November 25

Question 1

High G-C

Answer 1

Old terminology associated with Gram positive bacteria

>50% G-C (actinobacteria)

Question 2

Low G-C

Answer 2

Old terminology associated with Gram positive bacteria

<50% G-C

Question 3

Nonsporulating Gram Positive Examples

Answer 3

Staphylococcus, Mircococcus, Streptococcus, Enterococcus, Lactobacillus

Question 4

Staphylococcus

Answer 4

Aerobic cocci

Resistant to reduced H₂O production

Salt Tolerant

Question 5

Micrococcus

Answer 5

Aerobic cocci

Resistant to reduced H₂O production

Salt tolerant

Can be pigmented

Question 6

Staphylococcus aureus

Answer 6

Gram Positive

Aerobic

Opportunistic pathogen

20% of the population carries it in the nasal cavity

Question 7

Micrococcus luteus

Answer 7

Gram Positive

Aerobic

Pigmentation is produced at optimum temperature (yellow)

Question 8

Sarcina

Answer 8

Gram Positive

Obligate anaerobe

Extremely acid tolerant

Found in the stomach of monogastrous animals

Forms packets of 8 cells (cubes)

Question 9

Streptococcus

Answer 9

Gram Positive

Homofermentive

Chains of cocci

Used in production of buttermilk and silage

Pathogenic (sometimes)

Question 10

Streptococcus pyrogenes

Answer 10

“flesh eating”

Necrotizing faciitis

Question 11

Enterococcus

Answer 11

Gram positive

Fecal origin

Opportunistic pathogen

Question 12

Enterococcus faecalis

Answer 12

Part of natural microflora

Opportunistic pathogen

Nosocomial infections including UTIs and endocarditis

Question 13

Lactobacillus

Answer 13

Gram Positive rods

Resistant to low pH (as low as 4)

Common in dairy products

Ferment milk (yogurt)

Question 14

Endospore Forming Gram Positive Examples

Answer 14

Bacillus, Clostridium

Question 15

Endospore-forming Gram Positive Bacteria

Answer 15

Usually found in soil, the endospore is advantagous

Question 16

Bacillus

Answer 16

Gram positive rod

endospore forming

Can produce extracellular hydrolytic enzymes to breakdown various molecules

Question 17

Bacillus thuringiensis

Answer 17

Gram positive

Endospore-forming

Naturally produces insect larvicide

BT GMO crops: genes for these enzymes are put into a plant

Question 18

Two ways to genetically modify a plant

Answer 18

1. Gene gun
2. Use of Agrobacterium tumefociens

Question 19

How is a gene gun used to genetically modify a plant?

Answer 19

Gold or platinum particles are coated with a gene of interest which is then shot into plant tissue. The undifferentiated plant tissue (callus) is placed on agar with hormones to produce leaves, stems, roots, etc

Question 20

How is Agrobacterium tumefaciens used to genetically modify plants?

Answer 20

A. tumefaciens is the cause of crown gall disease, it inserts its tumor-inducing genes inot the plant’s genome to “feed” off of the plant. For genetic modification, the tumor inducing genes are replaced with genes of interest.

Antibiotic resistance could be added to seperate modified plants from not modified plants. The plant leaf sections are placed on agar with antibiotics, if it grows modification was a sucess.

Question 21

Clostidium

Answer 21

Gram positive

Endospore-forming

Anaerobic

Found in soil, mammalian GI tract

Some are pathogenic and some produce potent toxins

Question 22

Clostridium botulinum

Answer 22

Gram positive

Endospore-forming

Anaerobic

Associated with soil

Botulism toxin is the most potent toxin, blocks neuro-muscular junction resulting in paralysis (flaccid paralysis)

Death results from paralysis of diaphragm

Two types:

1. Adult botulism: comsume food with toxins present
2. Infant botulism: vegetative cells grow in intestines and produce toxins