Week 5: Whistle While you work

      Monday brought results, as usual. The sub-cultured experiment only resulted in manganese oxidation in the tube containing both lignin and manganese, suggesting that it can not only survive but also grow better on lignin as a carbon source, which is good news. I then looked at the plates that were derived from the culture prior to the sub-culture, and they were inconclusive. Because there was a shortage of LB plates, we had to use lept as well, and they grew differently as a result. Not only that, but there were too many colonies on each plate to count, and therefore, we couldn’t rely on that experiment in a quantitative sense. For the rest of the day, I made more MSTM media, which is quite a hassle mind you. But I didn’t have much time to start something entirely new, and we needed the media.

      This Tuesday was not a normal day. The interns actually got the opportunity to spend the day in Astoria to learn more about the fieldwork done there by CMOP and the Columbia River Estuary in general. We made the trek to Astoria and visited the site team first. It was an awesome experience to see what kind of methods and technologies they were using to gather data all around the estuary. I was most impressed with their glider that did all of its work without any direct human contact. It was programmed to do everything automatically, and I can only imagine the amount of engineering that went into it. After that, we headed up to the Astoria Column for lunch and an amazing view. Then we came back down the hill to go to the Columbia River Maritime Museum. It wasn’t really about the environment side of its history, but it was very interesting nonetheless. But towards the end, all of us were getting pretty tired and antsy to get home. After a big group picture, we finally started the trip back home, and I slept the entire way. It was a good day!

      It was good to get back to work on Wednesday. On Wednesday, I plated the sub-cultured experiment to test for levels of growth. Then, I started an experiment that used the wildtype strain, one with MnxG deleted (KG51), one with McoA deleted (KG152), and one with both of those genes deleted (KG180), because those are the suspected manganese oxidizing genes. Along with all of those strains, I used all of the carbon sources we have used in the past as well. This will tell us how much each protein is utilized within each carbon source.

      On Thursday, I looked at the preliminary results and discovered that the oxidizing mutants were all oxidizing in at least one carbon source. The only carbon source that was not being oxidized, however, was the glucose. In comparison, glucose has a lot of nutrients, so this suggests that GB-1 starts oxidation in response to starvation. I then used the rest of the day to pour plates and update my notebook.

      Friday was a results day. The cultures that were just described had started to oxidize in the glucose media (except for the non-oxidizing mutant). The plates that were done on Wednesday were now visible enough to perform plate counts. The cultures that were put in the water media had extremely low numbers with an average of 4 colonies, while the bacteria in the lignin media were doing much better with an average in the 200s. Kati and I then used the rest of the day to plan my activities for next week, because she was leaving on vacation for the entire next week.