title: Characterization of a Marine Microbial Community Used for Enhanced Sulfate Reduction and Copper Precipitation in a Two-Step Process.
abstract: Marine microorganisms that are obtained from hydrothermal vent sediments present a great metabolic potential for applications in environmental biotechnology. However, the work done regarding their applications in engineered systems is still scarce. Hence, in this work, the sulfate reduction process carried out by a marine microbial community in an upflow anaerobic sludge blanket (UASB) reactor was investigated for 190 days under sequential batch mode. The effects of 1000 to 5500 mg L-1of SO4-2and the chemical oxygen demand (COD)/SO4-2ratio were studied along with a kinetic characterization with lactate as the electron donor. Also, the feasibility of using the sulfide produced in the UASB for copper precipitation in a second column was studied under continuous mode. The system presented here is an alternative to sulfidogenesis, particularly when it is necessary to avoid toxicity to sulfide and competition with methanogens. The bioreactor performed better with relatively low concentrations of sulfate (up to 1100 mg L-1) and COD/SO4-2ratios between 1.4 and 3.6. Under the continuous regime, the biogenic sulfide was sufficient to precipitate copper at a removal rate of 234 mg L-1day-1. Finally, the identification of the microorganisms in the sludge was carried out; some genera of microorganisms identified were Desulfitobacterium and Clostridium.
authors.affiliation: Departamento de Bioprocesos, Laboratorio de Biotecnología Ambiental, Unidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional, 07340, México City, Mexico.
authors.forename: Octavio
authors.initials: O
authors.lastname: García-Depraect
authors.affiliation: Departamento de Bioprocesos, Laboratorio de Biotecnología Ambiental, Unidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional, 07340, México City, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Guerrero-Barajas
authors.affiliation: Departamento de Microbiología, Laboratorio de Biotecnología Ambiental, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340, México City, Mexico.
authors.forename: Janet
authors.initials: J
authors.lastname: Jan-Roblero
authors.affiliation: Unidad de Estudios Superiores de Tultitlan, Universidad Mexiquense del Bicentenario, Av. Ex-Hacienda de Portales s/n Villa Esmeralda C.P. 54910, Tultitlán de Mariano Escobedo, Mexico. alberto.ordaz@umb.mx.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ordaz
mesh_terms: D000693:Anaerobiosis / Q000502:physiology; D019149:Bioreactors; D003013:Clostridium / Q000254:growth & development*; D019327:Copper Sulfate / Q000378:metabolism*; D045858:Desulfitobacterium / Q000254:growth & development*; D059013:Microbial Consortia / Q000502:physiology*; D010084:Oxidation-Reduction
chemical_list: D019327:Copper Sulfate
keywords: Marine sediments; Metal recovery; Sulfate reduction; UASB reactor