Active-bromide and surfactant synergy for enhanced microfouling control

Area of Science:

• Microbiology
• Environmental Science
• Industrial Biotechnology

Background:

• Biofilms, microbial communities in extracellular polymeric substance (EPS) matrices, are problematic in industrial cooling systems.
• Nuclear power plants utilize active-bromide biocides for biological growth control in condenser cooling systems.
• Seawater cooling systems face challenges from planktonic and biofilm-forming bacteria.

Purpose of the Study:

• To evaluate the anti-bacterial and anti-biofilm efficacy of active-bromide against common seawater bacteria.
• To assess the impact of a surfactant, Triton-X 100, on active-bromide's efficacy.
• To determine optimal strategies for microfouling control in power plant cooling systems.

Main Methods:

• Tested active-bromide efficacy against planktonic Pseudomonas aeruginosa at 1 ppm.
• Assessed bacterial cell surface hydrophobicity changes with Triton-X 100.
• Conducted biofilm inhibition assays and epifluorescence microscopy with live/dead staining.

Main Results:

• Active-bromide at 1 ppm showed minimal killing of planktonic P. aeruginosa.
• Triton-X 100 reduced cell hydrophobicity, increasing susceptibility to active-bromide.
• 1 ppm active-bromide had limited biofilm inhibition, but 5-10 ppm showed significant inhibition.
• Combination of 1 ppm active-bromide and Triton-X 100 synergistically dispersed pre-formed biofilms.
• Microscopy confirmed extensive cell death in biofilms treated with the combination.

Conclusions:

• Active bromide alone may be insufficient for effective microfouling control in seawater cooling systems.
• A biocompatible surfactant can significantly enhance active bromide treatment efficacy by disrupting biofilms.
• Combination therapy offers a promising strategy for improved biofilm management in industrial settings.