African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5183

Full Length Research Paper

Screening endophytic actinobacteria with potential antifungal activity against Bipolaris sorokiniana and growth promotion of wheat seedlings

Elisandra Minotto
  • Elisandra Minotto
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar
Luciana Pasqualini Milagre
  • Luciana Pasqualini Milagre
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar
Cristina Spadari
  • Cristina Spadari
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar
Thaisa Feltrin
  • Thaisa Feltrin
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar
Ana Elisa Ballarini
  • Ana Elisa Ballarini
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar
José Carlos Germani
  • José Carlos Germani
  • Faculdade de Farmácia, Departamento de Produção de Matérias Pimas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
  • Google Scholar
Sabrina Pinto Salamoni
  • Sabrina Pinto Salamoni
  • Universidade do Oeste da Santa Catarina-UNOESC, Videira, SC, Brazil.
  • Google Scholar
Sueli Teresinha Van Der Sand
  • Sueli Teresinha Van Der Sand
  • Laboratório de Micologia Ambiental, Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, CEP: 90050-170, RS, Brazil.
  • Google Scholar


  •  Received: 19 June 2016
  •  Accepted: 06 September 2016
  •  Published: 28 September 2016

Abstract

Actinobacteria secrete substances that limit or inhibit the growth of plant pathogenic fungi and may be used in the biocontrol of these microorganisms. The aim of this study was to characterize physiological and enzymatic activity of endophytic actinobacteria, evaluate their antifungal activity against Bipolaris sorokiniana root colonization, and evaluate their efficiency in promoting the growth of wheat seedlings. Antibiosis was analyzed using the double-layer method, the agar well diffusion test, and volatile metabolites. Physiological and enzymatic activity was evaluated through chitinase, glucanase, siderophores, indole-3-acetic acid, nitrogen fixation and phosphate solubilization tests. In vivo assays were evaluated by root colonization, biocontrol test and efficiency to promote the growth of wheat seedlings. From all isolates tested, 69.6% of them presented antifungal activity against at least one B. sorokiriana isolate. Among these, 17% of the isolates produced bioactive metabolites in the supernatant when grown in submerging culture. The highest production of bioactive metabolites was at 30°C, between 72 and 96 h of incubation. Three isolates produced volatile compounds, chitinase, glucanase, siderophores and exhibited nitrogen fixation, produced indole-3-acetic acid, efficiently colonized the root system of seedlings of two wheat cultivars. The best isolate [6(2)] showed, under the greenhouse, the capacity to promote an increased biomass and tillers per wheat plant.

 

Key words: Antagonist actinobacteria, antifungal activity, biocontrol, spot blotch, lytic enzymes.