African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

The plant growth promoting bacterium Bacillus sp. CaSUT007 produces phytohormone and extracellular proteins for enhanced growth of cassava

Natthiya Buensanteai1,2*, Mathukorn Sompong1, Kanjana Thamnu3, Dusit Athinuwat4, Alain Brauman2 and Claude Plassard2
1School of Crop Production Technology, Institute of Agriculture Technology, Suranaree University of Technology, Nakhon Ratchasima, 30000 Thailand. 2Unité Mixte de Recherche Eco&Sols (Ecologie fonctionnelle & biogéochimie des Sols &des Agroécosystèmes), UMR 1222 INRA-IRD-SupAgro Montpellier, Place Pierre Viala, 34060 Montpellier cedex 01, France. 3Synchrotron Light Research Institute (public organization), Ministry of Science and Technology of the Royal Thai Government, Muang, 30000 Nakhonratchasima, Thailand. 4Major of Organic Farming Management, Faculty of Science and Technology, Thammasat University, Pathumthani, 12121, Thailand.
Email: [email protected]

  •  Accepted: 03 May 2013
  •  Published: 18 October 2013


Bacillus sp. strain CaSUT007, a plant growth promoting rhizobacterium isolated from cassava, was investigated for the secretion of compounds that might be involved in plant growth promotion. Extracts containing phytohormone and extracellular proteins were made from the cell-free fluid of CaSUT007 broth cultures. These extracts, along with a whole culture of CaSUT007 and the raw fluid and cellular fractions from a CaSUT007 culture, were applied separately to cassava stakes. The stakes were planted into pots of soil maintained in a greenhouse condition. Under this condition, all of the extracts including phytohormones and extracellular proteins increased root and shoot lengths and cassava biomass as compared to negative control. Our results indicate that the culture extracts, when applied to cassava stakes, increased root and shoot lengths by more than 30%, and increased fresh and dry weights by more than 25% compared to the distilled water control. Thus, photohormone and extracellular proteins secreted by CaSUT007 can influence plant growth and development. Analysis of the photohormone and extracellular proteins extracts revealed indole-3-acetic acid and peptides to be the primary compounds.


Key words: Cassava, growth promotion, Bacillus, extracellular proteins, phytohormone.