| Autor: |
Batista AMM; Department of Natural Resources, Environmental Sciences and Technologies, State University of Minas Gerais (João Monlevade Unit), Brasília Avenue, 1304 - Bau, 35930-314 João Monlevade, Minas Gerais, Brazil; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, 31270-010 Belo Horizonte, Minas Gerais, Brazil E-mail: cesar@desa.ufmg.br., Siqueira JC; Department of Environmental Engineering, Federal University of Lavras, Aquenta Sol, 37200-900, Lavras, Minas Gerais, Brazil., Meynet P; School of Civil Engineering and Geosciences, Newcastle University, NE1 7RU Newcastle upon Tyne, UK., Werner D; School of Civil Engineering and Geosciences, Newcastle University, NE1 7RU Newcastle upon Tyne, UK., Garcia GPP; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, 31270-010 Belo Horizonte, Minas Gerais, Brazil E-mail: cesar@desa.ufmg.br., Davenport RJ; School of Civil Engineering and Geosciences, Newcastle University, NE1 7RU Newcastle upon Tyne, UK., Pereira AD; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, 31270-010 Belo Horizonte, Minas Gerais, Brazil E-mail: cesar@desa.ufmg.br., Siniscalchi LAB; Department of Environmental Engineering, Federal University of Lavras, Aquenta Sol, 37200-900, Lavras, Minas Gerais, Brazil., Araújo JC; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, 31270-010 Belo Horizonte, Minas Gerais, Brazil E-mail: cesar@desa.ufmg.br., Mota Filho CR; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, 31270-010 Belo Horizonte, Minas Gerais, Brazil E-mail: cesar@desa.ufmg.br. |
| Abstrakt: |
This study assessed the bacterial community composition of a drinking water system (DWS) serving a mid-sized city (120,000 inhabitants) in Brazil. Water samples, including raw and treated water, were collected at seven points throughout the DWS. DNA was extracted and analysed using high-throughput sequencing (Ion Torrent). Free chlorine and turbidity were measured in situ. Results showed that the highest relative abundance of 16S rRNA genes was from phyla Proteobacteria, followed by Bacteroidetes and Actinobacteria. The next most abundant phylum was Cyanobacteria, represented by Arthronema, Calothrix, and Synechococcus. An interesting observation was that the DNA-based analysis suggested a bacterial community change in the distribution network, with treated reservoir water being very different from the network samples. This suggests active microbiology within the distribution network and a tendency for bacterial diversity to decrease after chlorine disinfection but increase after pipeline distribution. In raw water, a predominance of Proteobacteria was observed with reduced Cyanobacteria, showing a negative correlation. In treated water, Proteobacteria were negatively correlated with Bacteroidetes. Finally, 16S rRNA genes from Firmicutes (especially Staphylococcus) had a high abundance in the chlorinated water, which may indicate the phylum's resistance to chlorine residuals. Opportunistic pathogens, e.g., Mycobacteria, Legionella, and Staphylococcus, were also observed. |
