Responses of resident (DNA) and active (RNA) microbial communities in fluvial biofilms under different polluted scenarios

• Published in: Chemosphere (Oxford) Vol. 242; p. 125108
• Main Authors: Argudo, María, Gich, Frederic, Bonet, Berta, Espinosa, Carmen, Gutiérrez, Marina, Guasch, Helena
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-03-2020
• Subjects: Biofilm; Biofilms - drug effects; DNA, Bacterial - genetics; Environmental Monitoring; Environmental Pollutants - analysis; Environmental Pollutants - pharmacology; Environmental Pollution - analysis; Heavy metals; Metals, Heavy - analysis; Metals, Heavy - pharmacology; Microbial communities; Microbiota - drug effects; Mining; Nutrients; River; Rivers - chemistry; RNA, Ribosomal, 16S - genetics; Spain; Water Pollutants, Chemical - analysis; Spain; Biofilm; Nutrients; River; Microbial communities; Heavy metals
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2019.125108

Pollution from human activities is a major threat to the ecological integrity of fluvial ecosystems. Microbial communities are the most abundant organisms in biofilms, and are key indicators of various pollutants. We investigated the effects some human stressors (nutrients and heavy metals) have on the structure and activity of microbial communities in seven sampling sites located in the Ter River basin (NE Spain). Water and biofilm samples were collected in order to characterize physicochemical and biofilm parameters. The 16S rRNA gene was analysed out from DNA and RNA extracts to obtain α and β diversity. Principal coordinates analyses (PCoA) of the operational taxonomic units (OTUs) in the resident microbial community revealed that nutrients and conductivity were the main driving forces behind the diversity and composition. The effects of mining have had mainly seen on the taxonomic composition of the active microbial community, but also at the OTUs level. Remarkably, metal-impacted communities were very active, which would indicate a close link with the stress faced, that is probably related to the stimulation of detoxification.
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•Effects of nutrients and heavy metals on microbial communities from fluvial biofilms were studied.•Extraction of nucleic acids (DNA and RNA) provides complementary information of dynamics of microbial communities.•Nutrients and conductivity change the diversity and composition of resident microbial community.•Effects of mining metals are shown in the active microbial community at OTUs level.•Five genus of bacteria are proposed as potential bioindicators of low and chronic metal pollution.