Maris Leman's blog

This week was a busy one as I attempted to complete data analysis, create my poster, and finish my final paper. Data analysis had to be completed first since I needed to be able to analyze trends before drawing up any conclusions that could be included in my poster presentation or final paper. I spent all of Monday and most of Tuesday working on data analysis. Because I ran four experiments, I had over 24 graphs to compare and look for trends in. Matt helped me analyze these graphs, as it was hard to summarize such an enormous amount of data.

Collecting daily time points continued this week. On Monday and Tuesday, I collected two time points and spent time measuring manganese oxide samples. This consists of spinning down the samples and then pipetting a small amount into a 48 well plate for measurement via the spectrophotometer. Each sample already had LBB added to it—the reagent that turns blue in the presence of manganese oxides. The intensity of blue is what is measured on the spectrophotometer. Given absorbance values are then used to determine oxide concentration.

Monday and Tuesday, I spent most of the day collecting two time points. On Wednesday, I set up for the next time point and spent the rest of the day working on data analysis. Since I had been performing two time points a day, I had a lot of data to analyze.

On Thursday, I collected samples from two time points and then measured outstanding manganese oxide samples. Friday, I collected a time point and then attended the intern seminar on communication.

This week I continued with the schedule that my past weeks have exhibited. Each day I focused on collecting samples from two different time points. This, along with acid washing, occupied most of my mornings. On several of the days, I also measured outstanding manganese oxides samples. To do this I added LBB to the samples and measured the absorbance via the spectrophotometer.

Week 6 followed the same pattern of the previous couple weeks. On Monday, I ran two time points and then measured total dissolved manganese in outstanding samples via the formaldoxime assay. I also streaked a Lept plate with P. Putida GB 1 mutant 245.

Monday was my busiest day yet since I had two time points to measure. I measured time eight from experiment one in the morning and then acid washed equipment before measuring time one from experiment two. This took me quite awhile to accomplish and therefore I spent most of my day focusing on getting my two time points in. I spent the afternoon measuring the amount of manganese (III) present in outstanding samples. The samples already had LBB added to them so all I had to do was measure them.

This week marked my first full week running through my experiment. Matt was gone Monday and therefore it was up to me to make sure that I measured my daily time point correctly. My cultures had grown up over the weekend and therefore there were lots of bacteria in both of the light cultures. The dark cultures exhibited slower growth.

Monday morning found me working with one of the pH buffers again. Eventually, Matt told me to titrate the buffer with a 0.25 basic solution and this solved the problem. I also remade the 20 U/ml HRP solution that is used in the H₂O₂ assay. I made up more liquid Lept media and transferred my bacteria from plates to this medium. I left the bacteria to shake overnight.

The week began with the NSF annual site visit on Monday. This was an all day event that I attended with the other interns. It was really nice to hear a broad overview of what CMOP is all about and the research that is being performed throughout the program.

I am really excited about this opportunity to perform research through CMOP. I am interning in Dr. Brad Tebo’s lab. My frontline mentor is Dr. Matthew Jones, a post-doctoral researcher studying manganese cycling in the environment.