Fine grained compositional analysis of Port Everglades Inlet microbiome using high throughput DNA sequencing

Area of Science:

• Marine microbiology
• Environmental science
• Ecosystem dynamics

Background:

• Manmade inlets like Port Everglades Inlet (PEI) connect inland waters to the ocean, potentially impacting coastal environments.
• Understanding bacterioplankton (microbiome) composition in major ports is vital due to pollution risks to beaches and coral reefs.
• Previous studies lacked the high sampling frequency and scale needed to capture dynamic microbial fluctuations in such environments.

Purpose of the Study:

• To investigate seasonal microbial fluctuations within Port Everglades Inlet.
• To profile bacterioplankton communities using high-throughput 16S rRNA amplicon sequencing.
• To establish a baseline for inlet microbial communities and assess potential environmental impacts.

Main Methods:

• Weekly surface water sampling over one year, with four samples per month from two locations.
• High-throughput 16S rRNA amplicon sequencing for microbiome profiling.
• Statistical analyses including ANCOM for differential abundance and beta diversity analysis correlating with environmental factors.

Main Results:

• Significant differences in alpha diversity were observed between months and seasons, notably low richness and high evenness in August.
• Beta diversity analysis revealed significant variations in community composition influenced by month, season, water temperature, and salinity.
• Potentially pathogenic genera like *Staphylococcus* and *Streptococcus* were detected but not in significantly high abundances.

Conclusions:

• Bacterioplankton communities in PEI exhibit significant seasonal and monthly variations, linked to environmental factors like temperature and salinity.
• Specific conditions in August and the 2013-2014 dry season (warmer, wetter) influenced microbial community structure.
• The low, non-significant abundance of potential pathogens suggests a low public health risk, while the study provides a vital baseline for environmental monitoring.