Bacterial Visualization, Growth and Control Flashcards Preview

Microbiology > Bacterial Visualization, Growth and Control > Flashcards

Flashcards in Bacterial Visualization, Growth and Control Deck (112)
Loading flashcards...
31

3 techniques to obtain isolated colonies

streak plate
pour plate
spread plate

32

streak plate

easiest technique

33

pour plate

sample mixed in liquid agar
poured and allowed to harden

34

spread plate

sample poured on hardened agar
spread with sterile glass rod

35

culture media definition

solid or liquid containing nutrients or other agents required for growth

36

agar

polysaccharide from red algae

37

defined medium

known chemical composition

38

minimal defined medium

contains just enough nutrients to support growth

ex E. Coli mostly self-sufficient
Leuconostoc very demanding, requires many substances to grow

39

rich defined medium

excess nutrients
grows largest number of species

40

undefined (complex) medium

exact composition unknown, grows all species
contains: beef, blood, casein, yeast, soybeans

41

undefined medium examples

tryptic soy agar (TSA)
nutrient agar

42

selective medium

favors some species while inhibiting others
ex- salt agar isolates salt tolerant species from mixed sample
Staphylococcus

43

salt agar

isolates salt tolerant species from mixed sample
Staphylococcus

44

differential medium

growth characteristics on agar distinguish different species
ex- blood agar

45

blood agar

all species grow, colonies look different on blood

46

beta hemolysis

complete breakdown of red blood cells

47

alpha hemolysis

partial breakdown of red blood cells

48

gamma hemolysis

no effect on red blood cells, no hemolysins

49

mobility agar

all species grow
distinguished by movement in agar

50

selective and differential agar

selects some, differentiates by appearance

51

mannitol salt agar

selects for salt tolerant species
inhibits salt intolerant species
yellow color- Staphylococcus aureus

52

MacConkey agar

selects for Gram positives, inhibits Gram negatives
differentiates colonies by lactose fermentation- pinkish to reddish color

53

E. coli in MacConkey agar

ferments lactose
forms reddish colonies

54

Shigella and Salmonella in MacConkey agar

do not ferment lactose
form white colonies

55

enrichment procedure

expose mixed sample to unusual treatments

56

endospore isolation

boil sample, only spore formers survive

57

environmental conditions that directly influence bacterial growth

temperature, pH, oxygen

58

temperature maintenance

incubators, water baths, refrigerators

59

psychrophiles

cold tolerant bacteria

60

mesophiles

room temperature loving bacteria