Chapter 7: Microbial Nutrition, Ecology, And Growth

Front 1

Nutrition

Back 1

Process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities

Front 2

Essential nutrients

Back 2

Must be provided to an organism

Front 3

Macronutrients

Back 3

Required in large quantities; play principal roles in cell structure and metabolism

Front 4

Micronutrients (or trace elements)

Back 4

Required in small amounts; involved in enzyme function and maintenance of protein structure

Front 5

Organic nutrients

Back 5

Contain carbon and hydrogen atoms and are usually the products of living things

Front 6

Inorganic nutrients

Back 6

Atom or molecule that contains a combination of atoms other than carbon and hydrogen

Front 7

Chemical analysis of cell contents

Back 7

70% water

Proteins

96% of cell is composed of 6 elements (CHONPS)

Front 8

Sources of Essential Nutrients

Back 8

Heterotroph

Autotroph

Front 9

Heterotroph

Back 9

Must obtain carbon from an organic form made by other living organisms

Proteins, carbohydrates, lipids, and nucleic acids

Front 10

Autotroph

Back 10

Uses CO2 (inorganic gas) as its carbon source

Not nutritionally dependent on other living things

Front 11

Growth factors

Back 11

Essential organic nutrients

Organic compounds that cannot be synthesized by an organism because they lack the genetic and metabolic mechanisms to synthesize them

Must be provided as a nutrient

(Essential amino acids, vitamins, nucleotides)

Front 12

Energy source

Back 12

Chemotroph

Phototroph

Front 13

Chemotroph

Back 13

Gain energy from chemical compounds

Front 14

Phototrophs

Back 14

Gain energy through photosynthesis

Front 15

Majority are chemoheterotrophs which are

Back 15

aerobic respiration

Front 16

Two categories of heterotrophs

Back 16

Saprobes and Parasites

Front 17

Saprobes

Back 17

Free-living microorganisms that feed on organic detritus from dead organisms

Opportunistic pathogen

Facultative parasite

Front 18

Parasites

Back 18

Derive nutrients from host

Pathogens

Some are obligate parasites

Front 19

Passive transport

Back 19

Does not require energy

Substances move from areas of higher concentration toward areas of lower concentration diffusion

Osmosis

Facilitated diffusion - require a carrier

Front 20

Active transport

Back 20

Requires energy and carrier proteins

Gradient independent

Active transport

Group translocation

Bulk transport (endocytosis, exocytosis, pinocytosis)

Front 21

Endocytosis

Back 21

Eating and drinking by cells

Bringing substances into the cell through a vesicle or phagosome

Phagocytosis and Pinocytosis

Front 22

Phagocytosis

Back 22

ingests substances or cells

Front 23

Pinocytosis

Back 23

ingests liquids

Front 24

Environmental factors that influence microbes

Back 24

Temperature, oxygen requirements, pH, osmotic pressure, barometric pressure

Front 25

Niche

Back 25

Totality of adaptations organisms make to their habitat

Front 26

3 cardinal temperatures

Back 26

Minimum temperature

Maximum temp

Optimum temp

Front 27

Minimum temp

Back 27

Lowest temp that permits a microbe's growth and metabolism

Front 28

Maximum temp

Back 28

Highest temp that permits a microbe's growth and metabolism

Front 29

Optimum temp

Back 29

Promotes the fastest rate of growth and metabolism

Front 30

3 Temperature Adaptation Groups

Back 30

Psychrophiles, Mesophiles, Thermophiles

Front 31

Psychrophiles

Back 31

Optimum temperature below 15 degrees C

Capable of growth at 0 degrees C

Front 32

Mesophiles

Back 32

Optimum temperature below 20-40 degrees C

Most human pathogens

Front 33

Thermophiles

Back 33

Optimum temperature greater than 45 degrees C

Front 34

Gas requirement

Back 34

Oxygen

Front 35

As oxygen is utilized, it is

Back 35

transformed into several toxic products

Front 36

If a microbe is not capable of dealing with toxic oxygen,

Back 36

it is forced to live in oxygen free habitats

Front 37

Aerobe

Back 37

Utilizes oxygen and can detoxify it

Front 38

Obligate aerobe

Back 38

Cannot grow without oxygen

Front 39

Facultative anaerobe

Back 39

Utilizes oxygen but can also grow in its absence

Front 40

Microaerophilic

Back 40

Requires only a small amount of oxygen

Front 41

Anaerobe

Back 41

Does not utilize oxygen

Front 42

Obligate anaerobe

Back 42

Lacks the enzymes to detoxify oxygen so cannot survive in an oxygen environment

Front 43

Aerotolerant anaerobes

Back 43

Do not utilize oxygen but can survive and grow in its presence

Front 44

Carbon dioxide requirement

Back 44

All microbes require some carbon dioxide in their metabolism

Capnophile grows best at higher COs tensions than normally present in the atmosphere

Front 45

Symbiotic

Back 45

Mutualism, commensalism, parasitism

Front 46

Nonsymbiotic

Back 46

Synergism and Antagonism

Front 47

Commensalism

Back 47

One benefits, the other member is not harmed.

Front 48

Synergism

Back 48

Members cooperate and share nutrients

Front 49

Antagonism

Back 49

Some members are inhibited or destroyed by others

Front 50

Biofilms result when

Back 50

organisms attach to a substrate by some form of extracellular matrix that binds them together in complex organized layers

Front 51

Quorum sensing

Back 51

Communicate and cooperate in the formation and function of biofilms

Front 52

Binary fission (transverse)

Back 52

Parent cell enlarges, duplicates its chromosome, and forms a central transverse septum dividing the cell into two daughter cells

Front 53

Generation or doubling time

Back 53

Time required for a complete fission cycle

Front 54

Exponential growth

Back 54

Each new fission cycle increases the population by a factor of 2

Front 55

Growth curve

Back 55

Predictable pattern over time

Front 56

Lag phase

Back 56

"Flat" period of adjustment, enlargement; little growth

Front 57

Exponential growth phase

Back 57

A period of maximum growth will continue as long as cells have adequate nutrients and a favorable environment

Front 58

Stationary phase

Back 58

Rate of cell growth equals rate of cell death caused by depleted nutrients and O2, excretion of organic acids and pollutants

Front 59

Death phase

Back 59

As limiting factors intensify, cells die exponentially

Front 60

Turbidometry

Back 60

Degree of cloudiness, turbidity, reflects population size

Front 61

Enumeration of bacteria

Back 61

Viable colony count

Direct cell count

Front 62

Photoautotroph

Back 62

Energy source: Sun

Source of carbon: CO2

Examples: Plants, algae, bacteria, protozoa

Front 63

Photoheterotroph

Back 63

Energy source: Sun

Source of carbon: Organic compounds

Examples: Bacteria

Front 64

Chemoautotroph

Back 64

Energy source: Inorganic compounds
Source of carbon: CO2

Examples: Bacteria

Front 65

Chemoheterotroph

Back 65

Energy source: Organic compounds

Source of carbon: Organic compounds

Examples: Animals, fungi, bacteria, protozoa