonic Solution
* Water diffuses out of the cell
* shrinks the cell membrane away from the cell wall
* process called plasmolysis.
26
Endocytosis
* bringing substances into the cell through a vesicle or phagosome
27
Phagocytosis
* ingests substances or cells (pseudopods)
28
Pinocytosis
* ingests fluids and/or dissolved substances (microvilli)
29
Q: If a cell is in a concentrated glucose solution and the glucose is moving into the cell through a carrier protein, this would be an example of
Facilitated Diffusion
30
Niche
* totality of adaptations organisms make to their habitat
* Environmental factors affect the function of metabolic enzymes
* Factors include:
* Temperature
* Oxygen requirements
* pH
* Osmotic pressure
* Barometric pressure
31
Adaptations to Temperatures
* Minimum temperature
* lowest temperature that permits a microbe’s growth and metabolism
* Maximum temperature
* highest temperature that permits a microbe’s growth and metabolism
* Optimum temperature
* promotes the fastest rate of growth and metabolism
32
Temperature Adaptation Groups
* Psychrophiles
* optimum temperature below 15°C
* capable of growth at 0°C
* Mesophiles
* optimum temperature 20°-40°C
* most human pathogens
* Thermophiles
* optimum temperature greater than 45°C
33
Aerobe
* utilizes oxygen and can detoxify it
* Obligate aerobe
* cannot grow without oxygen
* Facultative anaerobe
* utilizes oxygen but can also grow in its absence
* Microaerophile
* requires only a small amount of oxygen
34
Anaerobe
* does not utilize oxygen
* Obligate anaerobe
* lacks the enzymes to detoxify oxygen
* cannot survive in an oxygen environment
* Aerotolerant anaerobes
* does not utilize oxygen
* can survive and grow in its presence
35
Capnophile
* grows best at higher CO2 tensions than normally present in the atmosphere
36
Effects of pH
* Neutrophiles
* grow at a pH between 6 and 8
* majority of organisms
* Acidophiles
* grow at extreme acid pH
* Alkalinophiles
* grow at extreme alkaline pH
37
Osmophiles
* require a high concentration of salt (halophile)
* Obligate halophiles
* grow optimally in solutions of 25% NaCl
* require at least 9% NaCl
* salt lakes
* ponds
* *Halobacterium, Halococcus*
38
Osmotolerant
* do not require high concentration of solute
* Facultative halophiles
* remarkably resistant to salt
* *Staphylococcus aureus*
39
Barophiles
* can survive under extreme pressure
* will rupture if exposed to normal atmospheric pressure
40
Q: *Chlamydomonas nivalis* grows on Alaskan glaciers and its photosynthetic pigments give the snow a red crust. This organism would be best described as a
Physchrophile
41
Symbiotic
* Organisms live in close nutritional relationships
* required by one or both members
* Mutualism:
* Obligatory, dependent
* both members benefit
* Commensalism:
* commensal benefits
* other member not harmed
* Parasitism:
* Parasite is dependent and benefits
* host harmed
42
Nonsymbiotic
* Organisms are free-living
* relationships not required for survival
* Syntrophy:
* Members cooperate and share nutrients
* Amensalism:
* Some members are inhibited or destroyed by others
43
Mutualism:
| (symbiotic)
* both members benefit
* Nonobligate Mutualism
* can be separated and live apart
* Ciliophoran *Euplotes*
* unicellular green algae
* Obligate Mutualism
* require each other to survive
* *Casseopeia* jellyfish
* dinoflagellates
44
Commensalism:
| (symbiotic)
* commensal benefits
* other member neither harmed nor benefited
* *Haemophilus*
* *Staphylococcus*
45
Parasitism:
| (symbiotic)
* parasite dependent and benefits;
* host is harmed
* *Rickettsia*
* *Chlamydia* bacteria
46
Syntrophy:
| (nonsymbiotic)
* Microbes sharing a habitat feed off substances released by other organism
* *Azotobacter*
* *Cellulomonas*
47
Amensalism:
| (nonsymbiotic)
* One member of an association produces a substance that harms or kills another
* antagonism, competition
* Antibiosis
48
Biofilms
* result when organisms attach to a substrate by some form of extracellular matrix that binds them together in complex organized layers
* Dominate the structure of most natural environments on earth
* Communicate and cooperate in the formation and function of biofilms – quorum sensing
49
Microbial Growth
* Microbial growth occurs at two levels
* growth at a cellular level with increase in size
* increase in population
* Division of bacterial cells occurs mainly through binary fission (transverse)
* Parent cell enlarges
* duplicates its chromosome
* forms a central transverse septum
* dividing the cell into two daughter cells
50
Growth Curve
1. Lag phase
* “flat” period of adjustment, enlargement; little growth
2. Exponential growth phase
* period of maximum growth when cells have adequate nutrients and a favorable environment
3. Stationary phase
* rate of cell growth equals rate of cell death caused by depleted nutrients and O2, excretion of organic acids and pollutants
4. Death phase
* limiting factors intensify
* cells die exponentially
