Discussion of gram positive phyla (firmicutes and actinobacteria). Begin discussing gram negative phyla (proteobacteria)

1. The Microbial Zoo 2
A stroll through the microbial world
Book: Section II
Dr. Rachel Mackelprang

2. Phylogenetic Diversity

3. Gram Postive Phyla

4. Gram Postive Phyla

5. Firmicutes (Low GC Gram-Postive)

6. Firmicutes (Low GC Gram-Postive)

7. Firmicutes (Low GC Gram-Postive)
Firm4 & Firm5

8. Firmicutes (Low GC Gram-Postive)
Firm4 & Firm5

9. Firmicutes (Low GC Gram-Postive)

10. Firmicutes (Low GC Gram-Postive)
Gut bacteria metabolize nutrients host can’t process
Nectar contains trace amounts of carbs that are
poisonous to honeybees (but bacteria can degrade them)

11. Firmicutes (Low GC Gram-Postive)
Bacillus
Most are endospore forming rods
V. common in soil
Typically aerobic

12. Firmicutes (Low GC Gram-Postive)
Bacillus
Most are endospore forming rods
V. common in soil
Typically aerobic
Bacillus anthracis

13. Firmicutes (Low GC Gram-Postive)
Bacillus
Most are endospore forming rods
V. common in soil
Typically aerobic
Biological weapon: spores sent in mail after
9/11. Germinate when exposed to water (e.g.
lungs). 22 cases and 5 deaths
Bacillus anthracis

14. Firmicutes (Low GC Gram-Postive)
Bacillus
Most are endospore forming rods
V. common in soil
Typically aerobic
Biological weapon: spores sent in mail after
9/11. Germinate when exposed to water (e.g.
lungs). 22 cases and 5 deaths
Bacillus anthracis
Lethal Factor
Adema Factor
Protective antigen

15. Firmicutes (Low GC Gram-Postive)
Clostridium
Most are endospore forming rods
V. common in soil and the gut
Typically anaerobic
C. botulinum produces neurotoxin.
Toxin, rather than organism kills.
Colonized gut, then toxin is
absorbed.

16. Firmicutes (Low GC Gram-Postive)
Clostridium botulinum
Clostridium
Most are endospore forming rods
V. common in soil and the gut
Typically anaerobic
C. botulinum produces neurotoxin.
Toxin, rather than organism kills.
Colonized gut, then toxin is
absorbed.

17. Firmicutes (Low GC Gram-Postive)
Clostridium botulinum
Clostridium
Most are endospore forming rods
V. common in soil and the gut
Typically anaerobic
C. botulinum produces neurotoxin.
Toxin, rather than organism kills.
Colonized gut, then toxin is
absorbed.
Adults and older kids can remove spores b/c of mature digestive
system. Babies can’t so spores germinate, multiply, and produce toxin

18. Firmicutes (Low GC Gram-Postive)
Clostridium botulinum
Clostridium
Most are endospore forming rods
V. common in soil and the gut
Typically anaerobic
C. botulinum produces neurotoxin.
Toxin, rather than organism kills.
Colonized gut, then toxin is
absorbed.
Adults and older kids can remove spores b/c of mature digestive
system. Babies can’t so spores germinate, multiply, and produce toxin
Botox blocks signals from nerves to muscles. The injected
muscle can no longer contract

19. Firmicutes (Low GC Gram-Postive)
Mollicutes
Lack peptidoglycan! Stain G-
Small—used to be grouped with viruses
Obligate parasites
Wide range of morphologies (non-rigid
envelope)

20. Firmicutes (Low GC Gram-Postive)
Mollicutes
Lack peptidoglycan! Stain G-
Small—used to be grouped with viruses
Obligate parasites
Wide range of morphologies (non-rigid
envelope)
Mycoplasma hominis

21. Firmicutes (Low GC Gram-Postive)
Mollicutes
Lack peptidoglycan! Stain G-
Small—used to be grouped with viruses
Obligate parasites
Wide range of morphologies (non-rigid
envelope)
Mycoplasma hominis
Opportunistic pathogen.
Asymptomatic in vagina. Disease
often associated with surgery.
Proliferates in deep surgical
wounds. Hard to treat. WHY?

