A. Chapter 27 Environmental Microbiology

• A. The hydrologic cycle & wastewater treatment

  • I. Hydrologic cycle & carbon runoff; biochemical oxygen demand; dead zones/zones of hypoxia; eutrophication and the process of eutrophication

  • II. Wastewater treatment: stages → preliminary/primary/secondary/tertiary; activated sludge; saprophytes; filamentous bacteria & protozoa → flocculation

• b. Nitrogen cycle

  • i. Sources of N and the nitrogen triangle

  • ii. Nitrogen fixation (nitrogenase); sensitive to oxygen, requires a lot of energy; symbiotic nitrogen fixation

  • iii. Nitrification (lithotrophy)

  • iv. Dentrification (anaerobic respiration); hypoxia & greenhouse gas formation → N2O

  • v. Ammonification

  B. Chapter 7 Controlling Microbial Growth

  • Terminology: be able to define the following → sterilization/disinfection/antisepsis/degerming/sanitation

  • Effect of antimicrobial agents: bacteriocidal /bacteriostatic effects

  • Microbial death curve; D-value (decimal reduction time); methods to test effectiveness (disk diffusion, etc)

  • Actions of control agents: denaturation of proteins & nucleic acids; plasma membrane disruption; chemically alter or break nucleic acids

  • Physical agents: (a) heat ; effect of high temp & pressure, autoclaving (standard conditions), pasteurization, dry heat, cold temp; (b) Filtration; (c) high pressure; (d) desiccation; (e) osmotic pressure; (f) radiation – effect of nonionizing vs. ionizing radiation

  • Chemical agents: principles of disinfection; testing efficacy of chemical agents (use-dilution test, disk diffusion method)

    • i. Phenolics; halogens (iodine, chlorine); alcohols (ethanol); heavy metals; surface-active agents (detergents, quats); food preservatives; gaseous sterilants (ethylene oxide)

  • Microbial resistance to biocides

Chapter 8 Microbial Genetics

• Inheritance, genotype & phenotype: know what these mean and represent in terms of cellular components/processes → transcription & translation; connection between genotype/phenotype

• Prokaryotic genome: characteristics, chromosome & plasmid(s)

• Flow of Information: DNA → RNA → Protein: what does this represent?

  • i. Components involved in the process

    • 1. RNA molecules: messenger RNA, transfer RNA, ribosomal RNA: what are their functions? Which are involved in transcription? in translation?

    • 2. Ribosomes: what are these? What do they do?

• Mutation: effects – silent/lethal/beneficial; auxotroph

  • i. Base substitution (point mutations) types: missense, nonsense, frameshift → compare these, how are they different?

• Mechanisms of Horizontal Gene Transfer (horizontal vs. vertical gene transfer); be able to characterize, explain the different mechanisms of horizontal gene transfer:

• Transformation: Griffith experiment; competence, artificial transformation

• Conjugation:

  • i. Sex pilus, Fertility factor, F+ vs, F- mating pairs

  • ii. Hfr formation: what is this? what is the outcome? What happens in an Hfr x F- conjugation?

• Transduction: DNA transfer via a phage (bacterial virus); generalized vs. specialized transduction

• Plasmids: describe & characterize; R factors

• Transposons: What are these?

  • i. transposition, transposase, insertion sequences; simple vs. complex transposons

• Recombination (RecA protein): What is this for? How can the cell benefit from this?

D. Chapter 12 (Fungi, Algae, Protozoa, & Helminths)

• Fungi:

  • i. Are chemoheterotrophs; absorb nutrients; decomposition; aerobic or facultatively anaerobic; both sexual & asexual reproduction

  • ii. Compared to bacteria, fungi, grow in more acidic environments; are more resistant to osmotic pressure; & can grow with very low moisture content

  • iii. Molds and Fleshy Fungi: filamentous; vegetative & aerial hyphae; mycelium; produce spores for reproduction

  • iv. Yeast: unicellular; reproduce by budding/fission

  • v. Dimorphic fungi

  • vi. Pathogens; fungal diseases → mycoses (systemic/cutaneous/subcutaneous)

• Lichens: symbiotic relationship between fungus and algae or cyanobacteria

  • i. Structure/features

  • ii. Contribution of each member

• Algae

  • i. Photosynthetic; unicellular (dinoflagellates/diatoms) & multicellular forms (red/brown/some green algae)

  • ii. Algal diseases due to toxins produced by certain algae; are not infectious

  • iii. Eutrophication/algal blooms

• Protozoans

  • i. Unicellular, mostly aerobic, heterotrophs

  • ii. Diverse features:

    • 1. Motility → ciliated types; amoeboid (pseudopodia); flagellated; undulating membrane

    • 2. Cyst formation; may have complex life cycles w/different stages & hosts (Apicomplexa - malaria)

    • 3. Nutritional adaptations

    • 4. Reproduction: sexual & asexual (fission/budding/schizogony)

• Helminths: parasitic worms (flatworms & roundworms)

  • i. Multicellular eukaryotic animals; specialized to live in hosts

  • ii. Platyhelminthes (hermaphroditic):

    • 1. Trematodes: flat; absorb food through cuticle; named for host tissue

    • 2. Cestodes: tapeworms; scolex attaches to tissue; absorbs food body surface; proglottid segments of body

    • 3. Pathogens: Schistozoma; Taenia

  • iii. Nematodes: complete digestive system; male/female sexes; free-living & parasitic types; eggs or larvae can be infective, depending on type. Ascaris; Trichenollosis; heartworm