Microbial Nutrition, Growth, And Ecology

Front 1

What is Microbial nutrition?

Back 1

Process by which living organisms acquire exogenous nutrients and utilize them for metabolism and growth

Front 2

What are the different nutrient sources for microogransims?

Back 2

C, H, O, K, N, S, Ca, Fe, Na, Cl, Mg

Front 3

What are macronutrients?

Back 3

Recquired in large quantities
Play a function in cell structure and metabolism

Front 4

What are micronutrients?

Back 4

Required in much smaller amounts
Play a function in enzyme activity and protein structure

Front 5

What is organic nutrients?

Back 5

Contains C and H atoms
usually from living organisms
for example CH4, carbs, proteins, and lipids

Front 6

What is inorganic nutrients?

Back 6

Composed of atoms other than C and H
Found in water, Earth, atmosphere
For example, minerals, gases, CO2

Front 7

What is the growth factor?

Back 7

Essential organic nutrient
This must be provided and includes the essential amino acids(from food)

Front 8

What is a heterotroph?

Back 8

Uses an organic source of carbon
Depends on other living organisms

Front 9

What is an autotroph?

Back 9

Uses CO2 for source of carbon
Does not depend on other living microorganisms

Front 10

What are the two nutritional categories based on energy sources?

Back 10

Phototrophs
Chemotrophs

Front 11

What are phototrophs?

Back 11

Use photosynthesis

Front 12

What are chemotrophs?

Back 12

Oxidize chemical compounds

Front 13

What is the nutrition based on carbon and energy sources?

Back 13

Photoautotroph
Chemoautotrohps
Saprobes

Front 14

What is an photoautotroph?

Back 14

Photosynthetic
Primary producers of organic matter

Front 15

What are chemoautotrophs?

Back 15

They derive energy from chemical rxns.
Depend totally on inorganic minerals

Front 16

What are saprobes?

Back 16

~They feed on dead organic matter
~Are involved in nutrient recycling
~Can become facultative parasite

Front 17

What is passive transport?

Back 17

Mov't of substances from an area of high concentration to an area of low conc. (diffusion)

Front 18

What is osmosis?

Back 18

Passage of water through a selective permeable membrane

Front 19

What are isotonic conditions?

Back 19

Most stable condition with no net change in volume.

Front 20

What is hypotonic?

Back 20

Less concentrated inside the cell than the outside

Front 21

What is hypertonic?

Back 21

More concentrated inside the cell than outside

Front 22

What is facilitated diffusion?

Back 22

Passive transport mechanism
Carrier molecule which exhibit specificity

Front 23

What is active transport?

Back 23

Brings substances against their natural gradient
Requires specific membrane proteins(permeases) and pumps
Uses energy
Uses endocytosis(Phagocytosis and Pinocytosis)

Front 24

What are Psychrophiles?

Back 24

Optimum temp is below 15 degreees C

Front 25

What is a mesophile?

Back 25

Grow better at intermediate temps(20-40C)
Represent the majority of fuman pathogens (30-40C)

Front 26

What are Thermophiles?

Back 26

Optimal growth at temp greater than 45 C such as in volcanoes

Front 27

What is the optimum pH for a microbe?

Back 27

6-8

Front 28

What are obligate acidophiles?

Back 28

live at pH extremes(pH 0-1)

Front 29

What are alkalinophiles?

Back 29

Live in very alkaline env't(up to 10)
Such as bacteria that transform urine to ammonia

Front 30

What are aerobes?

Back 30

utilizes gas oxygen and
Possess enzymes that allow destruction of toxic by products of oxygen

Front 31

What are obligate aerobes?

Back 31

Can only grow in oxygen

Front 32

What are facultative anaerobes?

Back 32

Aerobe that can live w/o oxygen if necessary

Front 33

What are microaerophiles?

Back 33

An aerobic organism that grows in env't containing small amounts of Oxygen (g)

Front 34

What is an Anaerobe?

Back 34

Cannot utilize Oxygen
Lack enzymes needed to break down the by-products of O2

Front 35

What are sites of anaerobic infection?

Back 35

Dental carries
Large intestines
Traumatic injuries (tetanus)

Front 36

What are aerotolerant anaerobes?

Back 36

Cannot utilize O2 but can survive in very low O2 content env't

Front 37

What are halophiles?

Back 37

Grow in env'ts high in salt content
S. aureus can grow in 20% NaCl

Front 38

What are barophiles?

Back 38

Live under extremely high hydrostatic pressure(deep sea)

Front 39

What are symbiosis?

Back 39

Two organisms living together in close partnership
The two organisms are called symbionts

Front 40

What is mutualism?

Back 40

Both will benefit from the relationship

Front 41

What is commensalism?

Back 41

One benefits but host is not damaged

Front 42

What is parasitism?

