title: p-Cresol mineralization and bacterial population dynamics in a nitrifying sequential batch reactor.
abstract: The ability of a nitrifying sludge to oxidize p-cresol was evaluated in a sequential batch reactor (SBR). p-Cresol was first transformed to p-hydroxybenzaldehyde and p-hydroxybenzoate, which were later mineralized. The specific rates of p-cresol consumption increased throughout the cycles. The bacterial population dynamics were monitored by using denaturing gradient gel electrophoresis (DGGE) and sequencing of DGGE fragments. The ability of the sludge to consume p-cresol and intermediates might be related to the presence of species such as Variovorax paradoxus and Thauera mechernichensis. p-Cresol (25 to 200mgC/L) did not affect the nitrifying SBR performance (ammonium consumption efficiency and nitrate production yield were close to 100% and 1, respectively). This may be related to the high stability observed in the nitrifying communities. It was shown that a nitrifying SBR may be a good alternative to eliminate simultaneously ammonium and p-cresol, maintaining stable the respiratory process as the bacterial community.
authors.affiliation: Department of Biotechnology - CBS, Universidad Autónoma Metropolitana - Iztapalapa, Mexico City 09340, Mexico; Department of Process and Technology-CNI, Universidad Autónoma Metropolitana - Cuajimalpa, Mexico City 05300, Mexico. Electronic address: csilva@correo.cua.uam.mx.
authors.forename: Carlos David
authors.initials: CD
authors.lastname: Silva
authors.affiliation: Department of Biotechnology - CBS, Universidad Autónoma Metropolitana - Iztapalapa, Mexico City 09340, Mexico.
authors.forename: Lizeth
authors.initials: L
authors.lastname: Beristain-Montiel
authors.affiliation: Department of Biotechnology - CBS, Universidad Autónoma Metropolitana - Iztapalapa, Mexico City 09340, Mexico.
authors.forename: Flor
authors.initials: F
authors.lastname: de Maria Cuervo-López
authors.affiliation: Department of Biotechnology - CBS, Universidad Autónoma Metropolitana - Iztapalapa, Mexico City 09340, Mexico. Electronic address: actx@xanum.uam.mx.
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Texier
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D003408:Cresols / Q000737:chemistry*; D058645:Denaturing Gradient Gel Electrophoresis; D059013:Microbial Consortia; D058465:Nitrification; D010084:Oxidation-Reduction; D017422:Sequence Analysis, DNA
chemical_list: D003408:Cresols; C032538:4-cresol
keywords: Ecological indices; Nitrification; Population dynamics; Sequential batch reactor; p-Cresol oxidation