Applied And Industrial Microbiology

Front 1

What are a few ways we preserve food?

Back 1

Dried/ salted fish resist decay, high sugar/salt prevents spoilage, soured milk resists decomposition, soured milk can be pressed and allowed to ripen (cheese)

Front 2

What are the agencies that inspect dairies and restaurants?

Back 2

FDA and USDA (usually can only detect contamination after it occurs)

Front 3

Hazard Analysis and Critical Control Point (HACCP)

Back 3

Identifies points at which foods may become contaminated, tries to prevent contamination before it happens by testing points of contact with the food for contamination

Front 4

What are the points of contact tested with food that are tested for contamination?

Back 4

slaughter houses, processing plants, distribution agencies

Front 5

Industrial Food Canning

Back 5

must kill endospore-forming Clostridium botulinum without spoiling food

Front 6

Commercial Sterilization

Back 6

steam under pressure in a retort- like a big autoclave, not as rigorous as complete sterilization

Front 7

12D treatment

Back 7

population of endospores decreased by 12 logarithmic cycles (1 survivor in 10^12 endospores). this is considered a safe level.

Front 8

What endospore formers may survive 12D treatment but remain dormant at 45 degrees celsius so they aren't a problem?

Back 8

Thermophilic endospores

Front 9

Thermophilic anaerobic spoilage

Back 9

spoilage from thermophilic bacteria that survive in low-acid canned foods, can well with gas- food has low pH and sour odor, species of Clostridium cause this

Front 10

Flat sour spoilage

Back 10

Thermophilic spoilage without gas, often caused by Geobacillus stearothermophilus

Front 11

Why does thermophilic anaerobic spoilage and flat sour spoilage occur?

Back 11

food is stored at too high of a temperature

Front 12

What bacteria spoils food in leaking cans?

Back 12

External mesophilic bacteria that is introduced in the sealing process causing putrefaction

Front 13

What happens in the sealing process?

Back 13

Hot cans are sprayed with cooling water or put in a cooling water trough- this creates a vacuum. If the can is not properly sealed, cooling water (containing bacteria) is drawn in to the can.

Front 14

Explain the can sealing process:

Back 14

1) blanching in hot water/steam softens the product to easily fill can- lowers microbial population 2) cans are filled to capacity, leaving minimal dead space 3) steam is used to exhaust dissolved air 4) cans are sealed 5) cans are sterilized by pressurized steam in a retort 6) cans are cooled by submersion in water both 7) cans are labeled and sold

Front 15

Aseptic Packaging

Back 15

packages made of materials that cannot tolerate heat, packaging is sterilized before sterile food is added

Front 16

What is paper and plastic sterilized with?

Back 16

hot hydrogen peroxide or UV light

Front 17

What are metal containers sterilized with?

Back 17

super-heated steam or high energy electron beams

Front 18

Radiation and Industrial Food Preservation

Back 18

ionizing radiation damages DNA and inhibits reproduction of bacteria, plants, and animals. Food or packaging never becomes radioactive- gamma passes through and is not absorbed

Front 19

Cobalt-60

Back 19

produces gamma rays

Front 20

What mechanisms does a gamma-ray irradiation facility use?

Back 20

Shielding- irradiation sources lifted from storage pool for processing period, materials to be irradiated, and conveyors to move material in and out of processing position

Front 21

High-Pressure Food Preservation- Pascalization

Back 21

prewrapped, precooked foods submerged into pressurized water tanks (87,000 psi), kills many pathogens and nonpathogenic, preserved food color and flavor, does not provoke concerns of irradiation

Front 22

Microorganisms in food production

Back 22

in the late 19th century, Pasteur and others began to understand the role of bacteria and yeast in food production. after that the industries of wine, beer, cheese, etc. production grew rapidly

Front 23

Usually _____ _____ producing bacteria are added to milk.

Back 23

lactic acid

Front 24

Curd

Back 24

made of protein casein and formed by the action of an enzyme (rennin) and lactic acid bacteria

Front 25

Whey

Back 25

liquid separated from curd

Front 26

What are hard cheeses ripened by?

Back 26

lactic acid bacteria (Propionibacterium produces carbon dioxide which makes holes in Swiss cheese)

Front 27

What are soft cheeses ripened by?

Back 27

produced aerobically by molds such as Penicillium on the surface of cheese (can be mixed into soft cheese aerobically to grow blue cheese)

Front 28

Butter

Back 28

flavor and aroma are from diacetyls produced by lactic acid bacteria

Front 29

Yogurt

Back 29

milk inoculated with Streptococcus thermopiles and Lactobacillus delbrueckii

Front 30

Kefir and kumiss

Back 30

fermented milk beverages made with lactic acid producing bacteria and lactose-fermenting yeast

Front 31

Nondairy Fermentations

Back 31

Bread dough and beer- Saccharomyces cerevisiae produces ethanol anaerobically. Sauerkraut, pickles, olives, chocolate

Front 32

How do you make wine?

Back 32

1) grapes are tested and picked 2) grapes are crushed and destemmed 3) sulfite is added to kill undesirable yeasts and bacteria 4) yeast inoculum is added 5) fermentation occurs 6) result in pressed to separate solids from wine 7) wine is clarified in settling vats

Front 33

Industrial fermentation

Back 33

large-scale cultivation microbes to produce a commercial substance, uses bioreactors

Front 34

Bioreactors

Back 34

often used for the fermentative or aerobic growth of genetically engineered microorganisms, these organisms have been engineered to produce human proteins such as insulin and growth hormone as well as some vitamins, amino acids and similar products which are used medicinally, huge amounts of these products can be produced very economically

Front 35

Biofuels

Back 35

Sugars are fermented by microorganisms to ethanol, cellulose is digested by cellulase to make ethanol, bacteria can be genetically engineered to make long-chain alcohols, algae yield 20% of their weight in oil; remained can be used to produce ethanol

Front 36

Industrial Microbiology and the Future

Back 36

food processing technologies, recombinant DNA technology, ethanol and hydrogen as renewable energies

Front 37

MFC's

Back 37

bacteria produce energy by the process of oxidation (LEO-produces electrons). Electricity is the flow of electrons. bacteria use wide variety of substances (industrial/agricultural waste) as the substrate for oxidation. so they get rid of waste products and produce electricity at the same time.

Front 38

Most MFC's use _________ as the final electron acceptor so they produce clean water

Back 38

oxygen

Front 39

Example (MFC produces hydrogen gas)

Back 39

1) plant waste fermentation produces acetic acid 2) bacteria consume acetic acid releasing electrons, protons, and CO2. 3) >0.2 volts are added from an outside source 4) electrons join with protons and form hydrogen gas 5) hydrogen is clean fuel that vehicles running on natural gas can use

Front 40

How can bacteria assist in powering vehicles without producing pollution?

Back 40

Bacteria that feed on vinegar and waste are zapped with a tiny shot of electricity and produce hydrogen gas that can be used to power vehicles