Does+the+type+of+light+effect+bactrial+growth?


 * How Different Lighting Effects Bacterial Growth -by Mady Leach, Hailey Trulock, and Courtney Kotowski **

Abstract: We made Agar and let it sit for a day. Then after we did that we put E. Coli on half of a petri dish on four petri dishes, while the other side had nothing on it and was marked as control. We did the same thing with M. Luteus and B. Cereus. One of each bacteria was marked as sunlight, and so we put them outside the window. One of each bacteria was marked as dark and we put them in the dark cabinet. One of each bacteria was marked U.V Light and we put it under a U.V light and put it under for 15 minute intervles We left them all there for two weeks. We didn't mess them so we wouldn't mess up the experiment. Then after the two weeks was up we checked on them and brought them in the classroom and recorded the results.

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 * Purpose: We are growing bacteria in different lighting to see what places in a house or building might be more susceptible to bacteria growth. We plan to grow the bacteria in a petri dish and swab a (toilet seat?). We will have three containers, put one in __ a window __ sill to get sunlight, one in complete darkness, and one in UV light. Then record the growth of bacteria every other day for a month. We will measure the width and length of the bacterial colonies(in cm) and compare the number of colonies We’re going to do 2-3 trials.  **======

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 * Background Information: Randy Abends experiment concluded that sunlight slows down the growth of bacteria, and that bacteria put in complete darkness will grow faster.(“Does Light Effect Bacterial Growth?” 2012) Kenneth Todars __ |information __ states that certain bacteria need light to grow and survive. (“Nutrition and Growth of Bacteria” 2012). Ultraviolet light effects the bacteria’s DNA. The damage occurs quickly, the bacteria cannot replicate and repairs itself. Exposure to the light can stop the growth and reproduction in some cases. (Nutrition and Growth of Bacteria). That is how we plan to test the way that light effects bacterial growth. If the bacteria is put in complete darkness, then the bacteria will grow faster than in other lighting's . We will need three petri dishes, a UV light, a ruler, and swabs.   ** (I have UV beads that can help determine the amount of UV as an Independant variable - Mr. K) ======
 * If we put the bacteria in the dark, then it will grow more than in sunlight or UV light.**

=**Data Table:**=
 * Analysis: Over a period of three weeks we recoreded the growth of the bacterium twice. Both times the UV light had more colonies of each type of bacteria. The baacteria that were put on a window sill were the least successful, E-coli had 4 colonies, B-Cereus had 0 colonies, and M-Luteus had 3 colonies. I predict that the low temperatures had to do with that, because there was ice on the lid of the petri dishes. Comparing the bacteria in the sunlight to those in UV and darkness, the other two were much more successful. The bacterium placed in the dark didn't have as many colonies as the bacterium placed in the UV. The dark E-coli had 5 colonies, B-Cereus had 0 colonies, and M-Luteus had 12 colonies, while the bacterium in UV lighting was as follows; E-coli: 11 colonies, B-Cereus: 7 colonies, M-Luteus: 14 colonies. I also think that the bacterium in the UV light grew more because the UV wasn't constant. The light we used would turn off every 15 minutes and was required to be turned back on, so the bacteria was in UV and darkness which gave it time to repair itself. However, if I did the experiment again I would know what to do differently to give me more accurate results.**
 * If we place the bacteria in the dark, then it will grow more than in sunlight or UV light. Our hypothesis was incorrect, the bacteria in the UV light grew the most. Our experiment was inaccurate because the temperature outside caused the bacteria i the sunlight to freeze, we should have put them inside or done the experiment in a warmer place, the UV light wasn't on all the time, we needed a light that could be on 24/7, and we should have recorded our data more often and done the experiment more than once. **


 * **Sun** ||  ||   || **Dark** ||   ||   || **UV** ||   ||
 * E-Coli || 4 ||  || E-Coli || 5 ||   || E-Coli || 11 ||
 * B-Cereus || 0 ||  || B-Cereus || 0 ||   || B-Cereus || 7 ||
 * M-Luteus || 3 ||  || M-Luteus || 12 ||   || M-Luteus || 14 ||

= = =**Graph:**= I don't believe it is necessary to put the titles "background info" or "work cited" - Liz Foster How are you going to quantify your data? (Mr. Kerwin) What if the weather outside is not sunny, I think that would affect the petri dish on a window sill (Tessendorf)


 * Work Cited: Abend, Randy. "Does Light Effect Bacterial Growth?" Does Light Effect Bacterial Growth? N.p., n.d. Web. 26 Nov. 2012. . **


 * Roberts, Susan. "The Effects of Ultra Violet Light on Bacterial Growth." EHow. __#|Demand Media__, 22 July 2010. Web. 29 Nov. 2012. . **


 * Todar, Kenneth. "Nutrition and Growth of Bacteria." Nutrition and Growth of Bacteria. N.p., n.d. Web. 27 Nov. 2012. . **