General Microbiology Lab Briefing

Exercise 3:  Kingdom Myceteae

Be sure to view the sort on-line lecture on the fungi in Vancko Hall Laboratory.  This will be a short introduction to the group since I won’t be getting to it in lecture before you have lab.

You will be examining fungi that are unicellular (yeasts) as well as those that are filamentous (molds).

Filamentous Fungi — Three representative genera are Penicillium, Rhizopus, and Aspergillus.

• View and draw these as they appear in an agar plate of Sabauroud Dextrose Agar.  Do not open the petri dishes — spores will escape and contaminate everything for the rest of the semester!!!!!
• View and draw them from a prepared slide that contains all three genera.  They are located on the slide in the order they are listed on the label.  View:
  • Aspergillus and Rhizopus at 100x
  • Penicillium at 400x
• The spores you see are asexual spores — either conidiospores or sporangiospores depending upon the genus.

Yeast:

• View yeast of two genera — make wet mounts — Candida (opportunistic pathogen) and Saccharomyces (bread and brewing yeast).
• Make a wet mount of my sourdough “sponge”.
  • A sponge is a culture of yeast (and in this case bacteria).
  • You will see abundant yeast and small rod-shaped bacteria between the cells of yeast.  The yeast breakdown carbohydrates and produce alcohol and the bacteria (Lactobacillus ) produce acid from the alcohol.  Hence the sour taste of sourdough bread!
• Try to culture some yeast from your tongue.  Follow directions in your lab book.  We’ll incubate them at 37 degrees C and you’ll check them on Thursday and maybe into next week.

Exercise 4:  Helminths (Multicellular Parasites)

Be sure to view the online lecture on Helminths in Vancko Hall — lecture section.

You will be looking at and drawing the following:

Here is the table from Microbiology Perspectives by Wistreich.  [Note this book will be very handy this week so if you have it, bring it to lab.]

• Cestodes (tape worms)
  • Slides:
    • Scolex and immature proglottids
    • Gravid proglottids
  • Whole or part tapeworms in bioplastic
• Trematodes (flukes):
  • Slides:
    • Chinese liver fluke (Clinorchis senensis) [I took invertebrate zoology with my fiance and we were going to name our first son Clinorchis -- good thing we never had kids, huh?]
      • Whole mount (w.m.)
      • Ova (eggs)
  • Sheep liver fluke (Fasciola hepatica)
    • These you do not need to look at because they are in the pictures on the diagram above.  They include:
      • cercarium
      • metacercarium
      • miracidium
  • Blood fluke (Schistosoma japonicum)
    • male
    • female
    • eggs
  • Also various whole flukes in bioplastic or other preservative.
• Nematodes (roundworms)
  • Trichinella spiralis slides:
    • muscle section
    • isolated larvae