Temporal compositional shifts in an activated sludge microbiome during estrone biodegradation
Microbial biodegradation is a key process for the removal of estrogens during wastewater treatment. At least four degradation pathways for natural estrogens have been proposed. However, major estrogen degraders and the occurrence of different estrogen biodegradation pathways in wastewater treatment...
Saved in:
Published in | Environmental science and pollution research international Vol. 29; no. 22; pp. 32702 - 32716 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.05.2022
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Microbial biodegradation is a key process for the removal of estrogens during wastewater treatment. At least four degradation pathways for natural estrogens have been proposed. However, major estrogen degraders and the occurrence of different estrogen biodegradation pathways in wastewater treatment plants have been rarely investigated. This study was conducted to elucidate estrone biodegradation pathway and to identify key estrone-degrading bacteria in activated sludge from a major wastewater treatment plant in Bahrain. The biodegradation experiments were performed in activated sludge microcosms supplemented with estrone. Sludge samples were retrieved at time intervals to analyze the biodegradation metabolites and the temporal shifts in the bacterial community composition. Chemical analysis revealed the biodegradation of more than 90% of the added estrone within 6 days, and the compounds 4-hydroxyestrone and pyridinestrone acid, which are typical markers of the 4,5-
seco
pathway of aerobic estrone biodegradation, were detected. Temporal shifts in the relative abundance of bacteria were most prominent among members of Proteobacteria and Bacteroidetes. While the alphaproteobacterial genera
Novosphingobium
and
Sphingoaurantiacus
were significantly enriched (from ≤ 6% to an average of 31%) in the estrone-amended activated sludge after 2 days of incubation, the bacteroidete
Pedobacter
was uniquely detected in these microcosms at day 10. The relative abundance of Polyangia (
Nannocyctis
) increased to an average of 10 ± 0.4% in the estrone-amended activated sludge after 4 days of incubation. Enrichment cultivation of bacteria from the activated sludge on estrone resulted in a mixed culture that was capable of degrading estrone. An estrone-degrading strain was isolated from this mixed culture and was affiliated with the known estrogen-degrading Alphaproteobacteria
Sphingobium estrogenivorans
. We conclude that estrone degradation in the activated sludge from the studied wastewater treatment plant proceeds via the 4,5-
seco
pathway and is most likely mediated by alphaproteobacterial taxa. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0944-1344 1614-7499 |
DOI: | 10.1007/s11356-021-18185-9 |