African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12275

Full Length Research Paper

Molecular characterization and insecticidal activities of Malian native crystalliferous Bacillus thuringiensis

Rokiatou Fane
  • Rokiatou Fane
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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Adounigna Kassogue
  • Adounigna Kassogue
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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Diakaridia Traore
  • Diakaridia Traore
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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Sognan Dao
  • Sognan Dao
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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Kadia Maiga
  • Kadia Maiga
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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Aliou Bah
  • Aliou Bah
  • Institut de Biotechnologie, Université de Montréal, Montréal (Québec) Canada.
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Fernando Hercos Valicente
  • Fernando Hercos Valicente
  • Embrapa Maize and Sorghum Research Center, C.P. 151, CEP: 35701 970 Sete Lagoas, Minas Gerais, Brasil.
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Amadou Hamadoun Babana
  • Amadou Hamadoun Babana
  • Faculty of Sciences and Techniques, University of Sciences, Techniques, and Technologies of Bamako, Bamako, BP E3206 Mali.
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  •  Received: 22 January 2017
  •  Accepted: 24 March 2017
  •  Published: 26 April 2017

Abstract

The objective of this work was to select the most active Bacillus thuringiensis (Bt) isolated from agricultural soils of Mali through the molecular characterization and the determination of insecticidal activities of the protein crystals, produced by these native isolates. Crystal proteins were extracted from B. thuringiensis culture, and characterized using the SDS-PAGE techniques. Their insecticidal activities were tested using third-instar larvae of Helicoverpa armigera in bioassay tests. The results showed that, of 62 B. thuringiensis treated, 52 isolates showed fragments varying between 10 and 140 kDa on 12% polyacrylamide gel. Cry1 and Cry2 protein crystals were recognized to be effective against Lepidoptera’s larvae, which were found in 21% of the tested isolates. In addition to these two expected crystal protein weights, other molecular weights were observed at different proportions, suggesting the presence of other cry genes in the local B. thuringiensis isolates. Four native B. thuringiensis isolates were able to kill 95 to 100% of H. armigera 3rd-instar larvae. Only one native of B. thuringiensis isolate was able to kill 100% of the H. armigera larvae. This is the first study for molecular characterization of Malian native B. thuringiensis isolates, showing the efficacy of the native B. thuringiensis against an important agricultural insect pest.

 

Key words: Protein crystals, Bacillus thuringiensis, cry genes, insecticidal activity, molecular characterization, Helicoverpa armigera, Mali.