Changes in bacterial community structure associated with coastal copper enrichment

Abstract

Marine bacterial communities isolated from the water column, sediment, the rock surface, and the green seaweed Ulva compressa were studied in an intertidal ecosystem. The study area included a coastal zone chronically affected by copper mine waste disposals. Bacterial community composition was analyzed by terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA genes, and multivariate analyses of T-RFLP data sets were used for comparisons. Results showed that diversity and richness indexes were not able to detect differences among compartments. However, comparisons within the same compartment clearly showed that copper enrichment was associated with changes in the composition of the bacterial communities and revealed that the magnitude of the effect depends on the compartment being considered. In this context, communities from sediments appeared as the most affected by copper enrichment. The present study also demonstrated that intertidal bacterial communities were dominated by Gammaproteobacteria, Firmicutes, and Actinobacteria and the changes in these communities were mainly due to changes in their relative abundances.

Sulfate reduction, molecular diversity, and copper amendment effects in bacterial communities enriched from sediments exposed to copper mining residues

“…This zone is essentially free of other pollutants [18]. Mean total Cu concentration found in these sediments (1,054 mg/kg) is much higher than levels associated with noncontaminated sediments, being approximately 30 times greater [32].…”

“…Values of R ! 0.5 account for high differences, whereas between 0.25 and 0.5 differences are considered as moderate [18].…”

“…Since 1990, Canal Palito, the actual discharge channel, releases tailings-free wastewater containing up to 31.5 mM of total Cu, at a rate of 200 to 250 L/s [17]. A previous study in the area demonstrated that bacterial communities from the sediment compartment were the most impacted by Cu pollution imposing a high toxic environmental pressure [18]. Hence, these sediments constitute an adequate model to evaluate the effects of Cu in these and other copper-exposed bacterial communities.…”

Current Advances in Functional Genomics in Aquaculture

“…As a result, metagenomics is currently being used to monitor the impact of anthropogenic activities on coastal microbial composition. Port et al [60] found an increase in antibiotic resistance genes caused by coastal eluent discharges, while Morán et al [61] showed signiicant changes in bacterial community structures caused by coastal copper disposal in La Lancha and Chañaral bay in the Paciic Ocean. Overall, these studies show that metagenomics is not only used to identify novel pathogens, but it is also used to monitor the impact of human activities on microbial composition in diferent aquatic environments.…”

Arctic microbial and next-generation sequencing approach for bacteria in snow and frost flowers: selected identification, abundance and freezing nucleation

“…Rochester, NY, USA). The liquid was centrifuged for 15 min at 18 000 g, and the pellet was re-suspended in 200 ul of 1X TBE buffer (Moran et al, 2008;Gharaibeh et al, 2009;Gantner et al, 2011;Medinger et al, 2010). Ready-Lyse ™ Lysozyme (Epicentre Technologies, Madison, USA) was used to lyse the cell, and DNA was extracted and purified using either a DNAeasy kit (Qiagen, Toronto, Canada) or a Master Pure DNA purification kit (Epicentre Technologies, Madison, USA) according to the manufacturer's instructions.…”