Microorganisms and Fermentation

Question 1

What product is Salmonella Enteritidis most commonly linked with? How does it get into this product? How can you prevent this bacterium from causing illness?

Answer 1

Eggs. Chicken feces would contaminate the egg through the micro cracks. Cook properly.

Question 2

How is Salmonella typhi transferred to foods? What does it cause? What is the only method that can be used to control the spread of Salmonella typhi?

Answer 2

Transfered through food through cross contamination of feces from an infected person. Causes Typhoid fever. Washing hands and practicing cleaning and sanitizing.

Question 3

How is E. coli O157:H7 spread to humans? What type of toxins does it produce? What syndrome does it cause? What are the symptoms/side effects of this syndrome? What products is this bacterium commonly associated with? How can you prevent the spread of this bacterium?

Answer 3

Fecal-Oral. Shiga toxins. Hemolytic-uremic syndrome. Profused Bloody Diarrhea or affect kidneys side effect. Under cooked or raw hamburger meat. Cook properly.

Question 4

What does Campylobacter jejuni cause (symptom)? What product is it commonly associated with? How can you control this bacterium?

Answer 4

Diarrhea. Associated with cattle, chickens, birds, and flies. Cook properly.

Question 5

Listeria monocytogenes does not produce spores, so why is such a concern in the food industry? What types of people does Listeriosis affect the most?

Answer 5

Ubiquitous (Everywhere) and very resistant to people. Pregnant women, newborns, elderly, and people with weakened immune systems.

Question 6

Describe Clostridium perfringens. Where is it commonly found/ products it is associated with? How does contamination of this bacterium occur? How can you prevent this type of contamination?

Answer 6

Spore former. Found in intestines, common in raw meat and poultry. Improper storage and reheated foods. Store and reheat properly.

Question 7

Why is Clostridium botulinum such a concern in the food industry (hint there are two reasons)? How does this bacterium’s toxin work?

Answer 7

Spore has high resistant to heat. Illness often leads to death if not treated. Causes Paralysis.

Question 8

Describe Norovirus. How is it spread? What are some commonly associated products? How can you prevent the spread of this virus?

Answer 8

Single RNA strand. Fecal-Oral Route. Products? Wash Hands

Question 9

Define outbreak

Answer 9

2 or more people eat same food and have same illness.

Question 10

List and describe the top three causes for foodborne illness.

Answer 10

Improper Temperature of storage or cooking (not cooked thoroughly)
Improper Personal Hygiene (washing hands)
Cross Contamination of food

Question 11

Describe how bacteria can be classified based on gram-staining.

Answer 11

Gram Positive - Has peptidoglycan which absorbs crystal violet
Gram Negative - Has outer cell which absorbs safranin

Question 12

What is the spore cycle?

Answer 12

1. Vegetative Cell
2. Sporulate
3. Spore
4. Germinate
5. Vegetative Cell

Question 13

All ____________________produce spores as well as some bacteria and yeast. Spores are dangerous in the food industry because they are _________________________ to heat, chemicals, and hostile environments.

Answer 13

Molds

Resistant

Question 14

What are the shapes of yeast? What are the bacterial shapes?

Answer 14

Yeast: Spherical or ellipsoidal
Bacteria: Cocci (Dots), Bacilli (Bars), Sparilla (Spirals/Springs)

Question 15

Molds grow by a network of hairlike fibers called ______________________ that produce spores called _______________________. The color of mold is based on the ___________________________. The hairlike fibers can penetrate deep into the food product, where it is ______________________________.

Answer 15

Myciluim
Conidia
Type of Mold
Mycelium

Question 16

Protozoa are single celled ___________________________ that we commonly call parasites. They do not grow in foods, but use animals as their __________________. They exist in the form of ____________________,which can then germinate when ingested.

Answer 16

Eukaryotes
Host
Cysts

Question 17

Viruses are small infectious agents that must have a living host __________________ for replication. They attach to the host cell and then inject their nuclear material into the cell. The ones that we worry about with food are often made up of ____________________________.

Answer 17

Cells

RNA containing viruses

Question 18

Mesophilic. microorganisms will grow at temperatures between ________________ and ____________________. Psychrophilic microorganisms grow at temperatures down to the point of freezing water, which is _________________.The last temperature group is called thermophilic and they grow at temperatures up to _________________.

Answer 18

60F
100F
32F
180F

Question 19

All molds and some bacteria are considered ___________________ because they require oxygen to grow. Some bacteria are unable to grow in the presence of oxygen and so they are called ____________________. Then there are the bacteria that can grow with or without oxygen and they are termed ______________________________.

