So Many Test Tubes, So Little Time...

I am not getting close to the end of my project. I have completed another four test to the same 9 bacterias, but I have to redo one of the test. Which was caused by, me letting it inoculate for too long. We also decided that the o/f medium (or oxidation fermentation medium) is very unreliable and difficult to read. This has given us the idea of finding a more efficient way of preforming this test. What this test detects is if acid is given off after fermentation or oxidation. This is suppose to allow for a color change to happen in the media, changing it to a yellow rather than the dark green that it began. This is due to a lowered pH after oxidation occurs in the process of inoculation. From my practice doing the test on all the bacterias, I realized that it was very difficult to get a significant amount of bacteria in the test tube, while still trying to follow the directions of how to correctly "stab" the media. This could have been one of the issues because its not given enough bacteria to react to.
The one test I really found interesting was the T.S.I Slants (Triple Sugar Iron Agar). This is another acid test that detects presence of acid and Sodium Thiosulfate (reduced to H2S gas). If positive for the gas the media would change colors from yellow to black (or a very dark red, in my test). The reaction occurs because H2S reacts with ferrous sulfide in order to create the black precipitate that grows mainly from the "butt" of the media in the test tube.

This is an example of a positive reaction for acid from sugar fermentation in the bacteria. What was so interesting about this tube in particular is the fact the the actual media moved that high in the tube. They all started off at the same height and as you can see in the image above, the media completely shifted upward in the tube.

 

These images above are examples of positive reactions for H2S gas. The very first one was the one that I found most fascinating mainly because of the intense color change. Remember, they all started off a yellow color, most similar to the media shown on the far top. 
Well that's pretty much where I am at now, and I just found out that I will doing all these test AGAIN, with 12 different bacteria's. So, wish me luck! :[

A little about me and what I've been doing

My name is Esperanza Echavarria. I am currently a Freshman here at Phoenix college and my major is in Biochemistry. I went to Bioscience High School which had first introduced me to the wonderful mentors Amanda Chapman, Josh and Matt (Sorry your guys last names didn't make the cut). I spent most of my Senior year working with Matt and Josh learning the ropes behind the scenes of the Biology lab. As a senior this was very exiting for me because I was able to get an experience first hand on what college life could be like.
I really enjoyed working along side with Matt and Josh, while they taught me how to make and pour media (better than Gilbert, I might say) and how to correctly inoculate different bacterias and so much more. I can say I have learned a lot while interning her in the Biology lab. Don't tell them I said so, but they are pretty great as mentors. They have dedicated so much time in teaching us and being patient with us, it's amazing they haven't completly lost their minds.
I have been in and around the entire Biology lab for about over a year now and with that I can say I have become really familiar with it. Currently I have been working on a little project involving all the bacteria in our lab. I have been testing all of the bacterias on different types of test to see if the correct reaction occurs.
I have been working with bacteria like E.Coli and B. Subilis (only two of the 9 that I have started with) and so far I have grown all of the bacterias on TSA plates. I've also gram stained all of them and grown the bacteria in Glucose, Mannitol and Lactose to test if acid and gas are present. I don't currently have the pictures of the plates but I will try and post te cooler looking ones later. Matt had told me before I began this project that I was going to become a professional microbiologist and now I am starting to believe that comment. It didn't seem to be too much work when I started but after having to keep track of everything and doing all the test without messing them up became a task all in it's own.

These are the individual acid/gas test for all nine of the bacterias. If acid was present in the bacteria then the solution would have turned yellow as you can see in many of them here have.
To determine presence of gas was a little more difficult. If you look closely at the glucose test you can see on the first and fourth tube, beginning from the left to the right, there is a gas bubble collected in the small tube inside. That is what I was looking for in order to determine the presence of gas in the bacterias.
You can also see it very well in the mannitol first tube, beginning from the left. What was interesting was that for the lactose test all of the bacterias has a positive for gas. I will of course have to redo ALL of those test again to see if that is conclusive but I am up for the challenge. =)

Ohh and can you please let me know if the pictures are too small I will try and upload them larger. Also, please excuse any mispellings. I am not the best speller and this Blogger thing doesn'thave spell check sadly. =(

Hello :)

Hi, my name is Esperanza. I have been an intern here in the biology lab for a little over a year now. I look foward to working and meeting the new interns. If you have any questions, I am more than happy to answer. :)