Planktonic and early-stage biofilm microbiota respond contrastingly to thermal discharge-induced seawater warming.

Thermal effluent discharges from coastal nuclear power plants impose a significant impact on bacterial communities of the residing water bodies, and thus understanding their influence is critical given the relevance to global warming. To determine the impact of thermal discharge-induced elevated seawater temperature on marine microbes, marine biofilms assembled on three artificial surfaces viz., stainless steel (SS), titanium (Ti), and high-density polyethylene (HP) over 3 days of immersion as well as peripheral seawater were collected from ambient and thermal discharge-impacted (warming) areas of a nuclear power plant, located at the southern coastal region of India. Bacterial community structure of the seawater and pioneering biofilm was then unveiled by employing Illumina MiSeq sequencing of the V3-V4 hypervariable regions of the 16S rRNA gene. The results of the study will elucidate the factors that shape the community assembly in the marine environment and thereby will advance the scientific understanding of the consequences of future ocean warming on marine biofilm assembly.