Date of Award
Spring 5-17-2025
Degree Type
Thesis
Degree Name
MS Microbiology
Department
Biology
Advisor
Tinchun Chu, PhD
Committee Member
Angela Klaus, PhD
Committee Member
Jane Ko, PhD
Keywords
Microbial Diversity, Seasonal Variation, Eutrophication, Freshwater Ecosystems, 16S rRNA sequencing, Lake Parsippany
Abstract
Seasonal fluctuations in temperature, pH, and rainfall can significantly influence microbial abundance, diversity, and eutrophication in freshwater ecosystems. This study examined how environmental changes shape microbial community composition in Lake Parsippany, New Jersey, during the summer of 2024. Water samples were collected biweekly from three georeferenced sites (Site 1: 40.84979°N, 74.42985°W; Site 2: 40.85313°N, 74.43729°W; Site 3: 40.84893°N, 74.43502°W) between late May and August. Physical parameters, including temperature, pH, and precipitation, were recorded at each sampling event. Microbial analysis was performed using both culture-based methods with Chelex DNA extraction and filtration-based extraction with the Qiagen DNeasy PowerWater Kit. DNA quality was confirmed via NanoDrop prior to 16S rRNA gene amplicon sequencing.
Sequencing of the V3–V4 regions revealed distinct temporal and spatial shifts in microbial composition. In May, Proteobacteria and Planctomycetota were moderately abundant. By June, Sphingomonadales increased markedly at Sites 1 and 2 (17% and 44%, respectively), while Cyanobacteria peaked at 46.6% at Site 3—collected during a rain event. July samples showed elevated levels of Escherichia-Shigella at Sites 2 and 3 (20.5% and 24.1%), and Lactobacillus dominated Site 1 (14.1%). By August, Cyanobacteria became the dominant group across all sites (up to 17%), suggesting eutrophic conditions. Bray-Curtis dissimilarity analysis confirmed strong spatial and temporal variation in microbial communities, influenced by nutrient input, rainfall, and temperature.
These results highlight the sensitivity of freshwater microbial communities to abiotic factors and suggest that environmental fluctuations are key drivers of microbial dynamics. This study enhances our understanding of seasonal microbial ecology and underscores the need for microbial monitoring in urban freshwater management.
Recommended Citation
Marino, Alyssa L., "Impact of Environmental Factors on Microbial Community Dynamics in Lake Parsippany" (2025). Seton Hall University Dissertations and Theses (ETDs). 4383.
https://scholarship.shu.edu/dissertations/4383
