|113-1||FUNGI OCCURRENCE AND DIVERSITY IN BIOFILMS OF A COLOMBIAN DRINKING WATER DISTRIBUTION SYSTEM|
|Autores:||Stefania Hurtado-mccormick (UNIANDES - Universidad de los Andes / CIIA - Environmental Engineering Research Center) ; Juliana Martínez (UNIANDES - Universidad de los Andes / CIIA - Environmental Engineering Research Center) ; Carolina Calderón (UNIANDES - Universidad de los Andes / LAMFU - Mycology and Plant Disease Laboratory) ; Diana Calvo (UNIANDES - Universidad de los Andes / CIIA - Environmental Engineering Research Center) ; Mildred Lemus (UNIANDES - Universidad de los Andes / CIIA - Environmental Engineering Research Center) ; Manuel Rodríguez (UNIANDES - Universidad de los Andes / CIIA - Environmental Engineering Research Center) |
Fungi are not controlled by water rule, but biofilms of drinking water distribution systems are reservoirs of these microorganisms that could produce detrimental substances to human health. In order to assess the fungi diversity in terms of gender/specie, biofilm samples were collected in primary and secondary network (i.e. pipelines, tanks and household showers) of a city from Colombia, during an eight-month period. First, culturing methods in potato dextrose, rose bengal and malt extract agars were used in order to grow and isolate fungi from biofilm samples. Second, isolation of axenic fungi and yeast cultures were conducted by puncture and depletion. Finally, phenotypic and genotypic identification was achieved using morphological and microscopic characters, and DNA sequencing by PCR and bioinformatic analysis. Results showed that 75% of the analyzed samples were positive for fungi, and its representativeness was reported in a range of 1-3000 CFU/mL. Seventeen isolated morphotypes were determined by the phenotypic identification, whereas 27 species were established by their genetic characters. From identification, 9 species of fungi and 4 species of yeast, mainly represented by the genders Paraconiothyrium(2935 CFU/mL), Penicillium (with a maximum of 29 CFU/mL), Paecilomyces (108 CFU/mL), Debaryomyces (143 CFU/mL), Rhodotorula (70 CFU/mL) and Cryptococcus (95 CFU/mL) were found. Although yeast showed higher traceability than fungi, the gender Penicillium in fungi had more relevance not only by diversity (6 species) but also by their role in micotoxines generation. Additionally, the results supported a higher diversity for secondary distribution systems (household showers), and also a higher predominance for the primary distribution systems. These results pointed that fungi and yeast of biofilms could be affecting water quality in both main network and before final point in tap water, probably increasing health impact. More research in this topic is suggested to determine the real effect of the identified microorganisms on water quality from drinking water network, expanding perspectives to implications in biodiversity, industry and environment.
Palavras-chave: biofilms, bioinformatic analysis, drinking water, fungi, yeast