Exam 3

Unit 7, 8, 9, 10 (I-III)

Pasteurization is

The use of mild heating to eliminate microbes.

Are the bacteria that do survive the process of pasteurization likely to cause disease?

No, it’s unlikely they cause disease.

Phosphate test will be inactive to determine if

Products have been pasteurized.

Temperature and time for pasteurization

72C for 15 seconds

High Osmotic Pressure (definition)

High concentration of salts and sugars to create a hypertonic environment where water leaves the cell

What leaves the cell and what stays with high osmotic pressure?

Bacteria is eliminated, but yeasts and molds still grow.

Ionizing Radiation

Gamma and X-rays, high energy electron beams (wavelength of \~1 nm)

How does ionizing radiation work?

Kills organisms by reacting with their cellular matter, like DNA, and damaging it

Uses of ionizing radiation

Vegetable, spices, certain meats, some medical equipment, even USPS mail

Non-ionizing Radiation

UV light, 1+ nm

How does non-ionizing radiation work?

Damages DNA of exposed cells by making bonds form between adjacent thymine bases

What does sodium nitrate/nitrite do?

Preserve the pleasing red color of meat by reaction with blood components

What does sodium nitrate/nitrite prevent and form?

It can prevent the germination and growth of any botulism endospores. It can form nitrosamines, a carcinogenic product

Sorbic Acid and Sodium Benzoate

Prevent molds from growing in certain acidic conditions, like with cheese and soft drinks.

Canning is done mainly to

Prevent C. botulinum

Describe 12D treatment

Give a theoretical population of C. botulinum of 10^12, after the canning process, 1 survivor would be left. It's a very reliable process

Vitamin B12 Production

Produced by Pseudomonas sp. and Propionibacterium sp.

Vitamin B2 Production

Fungi via fermentation, Ashbya gossypii

Vitamin C Production

Complicated modification go glucose by Acetobacter sp.

Steroid Transformation

Making a sterol a steroid is chemically complex, but some microbes like Streptomycin make it easy via the addition of a hydroxyl group, +HO.

Steroid Transformation Examples

Cortisol → Cortisone

Estrogens and progesterones (oral birth control)

Milk is

Sterile when in the udder

Enzyme required to make cheese

Rennin - under low pH

What microbes are used to produce lactic acid and lower pH?

S. lactic and S. cremoris

Butter - fat globules is made with … and requires …, …

Leuconstoc sp., S. lactis, and S. cremoris

What does Leuconstoc sp. produce?

Diacetyls (butter flavor)

Yogurt is made with

Lactobacillus and S. thermophilus

Kefir and Kumiss is milk fermented with … and has an alcohol contact between …

Yeast, 1-2%

Sauerkraut, pickles, and olives are made with

Leuconstoc and lactobacillus

Soy sauce is made with

Aspergillus oryzae

Vinegar is made with

Acetobacter or Gluconobacter, made from cider or wine.

Converts ethanol to acetic acid.

Single Celled Proteins are used as a supplement in

Livestock fodder (food)

… Microbe is high in protein which is why it’s used as a supplement in livestock fodder

Torsula sp.

Glutamic acid facts

1 million tons/year

Food condiment

Food allergies

Glutamic acid is produced by

Micrococcus and Corynebacterium glutamicum

Lysine production rate

250,000 tons/year

Lysine is produced by

Corynebacterium glutamicum

Citric acid production rate

1\.6 million tons/year

70% used in the food industry; 30% used for industrial purposes

Citric acid is produced by … which converts

Aspergillus niger, molasses to citric acid

Proteases are made with

Aspergillus sp. and Bacillus sp.

Proteases are found in

Detergents, meat tenderizers, leather production, chill-proofing beer

Amylases break down …, made with

Starches, Aspergillus sp. and Bacillus sp.

