On Monday I wasn't in class. I was at the oral surgeon getting a bone spur removed. I know I missed a lot, but my lab partner kind of filled me in. From my understanding Monday was an extremely long day. I was told that everyone did another DNA extraction (lucky them), rated their radiation plates, and checked their starch plates for amylase production. From what I understand our contamination rate went down (by the way I was responsible for the streaking of those plates). I'll just blame all the contaminants on Larry since he hasn't quite mastered the art of streaking...j/k Larry!!! To test for amylase production each group had to pour iodine onto the plates, in looking at our results almost all of our organisms tested positive for amylase production. In looking at the pictures below, you will see that strain 30 did in fact hydrolyze the starch, unlike strain 45.
Strain 30 - starch hydrolysis positive:
Strain 45 - starch hydrolysis negative:
In addition, in looking at the radiated plates pictured below you will see a drop in the survival of organisms as the amount of radiation they were exposed to increases. For example, at 0kGy the most organisms survived, however, at 16kGy no organisms survived.
Growth after O kGy exposure:
Growth after 3 kGy exposure: 
Growth after 6 kGy exposure: 
Growth after 16 kGy exposure:
On Wednesay....oh Wednesday...!! We had a midterm that I was somewhat frieghtened about. I thought that I was learning all of the wrong things and that while reading the papers I missed alot of important details. Well, lucky for us Miss Chrisi sent us all a study guide with pretty much everything we needed to know (keep up the good work girl). It turned out that the midterm wasn't anything foreign to either of us and was pretty much all the things we did and went over in class. I'll admit, I did go blank a few questions...hopefully that won't hurt my grade too bad. Next, after the test we plated our organisms on plates with different pH's. The pH's were 4-10. I suspect that very few organisms will grow at pH 4 since it's so acidic. However, I think a few more will grow at pH 10 since it's basic. But I don't know....we'll have to wait and see.
haha what did i do?
ReplyDeletemost of our organisms grow at a neutral pH--like 7-8.5(according to the papers we had to read), so I dont think that a strain is any more likely to grow at pH 10 than it is at pH 4 (but thats just an idea)
ReplyDeleteProbyONe...you are correct that most of our organisms grow at 7-8.5. However, i thought that since most of our strains came from the Atacama desert where the soil isn't that acidic, that they would grow at higher pH's. Correct me on this if i'm wrong
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