BIOL202

Grade Rubric Week 4: Project topic submission

Category Criteria Percentage

of Score

Element 1:

Topic chosen, Title Slide and presentation

format.

• The Title Slide must include the title of your presentation and must be directly what you chose for your project topic.

• The color scheme of the presentation is appropriate and visually pleasing.

*Any images/enhancements must include a descriptive title and appropriate legend.

10%

Element 2:

The Rationale: Why the topic

was chosen.

• The rationale must address why the topic chosen is important for exploration, research, and academic endeavors.

• The rationale should address why the topic chosen is currently, may in the future, or is of particular interest to the student.

• The rationale must address why the topic chosen is of importance for the betterment of humanity.

• The rationale slide(s) are titled.

35%

Element 3:

The Background: A background is

provided.

• The background must source from scholarly references (including APA formatted in-text citations and reference list).

• The background must provide substantial justification of its importance.

• The background must directly address the topic chosen.

• Correct scientific terminology must be utilized. • The background slide(s) are titled.

35%

Element 4:

Proposed Hypothesis

• Provide your proposed testable hypothesis 10%

Writing Standard

• The presentation is free of spelling, punctuation, and grammar errors.

• Writing is clear and articulated. • Ideas presented are easy to understand. • The font size and color choice of text are consistent

and appropriate.

10%

Diversity of Microbes Present on Common Surfaces

• I chose this topic because I’m in the medical field

• The exploration of microbes on common surfaces may identify novel species

• The data obtained adds to the academic repertoire of knowledge

• This study aids research efforts in the identification of diverse microbes

• Humanity benefits when new knowledge is obtained

Rationale

• Our environment is full of microbes (Dunn, Henley, & Leff, 2012)

• Objects with more exposure and contact with periodic or minimal cleaning will have higher

levels and more diversity of bacteria (Samet & Spengler, 2003)

• Air also adds to the diversity of microbes

• Microbes in our homes are responsible for most preventable illnesses (Kagan, Aiello, &

Larson, 2002)

Background

Hypothesis

What will have the most diverse microbes present? I hypothesize that the toilet handle in the bathroom will have the most diverse microbes.

Coffee Mug Bottle of bleach Shoe box 6 TSA Pour Tube

Distilled water Pot Permanent Marker Tap water

Glass Beaker (100 mL) Test Tube Rack Thermometer Bucket

6 Sterile swabs 6 Petri dish, 90 mm PPE

Materials

• Don proper PPE

• Pour 6 large TSA agar plates into 90 mm petri-dishes

• Allow plates to cool for 2 hours with lid laid over top but not completely covering

• Choose 5 locations to swab

• Use permanent marker to label each petri-dish with the location swabbed

• Add 20 mL of distilled water to a 100 mL glass beaker

• Saturate the swab in the liquid, swab the desired area

• Streak the agar plate with the contaminated swab- repeat for the 5 selected swab locations

• Allow 3-4 days incubation in a shoe box inside a 21-25 degree C dark room

• Record results at 24-hr intervals

• At the end of the incubation period, record the number of colonies, color, shape, size and appearance

• Negative control- swab distilled water only onto a TSA agar plate

Methods

Expected Data • Swabs collected from all locations will show no growth after 24 hours

• At 48 hours, all samples will be in the beginnings stages of growth. The Toilet Handle will show the greatest number of different colonies followed by the Car Keys, TV Remote, Cell Phone and then lastly, the Refrigerator Handle

• At 72 hours, the sample from the Toilet Handle will show the greatest number of different colonies followed by the Car Keys, TV Remote, Cell Phone and then lastly, the Refrigerator Handle. Most colonies will cover from 50% to 80% of the agar plates

• The negative control distilled water swab will not show any growth at 24, 48 or 72 hours

(Sample Results from Dunn et al, 2013) (Sample Photo Pixabay, n.d.)

Fraction of bacterial colonies counted, normalized to control (not shown) TSA agar plate with dispersed bacterial colonies.

Cell colors represent relative percentages found in each location.

Data

TSA agar streak plate Bacterial Growth

Data Sample Location and Incubation Time

Data Table 1. Sample collection locations and incubation times. Samples were collected and incubated separately for 24, 48 and 72 hours then numbers of colonies, types, size and percentage of plates covered with colonies were recorded.

• Growth of microbes were found present in all five sample locations

• The Refrigerator Handle and TV Remote showed no growth at 24 hours

• The Cell Phone and Car Keys showed one colony at 24 hours

• The Toilet Handle showed two different colonies at 24 hours

• The Refrigerator Handle showed four different types of colonies at 48 hours

• The Cell Phone, Car Keys and Toilet Handle showed two different types of colonies at 48 hours

• The TV Remove showed one type of colony present at 48 hours

Conclusions

Conclusions

• The Refrigerator Handle showed six different types of colonies present at 72 hours

• The Cell Phone showed four different types of colonies present at 72 hours

• The TV remove showed three different types of colonies present at 72 hours

• The Toilet Handle and Car Keys showed two different types of colonies present at 72 hours

• The negative control (data not shown) exhibited no growth after 24 and 48 hours but showed 2 single, small white colonies beginning after 72 hours

Conclusions

• The Refrigerator Handle grew the greatest diversity of microbes and spread across the agar plate fastest.

• The Toilet Handles grew the least diversity and was slowest to spread across the agar plate.

Dunn, R.R., Fierer, N., Henley, J.B., Leff, J.W., Menninger, H.L. (2013). Home Life: Factors Structuring the

Bacterial Diversity Found within and between Homes. PLoS ONE 8(5): e64133.

https://doi.org/10.1371/journal.pone.0064133

Samet, J. M., & Spengler, J. D. (2003). Indoor Environments and Health: Moving Into the 21st Century.

American Journal of Public Health, 93(9), 1489–1493.

Kagan, L.J., Aiello, A.E., Larson, E. (2002). The Role of the Home Environment in the Transmission of

Infectious Diseases. Journal of Community Health. Retrieved from

https://www.researchgate.net/publication/11197748_The_Role_of_the_Home_Environment_in_the_Transmissio

n_of_Infectious_Diseases

Petri-dish diversity. Digital image. Pixabay Retrieved from: https://pixabay.com/

References