IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
HOW INCREASING ROUGHNESS AFFECTS MARINE BACTERIA ADHESION TO PDMS COATED SURFACES
Autor/es:
JORGE N. CABRERA; M. JULIA PETTINARI; R. MARTÍN NEGRI; GONZALO N. CAGNOLA; NORMA B. D'ACCORSO
Lugar:
CABA
Reunión:
Congreso; Congreso SAIB-SAMIGE 2020; 2020
Institución organizadora:
SAIB-SAMIGE
Resumen:
Adhesion of different organisms to surfaces leading to biofilm formation can cause a number of problems in areas as diverse as health, food industry and the shipping industry. Submerged structures are quickly colonized by a succession of organisms in a process denominated biofouling that is of particular interest to the shipping industry, as it involves an important economic burden. Biofouling is a stepwise process that starts with the absorption of organic matter followed by the adhesion of different microorganisms, such as bacteria, that form a biofilm. Thisin turn facilitates the attachment and growth of other organisms, such as algae and barnacles.Among the different strategies used to prevent biofouling, the use of biocides has been banned in the last decade due to environmental concerns, and antibiofouling surface coatings appeared as an environmentally friendly alternative. Polydimethylsiloxane (PDMS) is a silicone coating with antifouling properties which may be modified to increase its roughness, as the presence of nanoscale roughness has been shown to decrease biofilm formation. Multi Walled Carbon Nanotubes (MWCNT) or exposure to Br2 vapors with or without UV irradiation, that produce depressions of different sizes. Bacterial adhesion in PDMS surfaces treated with MWCNT or with Br2 vapors was not strongly affected by the small differences in hydrophobicity among the different surfaces, but correlated with their average roughness (Ra), except when whole bacteria could fit inside depressionssuch as those encountered in surfaces treated with Br2 and UV.Surfaces exposed to Br2 (g) vapors are highly inhomogeneous, containing depressions or wells that can affect bacterial adhesion differently. In order to describe the topological properties of these surfaces we calculated the effective roughness (Raeff) of both bacteria on Br2 and Br2 + UV, and observed to affect bacterial adhesion and consequently biofilm formation in the same way as Ra in homogeneoussurfaces.The results obtained in this study indicate that micro-roughness, in dimensions that do not allow the bacteria to fit into depressions, decrease the ability of bacteria to colonize the PDMS surfaces. In the case of the surfaces treated both with Br2 and UV, a great number of depressions were large enough to accommodate bacteria, increasing biofilm formation compared to the Br2 treated PDMS, in which the size of the depressions were smaller that the bacterial cells. In contrast to Ra, when Raeff was considered, it was observed to be inversely proportional to adhesion both in surfaces with uniform roughness and highly inhomogeneous surfaces.