Characterization of estrogen-degrading bacteria isolated from an artificial sandy aquifer with ultrafiltered secondary effluent as the medium

Abstract

This study investigated the aerobic and anoxic biodegradation of four estrogens [estrone (E1), estradiol (E2), estriol (E3), and the synthetic 17 alpha-ethinylestradiol (EE2)] in microcosms constructed with marine sand and ulftrafiltered (UF) secondary effluent. Three estrogen-degrading bacteria, LHJ1, LHJ3, and CYH, were isolated. Based on gram-stain morphology and 16S rRNA sequence homology, LHJ1 and LHJ3 belong to the genus Acinetobacter and Agromyces, respectively; CYH matched to 95% with the genus Sphingomonas. Aerobically LHJ3 degrades E3, CYH degrades E1, and all three isolates oxidize E2 to E1. Under anoxic conditions, CYH degrades E1 and LHJ3 degrades E2, whereas E3 and EE2 were not degraded by the three isolates; EE2 was transformed in microcosms incubated with site ground water. The degradation kinetics of E1 and E2 by CYH and E2 by LHJ3 under aerobic conditions was linearly correlated with the initial concentration, which ranged from 50 to 2,000 microg/l. The degradation of E1 by CYH under anoxic conditions followed Michaelis-Menten kinetics. 16 alpha-Hydroxyestrone was found to be a transient transformation product of E3 under aerobic conditions.

Isolation and Bioaugmentation of an Estradiol-Degrading Bacterium and Its Integration into a Mature Biofilm

“…strain JEM-1, (98% 16S rRNA gene sequence similarity to EDB-LI1), isolated from a conventional activated sludge plant, was also shown to be able to degrade both E1 and E2 (13). Another E2-and E1-degrading bacterium, named CYH, isolated from an artificial sandy aquifer in Singapore, was also a member of the Sphingomonadaceae family (93% 16S rRNA gene sequence similarity to EDB-LI1) (17). It is interesting to note that bacteria of phylogenetic similarity were isolated from different geographical regions and exhibit the ability to degrade estrogens.…”

Biodegradation of Endocrine Disruptors in Solid-Liquid Two-Phase Partitioning Systems by Enrichment Cultures

“…In our study, the 16S rRNA gene sequences derived from pyrosequencing (Table 3), gene libraries (Table 4), and the cultured strains provided a good indication of the bacterial composition of the enrichment cultures and the presence of ED-degrading bacteria. There are multiple reports on the isolation of ED-degrading bacterial strains showing affiliations with Sphingomonas, Novosphingobium, Ochrobactrum, Microbacterium, Pusillimonas, Rhodococcus, Planctomyces, and Bacteroidetes/Sphingobacteriales (41,(60)(61)(62)(63)(64)(65)(66)(67)(68), among the genera detected in our enrichments.…”

“…Several Sphingomonas sp. strains capable of degrading EDs have been isolated from soil, wastewater, or activated sludge (63,64,(66)(67)(68)71). For instance, in Sphingomonas sp.…”

Removal of environmental estrogens by bacterial cell immobilization technique

“…KC8 could use E2 and E1 as the carbon and energy source and completely degrade them into noneestrogenic substance. Ke et al (2007) isolated three estrogendegrading bacteria from artificial sandy aquifer and Sphingomonas sp. CYH could degrade E1 under both aerobic and anoxic conditions.…”