Environmental Potential for Microbial 1,4-Dioxane Degradation Is Sparse despite Mobile Elements Playing a Role in...

Area of Science:

• Environmental microbiology
• Bioremediation
• Genomics

Background:

• 1,4-Dioxane is an emerging contaminant requiring effective remediation solutions.
• Bioremediation is a promising strategy, but understanding dioxane-degrading bacteria is limited.
• Current biomarkers, like dioxane monooxygenase (DXMO), are insufficient for comprehensive assessment.

Purpose of the Study:

• To create a curated suite of biomarkers for assessing 1,4-dioxane degradation potential.
• To investigate the functional and taxonomic diversity of bacteria capable of dioxane degradation.
• To analyze the global distribution of dioxane degradation genes in environmental metagenomes.

Main Methods:

• Collation of existing data on dioxane degraders to create curated biomarkers.
• Bioinformatic analysis of gene families, mobile elements, and genomic rearrangements.
• Screening of over 11,000 public metagenomes using the expanded biomarker set.

Main Results:

• Identified eight distinct gene families involved in dioxane degradation.
• Found that dioxane degradation genes are often on mobile elements, suggesting lateral gene transfer.
• Discovered a sparse and taxonomically limited distribution of dioxane degradation potential across environments.
• Observed distinct dioxane-degrading gene profiles in terrestrial, aquatic, and wetland environments.

Conclusions:

• A comprehensive set of biomarkers improves the assessment of dioxane degradation potential.
• The limited distribution of these genes suggests natural attenuation may be insufficient in most environments.
• Bioaugmentation, rather than biostimulation, is likely necessary for effective dioxane remediation.