Exercise 6: Survey of Microorganisms

Question 1

Habitat

Answer 1

where a specific microbe is found

Question 2

Niche

Answer 2

the broader ecological functional role of a microbe

-biotic and abiotic factors

Question 3

3 Domains of Life

Answer 3

Bacteria, Archaea, Eukarya

Question 4

3-Domain Classification System by Carl Woese

Answer 4

• 16S rRNA (Bacteria and Archaea)

- 18S rRNA (Eukarya)

Question 5

Euglena

Answer 5

• Domain: Eukarya
• photosynthetic protist
• motility (flagellum)
• asexual reproduction (divide longitudinally)
• plant and animal
• ID: nucleus, eyespot, green, cigar shape

Question 6

Amoeba

Answer 6

• Domain: Eukarya
• protist
• move using psuedopods
• engulf prey in vacuoles
• divide by binary fission
• medical application: causative agent of dysentary
• ID: nucleus, pseudopods

Question 7

Anabaena

Answer 7

• Domain: Bacteria
• cyanobacteria
• photosynthetic cells
• filamentous
• nitrogen fixation (heterocyst)
• akinete: resistant to cold and desiccation
• storage granules (not organelles)
• release O2
• ID: heterocyst (perfectly circular cell), akinete (large strx)

Question 8

Aspergillus

Answer 8

• Domain: Eukarya
• molds
• aflatoxin: carcinogen
• bioterrorism
• A. fumigatus: produces gliotoxin –> aspergillosis
• ID: round shape vesicle

Question 9

Candida albicans

Answer 9

• Domain: Eukarya
• yeast (not mold)
• opportunistic pathogen
• candidiasis or thrush (white patches on the human tongue)
• causes diseases in mouth, throat, vagina, lungs, toes, nails, scalp, GI tract
• Biofilms
• ID: large spores

Question 10

Saccharomyces

Answer 10

• Domain: Eukarya
• Fungi (yeast)
• no hyphae
• sexual budding
• brewers’ yeast
• ID: oval to round shape, 25x larger than bacterial cell

Question 11

Penicillium

Answer 11

• Domain: Eukarya
• discovery of antibiotic penicillin in 1929 by Alexander Fleming
• penicillin is a beta-lactam antibiotic that inhibits cell wall formation in bacteria
• ID: no vesicles

Question 12

Paramecium

Answer 12

• Domain: Eukarya
• protist
• ciliate (hair-like projections)
• micro/macro nucleus
• divide by transverse fission
• endosymbiotic algae
• ID: bigger than Euglena, LARGE nucleus, clear or green in color

Question 13

Bacillus cereus

Answer 13

• Domain: Bacteria
• Gram positive endospore forming
• commonly found in soil and food
• “Fried Rice Syndrome”
• Gastroenteritis –> endotoxin
• ID: candle shape, very distinct from others

Question 14

Rhodospirillum rubrum

Answer 14

• Domain: Bacteria
• Gram negative
• found in ponds/lakes/streams
• fermentation or respiration
• biotechnology

Question 15

Staphylococcus epidermidis

Answer 15

-Domain: Bacteria
-found on skin
-Gram positive
-can form biofilms with implants
-grape-like clusters
ID: purple sphere, perfect circles (cocci)

Question 16

Spirogyra

Answer 16

• Domain: Eukarya
• algae
• photosynthetic
• filamentous
• organelles (chloroplast, nucleus)