title: Construction of PAH-degrading mixed microbial consortia by induced selection in soil.
abstract: Bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils through the biostimulation and bioaugmentation processes can be a strategy for the clean-up of oil spills and environmental accidents. In this work, an induced microbial selection method using PAH-polluted soils was successfully used to construct two microbial consortia exhibiting high degradation levels of low and high molecular weight PAHs. Six fungal and seven bacterial native strains were used to construct mixed consortia with the ability to tolerate high amounts of phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP) and utilize these compounds as a sole carbon source. In addition, we used two engineered PAH-degrading fungal strains producing heterologous ligninolytic enzymes. After a previous selection using microbial antagonism tests, the selection was performed in microcosm systems and monitored using PCR-DGGE, CO2evolution and PAH quantitation. The resulting consortia (i.e., C1 and C2) were able to degrade up to 92% of Phe, 64% of Pyr and 65% of BaP out of 1000 mg kg-1of a mixture of Phe, Pyr and BaP (1:1:1) after a two-week incubation. The results indicate that constructed microbial consortia have high potential for soil bioremediation by bioaugmentation and biostimulation and may be effective for the treatment of sites polluted with PAHs due to their elevated tolerance to aromatic compounds, their capacity to utilize them as energy source.
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal San Inés Tecuexcomac-Tepetitla Km 1.5, C.P. 90700, Tepetitla de Lardizabal, Tlaxcala, Mexico.
authors.forename: German
authors.initials: G
authors.lastname: Zafra
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal San Inés Tecuexcomac-Tepetitla Km 1.5, C.P. 90700, Tepetitla de Lardizabal, Tlaxcala, Mexico.
authors.forename: Ángel E
authors.initials: ÁE
authors.lastname: Absalón
authors.affiliation: Universidad Politécnica de Pachuca, Laboratorio de Microbiología Molecular, Carretera Pachuca-Cd, Sahagún, Km 20, Ex-Hacienda de Santa Bárbara, Zempoala, Hidalgo, Mexico.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Anducho-Reyes
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Vicentina, C.P. 09340, México, D.F., Mexico.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Fernandez
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal San Inés Tecuexcomac-Tepetitla Km 1.5, C.P. 90700, Tepetitla de Lardizabal, Tlaxcala, Mexico. Electronic address: dcortes@ipn.mx.
authors.forename: Diana V
authors.initials: DV
authors.lastname: Cortés-Espinosa
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D005658:Fungi / Q000378:metabolism; D059013:Microbial Consortia; D059392:Petroleum Pollution / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants
keywords: Bioaugmentation; Microbial antagonism; Mixed degrading consortia; Polycyclic aromatic hydrocarbons (PAHs); Soil bioremediation