Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
By: Bethany Vogeney and Pahua Cha Mentor: Rachel McKenna Abstract Plants are growing all around us. Their chemical compounds serve many functions, including medicinal ones. For our experiment, 13 plant samples were collected from our “backyard” and were tested using bioassays to determine whether they had antibacterial and antifungal properties. Because more and more bacteria are beginning to build resistance against the tools we have at hand, it is important to keep searching for new medicinal options to fight microorganisms. Microorganisms We Tested On - To test for antibacterial properties we used two organisms: E. Coli which is gram negative and Pediococcus pentosaceus which is gram positive. These represent the two main types of bacteria. The main difference is the structure of the cell wall. - To test antifungal potential of plants, yeast was used. Plant Name Japanese Pieris Flowers Japanese Pieris Berries Cedar 3-point leave English Ivy Rose Garlic Cloves 5 star yellow flower Rusty leaves St. John's Wort Green leaves Lichen Solvent E. Coli Pediococcus pentosaceus Yeast Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol Hexane ------- Ethanol ---- ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- Hexane ---- ---- Ethanol ---- ---- ---- Hexane ---- ---- ---- Ethanol ---- ---- The Bioassays Bioassays are a method of testing a substance using living organisms. We conducted three types of bioassays to test for antibacterial (gram positive and gram negative), and antifungal properties. The microorganisms were cultured and put into a nutrient agar plate to grow. We loaded our compounds onto the plate, using the hexane and ethanol solutions. If the samples have any antimicrobial properties, there will be a clear zone around the sample in which the microorganism could not grow. Bioassays Making the plates: After the extraction of the two solutions, Petri dishes had to be prepared with a special media to promote the growth of the test subjects. To make the nutrient agar: 1) Dissolve the nutrient media and agar in water. 2) Sterilize by autoclaving 3) Inoculate sterile media with microorganism 4) Pour media into Petri dishes to make bioassay plates. -Use one plate for hexane extracts and one plate for the ethanol extracts. Pour the media and let it harden. Test the samples: 1)After media has hardened, bore wells in media and fill each with the sample. 2)Put each plate into the incubator overnight. 3)In the morning, measure the size of each zone around the samples. (A zone is a clear circle around a sample with no bacterial growth.) Plant Samples Japanese Pieris flowers Japanese Pieris berries Cedar English Ivy Rose Garlic Cloves Five star yellow flower Green leaves Rusty leaves St. Johns Wort Lichen Three point leaves Extraction Procedure 1) 2) 3) 4) Collect plant samples Cut or crush plant samples Pour samples into 70% ethanol and homogenize Filter mixtures and add hexane to the filtered ethanol 5)Mix gently and let the layers formulate and settle 6) Pipette the hexane layer and store separately do the same w/ the ethanol 7)The samples will be tested for antimicrobial compounds Plant Extraction Abstract To determine whether antimicrobial substances exist within a plant, it’s chemical compounds first must be extracted. Proteins, sugars, and lipids are the main molecular components in plants. These components may contain useful substances but stay undetected until they’re extracted and experimented on. Ethanol and Hexane are the solvents we used to extract the active compounds. The ethanol and hexane separate the proteins and sugars from the lipids. Ethanol is polar and attracts the polar sugars and protein, and hexane is non-polar and attracts the non-polar lipids. The two repel, separating the non-polar and polar matter. This makes it easier to determine which component of the plant effects certain organisms. Conclusion For centuries plants have provided us with the tools to fight off diseases. Many of these plants could easily be those found in our own backyard. Four out of thirteen or 31% of the plant samples tested positive for antibacterial or antifungal compounds. Antibacterial (gram+): Sugar, proteins and lipids of St. John’s wort and lichen Antibacterial (gram -) Sugars and proteins of clove and garlic Antifungal: Sugars and proteins of garlic