Metagenomic investigation of the microbial diversity in a chrysotile asbestos mine pit pond, Lowell, Vermont, USA

Here we report on a metagenomics investigation of the microbial diversity in a serpentine-hosted aquatic habitat created by chrysotile asbestos mining activity at the Vermont Asbestos Group (VAG) Mine in northern Vermont, USA. The now-abandoned VAG Mine on Belvidere Mountain in the towns of Eden and Lowell includes three open-pit quarries, a flooded pit, mill buildings, roads, and > 26 million metric tons of eroding mine waste that contribute alkaline mine drainage to the surrounding watershed. Metagenomes and water chemistry originated from aquatic samples taken at three depths (0.5 m, 3.5 m, and 25 m) along the water column at three distinct, offshore sites within the mine's flooded pit (near 44°46'00.7673″, - 72°31'36.2699″; UTM NAD 83 Zone 18 T 0695720 E, 4960030 N). Whole metagenome shotgun Illumina paired-end sequences were quality trimmed and analyzed based on a translated nucleotide search of NCBI-NR protein database and lowest common ancestor taxonomic assignments. Our results show strata within the pit pond water column can be distinguished by taxonomic composition and distribution, pH, temperature, conductivity, light intensity, and concentrations of dissolved oxygen. At the phylum level, metagenomes from 0.5 m and 3.5 m contained a similar distribution of taxa and were dominated by Actinobacteria (46% and 53% of reads, respectively), Proteobacteria (45% and 38%, respectively), and Bacteroidetes (7% in both). The metagenomes from 25 m showed a greater diversity of phyla and a different distribution of reads than the two upper strata: Proteobacteria (60%), Actinobacteria (18%), Planctomycetes, (10%), Bacteroidetes (5%) and Cyanobacteria (2.5%), Armatimonadetes (< 1%), Verrucomicrobia (< 1%), Firmicutes (< 1%), and Nitrospirae (< 1%). Raw metagenome sequence data from each sample reside in NCBI's Short Read Archive (SRA ID: SRP056095) and are accessible through NCBI BioProject PRJNA277916.