title: Potential biocontrol actinobacteria: Rhizospheric isolates from the Argentine Pampas lowlands legumes.
abstract: Control of fungal plant diseases by using naturally occurring non-pathogenic microorganisms represents a promising approach to biocontrol agents. This study reports the isolation, characterization, and fungal antagonistic activity of actinobacteria from forage soils in the Flooding Pampa, Argentina. A total of 32 saprophytic strains of actinobacteria were obtained by different isolation methods from rhizospheric soil of Lotus tenuis growing in the Salado River Basin. Based on physiological traits, eight isolates were selected for their biocontrol-related activities such as production of lytic extracellular enzymes, siderophores, hydrogen cyanide (HCN), and antagonistic activity against Cercospora sojina, Macrophomia phaseolina, Phomopsis sp., Fusarium oxysporum, and Fusarium verticilloides. These actinobacteria strains were characterized morphologically, physiologically, and identified by using molecular techniques. The characterization of biocontrol-related activities in vitro showed positive results for exoprotease, phospholipase, fungal growth inhibition, and siderophore production. However, none of the strains was positive for the production of hydrogen cyanide (HCN). Streptomyces sp. MM140 presented the highest index for biocontrol, and appear to be promising pathogenic fungi biocontrol agents. These results show the potential capacity of actinobacteria isolated from forage soils in the Argentine Pampas lowlands as promising biocontrol agents, and their future agronomic applications.
authors.affiliation: INIBIOMA, UNComahue, CONICET. CRUB, Quintral 1250, S. C. Bariloche, 8400, Argentina.
authors.forename: Mariana
authors.initials: M
authors.lastname: Solans
authors.affiliation: INIBIOMA, UNComahue, CONICET. CRUB, Quintral 1250, S. C. Bariloche, 8400, Argentina.
authors.forename: Jose Martin
authors.initials: JM
authors.lastname: Scervino
authors.affiliation: INIBIOMA, UNComahue, CONICET. CRUB, Quintral 1250, S. C. Bariloche, 8400, Argentina.
authors.forename: María Inés
authors.initials: MI
authors.lastname: Messuti
authors.affiliation: INIBIOMA, UNComahue, CONICET. CRUB, Quintral 1250, S. C. Bariloche, 8400, Argentina.
authors.forename: Gernot
authors.initials: G
authors.lastname: Vobis
authors.affiliation: Departamento de Ciencia y Tecnología, Programa de Interacciones Biológicas, UNQuilmes, CONICET, R. Saénz Peña 352, B1876BXD Bernal, Argentina.
authors.forename: Luis Gabriel
authors.initials: LG
authors.lastname: Wall
mesh_terms: D039903:Actinobacteria / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D000898:Antibiosis; D000935:Antifungal Agents / Q000494:pharmacology; D001118:Argentina; D001203:Ascomycota; D061046:Biological Control Agents / Q000302:isolation & purification*; D001688:Biological Products / Q000494:pharmacology; D007887:Fabaceae / Q000382:microbiology*; D005670:Fusarium / Q000187:drug effects; D006856:Hydrogen Cyanide / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D058441:Rhizosphere; D017262:Siderophores / Q000096:biosynthesis; D012988:Soil Microbiology; D013302:Streptomyces / Q000302:isolation & purification
chemical_list: D000935:Antifungal Agents; D061046:Biological Control Agents; D001688:Biological Products; D017262:Siderophores; D006856:Hydrogen Cyanide
keywords: Actinobacteria; Antagonistic activity; Biocontrol; Potential agronomic applications