22. Firmicutes (Low GC Gram-Postive)
Heliobacteriaceae
Only known phototrophic G+
Only C-souce: pyruvate & lactate

23. Firmicutes (Low GC Gram-Postive)
Heliobacteriaceae
Only known phototrophic G+
Helibacterium chlorum
Only C-souce: pyruvate & lactate

24. Actinobacteria (High GC Gram-Postive)

25. Actinobacteria (High GC Gram-Postive)

26. Actinobacteria (High GC Gram-Postive)
Filamentous Actinobacteria: Streptomyces (and
other related genera)

27. Actinobacteria (High GC Gram-Postive)
Filamentous Actinobacteria: Streptomyces (and
other related genera)
• Complex secondary metabolism
• Produce 2/3 of natural origin antibiotics.
• Produce geosmin
• Form branched filamentous hyphae (filamentous
actinos and filamentous fungi represent convergent
evolution)
• “Multicellular” bacteria
Cell-cell adhesion
Intercellular communication leading to
coordinated activity.
• Form arthrospores
•

28. Actinobacteria (High GC Gram-Postive)
Filamentous Actinobacteria: Streptomyces (and
other related genera)
• Complex secondary metabolism
• Produce 2/3 of natural origin antibiotics.
• Produce geosmin
• Form branched filamentous hyphae (filamentous
actinos and filamentous fungi represent convergent
evolution)
• “Multicellular” bacteria
Cell-cell adhesion
Intercellular communication leading to
coordinated activity.
• Form arthrospores
•
Streptomyces antibioticus
Produces actinomycin
Selman Waksman 1940s

29. Actinobacteria (High GC Gram-Postive)
• Acid-fast bacteria: Mycobacterium and relatives
• Members include M. tuberculosis and M. leprae
• Thick cell wall: waxy and rich in mycolic acids.
• Use acid fast stain to identify

30. Actinobacteria (High GC Gram-Postive)
• Acid-fast bacteria: Mycobacterium and relatives
• Members include M. tuberculosis and M. leprae
• Thick cell wall: waxy and rich in mycolic acids.
• Use acid fast stain to identify
mycolic acids
Acid fast stain:
Primary stain, acid decolorizer,
counter stain

31. Actinobacteria (High GC Gram-Postive)
Mycobacterium tuberculosis (red)
Tissue: blue
• Acid-fast bacteria: Mycobacterium and relatives
• Members include M. tuberculosis and M. leprae
• Thick cell wall: waxy and rich in mycolic acids.
• Use acid fast stain to identify
mycolic acids
Acid fast stain:
Primary stain, acid decolorizer,
counter stain

32. Actinobacteria (High GC Gram-Postive)
Tuberculosis (TB)
Called “phthisis” ancient Greece, “tabes
in ancient Rome, and “schachepheth” in
Hebrew.
Commonly called “consumption” in the
1800s. Killed 1 of every 7 people in the
US and Europe

33. Actinobacteria (High GC Gram-Postive)
Tuberculosis (TB)
Called “phthisis” ancient Greece, “tabes
in ancient Rome, and “schachepheth” in
Hebrew.
Commonly called “consumption” in the
1800s. Killed 1 of every 7 people in the
US and Europe
Treatment
Cocktail of antibiotics for
6-9 months.
Why might this be a
problem?

34. Actinobacteria (High GC Gram-Postive)
Tuberculosis (TB)
Called “phthisis” ancient Greece, “tabes
in ancient Rome, and “schachepheth” in
Hebrew.
Commonly called “consumption” in the
1800s. Killed 1 of every 7 people in the
US and Europe
Treatment
Cocktail of antibiotics for
6-9 months.
Why might this be a
problem?

35. Proteobacteria (Gram-Negative)

36. Proteobacteria
• Very large group.
• B/C so large, divided into classes
• Broad range of phenotypes
• Suggests they can change phenotypes rapidly
(evolutionarily)
• Named after shape-shifting sea god Proteus

37. Proteobacteria

38. Proteobacteria
Chromatium okenii
Purple sulfur bacteria.
Anoxygenic photosynthesis

39. Proteobacteria
Chromatium okenii
Purple sulfur bacteria.
Anoxygenic photosynthesis
Helicobacter pylori
Common stomach symbiont.
But sometimes colonization
results in ulcers

40. Proteobacteria
Chromatium okenii
Purple sulfur bacteria.
Anoxygenic photosynthesis
Helicobacter pylori
Common stomach symbiont.
But sometimes colonization
results in ulcers
Thiobacillus thioparus
Acid mine drainage

41. Proteobacteria
Chromatium okenii
Purple sulfur bacteria.
Anoxygenic photosynthesis
Helicobacter pylori
Common stomach symbiont.
But sometimes colonization
results in ulcers
Thiobacillus thioparus
Acid mine drainage
Rhizobium etli
Forms N-fixing symbiotic
relationship with plants