UNKNOWN CHARACTERISTICS CHART

04/11/16

Name:Partner:

BIOL 191 Lab Section:Unknown Number:

Complete Scientific Name of Unknown:

Although students work in groups, each individual must turn in an Unknown Characteristics Report and is individually responsible for the content.

Objectives:

  1. Students will record all test results from the student’s unknown.
  1. Students will research and record the expected,typical test results of ‘possible’ unknowns as indicated in the instructions.
  1. Students will eliminate bacteria from contention by comparing their unknown’s results with the typical results of the ‘possible’ unknowns.
  1. Students will determine the identity of their unknown and report the

complete, correctly written, scientific name of their unknown.

Note: Manuals and texts list the characteristics of importance to that particular species. All of the characteristics or test results for every ‘possible’ unknown may not be listed in Bergey’s Manual or other sources. If you cannot locate a particular expected resultfor a species, write “Not Listed”. However, be sure to research carefully, including online.

This report is organized into three sections:

  1. Morphological Characteristics (p. 3)
  • Students must research and record the expected results for ALL of the possible unknowns.
  • The Morphological Comparison Chart must be completed in order to compare your unknown with the other possible unknowns.
  1. Preliminary Elimination (p. 4)

Based on the personal results of the morphological tests and comparative research, students will eliminate species with a different shape and Gram stain.

  1. Biochemical Characteristics (pp. 5-6)
  • After eliminating species based on morphological characteristics, write those species remaining at the top of the chart and fill in their expected, typical biochemical characteristics. The chart can be used to compare your unknown with up to four similar species.
  • Students will record their unknown’s biochemical results in the Biochemical Test Comparison Chart.
  • Students will NOT perform every test listed (refer to the tables in the “Biochemical Characteristics” lab instructions).
  • If you do NOT perform a particular test, you do NOT have to research the expected results for the possible unknowns.
  • Use the chart to compare those species most similar to your unknown.

I. Morphological Characteristics

Research, in Bergey’s Manual or other manuals/texts/onlinethe morphological characteristics of ALL of the possible unknowns. Fill in the chart as follows:

Cell Shape: bacillus (rod), coccus (spherical), curved

Gram Stain: + or –

Motility: +, –, or +/-

Spore formation: + or –

Cell Shape / Gram Stain / Motility / Spore formation
Your results
Bacillus megaterium
Sporolactobacillus inulinus
Mycobacterium smegmatis
Staphylococcus aureus
Staphylococcus epidermidis
Streptococcus sanguis
Micrococcus luteus
Escherichia coli
Enterobacter aerogenes
Proteus vulgaris
Pseudomonas aeruginosa

II.Preliminary Elimination:

A. List all species eliminated based only on cell shape and Gram stain.

B. IN DETAIL, explain why they were eliminated.

III. Biochemical Characteristics

Students will not perform all tests listed, only those with the same shape and Gram stain.

  1. Write “NA” (Not Applicable) by any tests not to be performed (refer to the Tables in the ‘Biochemical Characteristics’ student lab instructions).
  2. Do not research the expected test results of any species for tests that you do not perform.
  3. Use Bergey’s or other manuals/texts (such as Difco),to describe the expected typical biochemical characteristics of thoseremaining possibilities, but only for the tests

actually performed on your unknown.

Therefore, you will write one of the following in each space in the Biochemical Test Comparison Chart on the following page:

1) Your test results- if you are unsure, indicate why.

2) NA (If you did not perform this test)

3) Atypical,expected test result (found in Bergey’s or other manuals/texts/online). Some results will be variable. If so, write “-/+” or otherwise indicate expected results may beinconsistent.

4) Not Listed (If the test is not listed in Bergey’s or other manuals/texts/online for that unknown). This is very rare. All but one or two of the results have been determined by searching the same resources as those used by students.

Your grade is based on:

  • Precise laboratory work and analysis of test results by comparing with controls
  • Thorough research of the ‘possible’ unknowns’ typical results
  • Careful record-keeping
  • Comparison and analysis of your unknown’s results with the known, typical
    characteristics of the ‘possible’organisms
  • Correctly reporting the complete scientific name of your unknown

Do not merely rely on your lab partner. You are responsible for your own work.

TEST / YOUR RESULTS / Compare with…
(Write possible unknown species below) / Compare with…
(Write possible unknown species below) / Compare with…
(Write possible unknown species below) / Compare with…
(Write possible unknown species below)
Lactose Fermentation
Acid:
Gas:
Sucrose Fermentation
Acid:
Gas:
Glucose Fermentation
Acid:
Gas:
Methyl Red
(MR in MR-VP)
Voges-Pros. (VP in MR-VP)
Indole Test
in tryptophane broth
Urea Hydrolysis
in urea broth
Hemolysis
on blood agar
EMB agar -
Colony morphology (e.g. color)
P. Isolation agar-
Growth:
Pigmentation:
Catalase test
on agar slant
Mannitol Salt agar-
Growth:
Fermentation:
Coagulase production

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