Answer 19

Microorganisms
Anaerob Organisms
Faculative

Question 20

________________________ organisms are ones that require chemicals in their diet and ______________________________ are microorganisms that require light to for growth and survival. The chemotrophic organisms can be further classified by their need for organic or inorganic chemical compounds. Microorganisms that feed off of organic compounds like sugar and carbohydrates are called ___________________________, where as the microorganisms that feed off of inorganic compounds such as minerals like iron are considered ____________________________. The microorganisms that we worry about in food science are considered to be __________________________________.

Answer 20

Chemotrophic
Phototrophic
Organotrophic
Lithotrophic
Chemotrophic

Question 21

How does a low pH inhibit microbial growth? (Hint what does it do to the cell)

Answer 21

pH determines the growth of bacteria, if very acidic, growth cannot take place if acidic level is higher then 4.6 (pH1-4). if pH 5-14 then growth can occur

Question 22

What are the temperatures in the temperature danger zone?

Answer 22

40F to 140F

Question 23

What is the term used to describe how bacteria replicate? How fast can bacteria replicate?

Answer 23

Binary Fission (Cell Division)
Can reproduce rapidly if in favorable environment (double in 20-30 min)

Question 24

What aw (Water Activity) do bacteria need for growth? Molds and yeasts? How does a low aw product inhibit microbial growth?

Answer 24

Bacteria: 0.9
Yeast: 0.7
Mold: 0.8
If lower than what is needed then it can not grow

Question 25

Define a food intoxication and intoxification. Define a food infection. Be sure to know the differences.

Answer 25

Infection- consumed microorganisms cause illness Intoxication- consumed toxin causes illness Intoxiflication- consumed microorganism produces toxins that cause illness

Question 26

___________________________ organisms attack fats, phospholipids, and other fatty substance and give rise to rancid and fishy odors and flavors. ________________________organisms break down proteins and other nitrogenous compounds and give rise to putrid and rotten odors and flavors.

Answer 26

Lipolytic | Proteolytic

Question 27

Pectin methyl esterare is an ________________________ that is naturally found in fruits and vegetables or can come from some bacteria and molds. It hydrolyzes the ______________________ in fruits and vegetables. Cellulase is an enzyme that comes from _______________________ and __________________ molds. It targets the _____________________ in fruits and vegetables and breaks apart their chemical bonds. By doing this, the enzyme causes the product to soften.

Answer 27

``` Enzyme Enzymatic Reaction Bacillus Species Asperguillus/Pencillium Galacturonic Acid ```

Question 28

_________________________________ is a bacteria that consumes lactose sugar. In return it produces _____________________, which can alter the product’s pH, cause sour flavors, off odors, and changes to consistency. Then there is the yeast __________________________, which consumes simple sugars like glucose to produce the alcohol, ____________________.

Answer 28

Lactobacillus Lactic Saccharomyces cerevisiae Ethanol

Question 29

Fermentation occurs when microorganisms feed on organic matter such as carbohydrates in food system and produce by-products such as alcohol, acid, and _____________________. Fermentation has been used for thousands of years to preserve food. This is because the fermentative microorganisms produce byproducts, which prevent the growth of _______________________, lipolytic, and _______________________ microorganisms.

Answer 29

? ? ?

Question 30

Fermented foods can actually be more ________________________ than their none fermented counterparts. One reason is because they have the ability to ______________________ several complex vitamins. The second way, is through the liberation of ________________________ looked in plant structures and cells by indigestible materials.

Answer 30

Nutritional Synthesize Cellulase

Question 31

What does FATTOM stand for? Know each of these letters, what they mean, and how they relate to the growth needs of microorganisms.

Answer 31

Food- Need a nutritional source. Chemotrophic - require chemical compounds like sugar and carbs. Phototropic require light Acid: Low acid foods pH4.6 or higher allow bacterial growth. High acid foods: pH4.6 or lower prevent growth Time- Temperature danger zone 40-140 F - dont keep foods that are out of it for more than 2 hours . Temp: Requirements Mesophilic: 60*F to 100*F Psychrophilic: 32*F Thermophilic: 180*F Oxygen: Anaerobic-( cant have oxygen). Aerobic- (Can have oxygen) Moisture: Bacteria Aw 0.9 Molds and yeast: Aw 0.8 low Aw causes cells to dry out (Osmotic Pressure)