title: A nanomolecular approach to decrease adhesion of biofouling-producing bacteria to graphene-coated material.
abstract: BACKGROUND
  Biofouling, the colonization of artificial and natural surfaces by unwanted microorganisms, has an important economic impact on a wide range of industries. Low cost antifouling strategies are typically based on biocides which exhibit a negative environmental impact, affecting surrounding organisms related and not related to biofouling. Considering that the critical processes resulting in biofouling occur in the nanoscale/microscale dimensions, in this work we present a bionanotechnological approach to reduce adhesion of biofilm-producing bacteria Halomonas spp. CAM2 by introducing single layer graphene coatings. The use of this nanomaterial has been poorly explored for antifouling application.
  
  
  RESULTS
  Our study revealed that graphene coatings modify material surface energy and electrostatic interaction between material and bacteria. Such nanoscale surface modification determine an important reduction over resulting bacterial adhesion and reduces the expression levels of genes related to adhesion when bacteria are in contact with graphene-coated material.
  
  
  CONCLUSIONS
  Our results demonstrate that graphene coatings reduce considerably adhesion and expression levels of adhesion genes of biofilm-producing bacteria Halomonas spp. CAM2. Hydrophobic-hydrophilic interaction and repulsive electrostatic force dominate the interactions between Halomonas spp. CAM2 and material surface in saline media, impacting the final adhesion process. In addition no bactericide effect of graphene coatings was observed. The effect over biofilm formation is localized right at coated surface, in contrast to other antifouling techniques currently used, such as biocides.
authors.affiliation: Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. carolina.parra@usm.cl.
authors.forename: Carolina
authors.initials: C
authors.lastname: Parra
authors.affiliation: Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. fernando.dorta@usm.cl.
authors.forename: Fernando
authors.initials: F
authors.lastname: Dorta
authors.affiliation: Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. edra.jimenez@usm.cl.
authors.forename: Edra
authors.initials: E
authors.lastname: Jimenez
authors.affiliation: Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. ricardo.henriquez@usm.cl.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Henríquez
authors.affiliation: Departamento de Ingeniería Química y Ambiental, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. cristian.ramirez@usm.cl.
authors.forename: Cristian
authors.initials: C
authors.lastname: Ramírez
authors.affiliation: Laboratorio de Patología Acuática, Departamento de Acuicultura, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile. rrojas@ucn.cl.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Rojas
authors.affiliation: Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile. patricio.villalobos@usm.cl.
authors.forename: Patricio
authors.initials: P
authors.lastname: Villalobos
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000187:drug effects*; D057219:Biofouling; D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006108:Graphite / Q000494:pharmacology*; D020632:Halomonas / Q000166:cytology* / Q000648:ultrastructure; D057927:Hydrophobic and Hydrophilic Interactions; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D055672:Static Electricity; D017155:Wettability
chemical_list: D018829:Adhesins, Bacterial; D020099:Coated Materials, Biocompatible; D006108:Graphite