title: Characterization of biocontrol bacterial strains isolated from a suppressiveness-induced soil after amendment with composted almond shells.
abstract: The improvement in soil quality of avocado crops through organic amendments with composted almond shells has a positive effect on crop yield and plant health, and enhances soil suppressiveness against the phytopathogenic fungus Rosellinia necatrix. In previous studies, induced soil suppressiveness against this pathogen was related to stimulation of Gammaproteobacteria, especially some members of Pseudomonas spp. with biocontrol-related activities. In this work, we isolated bacteria from this suppressiveness-induced amended soil using a selective medium for Pseudomonas-like microorganisms. We characterized the obtained bacterial collection to aid in identification, including metabolic profiles, antagonistic responses, hybridization to biosynthetic genes of antifungal compounds, production of lytic exoenzymatic activities and plant growth-promotion-related traits, and sequenced and compared amplified 16S rDNA genes from representative bacteria. The final selection of representative strains mainly belonged to the genus Pseudomonas, but also included the genera Serratia and Stenotrophomonas. Their biocontrol-related activities were assayed using the experimental avocado model, and results showed that all selected strains protected the avocado roots against R. necatrix. This work confirmed the biocontrol activity of these Gammaproteobacteria-related members against R. necatrix following specific stimulation in a suppressiveness-induced soil after a composted almond shell application.
authors.affiliation: Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain; Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Bulevar Louis Pasteur, 31, 29071 Málaga, Spain. Electronic address: cvida@uma.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Vida
authors.affiliation: Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain; Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Bulevar Louis Pasteur, 31, 29071 Málaga, Spain. Electronic address: cazorla@uma.es.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Cazorla
authors.affiliation: Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain; Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Bulevar Louis Pasteur, 31, 29071 Málaga, Spain. Electronic address: adevicente@uma.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: de Vicente
mesh_terms: D000898:Antibiosis; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D061046:Biological Control Agents / Q000302:isolation & purification*; D000076282:Composting; D018556:Crops, Agricultural; D004275:DNA, Ribosomal; D005658:Fungi / Q000235:genetics / Q000302:isolation & purification; D027421:Persea; D018517:Plant Roots / Q000382:microbiology; D000068181:Prunus dulcis; D011549:Pseudomonas / Q000235:genetics; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D061046:Biological Control Agents; D004275:DNA, Ribosomal; D012987:Soil
keywords: Biocontrol; Characterization; Gammaproteobacteria; Isolation; Pseudomonas