title: Rhizobacterial characterization for quality control of eucalyptus biogrowth promoter products.
abstract: Plant growth-promoting rhizobacteria strains from special formulations have been used to optimize eucalyptus cutting production. To undertake quality control for the formulated products, the rhizobacterial strains should be characterized to assess their purity and authentication. In the present study, we characterized nine strains of rhizobacteria, including three Bacillus subtilis (S1, S2 and 3918), two Pseudomonas sp. (MF4 and FL2), P. putida (MF2), P. fulva (Ca), Frateuria aurantia (R1), and Stenotrophomonas maltophilia (CIIb). The strains were differentiated by colony morphology after 24h of incubation in three different solid state culture media (glucose-nutritive agar, 523 medium and yeast extract-mannitol agar), sensitivity to a panel of 28 antibiotics (expressed according to the formation of inhibition halos of bacterial growth in the presence of antibiotics), and PCR-RFLP profiles of the 16S rDNA gene produced using nine restriction enzymes. It was possible to differentiate all nine strains of rhizobacteria using their morphological characteristics and sensitivity to antibiotics. The molecular analysis allowed us to separate the strains CIIb, FL2 and R1 from the strains belonging to the genera Bacillus and Pseudomonas. By using these three methods concomitantly, we were able to determine strain purity and perform the authentication.
authors.affiliation: Federal University of Viçosa, Department of Phytopathology, Viçosa, MG, Brazil.
authors.forename: Talyta Galafassi
authors.initials: TG
authors.lastname: Zarpelon
authors.affiliation: Federal University of Viçosa, Department of Phytopathology, Viçosa, MG, Brazil.
authors.forename: Lúcio Mauro da Silva
authors.initials: LM
authors.lastname: Guimarães
authors.affiliation: Federal University of Viçosa, Department of Microbiology, Viçosa, Minas Gerais State, Brazil.
authors.forename: Poliane
authors.initials: P
authors.lastname: Alfenas-Zerbini
authors.affiliation: Bio Soja Indústrias Químicas e Biológicas, São Joaquim da Barra, SP, Brazil.
authors.forename: Eli Sidney
authors.initials: ES
authors.lastname: Lopes
authors.affiliation: Fibria Centro de Tecnologia, Aracruz, ES, Brazil.
authors.forename: Reginaldo Gonçalves
authors.initials: RG
authors.lastname: Mafia
authors.affiliation: Federal University of Viçosa, Department of Phytopathology, Viçosa, MG, Brazil. Electronic address: aalfenas@ufv.br.
authors.forename: Acelino Couto
authors.initials: AC
authors.lastname: Alfenas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D005052:Eucalyptus / Q000254:growth & development* / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S
keywords: Biological product; Eucalyptus; Formulation; PGPR