A 17β-Estradiol-utilizing Bacterium, Sphingomonas Strain KC8: Part I - Characterization and Abundance in Wastewater Treatment Plants

Abstract

A 17beta-estradiol-utilizing bacterium, Sphingomonas strain KC8, was characterized in terms of its utilization kinetics toward 17beta-estradiol, estrone, and testosterone. The maximum specific substrate utilization rates (q(m)) are 0.37, 0.50, and 0.17 mg-substrate/mg-protein/day for 17beta-estradiol, estrone, and testosterone, respectively. The half-velocity constants (K(s)) are 1.9 mg/L for 17beta-estradiol, 2.7 mg/L for estrone, and 2.4 mg/L for testosterone. Strain KC8 can grow on testosterone, glucose, sodium succinate, and sodium acetate, but not on phenol. Also, strain KC8 cannot degrade two common wastewater micropollutants, bisphenol A (a plasticizer) and triclosan (an antimicrobial agent). Unlike Novosphingobium sp. ARI-1 (a known estrogen-degrader) that would lose its degradation ability toward estrone after growing on a nutrient-rich estrogen-free medium for 7 days, strain KC8 was still able to degrade both 17beta-estradiol and estrone after growing on the same medium for 15 days. Strains KC8 and ARI-1 were molecularly detected in activated sludge of municipal wastewater treatment plants (WWTPs) operating under solid retention times of 2-30 days. The concentrations of strain KC8 were 2-3 orders higher than those of strain ARI-1 in the WWTPs, suggesting that strain KC8 is ubiquitous in WWTPs and might play an important role in estrogen removal.

Anoxic Androgen Degradation by the Denitrifying Bacterium Sterolibacterium denitrificans via the 2,3-seco Pathway

“…The resulting cell suspension was anaerobically incubated at 28°C with shaking (180 rpm) for 2 h. We measured the amount of residual steroids using high-pressure liquid chromatography (HPLC) and determined the protein content of the S. denitrificans cell suspension using the bicinchoninic acid (BCA) assay. The determination of Monod kinetic parameters was carried out as described before (48).…”

Integrated multi-omics analyses reveal the biochemical mechanisms and phylogenetic relevance of anaerobic androgen biodegradation in the environment

“…The negative controls were DNA from strictly aerobic androgen degraders, C. testosteroni, Gordonia cholesterolivorans (Wang et al, 2013a), and Sphingomonas sp. KC8 (Roh and Chu, 2010). PCR products with the expected size of~1100 bp were amplified from the androgen-degrading anaerobes but not from the androgen-degrading aerobes (Figure 7bI).…”

General Fate Model for Microconstituents in an Activated Sludge System

“…Many researchers dealing with MCs assume that the degradation only happens in the liquid phase . Although there are some studied that suggests dissolved and sorbed MCs could be biodegraded with different or same rates Proteobacteria, Actinobacteria, and Bacteroidetes, were found to degrade estrogenic compounds at STPs (Roh and Chu, 2010;Yu et al, 2011b).…”