Degradation of 17β-estradiol and products by a mixed culture of Rhodococcus equi DSSKP-R-001 and Comamonas testosteroni QYY20150409

Abstract

In this study, we investigated environmental oestrogen 17b-estradiol (E2) degradation by a mixed culture of Rhodococcus equi DSSKP-R-001(RS) and Comamonas testosteroni QYY20150409(CT). The results demonstrated that the two strains exhibited synergistic E2 degradation activity, showing that multispecies bacterial systems can improve microbial survival and activity. The E2 degradation rate for the mixed culture system was 94% under conditions in which E2 was the sole source of carbon and growth energy, while the degradation rates of the R. equi DSSKP-R-001 and C. testosteroni QYY20150409 single strains were 86% and 76%, respectively. Comparing and analyzing the degradation products of E2, intermediate cross-metabolism products were observed in the culture containing the two bacteria. The metabolic products of benzene were essentially removed during the process of E2 degradation in the mixed culture, which showed stronger degradation ability than cultures of the individual strains. The results from this investigation on the degradation of E2 by individual and mixed bacterial cultures provide a theoretical basis for the microbial remediation of environmental oestrogens.

The Analysis of Estrogen-Degrading and Functional Metabolism Genes in Rhodococcus equi DSSKP-R-001

“…Although many detailed estrogen degradation pathways have been proposed [9,27,41], studies on the intracellular metabolism of estrogen have not been reported. At the same time, estrogen pollution is currently caused by multiple channels and multiple estrogens, and the study of bacterial estrogen degradation therefore has great practical significance.…”

Suitability of Immobilized Systems for Microbiological Degradation of Endocrine Disrupting Compounds

“…Bacteria that degrade these hormones belong to genera such as Bacillus , Virgibacillus , Novosphingobium , Rhodococcus , Acinetobacter , Pseudomonas , Sphingomonas , Enterobacter , Klebsiella , Aeromonas , Comamonas , Thauera , Deinococcus , Stenotrophomonas and cyanobacteria [ 3 , 4 , 6 , 7 , 10 , 12 , 25 , 28 , 31 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Raphidocelis subcapitata , Chlorella vulgaris , Chlorococcus and Scenedesmus quadricauda belong to algae capable of removing hormones [ 11 , 26 , 40 , 41 ].…”

“…In addition, 17β-estradiol is usually degraded faster while estrone and synthetic estrogens are decomposed slower [ 34 , 47 ]. Moreover, Wang et al [ 37 ] noted the synergistic effect of mixture strains during 17β-estradiol degradation. While individual strains degraded to 86% of the hormone, the mixture of strains almost completely degraded 17β-estradiol.…”

“…This is indicated by the analysis of intermediates in a mixed strain culture, which showed the appearance of two organic acids. These compounds were not identified during degradation of individual strains [ 37 ].…”

“…Wang et al [ 37 ] described 17β-estradiol degradation by a mixed culture of Rhodococcus equi DSSKP-R-001 and Comamonas testosteroni QYY20150409 and by individual strain. These authors showed that each strain degrades the hormone in a different pathway.…”