Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 16 Bacteria and Archaea

Bacterial biofilms cause plaque.

Learning Outcomes Describe the primary characteristics of bacteria Identify the features and functions of structures found in bacteria. Identify how bacteria are classified Describe the vertical and horizontal transmission of genetic material in bacteria

Learning Outcomes Differentiate and compare archaea with bacteria. Describe the different ways bacteria obtain energy from the environment. Describe how bacteria interact with other species in the environment.

16.1 Prokaryotes Are a Biological Success Story Prokaryote –Single-celled organism that lacks a nucleus and membrane-bounded organelles 2 prokaryotic domains –Bacteria –Archaea Figure 16.1 Diversity of Prokaryotic Life. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DOMAIN BACTERIA TEM (false color) 1 µm DOMAIN ARCHAEA SEM (false color) 1 µm ProkaryotesDOMAIN EUKARYA DOMAIN BACTERIA Fungi Plants Animals DOMAIN ARCHAEA Protista (top): © Kwangshin Kim/Photo Researchers; (middle): © Ralph Robinson/Visuals Unlimited/Getty Images

16.2 Prokaryote Classification Traditionally Relies on Visible Features A. Microscopes Reveal Cell Structures Internal structures –Cell membrane, DNA, cytoplasm, ribosomes –Nucleoid –Plasmids Figure 16.2 Prokaryotic Cell. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Plasmid CytoplasmRibosomeCell membrane Cell wall GlycocalyxFlagellum Nucleoid (chromosomal DNA) Pilus

16.2 Prokaryote Classification Traditionally Relies on Visible Features A. Microscopes Reveal Cell Structures External structures –Cell wall Peptidoglycan –3 common shapes Coccus, bacillus, spirillum Arrangements can also be important Figure 16.3 Cell Shapes. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. Coccusb. Bacillusc.Spirillum SEM (false color) 1.5 µm SEM (false color) 10 µm LM 100 µm a: © David M. Phillips/Visuals Unlimited; b: © SciMAT/Photo Researchers; c: © Ed Reschke/Peter Arnold/Photolibrary`

16.2 Prokaryote Classification Traditionally Relies on Visible Features A. Microscopes Reveal Cell Structures External structures –Gram stain Gram-positive –Thick peptidoglycan layer Gram-negative –Thinner cell walls –Outer membrane Figure 16.4 Gram Stain. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Gram-negative cell Gram-positive cell LM 10 µm © Jack Bostrack/Visuals Unlimited

16.2 Prokaryote Classification Traditionally Relies on Visible Features A. Microscopes Reveal Cell Structures External structures –Glycocalyx Capsule or slime layer –Pili Attachment or DNA transfer –Flagellum Not the same as eukaryote Figure 16.5 External Structures of Prokaryotic Cells. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. b. c.TEM (false color) Glycocalyx Pili 0.5 µm Flagella a: © George Musil/Visuals Unlimited; a: © CNRI/Photo Researchers; c: © Dr. Fred Hossler/Visuals Unlimited Pili

16.2 Prokaryote Classification Traditionally Relies on Visible Features A. Microscopes Reveal Cell Structures Endospores –Dormant, thick-walled structures –Clostridium botulinum Botulism –Bacillus anthracis Anthrax Figure 16.6 Endospores. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Endospore LM 4 µm © Michael Abbey/Photo Researche

16.2 Prokaryote Classification Traditionally Relies on Visible Features B. Metabolic Pathways May Be Useful in Classification Autotrophs –Carbon from inorganic sources Heterotrophs –Carbon from organic sources Phototrophs –Derive energy from sun Chemotrophs –Oxidize inorganic or organic chemicals

16.2 Prokaryote Classification Traditionally Relies on Visible Features B. Metabolic Pathways May Be Useful in Classification Photoautotroph –Plants and cynaobacteria –Sunlight for energy and CO 2 for carbon Chemoheterotroph –Disease-causing bacteria use host as carbon and energy source

16.2 Prokaryote Classification Traditionally Relies on Visible Features B. Metabolic Pathways May Be Useful in Classification Oxygen requirements –Obligate aerobe –Obligate anaerobe –Facultative anaerobe

16.2 Prokaryote Classification Traditionally Relies on Visible Features C. Molecular Data Reveal Evolutionary Relationships Revolution in microbial taxonomy Used rRNA sequences Closer to taxonomy that reflects evolution

16.3 Prokaryotes Transmit DNA Vertically and Horizontally Vertical gene transfer –Transmit DNA from generation to generation as they reproduce –Binary fission asexual Figure 16.7 Vertical Gene Transfer. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The result of binary fission: two daughter cells, each identical to the original. Membrane growth between the two attachment points moves the DNA molecules apart as new cell wall material is deposited Cell membrane DNA Cell wall Parent cell contains one chromosome. DNA replicates and attaches to cell membrane.

