title: Changes in the microbial community during bioremediation of gasoline-contaminated soil.
abstract: We aimed to verify the changes in the microbial community during bioremediation of gasoline-contaminated soil. Microbial inoculants were produced from successive additions of gasoline to municipal solid waste compost (MSWC) previously fertilized with nitrogen-phosphorous. To obtain Inoculant A, fertilized MSWC was amended with gasoline every 3 days during 18 days. Inoculant B received the same application, but at every 6 days. Inoculant C included MSWC fertilized with N-P, but no gasoline. The inoculants were applied to gasoline-contaminated soil at 10, 30, or 50g/kg. Mineralization of gasoline hydrocarbons in soil was evaluated by respirometric analysis. The viability of the inoculants was evaluated after 103 days of storage under refrigeration or room temperature. The relative proportions of microbial groups in the inoculants and soil were evaluated by FAME. The dose of 50g/kg of inoculants A and B led to the largest CO2emission from soil. CO2emissions in treatments with inoculant C were inversely proportional to the dose of inoculant. Heterotrophic bacterial counts were greater in soil treated with inoculants A and B. The application of inoculants decreased the proportion of actinobacteria and increased of Gram-negative bacteria. Decline in the density of heterotrophic bacteria in inoculants occurred after storage. This reduction was bigger in inoculants stored at room temperature. The application of stored inoculants in gasoline-contaminated soil resulted in a CO2emission twice bigger than that observed in uninoculated soil. We concluded that MSWC is an effective material for the production of microbial inoculants for the bioremediation of gasoline-contaminated soil.
authors.affiliation: Instituto Federal Sul-rio-grandense, Bagé, Rio Grande do Sul, Brazil.
authors.forename: Aline Jaime
authors.initials: AJ
authors.lastname: Leal
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil. Electronic address: edmomontes@yahoo.com.br.
authors.forename: Edmo Montes
authors.initials: EM
authors.lastname: Rodrigues
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil.
authors.forename: Patrícia Lopes
authors.initials: PL
authors.lastname: Leal
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil.
authors.forename: Aline Daniela Lopes
authors.initials: ADL
authors.lastname: Júlio
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil.
authors.forename: Rita de Cássia Rocha
authors.initials: RCR
authors.lastname: Fernandes
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil.
authors.forename: Arnaldo Chaer
authors.initials: AC
authors.lastname: Borges
authors.affiliation: Universidade Federal de Viçosa, Departamento de Microbiologia, Laboratório de Biotecnologia Ambiental e Biodiversidade, Viçosa, Minas Gerais, Brazil. Electronic address: totolaufv@gmail.com.
authors.forename: Marcos Rogério
authors.initials: MR
authors.lastname: Tótola
mesh_terms: D058491:Bacterial Load; D001673:Biodegradation, Environmental; D058448:Biota / Q000187:drug effects*; D002245:Carbon Dioxide / Q000032:analysis; D002274:Carcinogens, Environmental / Q000378:metabolism*; D005742:Gasoline; D006838:Hydrocarbons / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D002274:Carcinogens, Environmental; D005742:Gasoline; D006838:Hydrocarbons; D012989:Soil Pollutants; D002245:Carbon Dioxide
keywords: Bioremediation; Gasoline degradation; Inoculant storage; Microbial inoculants; Soil contamination