Spatiotemporal and seasonal dynamics in the microbial communities of a landfill-leachate contaminated aquifer

Abstract

The microbiome of an aquifer contaminated by landfill leachate and undergoing intrinsic remediation was characterised using 16S rRNA metabarcoding. The archaeal/bacterial V3-V4 hypervariable region of the 16S rRNA gene was sequenced using Illumina MiSeq, and multivariate statistics were applied to make inferences. Results indicate that the aquifer recharge and aquifer sediment samples harbour different microbial communities compared to the groundwater samples. While Proteobacteria dominated both the recharge and groundwater samples, Acidobacteria dominated the aquifer sediment. The most abundant genera detected from the contaminated aquifer were Polynucleobacter, Rhodoferax, Pedobacter, Brevundimonas, Pseudomonas, Undibacterium, Sulfurifustis, Janthinobacterium, Rhodanobacter, Methylobacter and Aquabacterium. The result also show that the microbial communities of the groundwater varied spatially, seasonally and interannually, although the interannual variation was significant for only one of the wells. Variation partitioning analysis indicates that water chemistry and well distance are intercorrelated and they jointly accounted for most of the variation in microbial composition. This implies that the species composition and water chemistry characteristics have a similar spatial structuring, presumably caused by the landfill leachate plume. The study improves our understanding of the dynamics in subsurface microbial communities in space and time.

A comparative analysis employing a gene- and genome-centric metagenomic approach reveals changes in composition, function, and activity in waterworks with different treatment processes and source water in Finland

“…It is unclear why these taxonomic group showed higher abundances in ND systems ( Waak et al, 2019 ). It can be speculated that recharge water (i.e., artificial groundwater) brings along nutrients that specifically favors these microorganisms ( Abiriga et al, 2021 ).…”

“…It is unclear why these taxonomic group showed higher abundances in ND systems (Waak et al, 2019). It can be speculated that recharge water (i.e., artificial groundwater) brings along nutrients that specifically favors these microorganisms (Abiriga et al, 2021). Contrary to the ND systems, the analysis of the CHM system indicated an increase in the active community for most of the dominant group-level taxa at various taxonomic levels (Fig.…”