title: Effect of arbuscular mycorrhizal and bacterial inocula on nitrate concentration in mesocosms simulating a wastewater treatment system relying on phytodepuration.
abstract: High nitrogen concentration in wastewaters requires treatments to prevent the risks of eutrophication in rivers, lakes and coastal waters. The use of constructed wetlands is one of the possible approaches to lower nitrate concentration in wastewaters. Beyond supporting the growth of the bacteria operating denitrification, plants can directly take up nitrogen. Since plant roots interact with a number of soil microorganisms, in the present work we report the monitoring of nitrate concentration in macrocosms with four different levels of added nitrate (0, 30, 60 and 90 mg l(-1)), using Phragmites australis, inoculated with bacteria or arbuscular mycorrhizal fungi, to assess whether the use of such inocula could improve wastewater denitrification. Higher potassium nitrate concentration increased plant growth and inoculation with arbuscular mycorrhizal fungi or bacteria resulted in larger plants with more developed root systems. In the case of plants inoculated with arbuscular mycorrhizal fungi, a faster decrease of nitrate concentration was observed, while the N%/C% ratio of the plants of the different treatments remained similar. At 90 mg l(-1) of added nitrate, only mycorrhizal plants were able to decrease nitrate concentration to the limits prescribed by the Italian law. These data suggest that mycorrhizal and microbial inoculation can be an additional tool to improve the efficiency of denitrification in the treatment of wastewaters via constructed wetlands.
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Lingua
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.|Mybasol S.r.l., via Gentilini 3, 15121, Alessandria, Italy.|C.R.A.-Unità di ricerca per le produzioni legnose fuori foresta, Strada Frassineto 35, 15033, Casale Monferrato, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Copetta
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Musso
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.|Mybasol S.r.l., via Gentilini 3, 15121, Alessandria, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Aimo
authors.affiliation: Giardino Botanico di Alessandria "Dina Bellotti", via Monteverde 24, 15121, Alessandria, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Ranzenigo
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buico
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Gianotti
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Osella
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel 11, 15121, Alessandria, Italy. graziella.berta@uniupo.it.|Mybasol S.r.l., via Gentilini 3, 15121, Alessandria, Italy. graziella.berta@uniupo.it.
authors.forename: Graziella
authors.initials: G
authors.lastname: Berta
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D005068:Eutrophication; D005658:Fungi / Q000254:growth & development*; D038821:Mycorrhizae / Q000254:growth & development*; D009566:Nitrates / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D017680:Potassium Compounds / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods; D053833:Wetlands
chemical_list: D009566:Nitrates; D017680:Potassium Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical; C023844:potassium nitrate
keywords: Arbuscular mycorrhizae; Constructed wetland; Denitrification; Phragmites australis; Phytoremediation; Plant growth-promoting bacteria