STUDY OF BIOFOULING IN SURFACES TREATED WITH NANOTECHNOLOGY

J. NICOLÁS CABRERA; MARIELA P. MEZZINA; M. JULIA PETTINARI; GONZALO N. CAGNOLA; R. MARTÍN NEGRI

San Luis

Congreso; Asociación Civil de Microbiología General (SAMIGE) 2018; 2018

Ship hulls and other structures undergo a process called biofouling, that consists on the colonization of the substrate by microorganisms (i.e. bacteria, algae) that once settled, produce bioactive molecules that aid the invasion of macroorganisms (i.e. barnacles) which in turn can degrade the surface by chemical or physical reactions. Deterioration of ship hulls by biofouling produce an increment in hydrodynamic drag and in fuel consumption with the concomitant economic loss associated. Marine vessels are usually painted with an antifouling coat, that contains metals such as copper and tributyltinthat have an adverse effect on the marine environment.Nanotechnology treated surfaces have been proposed as an environmentally friendly alternative to antifouling coats, as the presence of nanoscaleroughness has been shown to prevent the colonization of surfaces by microorganisms, through a physical interaction that does not harm the environment. Polydimethylsiloxane (PDMS) is a silicone coating with antifouling properties which may be modified to increase its roughness, in this case with multi-walled carbon nanotubes (MWCNT). In this project, we studied the growth and biofilm formation of different bacteria on treated surfaces. We selected two marine species, Marinobacter hydrocarbonoclasticus and Cobetia marina, that have agreat capacity to form biofilms in hydrophobic and hydrophilic surfaces respectively, and two fresh water bacteria representatives, Pseudomonas fluorescens Pf-5 isolated from soil, and Pseudomonas veronii, isolated from tap water.First, we tested different culture media and conditions to study growth and biofilm formation of these strains was assessed in 24-well plates. Biofilm formation was quantified via Crystal Violet (CV) Assay in 48 h cultures. M9 minimal medium Glucose as carbon source, was observed to be suitable forbiofilm formation of Pseudomonas species, whilemarine bacteria in modify Sea Salt Peptone (SSP) medium. Preliminary studies with M. hydrocarbonoclasticus were performed with: i) aluminum coated with PDMS, and ii) aluminum coated with PDMS+MWCNT. When biofilm formation on the two silicone coated surfaces were compared, the lowest was present in the bacteria grown on the surfacescontaining the carbon nanotubes, indicating that the nanotechnology treated surface inhibited adhesion of bacteria and consequently biofilm formation. Bacterial growth was similar in the presence of both surfaces.Nanotechnology treated surfaces have a great potential for antifouling applications, as they can lead to a reduction in the colonization by invading species without the use of chemical coating, which is toxic for the environment.