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

Optimization of culture conditions for phosphate solubilizing by Acinetobacter calcoaceticus YC-5a using response surface methodology

D. D. Fan1,3*, Y. X. Ren1,3, X. L. Zhu2,3, P. Ma1,3 and L. H. Liang2,3
1Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering, Northwest University, Taibai North Road 229, Xi’an, Shaanxi 710069, China. 2School of Urban and Environmental Sciences, Northwest University, Xi’an 710127, China. 3R & D Center of Fermentation Engineering and Biomaterials Technology of Shaanxi Province, Northwest University, Xi’an 710069, China.
Email: [email protected]

  •  Accepted: 26 August 2011
  •  Published: 30 September 2011


Response surface methodology was employed to optimize the composition of medium for phosphate solubilization by Acinetobacter calcoaceticus YC-5a, which is less well known as phosphate solubilizing plant-associated bacteria. (NH4)2SO4, Ca3(PO4)2 and KCl were found to have significant effects on phosphate solubilization by the Plackett-Burman design. The steepest ascent method was used to access the optimal region of the medium composition, followed by an application of response surface. The analysis revealed that the optimum values of the tested variables were (NH4)2SO4 0.2 g/L, Ca3(PO4)2 12.98 g/L and KCl 0.49 g/L, respectively. Phosphate solubilization of 747.72 mg/L, which was in agreement with the prediction, was observed in verification experiment. In comparison to the original level (405.4 mg/L), 1.83-fold increase had been obtained.


Key words: Phosphate solubilizing, Acinetobacter calcoaceticus, medium optimization, response surface.