Back 42

One benefits and host is harmed

Front 43

What are the different types of non-symbiotic interaction?

Back 43

Synergism and
Antagonism

Front 44

What are different types of symbiosis?

Back 44

Mutualism
Commensalism
Parasitism

Front 45

What is synergism?

Back 45

Mutually beneficial relationship
not obligatory for their survival

Front 46

What is antagonism?

Back 46

Competition between microorganisms and leads to inhibition or death of one microbe

Front 47

Where do symbiotic microbes live in the human body?

Back 47

Oral cavity
GI tract
Urogenital Tract
Skin

Front 48

____________ microbes may become parasitic and cause diseases in humans.

Back 48

Commensal

Front 49

What is microbial growth dependent on?

Back 49

availability of nutrients
favorable env'tal conditions

Front 50

What is microbial growth characterized by?

Back 50

the increase in cell size
increase in cell number

Front 51

The viable count technique uses a __________ system.

Back 51

Closed

Front 52

What is a closed system?

Back 52

Nutrietns and spaces are finite
There are no mechanisms for removal of waste products

Front 53

What is binary fission?

Back 53

Division of a parent bacterial cell
formation of 2 daugther cells
leads to population increase

Front 54

What is the generation time?

Back 54

the duration of each division from parent cell to 2 daughter cells
Doubling effect is dependent upon favorable env't

Front 55

What is the average generation time under optimum conditions?

Back 55

30-60 minutes.

Front 56

What is antagonism?

Back 56

Competition between microorganisms and leads to inhibition or death of one microbe

Front 57

Where do symbiotic microbes live in the human body?

Back 57

Oral cavity
GI tract
Urogenital Tract
Skin

Front 58

____________ microbes may become parasitic and cause diseases in humans.

Back 58

Commensal

Front 59

What is microbial growth dependent on?

Back 59

availability of nutrients
favorable env'tal conditions

Front 60

What is microbial growth characterized by?

Back 60

the increase in cell size
increase in cell number

Front 61

The viable count technique uses a __________ system.

Back 61

Closed

Front 62

What is a closed system?

Back 62

Nutrietns and spaces are finite
There are no mechanisms for removal of waste products

Front 63

What is binary fission?

Back 63

Division of a parent bacterial cell
formation of 2 daugther cells
leads to population increase

Front 64

What is the generation time?

Back 64

the duration of each division from parent cell to 2 daughter cells
Doubling effect is dependent upon favorable env't

Front 65

What is the average generation time under optimum conditions?

Back 65

30-60 minutes.

Front 66

Short doubling times are associated with __________.

Back 66

Pathogenicity

Front 67

What is the exponential growth rate?

Back 67

population doubles with each generation

Front 68

What is the bacterial growth curve?

Back 68

Illustrates the events that occur over the course of time within a population of bacteria.

Front 69

What is the growth cure...

Back 69

A graphic representation of a close population over time
This allows estimation of the bviable count(live cells)

Front 70

What are the four distinct phases of the growth curve?

Back 70

Lag phase
Exponential growth phase
Stationary growth phase
Death phase

Front 71

What is the lag phase?

Back 71

First few house of the curve
Flat portion of the curve

Front 72

Why is the population not growing yet or growing very slowly during the lag phase?

Back 72

the bacteria need to adjust to the env't
Cells have not yet reached their max multiplication rate
Cells may be diluted excessively

Front 73

What is the exponential growth phase?

Back 73

Viable cells increase rapidly, needs nutrients and environmental conditions
Binary Fission!

Front 74

Why do symptoms of infections usually develop during the (exponential growth phase) log phase?

Back 74

Bacterial toxins and
Tissue Damage

Front 75

What is the stationary growth phase?

Back 75

The curve levels off

Front 76

Why do the cells stop growing during the stationary growth phase?

Back 76

Changes in vigor of the population
Cell death balances out cell multiplication
Depletion of nutrients and oxygen
Excretion of waste products into the growth medium

Front 77

What is the death phase?

Back 77

Curve dips downward slowly
Cells begin to die in exponential numbers
Numbers of dying cells exceeds the number of new cells formed
And cells are unable to multiply

Front 78

Why is the growth curve important?

Back 78

the phases of the growth cure are important in microbial control, infection, and food microbiology

Front 79

Microbes in the exponential growth phase are ______ ____________- to antimicrobial agents than microbes in the other phases of the growth curve

Back 79

More responsive

Front 80

Young cell cultures provide reliable results when studying bacterial characteristics such as...?

Back 80

staining bacterial motility

Front 81

What is turbidometry?

Back 81

The observation of clear nutrient solution that becomes cloudy

Front 82

What are signs of microbial growth in terms of turbidity?

Back 82

Increased cloudiness is a sign of microbial growth and....
The greater the turbidity, the larger the bacterial population.

Front 83

What can you use to measure the turbidity?

Back 83

Spectrophotometer