Understanding Prokaryotic Microbes: Diversity, Pathogenicity, and Commercial Importance
This chapter delves into the world of prokaryotic microbes, focusing on common disease agents, commercially significant species, and obligate parasites, while highlighting their defining characteristics. It also touches upon the ancient lineages represented among various phyla, emphasizing the importance of rRNA sequencing in classification. The content is organized into discussions on the domains Archaea and (Eu)bacteria, covering hyperthermophiles, methanogens, and diverse bacterial groups such as Proteobacteria and Gram-positive bacteria, revealing their ecological roles and human relevance.
Understanding Prokaryotic Microbes: Diversity, Pathogenicity, and Commercial Importance
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Presentation Transcript
Prokaryotic microbes Chapter 11
I. Keep in mind some of the big picture questions: • What are some of the most common disease agents? • Which species are important commercially and why? • Which species are obligate parasites and what are characteristics that dictate this? • Which species represent the most ancient lineages?
Many phyla overlap, so it is important to remember that the 14 phyla (currently) described have been classified not only by characteristics, but by comparative rRNA sequencing
A. Hyperthermophiles • B. Methanogens • C. Extreme Halophiles
A. Gram negative “non proteo” • 1. “Deeply branching” • Thermotoga maritima • Thermus aquaticus • Deinococcus radiodurans
2. Bacteroidetes • 3. Anoxygenic photosynthetic bacteria • a. Green nonsulfur bacteria • b. Green sulfur bacteria
4. Spirochetes • Treponema pallidum • Borrelia spp.
5. Chlamydia • 6. Oxygenic phototrophs • Cyanobacteria • Anabaena
B. Proteobacteria (Phylum XII) • All gram negative • Six major groups • Phototrophs, chemolithotrophs or chemorganotrophs
1. proteobacteria • Require only low nutrient concentrations • MOD examples • Rhizobium • Agrobacterium Other examples
Often use diffusible substrates MOD examples: Nitrosomonas Other examples 2. proteobacteria
Largest group MOD example Pseudomonas Other examples 3. proteobacteria
Enterics • Escherichia • Proteus • Salmonella • Serratia • Shigella • Enterobacter • Klebsiella • Citrobacter • Yersinia
4. proteobacteria • 5. proteobacteria
C. Gram-positive: Low GC • MOD examples • Lactobacillales • Lactobacillus • Streptococcus
