Down the drain: exploring wastewater's role in coastal microbiome transformations

Area of Science:

• Environmental microbiology
• Coastal ecosystem ecology
• Biogeochemical cycling

Background:

• Coastal ecosystems face threats from wastewater, altering microbial communities and functions.
• Understanding the resilience of native coastal microbiomes to pollution is crucial.

Purpose of the Study:

• To investigate the immediate ecological impact of treated wastewater on coastal seawater microbiomes.
• To differentiate effects of nutrients/pollutants versus microbes from wastewater.

Main Methods:

• Short-term microcosm experiments exposing coastal microbiomes to filtered and unfiltered treated wastewater.
• Integration of multi-omics (genomics, transcriptomics, proteomics) and metabolic assays.

Main Results:

• Wastewater nutrients and organic matter reorganized microbial metabolic pathways, enhancing protein, amino acid, lipid, and carbohydrate metabolism.
• Elevated phosphorus from wastewater reduced phosphorus-scavenging enzyme activity in native microbes.
• Wastewater decreased the abundance and activity of Synechococcus, potentially impacting carbon cycling, but dissolved organic carbon was rapidly utilized.

Conclusions:

• Coastal microbiomes demonstrate resilience to wastewater by adapting metabolic functions rather than taxonomic composition.
• Wastewater-induced shifts in nutrient cycling (phosphorus, carbon) may have long-term ecosystem consequences.
• Findings inform assessments of anthropogenic impacts on coastal environments.