Possession Sound, located in Everett, Washington, includes the second largest source of freshwater in Puget Sound from the Snohomish River. This salt-wedge estuary serves as a home to a wide selection of phytoplankton, which provide energy to a variety of organisms farther up the food chain. Water chemistry often determines where phytoplankton accumulate prior to their recycling as nutrients. Ocean Research College Academy students utilize water chemistry data (temperature, salinity, dissolved oxygen, pH, turbidity and chlorophyll concentration) from two sensors deployed in Possession Sound: One in the river and one two miles away at Mukilteo. While plankton samples are collected in the Sound, rarely are plankton collected in the river and compared to chlorophyll concentrations. This study will look at abundance and diversity of phytoplankton collected in the river at various tide stages and compare these to Mukilteo samples. I hypothesize that flood tide samples will be similar, while ebb tide phytoplankton and chlorophyll levels will decrease. The preliminary data revealed that chlorophyll and temperature levels did not vary significantly between the two sites despite the widely differing salinity levels. The next steps of the study are to determine the plankton density of phytoplankton species across the two most recent years of data. Results will enable us to explore further into plankton presence in relation to chemical variance in water systems. 

Irritable bowel syndrome (IBS) is a disease that affects many people worldwide. Clinical trials using probiotic bacteria to treat IBS show promising outcomes, although the molecular mechanisms of probiotics and their effect on gut health is not completely understood. Multiple studies comparing different strains of probiotics show Lactobacillus plantarum and Bifidobacterium longum as the most effective strains in inhibiting the release of proinflammatory factors in the gut and promoting proliferation of healthy gut bacteria. The purpose of this study is to evaluate the protein profile of probiotic bacteria Lactobacillus plantarum and Bifidobacterium longum in both healthy gut and IBS gut conditions. To observe how Lactobacillus plantarum and Bifidobacterium longum respond to different simulated gut conditions, samples of the bacteria will be isolated from probiotic supplements. These samples will be grown in aliquots representing different simulated anaerobic gut conditions for 12-16 hours at 37°C. Lactobacillus plantarum and Bifidobacterium longum will be grown separately and grown combined within these conditions. To enrich secreted proteins, the supernatant from each aliquot sample will be clarified using centrifugation. Secreted proteins will be solubilized and denatured with sodium deoxycholate. The denatured proteins will be reduced with dithiothreitol and alkylated with iodoacetamide. The sample will be diluted using ammonium bicarbonate and digested by trypsin. Tryptic peptides will be analyzed using liquid chromatography and mass spectrometry. Tryptic peptides will be identified using the SEQUEST search engine with a reference database. I anticipate the probiotic strains will demonstrate differential proteomics when isolated and combined in the healthy gut and IBS gut conditions. The secreted protein analysis completed in this study will further the understanding of the probiotic molecular mechanism of promoting gut health.

Antibiotics are medicines that inhibit the growth of or kill microorganisms. The discovery and production of new antibiotics has greatly decreased in the past 30 years, while the number of antibiotic-resistant microorganisms has increased. Microorganisms growing in soil are a potential source to discover new antibiotics. The goal of our study was to identify and characterize soil microbes that are antibiotic producers. A soil sample was diluted in water and plated onto complex media. Of the 300-400 colonies that grew, 26 soil isolates were screened for the ability to produce antibiotics and inhibit the growth of the five ESKAPE-safe relatives (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and several species of Enterobacter). Of the 26 soil isolates screen, 7.7% were found to produce antibiotics. The identity of the antibiotic producers was determined by PCR of the 16S rRNA gene and DNA sequence analysis. One of the antibiotic producers was of the genus Flavobacterium and the other is Streptomyces. Our plan is to perform future biochemical analysis of the antibiotic producers. In conclusion, our study supports the hypotheses that soil is an excellent source for potential antibiotic discovery.

The ability of ecosystems’ organisms to adapt and thrive is dependent on the water chemistry. One key component of water chemistry is measured by the acidity of the water, or pH. The speed of change in pH affects the ability for microorganisms to adapt and thrive. Globally, the pH of the ocean is decreasing due to increasing anthropogenic CO₂ emissions. Possession Sound, a smaller portion of the Salish Sea located off the shores of Everett, Washington, hosts a variety of organisms, all of which are affected directly and indirectly by the pH of the water. The well-being of Possession Sound was explored by examining changes in pH seasonally and spatially. Data were collected with a YSI EXO Sonde from 2016-2022 at four sampling locations with varying distances from shore and the mouth of the Snohomish River that deposits into Possession Sound. A YSI EXO Sonde is a tool used to monitor water quality with sensors to detect depth, pH, dissolved oxygen, and more. Spatially, it was found that lower pH could be found at the sites located nearer to shore. Seasonally, pH increased in the fall and winter and decreased in the spring and summer. Overall, there was less variation in the data that came from the sites located further from shore and more variation in the nearshore site. This could be attributed to the natural mixing that occurs between the freshwater influence of the Snohomish River and the ocean, along with several other factors. Future research examining pH would benefit from the addition of more data sites. Long term monitoring of the water chemistry is important because, as anthropogenic emissions increase, estuaries like that of Possession Sound will feel the effects of climate change first.