title: Isolation of bacterial strains able to degrade biphenyl, diphenyl ether and the heat transfer fluid used in thermo-solar plants.
abstract: Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Blanco-Moreno
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
authors.forename: Lara P
authors.initials: LP
authors.lastname: Sáez
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Luque-Almagro
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Roldán
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain. Electronic address: bb1movic@uco.es.
authors.forename: Conrado
authors.initials: C
authors.lastname: Moreno-Vivián
mesh_terms: D042402:Achromobacter / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001709:Biotechnology; D001713:Biphenyl Compounds / Q000378:metabolism*; D006358:Hot Temperature; D007218:Industrial Microbiology; D010647:Phenyl Ethers / Q000378:metabolism*; D011549:Pseudomonas / Q000302:isolation & purification / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000378:metabolism; D044204:Pseudomonas oleovorans / Q000302:isolation & purification / Q000378:metabolism; D058441:Rhizosphere; D012988:Soil Microbiology; D012993:Solar Energy
chemical_list: D001713:Biphenyl Compounds; D010647:Phenyl Ethers; C010574:biphenyl; C031538:phenyl ether
keywords: Bacteria; Biodegradation; Biphenyl; Diphenyl ether; Heat transfer fluid; Thermo-solar plants