title: Detoxification of 1,1,2-trichloroethane to ethene in a bioreactor co-culture of Dehalogenimonas and Dehalococcoides mccartyi strains.
abstract: 1,1,2-Trichloroethane (1,1,2-TCA) is a non-flammable organic solvent and common environmental contaminant in groundwater. Organohalide-respiring bacteria are key microorganisms to remediate 1,1,2-TCA because they can gain metabolic energy during its dechlorination under anaerobic conditions. However, all current isolates produce hazardous end products such as vinyl chloride, monochloroethane or 1,2-dichloroethane that accumulate in the medium. Here, we constructed a syntrophic co-culture of Dehalogenimonas and Dehalococcoides mccartyi strains to achieve complete detoxification of 1,1,2-TCA to ethene. In this co-culture, Dehalogenimonas transformed 1,1,2-TCA via dihaloelimination to vinyl chloride, whereas Dehalococcoides reduced vinyl chloride via hydrogenolysis to ethene. Molasses, pyruvate, and lactate supported full dechlorination of 1,1,2-TCA in serum bottle co-cultures. Scale up of the cultivation to a 5-L bioreactor operating for 76d in fed-batch mode was successful with pyruvate as substrate. This synthetic combination of bacteria with known complementary metabolic capabilities demonstrates the potential environmental relevance of microbial cooperation to detoxify 1,1,2-TCA.
authors.affiliation: Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
authors.forename: Siti Hatijah
authors.initials: SH
authors.lastname: Mortan
authors.affiliation: Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Martín-González
authors.affiliation: Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Vicent
authors.affiliation: Institut de Química Avançada de Catalunya (IQAC) CSIC, Barcelona, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Caminal
authors.affiliation: Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Nijenhuis
authors.affiliation: Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Adrian
authors.affiliation: Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain. Electronic address: ernest.marco@uab.cat.
authors.forename: Ernest
authors.initials: E
authors.lastname: Marco-Urrea
mesh_terms: D039903:Actinobacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D041862:Chloroflexi / Q000378:metabolism*; D018920:Coculture Techniques; D014240:Trichloroethanes / Q000378:metabolism*
chemical_list: D014240:Trichloroethanes; C024567:1,1,2-trichloroethane
keywords: 1,1,2-Trichloroethane; Dehalococcoides; Dehalogenimonas; Fed-batch reactor; Organohalide-respiring bacteria