title: Fungal-bacterial consortia increase diuron degradation in water-unsaturated systems.
abstract: Bioremediation of pesticide-polluted soil may be more efficient using mixed fungal-bacterial cultures rather than the individual strains alone. This may be due to cooperative catabolism, where the first organism transforms the pollutant to products which are then used by the second organism. In addition, fungal hyphae may function as transport vectors for bacteria, thereby facilitating a more effective spreading of degrader organisms in the soil. A more rapid mineralization of the phenylurea herbicide diuron was found in sand with added microbial consortia consisting of both degrading bacteria and fungi. Facilitated transport of bacteria by fungal hyphae was demonstrated using a system where herbicide-spiked sand was separated from the consortium by a layer of sterile glass beads. Several fungal-bacterial consortia were investigated by combining different diuron-degrading bacteria (Sphingomonas sp. SRS2, Variovorax sp. SRS16, and Arthrobacter globiformis D47) and fungi (Mortierella sp. LEJ702 and LEJ703). The fastest mineralization of (14)C-labeled diuron was seen in the consortium consisting of Mortierella LEJ702, Variovorax SRS16, and A. globiformis D47, as measured by evolved (14)CO2. In addition, the production of diuron metabolites by this consortium was minimal. Analyses of 16S rDNA suggested that bacteria were transported more efficiently by LEJ702 than by LEJ703. Finally, it was determined that the fungal growth differed for LEJ702 and LEJ703 in the three-member consortia. This study demonstrates new possibilities for applying efficient fungal-bacterial consortia for bioremediation of polluted soil.
authors: Department of Biology, Copenhagen University, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark; Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark. Electronic address: Leael@bio.ku.dk.
authors: Lea
authors: L
authors: Ellegaard-Jensen
authors: Berith Elkær
authors: BE
authors: Knudsen
authors: Anders
authors: A
authors: Johansen
authors: Christian Nyrop
authors: CN
authors: Albers
authors: Jens
authors: J
authors: Aamand
authors: Søren
authors: S
authors: Rosendahl
mesh_terms: D001173:Arthrobacter / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D042621:Comamonadaceae / Q000378:metabolism; D004237:Diuron / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006540:Herbicides / Q000378:metabolism*; D025301:Hyphae / Q000502:physiology; D059013:Microbial Consortia; D020094:Mortierella / Q000235:genetics / Q000378:metabolism*; D020578:Sphingomonas / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D006540:Herbicides; D004237:Diuron
keywords: Biodegradation; Fungal highway; Microbial consortia; Pesticide; Phenylurea herbicide; Synergistic interactions