Bacterial Growth Characteristics Assignment
Bacterial Growth Characteristics Assignment
Lab Exercise: Bacterial Growth Characteristics
Purpose and Learning Outcome
After completing this exercise, you should (1) be aware that certain bacterial species have unique growth patterns on certain growth media, (2) be able to identify some bacterial species based on their unique growth patterns, (3) be practiced at categorizing bacterial species according to their oxygen requirements, and (4) be practiced at interpreting blood agar results.
The skills/abilities listed above are important because they can be used to help identify bacterial species.
Required Materials and Equipment
A device with internet access
Instructions for Part 1: Growth Characteristics on TSA
In the table below, click on the name of each bacterial species to see a photo of what it looks like when grown on a TSA plate for 24 hours at 37 degrees C (unless otherwise noticed). After viewing each photo, fill out the two columns to the right of the species name.
Non-unique (common) growth on a TSA plate looks like this. If a bacterial species has an obviously different color and/or texture than that when growth on a TSA plate, then consider it unique.
Bacterial species Unique growth characteristics when grown on TSA plate?
Y or N If the species has unique growth characteristics on TSA, then describe them. If the species has no unique growth characteristics, then you do not have to type anything in this column.
Alcaligenes faecalis
Bacillus cereus
Bacillus megaterium
Bacillus mycoides
Bacillus subtilis
Citrobacter freundii
Corynebacterium xerosis
Enterobacter aerogenes
Enterococcus faecalis
Escherichia coli
Klebsiella pneumoniae
Micrococcus luteus
Micrococcus roseus
Moraxella catarrhalis
Mycobacterium smegmatis
Neisseria sica
Proteus mirabilis
Proteus vulgaris
Pseudomonas aeruginosa
Salmonella typhimurium
Serratia marcescens (growth at room temp)
Serratia marcescens (growth at 37 degrees C)
Staphylococcus aureus
Staphylococcus epidermidis
Streptococcus salivarius
Instructions for Part 2: Interpreting blood agar results
View these photos of different bacteria grown on TSA plates containing 3% sheep’s blood. All the plates in the photos were growth at 37 degrees C for 24 hours. After viewing the photos, complete the table below. Hint: The 3 species in the table below all show different types of hemolysis. For help, you can read through p. 6 of the Lab Exercise on Selective/Differential Media and/or view this video tutorial on how to interpret blood agar results.
Column A:
Bacterial species Column B:
Type of hemolsyis (alpha, beta, or gamma)? Column C:
Explanation for your answer to Column B
Enterococcus faecalis
Staphylococcus aureus
Staphylococcus epidermidis
Instructions for Part 3: Determining oxygen requirements for bacteria
Here are 4 different bacterial species grown on a TSA plate at 37 degrees C for 24 hours in the presence of oxygen.
Here are the same 4 bacterial species grown in the absence of oxygen (i.e. grown inside a Gas Pak).
After viewing the photos linked above, fill in the table below. For help, you can read pp. 3-6 of the Lab Exercise on Bacterial Growth Characteristics and/or view this video tutorial on how to interpret Gas Pak results.
Column A:
Bacterial species Column B:
Oxygen requirement (obligate aerobe, obligate anaerobe, facultative, aerotolerant, or microaerophile) Column C:
Explanation for your answer to Column B
Micrococcus luteus
Clostridium sporogenes
Enterococcus faecalis
Staphylococcus epidermidis
You must proofread your paper. But do not strictly rely on your computer’s spell-checker and grammar-checker; failure to do so indicates a lack of effort on your part and you can expect your grade to suffer accordingly. Papers with numerous misspelled words and grammatical mistakes will be penalized. Read over your paper – in silence and then aloud – before handing it in and make corrections as necessary. Often it is advantageous to have a friend proofread your paper for obvious errors. Handwritten corrections are preferable to uncorrected mistakes.
