Blair Bean Grade 9 Pittsburgh Central Catholic Highschool
Variety of organisms that live in and on the body Skin Gastrointestinal tracts Nose Pharynx Mouth Conjunctiva Provide moisture, nourishment, and a stable ph for body to properly function
Fungi Yeast Malassezia fungi Bacterium Enterobacteriae Streptococcus salivarius Staphylococcus epidermidis Neisseria meningitides
Enterobacteriae One of the most used models in history Found in intestines Gram negative Cell wall Mostly nonpathogenic Rod-shaped Important part of healthy intestines Vitamin B12 and K Aerobic
Common model Lives on skin Infects cuts, pimples, and acne Gram positive Cell wall More pathogenic Round and clumped together Aerobic
Cucumis sativius 97% water Vitamin K2 Helps blood coagulate Molybdenum Needed for sulfite enzymes Detoxes body Source of energy through complex carbohydrates Reduces risk of estrogen cancers
Not a GMO Contains none or few seeds capable of reproduction Triploid (three sets of chromosomes) Altered by using growth hormones and gene transfer on the triploid DNA strain
Contains seeds capable of reproduction Diploid or tetraploid Horticulturists grow the perfect strain Unaltered by hormones and gene transfer
Do cucumber extracts affect the survivorship of microbial flora? Determine if there is a difference in the effects of seedless and seeded cucumber on microbial flora
Microbial flora is important to the overall health of the human body Humans eat both seedless and seeded cucumber everyday How do cucumbers affect the flora?
Null: Cucumber extract will not significantly affect microbial flora survivorship. Alternative: Cucumber extract will significantly affect microbial survivorship Alternative: There will be a significant difference in the effects of seedless and seeded cucumber on microbial flora.
Micropipettes Sterile pipette tips Escherichia coli (nonpathogenic) Staphylococcus epidermidis (nonpathogenic) Seedless cucumber Seeded cucumber Sterile dilution fluid (100mM KH2PO4, 100mM K2HPO4, 10mM MgSO4, 1mM NaCl) LB Agar Plates (1% Tryptone, 0.5% Yeast Extract, 1% NaCl) LB Media (0.5% yeast extract, 1% tryptone, 1% sodium chloride) Spreader bars Vortex Test tube rack Sidearm flask Klett Spectrophotometer Ethanol Bunsen burners Latex gloves Permanent markers Filter paper Cheese cloth Glass jars with lids
Both cucumbers used in the experiment were ground in separate food processors The resulting slurry was separately filtered through cheese cloth into two different glass jars with lids The jars were refrigerated overnight Escherichia coli and Staphylococcus epidermidis were also grown overnight in sterile LB media. A sample of each culture was added to separate LB media in a separate sidearm flask.
The cultures were incubated until a density of 50 Klett spectrophotometer units was reached. This represents a density of 10^8 cells/ml The cultures were then diluted in a sterile dilution fluid to a density of 10^5 cells/ml The individual cucumber juices were drained through filter paper and sterile filtered through 0.2 micron filters into separate test tubes until a consistency that could easily be micro pipetted was met The following ingredients were mixed to create the desired cucumber extract exposures
Contents 0x Concentration 1x Concentration 10x Concentration Sterile Dilution Fluid E. Coli or Staph Additional Sterile Fluid Seedless or Seeded Cucumber Juice Total Volume 8.9ml 8.9ml 8.9ml 0.1ml 0.1ml 0.1ml 1ml 0.9ml 0ml 0ml 0.1ml 1ml 10ml 10ml 10ml
Tubes were allowed to sit for 10 minutes. Then after vortexing each of the 8 tubes to evenly suspend cells, 0.1 ml aliquots from each tube was spread evenly on 50 LB agar plates Tubes were allowed to sit for another 20 minutes and the plating process was then repeated The plates were incubated overnight The resulting colonies were counted and recorded. Each colony was assumed to have risen from one cell.
Number of surviving colonies 700 600 500 400 300 200 100 0 E. coli 10 Minute 0.4626 Control 1x 10x Concentrations of Extract 0.9870 P-value 0.000789973 Seeded Seedless
Number of surviving colonies 700 600 500 400 300 200 100 0 E. coli 30 Minute 0.2496 0.8641 Control 1x 10x Concentration of Extract P-value 0.001199133 Seeded Seedless
Number of surviving colonies 700 600 500 400 300 200 100 0 Staph 10 Minute 0.9349 0.8461 Control 1x 10x Concentration of Extract P-value 2.50902E-07 Seeded Seedless
Number of surviving colonies 700 600 500 400 300 200 100 0 Staph 30 Minute 0.5817 Control 1x 10x Concentration of Extract 0.3608 P-value 0.02884179 Seeded Seedless
Cucumber did significantly affect microbial survivorship across all concentrations Seeded and seedless cucumber did not show significant variance in their effects on microbial survivorship. The different cucumbers did not affect the microbial flora differently The E. coli graphs suggest a trend of growth while the Staph graphs suggest a trend of decreasing colonies
Limitations Plating was not completely synchronized Only two exposure times Only two concentrations Only one type of exposure Extensions More replicates Infuse agar instead of just liquid pulse More concentrations Test GMO plants and compare them to cucumbers
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