Week #10 4/05-4/11

I have so much to share with my fellow scholars this week so I hope to keep it close to 400 words lest Dijana go cross-eyed while grading our contributions. :-)

First, let me make a few confessions.

1) I am really excited about our field trip tomorrow and would like to thank Professor Schampel in advance for guiding us through the botanical gardens!

2) I am equally excited that my project was accepted for the Estrella Mountain conference. Congratulations to all of my colleagues who were also accepted and for those who won't have a chance this time, chin up, in science we can only go one direction: UP! 

3) I wish I could type this one in smaller font because I have been making a mistake with my project and just discovered it about a week ago. It's not catastrophic by any means, but noteworthy nonetheless. I haven't been measuring my zones of inhibition correctly on my lawn cultures. Instead of measuring the diameter of the zone, I have been measuring the radius from the edge of the disk. I know you must be thinking, no big deal, just double it; however, it does mean that my results are even better than before. For example, when I indicated that Mesquite had a 2 mm zone of inhibition it would actually be more like 6 mm as I would have to double the radius and account for the size of the disk. Confused yet? Let's proceed to this week's results.

If you have been following my blog, you already know that I have changed my protocol several times to optimize my results. Currently, I am using a 70% ethanol extraction method in conjunction with the Kirby Bauer method to measure the areas in which the bacteria are unable to grow. It is important to note that different extraction methods will yield different results because the extraction of a bioactive property of a plant is contingent upon a given method. This is precisely what we are try to perfect. Last week, using ethanol, horseradish didn't show any zones; however, this week, I placed disks in ground horseradish with 100 ml of vinegar and let it set for 48 hours. Below you can see the results.

My horseradish/vinegar extraction worked. I would have expected it to have more of an effect on Staphylococcus aureus than Escherichia coli; however, zones of inhibition were only illustrated on the latter. 

Since we are preparing for the Estrella conference, I am refining my protocol and testing as many specimens as I can. Below, you will see that Bitter Orange Blossom (Citrus Aurantium) had no effect; nevertheless, I spent a few hours in the lab today to prepare 20 more cultures (some of which will be controls). I will have more results for you next week.