Lactase breaks down …, made with

Lactose, yeast

Antibiotics produced by fungus Penicillum

Penicillin and griseofulvin

Antibiotics produced by fungus Cephalosporium

Cephalothins

Antibiotics produced by bacteria Bacillus

Bacitracin and polymyxin

Antibiotics produced by bacteria Streptomyces sp. 

Streptomycin, tetracycline, amphotericin, chloramphenicol

Rhizobium will mix with

Peat moss to retrain moisture and then seeded with legumes to ensure infection of the plant

Bacillus thuringiensis (Bt) is a microbe that

Eats mosquito larvae and gypsy moths, used in municipal control programs and home gardens

Biomass

Organic matter produced by living organisms, including crops, waste, and trees

Bioconversion

Using microbes to convert biomass into energy

Biofuels

Ethanol from agricultural crops; methane from landfills for electricity

Recombinant DNA (genetic engineering)

Any artificial manipulation of genes within a species or between different species

Restriction enzymes

Enzymes that cut DNA into pieces that are easy to recombine in-vitro

Vector

Transports foreign DNA into a cell. Plasmid or virus that inserts genes into a cell

Clone

Genetically identical cells

Human insulin

E. coli carries human gene that makes this hormone

Human Growth Hormone

Somatotropin (used to be extracted from cadavers)

Hepatitis B Vaccine

Yeast carries viral gene

Gene therapy

Replace a defective or mutated gene

Cystic Fibrosis

Inhalation of a harmless cold virus that carries the healthy gene that the person lacks, virus is a vector.

Agammaglobulinemia

Inability to produce antibodies.

Agammaglobulinemia therapy

Addition of genetically engineered virus to the bone marrow

Bovine Growth Hormone (BGH)

E. coli carries gene

Insertion of nitrogen-fixation genes into plants…

using Rhizobium

CRISPR enzymes come from

Archae and Baceria

CRISPR

Enzymes can destroy DNA mutations using a small RNA molecule to target the mutated DNA and replace it.

Disease

Abnormal state in which the body isn’t capable of carrying on its normal function

Infection

Invasion or colonization of the body by pathogenic microbes

Pathogens

Disease causing microbes

Pathology

Study of disease

Etiology

Cause of disease → Koch’s Postulates

Normal Flora: Commensals

Important in location and concentration

Sporadic

Disease occurs occasionally in a population

Endemic

Disease constantly in a population

Epidemic

Many people in a given area acquire a disease in a short period of time

Pandemic

Worldwide epidemic

Acute

Disease develops rapidly, but lasts a short time, like the flu

Chronic

Disease develops slowly, bodies reaction are less severe and disease process is likely to be continual or recurrent for a long time, like ringworm

Subacute

Disease that is intermediate between acute and chronic

Subacute disease example

Sclerosing panencephalitis

Latent

Causative agent remains inactive for a period of time but then becomes active

Localized

Microbes are limited to an area, boils or abcesses

Generalized or systemic

Microbes or products spread via the blood and lymphatic system, like measles

Focal

Infection starts as local, but then becomes generalized

What do focal infections arise from?

Infections of the teeth, tonsils, and sinuses

Primary Infections, HIV

Infection that causes initial illness

Secondary Infections, Toxoplasmosis

Infection that is caused by an opportunist microbe because the body is weakened

Nosocomial

Hospital Acquired Infections (HAI)

Rate of nosocomial infections has risen 36% over 20 years because of

Microbes in the environment

Compromised host

Chain of transmission

Types of HAIs

Lower RT

Surgical sites

UTIs (insertion of catheter)

Types of HAI causing microbes

E. coli

Staph/Strep

Pseudomonas

C. difficiles

Bacteremia

Bacteria in blood

Septicemia (sepsis)

Pathogens multiplying in blood, blood poisoning

Toxemia

Toxins in blood, like tetanus

Viremia

Viruses in blood, measles

Pyemia

Pus forming microbes in blood

Signs are

Measured, like temperature

Symptoms are

Felt, like muscle-aches

Period of incubation:

Interval between initial infection and appearance of signs/symptoms