An integrated approach for assessing the bioreceptivity of glazed tiles to phototrophic microorganisms

18 páginas.-- 7 figuras.-- 5 tablas.-- 63 referencias

A laboratory-based methodology was designed to assess the bioreceptivity of glazed tiles. The experimental set-up consisted of multiple steps: manufacturing of pristine and artificially aged glazed tiles, enrichment of phototrophic microorganisms, inoculation of phototrophs on glazed tiles, incubation under optimal conditions and quantification of biomass. In addition, tile intrinsic properties were assessed to determine which material properties contributed to tile bioreceptivity. Biofilm growth and biomass were appraised by digital image analysis, colorimetry and chlorophyll a analysis. SEM, micro-Raman and micro-particle induced X-ray emission analyses were carried out to investigate the biodeteriorating potential of phototrophic microorganisms on the glazed tiles. This practical and multidisciplinary approach showed that the accelerated colonization conditions allowed different types of tile bioreceptivity to be distinguished and to be related to precise characteristics of the material. Aged tiles showed higher bioreceptivity than pristine tiles due to their higher capillarity and permeability. Moreover, biophysical deterioration caused by chasmoendolithic growth was observed on colonized tile surfaces.

This work was supported by the Portuguese Foundation for Science and Technology (FCT) [grant SFRH/BD/46038/2008; project UID/EAT/00729/2013]. A.Z. Miller acknowledges support from a Marie Curie Intra-European Fellowship of the European Commission’s 7th Framework Programme [PIEF-GA-2012-328689]. J.P. Veiga and H. Águas acknowledge funding by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT [project UID/ CTM/50025/2013]. This work was supported by the European Commission’s 7th Framework Programme, through the Marie Curie International Research Staff Exchange Scheme [NANO_GUARD (PIRSES-GA-2010-269138)].

Peer reviewed