null

PAGE
1

Student Name:__________________________
Identifier for your unknown (unknown portfolio number):_________
MCB 2010C Unknown Laboratory Report

Due Date:____________

Directions:

1. Fill in your name and unknown number at the top of this page.

2. Complete the following packet by filling in the required information into the space provided (typed or hand-written; make sure answers are legible!).
3. During the observation/conclusion section, be sure to write what you have visually observed for the observation section and what you can learn from your observation in the conclusion section.

4. Failure to FOLLOW DIRECTIONS will result in point deductions!
**
Late reports will be accepted after the due date, however, point deductions (up to 50% deductions) will be taken

. This report is worth 40 points toward your overall laboratory grade.
.

Your unknown microorganism is one of the following microbiological species.

Bacillus subtilis

Bacillus cereus

Escherichia coli

Serratia marcescens

Citrobacter freundii

Staphylococcus epidermidis

Staphylococcus aureus

Kocuria rhizophila

Part I (25 points): Complete the following data tables with test observations and conclusions from experiments performed on your microbial unknown. Please use complete sentences; don’t just state “positive” or “negative” for the conclusions or you will be marked off.

Note: When filling out an observation, describe what you see (i.e. lactose fermentation media has turned yellow and there is air present in the inverted Durham tube). When filling out a conclusion, describe what you can learn from your observation (i.e. the unknown is capable of fermenting lactose to an acid and a gas).

Test Condition

Observation

Conclusions

Colony pigmentation on TSA plate

N/A

Colony form on TSA plate

N/A

Colony elevation on TSA plate

N/A

Colony margin on TSA plate

N/A

Gram Stain Reaction

(Color?)

(Gram-positive or Gram-negative?)

Cell Morphology (as viewed under oil immersion lens 1000x)

(Shape? Arrangement?) – Remember to list both!

N/A

Test Condition

Observation

Conclusions

Phenylethyl alcohol agar (PEA)

(Growth?)

(Gram positive or Gram negative?)

Mannitol Salt Agar (MSA)

(Growth? Color of colonies? Color of plate?)

(Halophile or non-halophile? Mannitol fermenter?)

MacConkey Agar

(Growth? Color of colonies? Color of plate?)

(Gram positive or Gram negative? Lactose fermenter?)

Eosin-Methylene Blue Agar (EMB)

(Growth? Color of colonies? Color of plate?)

(Gram positive or Gram negative? Lactose fermenter?)

Test Condition

Observation

Conclusions

Presence of Amylase
-Starch plate

(Clearing?)

(Amylase present?)

Glucose Fermentation (as evidenced in glucose/dextrose fermentation tube)

(Color? Gas? )

(Glucose fermented to acid and/or gas?)

Lactose Fermentation (as evidenced in lactose fermentation tube)

(Color? Gas?)

(Lactose fermented to acid and/or gas?)

Test Condition

Observation

Conclusions

Sucrose Fermentation (as evidenced in sucrose fermentation tube)

(Color? Gas?)

(Sucrose fermented to acid and/or gas?)

Presence of
Gelatinase
-Gelatin deep

(Liquification?)

(Gelatinase present?)

Indole Production (Presence of Tryptophanase)
– SIM deep

(Color of reagent layer?)

(Tryptophanase present?)

Test Condition

Observation

Conclusions

Methyl-Red Test

-MRVP broth

(Color?)

(Glucose fermented to acid?)

Vogues-Proskauer Test

-MRVP broth

(Color of liquid layer?)

(Glucose fermented to neutral end products?)

Citrate Utilization

– Citrate slant

(Color? Growth?)

(Citrate utilized as carbon source?)

Oxidase test

– Oxidase dry slide with culture taken from TSA plate/slant

(Color?)

(Oxidase present?)

Test Condition

Observation

Conclusions

Presence of Urease

-Urea broth or slant

(Color?)

(Urease present?)

Triple Sugar Iron (TSI) Slant (be sure to mention H2S production!)

-TSI slant

(Color of slant/butt? Breaks in agar? Blackening?)

(Carbohydrates fermented? Gas production? Hydrogen sulfide made?)

Presence of Catalase

-TSA slant

(Bubbles?)

(Catalase present?)

Part II (7 points): Scientific Name of your Unknown Isolate (include the full genus and species as shown on p. 2):

Part III (8 points): Based on theanswer you provided in Part II, complete the following questions related to your unknown microorganism.

1. (6 points) Please answer each of the following questions:
a. Where is the microorganism most commonly found (i.e. lakes, humans, etc.) (1 point)
b. List 2 facts about the growth of this microbe (this can include oxygen requirements, temperature requirements, pH requirements etc.) (1 point)
c. List a disease known to be caused by this microorganism (note: this disease may only be present in immune-compromised individuals). (1 point)
d. List symptoms of the disease mentioned in part “c”. (1 point)
e. If you were infected with this microorganism, list one antimicrobial drug that would be effective against this microorganism (pay attention to Gram reaction!) (1 point)
f. What does this antimicrobial drug target (i.e. protein synthesis, cell wall, etc.)? (1 point)
2. (2 points) List 2 references that you used to complete the answers for this section. Please cite your references in APA format!