title: Effect of Cd⁺² on phosphate solubilizing abilities and hydrogen peroxide production of soil-borne micromycetes isolated from Phragmites australis-rhizosphere.
abstract: The aims of this work were to evaluate the phosphate-solubilization and hydrogen peroxide (H2O2) production by the soil-borne micromycetes, Aspergillus japonicus, Penicillium italicum and Penicillium dipodomyicola, isolated from Phragmites australis rhizosphere and to study the effect of several concentrations of Cadmium (Cd(2+)) on both variables. Our results showed that P. italicum achieved a higher P-solubilization and H2O2 production than A. japonicus and P. dipodomyicola, as only P. italicum showed a positive correlation (R(2) = 0.71) between P-solubilization and H2O2 production. In dose-response assays, P. italicum was also more tolerant to Cd(2+) (0.31 mM) in comparison to A. japonicus (0.26 mM). Analysis of the 2(4) factorial experimental design showed that P-solubilization by P. italicum was negatively affected by increases in Cd(2+) (p = 0.04) and yeast extract (p = 0.02) in the culture medium. The production of H2O2 was positively affected only by glucose (p = 0.002). Fungal biomass production was reduced significantly (p = 0.0009) by Cd(2+) and increased (p = 0.0003) by high glucose concentration in the culture medium. The tolerance and correlation between P-solubilization and H2O2 production in the presence of Cd(2+) was strain and species dependent. The effects of Cd(2+), glucose, ammonium sulfate and yeast extract on those variables were evaluated through a two-level factorial design. P. italicum is promising for P-solubilization in soils contaminated with Cd(2+) and may be an alternative for manufacture of biofertilizers to replace chemical fertilizers.
authors.affiliation: Department of Biotechnology and Bioengineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, San Pedro Zacatenco, 07360, México, DF, Mexico.
authors.forename: Jose Roberto
authors.initials: JR
authors.lastname: Zúñiga-Silva
authors.affiliation: Laboratorio de Fitopatología y Micología Aplicada, Facultad de Ciencias Biológicas y Agropecuarias, Universidad de Colima, Autopista Colima-Manzanillo km 40, C. P. 28100, Tecomán, Colima, México.
authors.forename: Wilberth
authors.initials: W
authors.lastname: Chan-Cupul
authors.affiliation: Department of Environmental Biotechnology, Centre for Environmental Research Leipzig-Halle UFZ, Permoserstrasse15, 04318, Leipzig, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Kuschk
authors.affiliation: Department of Biotechnology, Universidad Autónoma Metropolitana Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, Iztapalapa, 09340, México, DF, Mexico.
authors.forename: Octavio
authors.initials: O
authors.lastname: Loera
authors.affiliation: Department of Biotechnology and Bioengineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, San Pedro Zacatenco, 07360, México, DF, Mexico.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Aguilar-López
authors.affiliation: Department of Biotechnology and Bioengineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, San Pedro Zacatenco, 07360, México, DF, Mexico. rrodrig@cinvestav.mx.
authors.forename: Refugio
authors.initials: R
authors.lastname: Rodríguez-Vázquez
mesh_terms: D001230:Aspergillus / Q000378:metabolism*; D002104:Cadmium / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008800:Mexico; D010407:Penicillium / Q000378:metabolism*; D010710:Phosphates / Q000737:chemistry*; D006109:Poaceae / Q000382:microbiology*; D058441:Rhizosphere; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000009:adverse effects*; D012995:Solubility
chemical_list: D010710:Phosphates; D012989:Soil Pollutants; D002104:Cadmium; D006861:Hydrogen Peroxide
keywords: Dose–response assay; Ecotoxicology; Penicillium italicum; Phosphate-solubilizing fungi