Study of the mycobiota from two La Plata buildings

GAMEZ ERASMO; BELLOTTI NATALIA; DEYA CECILIA; CABELLO MARTA

Santiago

Congreso; X Congreso Latinoamericano de micología; 2020

Asociación Latinoamericana de Micología

Fungal deterioration of building materials causes economic losses due to restoration processes and because it affects the health of the people exposed. Therefore, it is necessary to obtain highly deteriorating fungal strains to carry out studies focused on biodeterioration control. The aim of this research was to study the mycobiota involved in deterioration of facades through the isolation and characterization of fungal strains. Samples were taken from bricks and concrete with visible biodeterioration of the Cathedral of La Plata and the Experimental Station of the Centro de Investigación y Desarrollo en Tecnología de Pinturas (CIDEPINT). The isolates were identified to the lowest possible taxon based on their reproductive, somatic structures and colony cultural characteristics. Relative density, apparition relative frequency, and ecological category of fungi isolates were determined. The deteriorating attributes were determined by carbonate dissolution test, pigment secretion assay, acid production test and brick weight variation. Taxonomic identification was confirmed by molecular methods based on the analysis of sequences coding for ITS (Internal Transcribed Spacers) rRNA region only in the most deteriorating fungal isolates. Evolutionary analyses were conducted in MEGA 10.0.5®. RStudio 1.1.463® program was used to analyze the association between certain variables and the mycobiota using Principal Component Analysis (PCA). The conventional microbiological techniques allowed the isolation and identification of 43 filamentous fungi belonging to phyla Mucoromycota, Ascomycota or Basidiomycota. Cladosporium sp., Penicillium sp. and Aspergillus sp. were the taxa with the highest apparition relative frequency and abundance. Aspergillus niger MN371276, Lasiodiplodia theobromae MN371283, Cladosporium sphaerospermum MN371394, Penicillium commune MN371392 and Arthothelium spectabile MT071822 were the strains with the highest biodeteriorant activity. Phylogenetic tree showed fungi grouped according to their Family. PCA ordination of fungal isolates according to the variables analyzed. Axis 1 shows relative density, sample place, structural material, relative frequency, carbonate dissolution and acid production with 27.3 % of variation. On the other hand, axis 2 shows that 20.1% corresponded to the variation of brick weight, pigment secretion and the recollection height. These strains can be used in studies on biodeterioration control of buildings materials.