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16.3 Prokaryotes Transmit DNA Vertically and Horizontally Horizontal gene transfer 1.Transformation Naked DNA 2.Transduction Virus mediated 3.Conjugation Sex pilus Figure 16.8 Horizontal Gene Transfer. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. Transformation DNA fragments Plasmid Chromosome b. Transduction Virus containing DNA from another cell Recipient cell Donor cell c. Conjugation Sex pilus through which DNA is transferred

16.4 Prokaryotes Include Two Domains with Enormous Diversity A. Domain Bacteria Includes Many Familiar Groups –23 phyla –Evolutionary relationships unclear –Phylum Proteobacteria Exemplify overall diversity Helicobacter, E.coli, Salmonella –Cyanobacteria First to produce O 2 from photosynthesis Figure 16.9 Two Types of Bacteria. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. TEM (false color) 0.5 µm LM 7 µm (left): © John Walsh/Photo Researchers; (right): © Dr Gopal Murti/Photo Researchers b.

16.4 Prokaryotes Include Two Domains with Enormous Diversity B. Many, But Not All, Archaea Are “Extremophiles” Originally found in very hot, acidic, or salty environments 3 phyla Important roles in global element cycling Figure Extremophiles. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. SEM (false color) 1 µm © Ralph C. Eagle, Jr./Photo Researchers; (inset): © Eye of Science/Photo Researchers

Clicker Question Which below is NOT found in prokaryotes? A.DNA B.Cell wall C.Nucleus D.Ribosomes

16.5 Bacteria and Archaea Are Important to Human Life A. Microbes Form Vital Links in Ecosystems Microbes play essential role in global carbon cycle Nitrogen fixation –Convert atmospheric nitrogen to ammonia –Rhizobium Figure Nitrogen-Fixing Bacteria. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nodule SEM4 µm b. a. a: © Dr. John D. Cunningham/Visuals Unlimited; b: © Science VU/Visuals Unlimited

16.5 Bacteria and Archaea Are Important to Human Life B. Bacteria and Archaea Live in and on Us –Normal residents are beneficial Crowd out disease-causing bacteria –No archaea cause human disease –May release harmful toxins –May trigger immune reaction Figure A Human Habitat. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nose and throat (upper respiratory system) Urinary and genital systems (lower urethra in both sexes and vagina in females) Scalp Eyes Mouth Skin Large intestine

16.5 Bacteria and Archaea Are Important to Human Life C. Humans Put Many Prokaryotes to Work –Foods- sauerkraut, vinegar, cheese –Industry – vitamins, ethanol, acetone –Transgenic bacteria – insulin –Water and waste treatment Figure Bacteria at Work.

16.5 Mastering Concepts What are some practical uses of bacteria and archaea?

16.6 Investigating Life: A Bacterial Genome Solves Two Mysteries Staphylococcus aureus –Variety of symptoms from genetic diversity –Studies 37 strains –Used DNA microarrays –Interested in origin of MRSA Found it had multiple origins not just 1 Figure Staphylococcus aureus Relationships. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. MSA2885 MRSA Toxic shock syndrome COL MSA3410 MSA890 MSA3426 MSA817 MSA961 MSA820 MSA3400 MSA3405 MSA2120 RF122 MSA2965 MSA2348 MSA2020 MSA535 MSA551 MSA2389 MSA1601 MSA2099 MSA3412 MSA3407 MSA2335 MSA2754 MSA2345 MSA1836 MSA1827 MSA700 MSA2786 MSA3095 MSA2346 MSA1205 MSA1832 MSA537 MSA3418 MSA3402 MSA1695

16.6 Investigating Life: A Bacterial Genome Solves Two Mysteries Origin of toxic shock syndrome epidemic of 1980 –Most linked to tampon use –Found S. aureus 90% of time –Found multiple strains caused epidemic Figure Toxic Shock Syndrome Epidemic. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Number of cases Year Nonmenstrual Menstrual Total Tampon absorbency lowered FDA requires tampon labeling