title: Isolation and bioaugmentation of an estradiol-degrading bacterium and its integration into a mature biofilm.
abstract: Bioaugmentation can alter the potential activity as well as the composition of the naturally occurring microbial biota during bioremediation of a contaminated site. The focus of the current study is the pollutant 17β-estradiol (E2), which can cause endocrine effects and is potentially harmful to aquatic biota and to public health. The community composition and function of biofilms, originating from a wetland system, as affected by augmentation of an estradiol-degrading bacterium (EDB-LI1) under different conditions, were investigated. EDB-LI1 inoculation into biofilm from two wetland ponds representing early and advanced water treatment stages, respectively, yielded three significant observations, as follows: (i) EDB-LI1, enriched from a biofilm of a constructed wetland wastewater treatment system, was detected (by quantitative PCR [qPCR] analysis) in this environment in the augmented biofilm only; (ii) the augmented biofilm acquired the ability to remove estradiol; and (iii) the bacterial community composition (analyzed by PCR-denaturing gradient gel electrophoresis [DGGE]) of the augmented biofilm differed from that of the control biofilm. Furthermore, EDB-LI1 bioaugmentation showed a higher level of removal of estradiol with biofilms that originated from the advanced-treatment-stage wetland pond than those from the early-treatment-stage pond. Hence, the bioaugmentation efficiency of EDB-LI1 depends on both the quality of the feed water and the microbial community composition in the pond.
authors.affiliation: Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel.
authors.forename: Lilach
authors.initials: L
authors.lastname: Iasur-Kruh
authors.forename: Yitzhak
authors.initials: Y
authors.lastname: Hadar
authors.forename: Dror
authors.initials: D
authors.lastname: Minz
mesh_terms: D001419:Bacteria / Q000302:isolation & purification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D018441:Biofilms / Q000254:growth & development*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D004958:Estradiol / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D053833:Wetlands
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D004958:Estradiol