Most of our new gadgets and gizmos for water chemistry have finally come in, so we have started testing them out. Some of the kits we ordered include tests for nitrate, nitrite, phosphorus, chlorine, hardness, sulfate, and iron. At first, we were testing the kits out on tap water to get comfortable with all the tests, and then Matt collected sea water samples from one of the tanks so we started using those.
Today I tried the nitrate kit, which has never been used before. It was a surprisingly simple and quick test, and I found 79.5 ppm (mg/L) nitrate in the sea water. Unfortunately, I do not know the significance of this value, so David suggested that I try the test on tap water for comparison. The amount of nitrate in the tap water sample was 23.2 ppm (mg/L). According to Wikipedia, marine aquariums are only supposed to have trace amounts of nitrate in order to be healthy, so I do not know what our values mean.
A few of the kits we ordered do not have the range to collect values from sea water, so we are thinking of diluting our sea water samples with DI water. We will then use that mixture to conduct the tests that did not work (i.e. the phosphorus and hardness tests). In order for this plan to work, however, there must be small amounts of chemicals in the DI water or our data will be skewed. I checked the level of phosphorus in the DI water and the value came out to be 34 ppb. I am not sure if this means that our dilutions will work, but I am sure we will be able to figure out how to analyze our data after doing some more research.
Our project is starting to pick up! After our initial sampling/sequencing period, we realized that there is actual DNA we can work with from the tanks. This past week, we started our actual sample collecting from the tropical tank. We collected 3 sets of samples from the sediment, walls, and water. Throughout the week, we extracted the DNA and ran PCR on all 9 samples (plus one negative control). Today, we completed the gel electrophoresis and got some unpleasant results. Unfortunately, we couldn’t see the primer bands and the DNA bands didn’t show up like we thought they would. This means something went wrong in our PCR, but we don’t know if it was during PCR16SA or PCR16SB. Well, it’s back to the drawing board! Starting next week, we will be re-running the PCR on the 9 samples and possible collecting more samples from other tanks.
Although this week’s results were a bust, we know that there is definitely some DNA present that we can work with. I’m sure we’ll be finding some pretty cool things as we continue sampling and sequencing. 🙂
I’m Sabreen Aulakh, one of the undergraduates working on the Undergraduate Aquarium Project! I’m a third year Microbiology major, and my plan is to go to medical school some time in the near future. I’m from San Jose, and I love to dance, specifically Bhangra, which is a traditional North Indian dance from Punjab, India. For those who are curious as to what it looks like, here’s a video of my team. (Nope, I’m not in this video because I was still in school.)
There’s just something about how those teeny tiny microbes have huge impacts on their environment that’s so darn interesting to me! I’m very excited to be a part of this lab, and can’t wait to see how this project unfolds. 🙂