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Flashcards in Exam 1 Deck (123):
1

Size of molds and yeasts

5-12 microns in diameter

2

Size of Bacteria

1-2 microns

3

Has asexual-spores

Molds

4

Slow reproduction

Molds

5

Fast reproduction

Bacteria

6

binary fission

Bacteria

7

Has high diversity

Molds, Bacteria

8

Primary metabolites

Ethanol, lactic acid

9

Secondary metabolites

antibiotics

10

Who has the most end products (greatest to least)

Molds
Bacteria
Yeasts

11

Highest range of substrate utilization (greatest to least)

Bacteria
Molds (high)
Yeasts (low)

12

Why do Bacteria have a high diversity?

Lateral gene transfer

13

3 methods of lateral gene transfer

Conjugation
Transduction
Transformation

14

Mold pH range

3-8 pH

15

Yeast pH range

4-8 pH

16

Bacteria pH range

5-10 pH

17

Obligate aerobic organisms

Molds

18

Facultative anaerobic organisms

Yeasts

19

Aerobic or anaerobic organisms

Bacteria

20

Why do Bacteria have the highest substrate utilization?

They are lithotropic and organotrophic

21

What role do Archaea have in food?

none

22

Mold moisture tolerance

Very Dry

23

Yeast moisture tolerance

High level of water

24

Bacteria moisture tolerance

High level of water

25

Grows on neutral pH foods w/ high water content

Bacteria

26

Grows on low pH foods which are dry

Molds

27

Grows on low pH foods w/ high water content

Yeasts

28

Reproduction speed (fastest to slowest)

Bacteria
Yeasts
Molds

29

Budscars-limit

Yeast

30

Sexual-ascus

Yeasts

31

Divide infinitely

Bacteria

32

Up to 25 microns in length

Molds

33

End product of aerobes

CO2

34

End product of anaerobes

ethanol, acids

35

Are mold spores heat resistant

Mostly no

36

List the main classes of Molds

Deuteromycota
Ascomycota
zygomycota

37

Genus involved in peanut spoilage

Aspergillus

38

Genera of mold which can form heat resistant spores

Byssochlamys

39

Group with both sexual and asexual reproduction

Zygomycota

40

Three genera of Deuteromycota

Aspergillus
Botrytis
Candida

41

Three genera of Ascomycota

Byssochlamys
Debaromyces
Saccharomyces

42

1 Genera of Zygomycota

Rhizopus

43

Holds several species that cause bread molds

Rhizopus

44

Temperature danger zone

allows for rapid growth of bacteria, yeasts and molds
40 F to 140 F

45

4 Pathogenic genera of Bacteria

Salmonella
Shigella
Vibrio
Yersinia

46

Highest possible value for Water Activity

1

47

Eight sources of Bacteria and Protozoa in Foods

Soil and Water
Plants and plant products
Cross contaminated utensils
Gastrointestinal Tract (fecal oral route)
Food Handlers
Animal feeds
Animal hides
Air and Dust

48

"eats anything"

pseudomonas

49

"has sex with anything"

Enterobacter

50

What is the temp danger zone?

40 F to 140 F
Allows for rapid growth of B,Y,M

51

Best storage temp for frozen foods

0 F and -10 F

52

Best storage temp for canned and dried foods

50 F and 70 F

53

Food warming temperatures

140 F and 165 F

54

List 7 spices with antimicrobial compounds

Cloves
Cinnamon
Oregano
Thyme
Sage
Rosemary
Vanillin

55

Essential oil of Cloves

Eugenol

56

Essential oil of Cinnamon

Cinnamon aldehyde

57

Essential oil of Oregano

carvacrol

58

Essential oil of Thyme

Thymol

59

Terpenes, borneol, camphor, thujone are essential oils of what?

Sage, Rosemary

60

4-Hydroxy-3-methoxy-benzaldehyde is the essential oil of what?

Vanillin

61

Cloves and Oregano inhibit what 3 microorganisms?

E. coli, salmonella and Staph aureus

62

Spices which Inhibit gram positive bacteria

Sage and rosemary

63

Oregano, Thyme and Vanillin inhibit what microorganism?

