Honors Theses and Capstones

Date of Award

Spring 2023

Project Type

Senior Honors Thesis

College or School



Molecular & Cellular Biology

Program or Major

Biomedical Sciences: Medical Microbiology

Degree Name

Bachelor of Science

First Advisor

Semra Aytur

Second Advisor

John Bucci


Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as biosynthetic gene clusters (BGCs) that facilitate the production and secretion of secondary metabolites with an immense range of functions. It has been confirmed that Streptomyces produce natural products categorized as several different metabolite classes, but their polyketide synthases (PKSs) and nonribsomal peptide synthetase (NRPS) BGCs are of increased interest for the discovery of chemotherapeutic drugs that exhibit cytotoxicity. In this study, marine sediment samples were collected from the Stellwagen Bank National Marine Sanctuary (SBNMS) where the presence of Streptomyces has been confirmed in order to search for BGCs of interest to assess for cytotoxicity. Streptomyces hygroscopicus has been studied previously for multiple research purposes. It contains polyketide, polyether, and NRPS BGCs within its genome, resides in terrestrial and marine�derived soils and is one of the most abundant species of Streptomyces in SBNMS samples from prior research. Marine ecosystems are home to a vast reservoir of undiscovered microbes harboring novel antimicrobial, antitumor, antiviral, and antiparasitic compounds waiting to be identified; preserving marine sanctuaries such as SBNMS allows for the organisms in these unique environments to thrive. This opens the opportunity for future biomedical and ecological research to be conducted for the wellbeing of public health and medicine.