African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5045

Full Length Research Paper

Characterization of phosphate solubilizing rhizobacteria isolated from lentil growing areas of Ethiopia

Mulissa J. Midekssa*
  • Mulissa J. Midekssa*
  • Department of Biology, College of Natural and Computational Sciences, Wollega University, Ethiopia
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Carolin R. Loscher
  • Carolin R. Loscher
  • Institute fur Allgemeine Mikirobiologie, Christian-Albrechts-Universitat Kiel, Germany
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Ruth A. Schmitz
  • Ruth A. Schmitz
  • Institute fur Allgemeine Mikirobiologie, Christian-Albrechts-Universitat Kiel, Germany
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Fassil Assefa
  • Fassil Assefa
  • Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Ethiopia
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  •  Received: 10 March 2015
  •  Accepted: 15 June 2015
  •  Published: 24 July 2015

Abstract

Lentil (Lens culnaris Medik.) is an invaluable source of dietary protein for the majority of Ethiopian population. The low availability of phosphorus is one of the major soil related stresses that limit the production of this crop. This study was aimed at isolation and characterization of phosphate solubilizing bacteria from lentil growing areas of Ethiopia and evaluating their effects on growth of this crop under greenhouse conditions. In total, 41 phosphate solubilizing bacterial strains were isolated from lentil rhizosphere and characterized using biochemical tests and 16S rDNA sequence analysis. The results showed the presence of genera Acinetobacter, Agrobacterium, Bacillus, Burkholderia, Chryseomonas, Enterobacter, Pseudomonas, Ralstonia and Sphingomonas. Phosphate solubilzing efficiencies of these isolates were evaluated in liquid medium using different insoluble P-sources and the result indicated that they released considerable amount of phosphates from tricalcium phosphate, rock phosphate and bone meal. Besides, some of these isolates exhibited multiple plant growth promoting characteristics such as indole acetic acid production and growth inhibition of Fusarium oxysporum under in vitro conditions. The effects of inoculation of Enterobacter kobei (PSBL5), Bacillus subtilis (PSBL21), Enterobacter species (PSBL26), Bacillus species (PSBL31) and Pseudomonas fluorescence (PSBL37) on lentil growth, nodulation, N and P content of shoot were evaluated under a greenhouse conditions and the results showed that these features were significantly increased over uninoculated control plants. Based on the results of this study, we conclude that lentil rhizosphere soil from producing areas of Ethiopia harbor diverse phosphate solubilizing bacterial strains with excellent phosphate solubilization and plant growth promotion ability. Thus, most of the promising strains should be tested in the field conditions under different agroecology of the country.

Key words: Rhizosphere soil, PGPR, rock phosphate, bone meal.