Meta-Transcriptomic Response to Copper Corrosion in Drinking Water Biofilms.

Area of Science:

• Microbiology
• Environmental Science
• Materials Science

Background:

• Drinking water biofilms host complex microbial communities.
• The impact of copper (Cu) corrosion on microbial metabolism and resistance in biofilms remains poorly understood.

Purpose of the Study:

• To evaluate how upstream copper pipe materials affect downstream microbial communities in drinking water biofilms.
• To assess changes in viable community structure, pathogen populations, and metatranscriptomic responses.

Main Methods:

• Generated and sequenced randomly transcribed cDNA from downstream biofilm samples.
• Compared biofilms from unplasticized polyvinylchloride (PVC) and copper (Cu) coupons.

Main Results:

• Cu-influenced biofilms showed enriched pathogen-like and opportunistic pathogens.
• Upregulated genes in Cu biofilms were linked to potassium (K) metabolism, mycolic acid synthesis, stress responses, and toxic compound resistance.
• Downregulated genes included those for ion interactions, respiration, RNA/nitrogen metabolism, virulence, and antibiotic resistance.

Conclusions:

• Microbial biofilms adapt to Cu plumbing by altering gene expression, metabolic pathways, and structural organization.
• Copper inhibits many microbes but promotes resistance and specific adaptations in others within drinking water biofilms.