Tuning the performance of a natural treatment process using metagenomics for improved trace organic chemical attenuation

Abstract

By utilizing high-throughput sequencing and metagenomics, this study revealed how the microbial community characteristics including composition, diversity, as well as functional genes in managed aquifer recharge (MAR) systems can be tuned to enhance removal of trace organic chemicals of emerging concern (CECs). Increasing the humic content of the primary substrate resulted in higher microbial diversity. Lower concentrations and a higher humic content of the primary substrate promoted the attenuation of biodegradable CECs in laboratory and field MAR systems. Metagenomic results indicated that the metabolic capabilities of xenobiotic biodegradation were significantly promoted for the microbiome under carbon-starving conditions.

Can meta-omics help to establish causality between contaminant biotransformations and genes or gene products?

“…Given these limitations along with the increasing accessibility of high-throughput sequencing and mass spectrometry techniques, there is growing interest in using molecular data generated via meta-omics methodologies (i.e., methodologies that attempt to characterize the complete set of genes, transcripts, or enzymes of a community) to elucidate causal associations with biotransformations. [16][17][18][19][20] The general strategy is to isolate and characterize aggregate DNA, RNA, or proteins from in situ environmental communities and use the abundances of genes or gene products to establish associations that reflect the communities' potential for biotransforming one or more contaminants (referred to here as a meta-omics association study). In this context, we use the term "association" to refer to a statistical relationship between two variables, which may be described quantitatively (e.g., a linear or monotonic relationship) or qualitatively (e.g., a co-occurrence relationship).…”

Microbiome-Triggered Transformations of Trace Organic Chemicals in the Presence of Effluent Organic Matter in Managed Aquifer Recharge (MAR) Systems

“…A key parameter for cometabolic transformation of TOrCs is the availability of biodegradable DOC (BDOC) as primary substrate, both with respect to its quality and quantity 1,9 . Previous studies revealed that both the composition and the concentration of BDOC affect the total amount of biomass and the structure of the microbial community [10][11][12] as well as their functionality 13 and, therefore, 56 TOrCs removal 9 . It is well established that the transformation of TOrCs is enhanced under 57 carbon-limited conditions 3,13,14 .…”

“…Previous studies revealed that both the composition and the concentration of BDOC affect the total amount of biomass and the structure of the microbial community [10][11][12] as well as their functionality 13 and, therefore, 56 TOrCs removal 9 . It is well established that the transformation of TOrCs is enhanced under 57 carbon-limited conditions 3,13,14 . Primary substrate comprised of refractory organic compounds, 58 such as humic acid like organic matter, led to an increased TOrCs removal compared to systems using a high fraction of easily degradable compounds like peptone/yeast 9,13 .…”

Impacts of Accumulated Particulate Organic Matter on Oxygen Consumption and Organic Micro-Pollutant Elimination in Bank Filtration and Soil Aquifer Treatment

“…The degradation of organic compounds can have a significant impact on redox-conditions in the subsoil. Furthermore, POC and DOC can be competitive substrates for OMP removal [12]. Still, DOC removal is a desired effect for BF and SAT.…”