Bacterial community responses to a gradient of alkaline mountaintop mine drainage in Central Appalachian streams

Abstract

Microbial community composition and diversity change along chemical gradients, leading to the expectation that microbial community information might provide new gradient characterizations. Here we examine stream bacteria composition and diversity along a strong chemical gradient in Central Appalachian streams. Coal mining in the region generates alkaline mine drainage (AlkMD), causing dramatic increases in conductivity, alkalinity, sulfate and metals sufficient to degrade stream macrobiota communities throughout the ecoregion. In this study, we examined the relationship between water and biofilm chemistry and biofilm bacteria taxonomic composition in streams where active and reclaimed surface coal mines occupied 0-96% of watershed surface area. We incubated wood veneers in each stream site for 4 months to develop biofilms on similar substrates. We sampled water chemistry at the time of deployment and collection, and after 1 month. Following incubation, we collected biofilms for microbial and chemical characterization. Microbial composition was determined by pyrosequencing 16S rRNA amplicons. Biofilm subsamples were analyzed by inductively coupled plasma mass spectrometry to determine metal concentrations. Our results show that microbial community composition differed significantly between AlkMD-exposed and AlkMD-unexposed sites, and that compositional dissimilarity increased with AlkMD loading. Diversity was not correlated with pH or extent of upstream mining, but instead correlated with biofilm concentrations of Cd, Mn, Zn and Ni. Within mined sites, the extent of upstream mining was negatively correlated with taxonomic richness. Despite major compositional shifts, functional capacity predicted with PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) correlated with mining in only 3 of 43 level-2 KEGG (Kyoto Encyclopedia of Genes and Genomes) Orthology groups.

Bacterial community structure and function shift along a successional series of tidal flats in the Yellow River Delta

“…This study employed PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) to predict functional differences in the tidal flat gradient58. The OTU table was used as the input file for metagenome imputation of individual sediment samples.…”

Spatial and temporal relationships among watershed mining, water quality, and freshwater mussel status in an eastern USA river

“…Depressed richness of benthic macroinvertebrate communities often occurs in mining-influenced low-order streams with elevated SC (Green et al, 2000;Hartman et al, 2005;Pond et al, 2008;Cormier et al, 2013aCormier et al, , 2013bPond et al, 2014;Timpano et al, 2015). Recent studies have also found fish assemblage structure (Hitt and Chambers, 2014), salamander abundance (Wood and Williams, 2013) and richness (Muncy et al, 2014), and microbial community composition (Bier et al, 2015) to be altered in salinized mining-influenced streams; and freshwater mussel richness and densities to be depressed in salinized river segments . Water borne trace elements often occur at elevated concentrations in association with elevated salinity in such waters (Pond et al, 2008;Lindberg et al, 2011;Pond et al, 2014) and are also of concern due to potential biotic impacts (Palmer et al, 2010;Johnson et al, 2014).…”

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River

“…Some other studies21222324 have reported variations in bacterioplankton and archaeaplankton communities across freshwater and ocean environments, demonstrating that spatial variability was greater than seasonal patterns of variation. In addition to habitat heterogeneity25, planktonic bacterial and archaeal communities can also respond to changes in many environmental factors in water, such as salinity2627, dissolved organic matter (DOM)28, alkalinity29, temperature, and soluble reactive phosphorus (SRP)20. Moreover, temporal variation in the microbial community has been shown to be greater than spatial variation in the same habitat153031.…”