Antibiofilm activities of metal modified kaolinite incorporated paint against Marinomonas communis and alteromonas sp.

Abstract

Marine biofilm is a layer of microorganisms adhering on marine structures and has a major concern in marine industry. The detrimental effect of commercial antibiofouling coating to the environment increased the interest among researchers and industries in formulating new, effective and environmental friendly alternative antibiofouling coating. In this study, silver modified kaolinite and copper modified kaolinite incorporated paint (Ag-Kao-P; Cu-Kao-P) have been applied for the inhibition of biofilms of two marine bacterial strains, Marinomonas communis and Alteromonas sp.. The growth profiles of both bacteria were determined by monitoring the absorbance at OD600nm and the viable cell count (CFU/mL). The antibiofilm efficacy of the Ag-Kao-P and Cu-Kao-P was tested via a homemade drip flow reactor system. The marine broth was allowed to flow continuously through flow reactor for 7 days at constant flow rate of 0.1 mL/min. The grown biofilm were observed under Atomic Force Microscopy (AFM). In a quantitative results, both Ag- Kao-P and Cu-Kao-P exhibit considerable antibiofilm activity against M. communis and Alteromonas sp.. Ag-Kao-P showed higher antibacterial activity against M. communis and Alteromonas sp. biofilm with 85% and 73% reduction, respectively. Conversely, only 76% biofilm reduction for M. communis and 60% to Alteromonas sp. for the Cu-Kao-P. Therefore, it can be concluded that Ag-Kao-P revealed the higher efficacy towards tested marine bacteria compared to Cu-Kao-P and can be suggested to be a future potential antibiofouling coating in marine industry.