Theses and Dissertations

The incidence of childhood obesity has become increasingly prevalent in the United States in recent years. The development of obesity at any age, but especially in adolescence, can have lasting negative effects in the form of cardiometabolic disease, increased incurred healthcare costs, and potential negative effects on quality of life. In recent years, a rising trend of obesity, in both adults and adolescents, has been observed in lower income and ethnic groups. Increased adiposity can be influenced by modifiable factors -(physical activity, caloric intake, or sleep) or by non-modifiable factors (ethnicity, genetic predispositions, and socioeconomic status). The influence of these factors can be observed in individuals of all ages, including infants. A common indicator of the development of childhood obesity is rapid weight gain (RWG) within an infant’s first year of life. The composition of the gut microbiome can act as a predictor for RWG and the development of childhood obesity. Infants are exposed to an immense microbial load when they are born and their gut microbiome is continually diversified through their method of feeding and the subsequent introduction to solid foods. While currently understudied, it is understood that cultural and socioeconomic factors influence the development of the gut microbiome, which is further explored in this analysis. The DNA from 51 fecal samples from infants ranging from 3 weeks to 12 months in age was extracted and sequenced using next-generation sequencing, and the resulting sequences were analyzed using QIIME 2. Results from alpha-diversity and beta-diversity metrics showed significant differences in the gut microbiome of infants when comparing groups based on baby race/ethnicity, household income, and mom’s education. These findings suggest the importance of sociodemographic characteristics in shaping the gut microbiome and suggest the importance of future studies including diverse populations in gut microbiome work.

Hybrid metalloproteins incorporating synthetic organometallic active sites within a protein scaffold are being researched as viable catalysts for the production of hydrogen fuel. Our group and others have shown that the incorporation of cobalt protoporphyrin IX in cytochrome b₅₆₂ yields artificial enzymes that reduce protons to molecular hydrogen in the presence of photoinductive light and photosensitizers. Using random mutagenesis via error-prone PCR we have created a library of mutants to use in directed evolution to optimize hydrogen catalysis, though a challenge in this project is that testing individual variants by gas chromatography is not feasible on a large scale. For this reason, we are developing a gasochromic, hydrogen assay that is based on the interaction of molecular hydrogen with tungsten trioxide with a palladium catalyst. Initially, results show this assay to be qualitatively accurate between trials; however, its application in screening remains a challenge.