In the past month, no significant progress has been made towards finding sources of dog urine for our prospective project. Many dog owners declined to donate dog urine since the process of collecting urine is stressful for the dog. Because thirty-five gallons is simply too large to collect manually, we have decided to synthesize dog urine in the lab. We initially planned to research its average composition and synthesize it but failed to find recently published literature on the composition of dog urine. Instead, we plan to use nuclear magnetic resonance spectroscopy to determine the physical and chemical properties of the mere 30 milliliters of dog urine sample that we struggled to collect at the Bideawee dog shelter. From there, we will have the list of ingredients needed for our dog urine recipe.
A familiar lab technique I revisited this past month since general chemistry lab last fall is measuring the pH of a given sample. For a few days, I used a pH probe to measure the pH values of soil samples in water. Measuring the pH, or the soil’s acidity or alkalinity is important because we want to determine the relationship (if any) between soil microbes and the pH of the soil samples. For further analysis, we computed the moisture content of the collected soil samples. We oven-dried a pinch of soil from each sample and compared it with its respective wet weight.
On June 19th, I went on a lab excursion to a one-day conference (Microbes in the City: Mapping the Urban Genome) at the New York Academy of Sciences. I was very excited about this opportunity because the relationship between microbes and human health is poorly studied. The conference successfully tackles the recent discoveries on microbes in urban areas and their relationship with humans and our health. Many findings were fascinating! As a commuting student researcher in the microbial ecology lab, the presentations about the microbiome in urban mass transit, in particular, caught my attention. The various microbial organisms that seep into the cracks of the wooden subway benches grossed me out. I learned that more than 40% of the DNA obtained from sampling in the NYC subway system did not match any currently known species of microbial organisms. We don’t even know what microbes we are coming in contact with. It is safe to bet that I will never sit on the subway benches ever again! Subway poles, however, are supposedly germ-resistant. As quoted by one of my favorite presenters, “you will probably be fine if you like a subway pole.”
In the upcoming weeks, we will be doing soil sampling for the Green Roof Assembly Project. In this project, we aim to create better green spaces throughout New York City to help capture stormwater runoff after a heavy precipitation event. Without the addition of green infrastructures in the city, the water quality will surely be negatively impacted as the runoff combines with raw sewage. For this project, we have been collecting soil samples from nearby parks and recreation centers once a month since 2012. We hope to explore and compare the diversity of microbes among green roofs with different plant communities. Additionally, we hope to explore the differences in the soil and microbes throughout the years. In this past month, my lab mates and I have been working hard to finish DNA extractions and perform PCR (polymerase chain reaction) to amplify a segment of DNA. We will send these DNA samples to another lab for sequencing. We will also be using the PLFA (phospholipid fatty acid) process to measure the microbial biomass and composition. We hypothesize that microbial biomass is directly correlated with the ability of soil to retain water.