Microfouling bacteria and the use of enzymes in eco-friendly antifouling technology

Abstract

Biofouling leads to unfavorable problems in underwater structures like ships’ hulls, aquaculture cages, fishnets, petroleum pipelines, sensors, and other equipment. The main target of antifouling applications is to prevent the early steps of fouling, namely microfouling (bacterial biofilm). In recent years, investigations into the development of environmentally friendly, nontoxic products in antifouling coating technology are becoming more widespread. The main purpose of this study was to investigate the antibiofilm activity of commercial hydrolytic enzymes (α-amylase, xylanase, glucanase, protease, pectinase, lipase, viscozyme, and lysing complex) against marine biofilm bacteria (Pseudoalteromonas agarivorans FJ040188, Vibrio lentus FJ200649, and Exiguobacterium homiense FJ200653). The experimental method involved a prevention and detachment test based on bacterial adhesion in a microplate and biomass quantification of the total biofilm using DAPI fluorescent dye after a 24-hour incubation period. Results from the screening of the biofilm percentage reduction in the enzymes, a lysing complex enzyme, were seen to be the most effective in both the prevention of bacterial adhesion and the detachment of adhered bacteria. Epifluorescence microscopy analysis of DAPI-stained adhered bacteria using lysing complex confirmed these results. It was seen that the mixtures of enzymes selected for present study have the potential to be employed as environmentally friendly antifouling additives in marine antifouling coatings.