Molds

64

Broadest pH growth range for foodborne organisms

Molds

65

Narrowest pH growth range for foodborne organisms

Vibrio

66

Organisms which Reduce substrates

Anaerobes

67

Organisms which Oxidize substrates

Aerobes

68

Minimal Water Activity is 0.91 - 0.88

Bacteria

69

Minimal Water activity is 0.88

Yeast

70

minimal water activity is 0.80

Mold

71

Spore forming bacteria

Bacillus and Clostridium

72

Aerobic or Anaerobic? Bacillus, Clostridium

Bacteria - Aerobic
Clostridium - Anaerobic

73

Bacteriosins

Kill competing bacteria
known as antibiotics
come from actinomycetes

74

Biggest extrinsix factor

Temperature

75

Intrinsic Properties

Properties of food that affect microbial growth

76

Extrinsic Properties

Properties of the environment that affect microbial growth

77

Chemicals that increase shelf life without refrigeration

Lactoperoxydase
thiocynate
hydrogen peroxide

78

7000 BC

Babylonians and alcohol

79

6000 BC

1st reference to food spoilage

80

3000 BC

Egyptians made cheese and butter.
Ancient cultures used salt to preserve meat

81

1000 BC

Romans used cold temperatures, smoking and fermenting to preserve meat

82

He showed that maggots wouldn't grow in meat if flies were blocked from laying their eggs.
First step away from the doctrine of spontaneous generation.

Francesco Redi

83

Examined and described bacteria through a microscope.
Regarded as the person who discovered the microbial world.

Anton Van Leeuwenhoek

84

Food boiled and sealed remained sterile.
discounted his work because they believed his treatment excluded O2.

Spallanzani

85

Known for food preservation by canning

Nicholas Appert

86

Father of Food Microbiology

Louis Pasteur

87

Surgeon who developed aseptic procedures

Joseph Lister

88

His experiment showed that heated infusions remained sterile in presence of heat sterilized air.

Schwann

89

12 D process

conservative heat treatment against C. botulinum

90

Food "safe" bacteria

lactic acid bacteria

91

When we discuss the relative safety or potential for spoilage of a food, we need to focus on two things:

What are the total number of microorganisms per gram or ml?

What types of organisms are represented in this number?

92

Taxonomists group organisms_______

phylogenetically

93

phyogenetic classification

a classification scheme that mirrors evolutionary (genetic) relationships

94

7 Criteria used to classify types of organisms include:

1. Morphological/gram stain
2. Biochemical characteristics
3. Cell wall composition. e.g. type of peptidoglycan monomer
4. Homology between 16S rRNA sequences
5. Serology; cell-wall antigens
6. Fatty acid profiles
7. Growth requirements

95

Biochemical characteristics

type of endospore, flagella, and types of substrates utilized.

96

Homology between 16S rRNA sequences

16S subunit is an integral part of the ribosome and participates in protein synthesis in all bacteria, some portions of this molecules’ sequence are highly conserved
measure of bacterial evolutionary divergence

97

Fatty acid profiles

Ratios of various fatty acids in the cell membrane are characteristic of different species and some microorganisms produce unique fatty acids

98

Growth requirements

optimal growth temperatures, oxygen requirements, and particular nutritional requirements

99

cause about 70% of all major crop diseases

Fungal pathogens

100

filamentous fungi

molds

101

individual filaments of molds

hyphae

102

Grouped mass of hyphae

mycelium

103

Hyphae of higher molds are compartmentalized by membrane divisions called ______

Septa

104

Unicellular fungi that multiply by budding or by binary fission

Yeast

105

More adaptable to severe environmental stress than other microorganisms

Fungi

106

Optimal temperature range for Fungi

20-30 degrees Celsius

107

Most common habitat of molds

soil

108

How are Mold spores dispersed?

dust

109

Reproduce by both sexual or asexual means, but in either case spores are usually produced

Fungi

110

Fungi which spoil syrups and jams

Osmophiles

111

Single reproductive cell of mycelium

spore

112

Full definition of mycelium

a multinucleate mass of cytoplasm enclosed within a rigid, branch system of tubes

113

Can grow on milk

anything

114

can grow in jerky

xerophilic mold

115

MO which can grow below a pH of 4

LAB
yeasts
molds

116

Lactic, sorbic & propionic acid are generally more inhibitory than______

HCl

117

What does adverse pH do to microbial cells

1. Retards the function of microbial enzymes
2. Retards the cells' ability to transport nutrients across its' membrane

118

Convinced the scientific world that all fermentative processes were caused by microorganisms.

Louis Pasteur

119

Proved that souring milk was caused by microbes

Louis Pasteur

120

Showed that heat destroyed undesirable microbes in wine and beer

Louis Pasteur

121

His Swan-necked flasks disproved spontaneous generation

Louis Pasteur

122

Proposed that microbes were causative agents in disease

Louis Pasteur

123

Invented vaccines

Louis Pasteur