Use a standard 10 to 12 point (10 to 12 characters per inch) typeface. Smaller or compressed type and papers with small margins or single-spacing are hard to read. It is better to let your essay run over the recommended number of pages than to try to compress it into fewer pages.
Likewise, large type, large margins, large indentations, triple-spacing, increased leading (space between lines), increased kerning (space between letters), and any other such attempts at “padding” to increase the length of a paper are unacceptable, wasteful of trees, and will not fool your professor.
The paper must be neatly formatted, double-spaced with a one-inch margin on the top, bottom, and sides of each page. When submitting hard copy, be sure to use white paper and print out using dark ink. If it is hard to read your essay, it will also be hard to follow your argument.
ADDITIONAL INSTRUCTIONS FOR THE CLASS
Discussion Questions (DQ)
Initial responses to the DQ should address all components of the questions asked, include a minimum of one scholarly source, and be at least 250 words.
Successful responses are substantive (i.e., add something new to the discussion, engage others in the discussion, well-developed idea) and include at least one scholarly source.
One or two sentence responses, simple statements of agreement or “good post,” and responses that are off-topic will not count as substantive. Substantive responses should be at least 150 words.
I encourage you to incorporate the readings from the week (as applicable) into your responses.
Weekly Participation
Your initial responses to the mandatory DQ do not count toward participation and are graded separately.
In addition to the DQ responses, you must post at least one reply to peers (or me) on three separate days, for a total of three replies.
Participation posts do not require a scholarly source/citation (unless you cite someone else’s work).
Part of your weekly participation includes viewing the weekly announcement and attesting to watching it in the comments. These announcements are made to ensure you understand everything that is due during the week.
APA Format and Writing Quality
Familiarize yourself with APA format and practice using it correctly. It is used for most writing assignments for your degree. Visit the Writing Center in the Student Success Center, under the Resources tab in LoudCloud for APA paper templates, citation examples, tips, etc. Points will be deducted for poor use of APA format or absence of APA format (if required).
Cite all sources of information! When in doubt, cite the source. Paraphrasing also requires a citation.
I highly recommend using the APA Publication Manual, 6th edition.
Use of Direct Quotes
I discourage overutilization of direct quotes in DQs and assignments at the Masters’ level and deduct points accordingly.
As Masters’ level students, it is important that you be able to critically analyze and interpret information from journal articles and other resources. Simply restating someone else’s words does not demonstrate an understanding of the content or critical analysis of the content.
It is best to paraphrase content and cite your source.
LopesWrite Policy
For assignments that need to be submitted to LopesWrite, please be sure you have received your report and Similarity Index (SI) percentage BEFORE you do a “final submit” to me.
Once you have received your report, please review it. This report will show you grammatical, punctuation, and spelling errors that can easily be fixed. Take the extra few minutes to review instead of getting counted off for these mistakes.
Review your similarities. Did you forget to cite something? Did you not paraphrase well enough? Is your paper made up of someone else’s thoughts more than your own?
Visit the Writing Center in the Student Success Center, under the Resources tab in LoudCloud for tips on improving your paper and SI score.
Late Policy
The university’s policy on late assignments is 10% penalty PER DAY LATE. This also applies to late DQ replies.
Please communicate with me if you anticipate having to submit an assignment late. I am happy to be flexible, with advance notice. We may be able to work out an extension based on extenuating circumstances.
If you do not communicate with me before submitting an assignment late, the GCU late policy will be in effect.
I do not accept assignments that are two or more weeks late unless we have worked out an extension.
As per policy, no assignments are accepted after the last day of class. Any assignment submitted after midnight on the last day of class will not be accepted for grading.
Communication
Communication is so very important. There are multiple ways to communicate with me:
Questions to Instructor Forum: This is a great place to ask course content or assignment questions. If you have a question, there is a good chance one of your peers does as well. This is a public forum for the class.
Individual Forum: This is a private forum to ask me questions or send me messages. This will be checked at least once every 24 hours.