title: Phenotypic comparison of clinical and plant-beneficial strains of Pantoea agglomerans.
abstract: Certain strains of Pantoea are used as biocontrol agents for the suppression of plant diseases. However, their commercial registration is hampered in some countries because of biosafety concerns. This study compares clinical and plant-beneficial strains of P. agglomerans and related species using a phenotypic analysis approach in which plant-beneficial effects, adverse effects in nematode models, and toxicity were evaluated. Plant-beneficial effects were determined as the inhibition of apple fruit infection by Penicillium expansum and apple flower infection by Erwinia amylovora. Clinical strains had no general inhibitory activity against infection by the fungal or bacterial plant pathogens, as only one clinical strain inhibited P. expansum and three inhibited E. amylovora. By contrast, all biocontrol strains showed activity against at least one of the phytopathogens, and three strains were active against both. The adverse effects in animals were evaluated in the plant-parasitic nematode Meloidogyne javanica and the bacterial-feeding nematode Caenorhabditis elegans. Both models indicated adverse effects of the two clinical strains but not of any of the plant-beneficial strains. Toxicity was evaluated by means of hemolytic activity in blood, and genotoxicity with the Ames test. None of the strains, whether clinical or plant-beneficial, showed any evidence of toxicity.
authors.affiliation: Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Bonaterra
authors.affiliation: Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Badosa
authors.affiliation: Agroscope Changins-Wädenswil ACW, Division of Plant Protection, Wädenswil, Switzerland.|Zurich University of Applied Sciences ZHAW, LSFM-IUNR, Environmental Genomics and Systems Biology Research Group, Wädenswil, Switzerland.
authors.forename: Fabio
authors.initials: F
authors.lastname: Rezzonico
authors.affiliation: Agroscope Changins-Wädenswil ACW, Division of Plant Protection, Wädenswil, Switzerland.|Zurich University of Applied Sciences ZHAW, LSFM-IUNR, Environmental Genomics and Systems Biology Research Group, Wädenswil, Switzerland.
authors.forename: Brion
authors.initials: B
authors.lastname: Duffy
authors.affiliation: Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Montesinos
mesh_terms: D000818:Animals; D000898:Antibiosis; D017173:Caenorhabditis elegans / Q000382:microbiology; D044084:Erwinia amylovora / Q000502:physiology; D005638:Fruit / Q000382:microbiology; D027845:Malus / Q000382:microbiology; D020636:Pantoea / Q000502:physiology*; D010407:Penicillium / Q000502:physiology; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology* / Q000517:prevention & control
keywords: Ames test; Caenorhabditis elegans; Erwinia amylovora; Meloidogyne javanica; Pantoea agglomerans; Penicillium expansum; biocontrol; biosafety; hemolytic activity; toxicity