Unit 1-- Lecture 3 (Bacterial Diversity)

Question 1

Gram-Positive Bacteria

Answer 1

Rods and Cocci

No outer membrane

Thick cell wall

Many are pathogens– Staphylococcus, Streptococcus

Listeria

Question 2

Lactobacillales

Answer 2

Key genera: Lactobacillus, Streptococcus

Produce lactic acid

Food production and preservation

Question 3

Leuconostoc

Answer 3

Sauerkraut

Question 4

Nonsporulating Bacillales and Clostridiales

Answer 4

Key genera: Listeria, Staphylococcus, Sarcina

Question 5

Staphylococcus

Answer 5

Catalase-positive, distinguishing from Streptococcus and lactic acid bacteria

Tolerate drying and high salt

Question 6

Sporulating Bacillales and Clostridiales

Answer 6

Key genera: Bacillus, Clostridium

Endospore-forming bacteria

Question 7

Gram-Positive Endospores

Answer 7

Toxin-formers:

Clostridium– tetanus, botox, gangrene

Bacillus– anthrax, botulism

Question 8

Bacillus

Answer 8

Many produce extracellular hydrolytic enzymes

Many produce antibiotics

Question 9

Clostridium

Answer 9

Some are pathogenic, causing botulism, tetanus, and gangrene

Question 10

Tenericutes (The Mycoplasmas)

Answer 10

Key genera: Mycoplasma, Spiroplasma

Lack cell walls

Some of the smallest organisms

Question 11

Actinobacteria (Coryneform and Propionic Acid Bacteria)

Answer 11

Key genera: Corynebacterium

Rod-shaped to filamentous

Mostly harmless commensals with exception of Mycobacterium

Antibiotics and fermented dairy products

Question 12

Gram-Positive Actinobacteria

Answer 12

Acid-fast cell walls– waxy lipids in cell wall

Many form long, multicellular filaments
-aerial mycelia carry arthrospores
-Streptomyces

Question 13

Gram-Negative Proteobacteria

Answer 13

Largest group

Question 14

Alpha Proteobacteria

Answer 14

Photoheterotrophs

Endosymbionts
-Rhizobium, Agrobacterium
-Rickettsias

Question 15

Beta Proteobacteria

Answer 15

Lithotrophs
-Nitrosomonas

Pathogens
-Neisseria gonorrhoeae

Question 16

Gamma Proteobacteria

Answer 16

Lithotrophs
-some are phototrophs
–purple sulfure bacteria

Question 17

Enteric Gamma Proteobacteria

Answer 17

Escherichia coli

Question 18

Delta Proteobacteria

Answer 18

Myxococcus xanthus
-attacks other bacteria in packs
-disperses myxospores

Bdellovibrio bacteriovorus
-parasitizes other bacteria

Question 19

Epsilon Proteobacteria

Answer 19

Smallest group of proteobacteria

Helicobacter pylori
-cause of stomach ulcers

Question 20

Nitrospirae

Answer 20

Spiral shape

Most oxidize nitrite to nitrate

Question 21

Bacteroidetes and Chlorobi

Answer 21

Obligate anaerobes
-bacteroides

Chlorobium
-green sulfur bacterium

Question 22

Spirochetes

Answer 22

Flexible, narrow spiral shape
-flagella at ends

Question 23

Chlamydiae

Answer 23

Obligate intracellular parasites
-larger reticulate body
–grows within cells
–does not survive outside host

Small elementary bodies
-survives outside host cells

Question 24

Planctomycetes

Answer 24

Multiple internal membranes

Verrucomicrobia
-irregular shape
-contains tubulin

Question 25

Cyanobacteria

Answer 25

Oxygenic phototrophs
-many fix nitrogen

-subcellular structures
–thylakoids
—site of photosynthesis
–carboxyzomes– lipid bodies

Many form akinetes

Question 26

Deep-Branching Thermophiles

Answer 26

Chloroflexi
-green nonsulfur bacteria
-filamentous phototrophs
-many have chlorosomes

Question 27

Deinococcus–Thermus

Answer 27

Key genera: Deinococcus, Thermus

Aerobic chemoorganotrophs

Thermales
-thermophiles or hyperthermophiles
-Thermus aquaticus (source for Taq DNA for PCR)

Radiation resistance of Deinococcus radiodurans