Microbiology Unknown Project - 2011
Instructions.
General. For the next several weeks, your sole responsibility will be to identify the two
microbes in the test tubes you have been handed. You will find Bergey's Manual of
Determinative Microbiology to be a very helpful resource. It can be found online at
http://openlibrary.org/books/OL23280747M/Bergey%27s_manual_of_determinative_bac
teriology.
Final Unknowns Report. You must use the Unknown Excel Template to develop a
separate page for each of your bacteria. The template can be found linked to the class
syllabus. These Excel Documents must also be linked to your electronic portfolio under
the laboratory skills section. In addition to filling out all of the required information in
the Excel Document, you must:
1) Bring me a Petri plate for each bacterium that has at least 5 well-isolated
colonies, and no contaminants.
2) Keep a complete laboratory notebook documenting all of the work that you do
on your unknown. Each page (from now on) should be dated, titled, describe
what tests you did, and describe/interpret any results you observed. I will be
collecting the lab notebooks at the end of the semester.
Due Date: Your microbial identifications and Final Unknowns Reports are due no later
than April 27 at 1:00 pm via email.
Final Lab Cleanup April 27. You must come to lab on April 27 for a final lab
walkthrough/cleanup. No one will receive a final grade in Microbiology Lab until the
entire lab area is clean. IF you skip the final clean up, you will receive a zero for the
unknown project.
Clean-up Rules.
1. Daily.
a. You are each responsible for keeping 232 and the prep room clean at
all times during this project. You must wash all of the glassware that
you use to make media as you use it. Do not leave it in the prep room
or the lab for someone else to wash.
b. Make sure to put all media/reagents back on the correct shelves, and to
clean up the weighing station every time you finish making media.
c. Do not let your Petri plates linger in the incubator for more than 2-3
days. I have a nasty habit of throwing ‘rogue’ plates away.
d. Old Petri plates should be placed in the biohazard bag in 232. Old test
tubes should be placed in the “Kill Racks” in 232. Please separate
tubes with agar from tubes with just broth.
e. Each student may store up to two slant cultures and three Petri plate
cultures of each of their unknowns in the refrigerator in 232 at any one
time. Older cultures should be properly disposed of in the biohazard
bag (for plates), or in the “Kill Rack” in 232 for test tubes. No other
cultures/plates may be stored in that (or any other!) refrigerator.
f. Test tubes/Petri plates containing experimental results must be
disposed of immediately as described in (d).
2. Weekly.
a. Twice a week (starting next week) one of you will be in charge of
making sure that the media area in 232 is in good order, that 232 is as
neat as possible, and that all tubes in the ‘Kill Racks’ are autoclaved,
emptied, cleaned and put away. There will be a sign-up calendar in
232. Each of you should sign up for one clean up slot. You may pick
the week/day, but no two clean ups can be on back-to-back days.
Ideally, they should be spread apart by at least 3 days.
Frequently-Asked Questions (and my answers):
1. Q: Is this a positive? (Or any other version of is this right, did this work,
etc…)
A: Did you run a positive control (a bacterium that is known to be positive for
the reaction you are doing) and a negative control (media with no bacteria in
it, but otherwise treated just like the experimental media/culture)? If you did,
you should be able to answer the question for yourself.
2. Q: How do I get a positive control?
A: To run a positive control, you must ask me for a particular microbial
species that you know is positive (see your lab manuals!). I will provide you
with access to that species, but you must provide the medium (A TSB slant) in
which to grow the microbe. We will keep a rack of “Control” bacteria in the
refrigerator in 232, but please do not use them without asking, as I need to
replace them periodically – depending on how much use they are getting.
3. Q: How do I make_____?
A: First, look in the back of your lab manual, or in the text of the lab
experiment that you are doing. The recipe is almost always there. Also, don’t
forget to check the microbiology media area for premixed powders. We often
have them for the most popular tests (for example, we have phenol red broth
base…just add sugar). If your media/reagent formulations are not in either
place, then feel free to ask. Just remember that it will take us a while (at least
a week) to get particularly strange media – so plan ahead to make sure you
have what you need.
4. Q: What if I name the wrong bacterium at the end of all this?
A: Don't panic. You will get points for the percent of tests that you did
correctly. In other words, it is possible (though less likely) to name the wrong
bacterium, and still get an A. You may also use the final paragraph (just one
paragraph!!!) to document any specific uncertainties that you have. If they are
lucid, and actually correct, they MAY net you an additional point or two.
5. Oh, please! Give us a Hint!
Well, ok then. Your bacteria can be found in the list below. Unknowns may
be repeated, so don’t panic if someone else seems to have the same unknown
that you do.
Alcaligenes denitrificans
Alcaligenes faecalis
Bacillus megaterium
Bacillus subtilis
Caulobacter vibroides
Chromobacterium violaceum
Citrobacter freundii
Corynebacterium xerosis
Enterobacter aerogenes
Enterococcus faecalis (Streptococcus faecalis)
Escherichia coli
Haemophilus parainfluenzae
Klebsiella pneumoniae
Kocuria rosea (Micrococcus roseus)
Lactobacillus acidophilus
Lactobacillus sanfrancisco
Lactococcus lactis
Micrococcus luteus
Micrococcus roseus
Moraxella (Branhamella) catarrhalis
Morganella morganii
Mycobacterium smegmatis
Neisseria subflava
Proteus vulgaris
Pseudomonas aeruginosa
Psuedomonas syringae
Salmonella enteritidis
Salmonella paratyphi
Serratia marcescens
Shigella flexneri
Sporosarcina ureae
Staphylococcus aureus
Staphylococcus epidermidis
Streptococcus salivarius