Microbiology Chapter 6 Microbial Growth Notes

Front 1

the increase in number of cells, not cell size

Back 1

microbial growth

Front 2

what is one physical requirement for growth

Back 2

temperature

Front 3

3 types of temperature

Back 3

minimum
optimum
maximum

Front 4

psychrotrops cause

Back 4

food spoilage

Front 5

most bacteria grow between pH

Back 5

6.5 and 7.5

Front 6

molds and yeasts grow between pH

Back 6

5 and 6

Front 7

acidophiles grow in

Back 7

acidic environments

Front 8

hyptertonic environments increase

Back 8

salt or sugar

Front 9

hypertonic environmnts cause

Back 9

plasmolysis

Front 10

extreme or obligate halophiles require

Back 10

high osmotic pressure

Front 11

facultative halophiles tolerate

Back 11

high osmotic pressure

Front 12

carbon: structural organic molecules use

Back 12

energy source

Front 13

chemoheterotrops use

Back 13

organic carbon sources

Front 14

autotrophs use

Back 14

CO2

Front 15

nitrogen is in

Back 15

amino acids and proteins

Front 16

some bacteria use

Back 16

NH4+ or NO3-

Front 17

a few bacteria use N2 in

Back 17

nitrogen fixation

Front 18

sulfur in amino acids is

Back 18

thiamine and biotin

Front 19

momost bacteria in both sulfur and nitrogen decompose

Back 19

proteins

Front 20

some bacteria use

Back 20

SO42- or H2S

Front 21

phosporus is in

Back 21

DNA, RNA, ATP, and membranes

Front 22

what is a source of phosphorus

Back 22

PO43-

Front 23

inorganic elements required in small amounts

Back 23

trace elements

Front 24

trace elements are usually as

Back 24

enzyme cofactors

Front 25

obligate aerobes
facultative anaerobes
obligate anaerobes
aerotolerant anaerobes
micro-aerophiles

Back 25

types of oxygen (O2)

Front 26

singlet oxygen is toxic because

Back 26

02 boosted to a higher-energy state

Front 27

superoxide free radicals goes through

Back 27

superoxide dimultase

Front 28

peroxide anion goes through

Back 28

catalase
peroxide

Front 29

toxic forms of oxygen

Back 29

singlet oxygen
hydroxyl radical

Front 30

singlet oxygen types

Back 30

superoxide free radicals
peroxide anion

Front 31

organic compounds are obtained from

Back 31

the environment

Front 32

what are some organic compounds

Back 32

vitamins, amino acids, purines, and pyrimidines

Front 33

nutrients prepared for microbial growth

Back 33

culture medium

Front 34

no living microbes

Back 34

sterile

Front 35

introduction of microbes into medium

Back 35

inoculum

Front 36

microbes growing in/on culture medium

Back 36

culture

Front 37

agar has complex

Back 37

polysaccharide

Front 38

what is used as a solidifying agent for culture media in

Back 38

Petri plates, slates, and deeps

Front 39

agar is generally not metabolized by

Back 39

microbes

Front 40

agar liquefies at

Back 40

100*C

Front 41

solidifies at

Back 41

-40*C

Front 42

exact chemical composition is known

Back 42

chemically defined media

Front 43

extracts and digests of yeast, meat or plants

Back 43

complex media

Front 44

types of complex media

Back 44

nutrient broth & agar

Front 45

reducing media contains chemicals that

Back 45

combine 02

Front 46

reducing media is heated to

Back 46

drive off 02

Front 47

heated to drive off 02

Back 47

anaerobic jar
anaerobic chamber

Front 48

require high CO2

Back 48

capnophiles

candle jar
Co2-packet

Front 49

suppress unwanted microbes and encourage desired microbes

Back 49

selective media

Front 50

make it easy to distinguish colonies of different microbes

Back 50

differential media

Front 51

encourages growth of desired microbe

Back 51

enrichment media

Front 52

contains only one species or strain

Back 52

pure culture

Front 53

a population of cells arising from a single cell or spore or from a group of attached cells

Back 53

colony

Front 54

a colony is often called a

Back 54

colony-forming unit (CFU)

Front 55

deep-freezing

Back 55

-50*C to -95*C

Front 56

lyophilization

Back 56

freeze-drying

frozen (-54*C to-72*C) and deydrated in a vacuum

Front 57

reproduction in prokaryotes

Back 57

binary fission
budding
conidiospores
fragmentation of filaments

Front 58

perform serial dilutions of a sample

Back 58

plate counts

Front 59

inoculate Petri plates from

Back 59

serial dilutions

Front 60

after incubation

Back 60

count colones in plates that have 25-250 colonies

Front 61

direct measurements of microbial growth

Back 61

filtration
multiple tube MPN test
direct microscope count
capillary actions

Front 62

count positive tubes and compare to statistical MPN table

Back 62

multiple tube MPN test

Front 63

how do you estimate bacterial numbers by indirect methods

Back 63

turbidity

#of bacteria-ml or # of cells counted / volume

Front 64

direct methods of measuring microbial growth

Back 64

plate counts
filtration
MPN
direct microscopic count
dry weight

Front 65

indirect method of measuring microbial growth

Back 65

turbidity
metabolic activity
dry weight