Deciphering 17β-estradiol-3-sulfate biotransformation: From microbial interactions to strain-level biotransformation

Area of Science:

• Environmental Microbiology
• Biotechnology
• Wastewater Treatment

Background:

• 17β-estradiol-3-sulfate (E2-3S) is an environmental estrogen of concern in wastewater.
• Biodegradation offers a promising but mechanistically unclear method for E2-3S removal.

Purpose of the Study:

• To elucidate the mechanisms of E2-3S biodegradation at both microbial community and individual strain levels.
• To identify key microbial players and pathways involved in E2-3S degradation and estrogenic activity reduction.

Main Methods:

• Construction of microbial co-occurrence networks in various reaction environments.
• Isolation and characterization of E2-3S-degrading bacteria from activated sludge.
• Analysis of degradation pathways and estrogenic activity reduction by isolated strains.

Main Results:

• Activated sludge achieved over 90% E2-3S removal, with variable estrogenic activity reduction.
• Pseudomonas species were identified as keystone taxa, interacting synergistically with other bacteria.
• Isolated strain Pseudomonas CE2S demonstrated high E2-3S degradation (>90%) and estrogenic activity reduction (>70%).
• Proposed E2-3S degradation pathways for strain CE2S involve deconjugation, hydroxylation, and ring cleavage.

Conclusions:

• This study provides a comprehensive mechanistic understanding of E2-3S biodegradation from community to strain levels.
• The isolation of Pseudomonas CE2S offers a novel bioaugmentation candidate for simultaneous E2-3S degradation and estrogenic activity reduction in wastewater treatment.