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 in vitro antioxidant properties of Bacillus simplex XJ-25 isolated from sand biological soil crusts

  Z. R. Wang1,2, J. P. Sheng1, X. L. Tian2, T. T. Wu2, W. Z. Liu2 and L. Shen1*  
  1College of Food Science and Nutritional Engineerin, China Agricultural University, Beijing100083, China. 1School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China.
Email: [email protected]

  •  Accepted: 25 October 2011
  •  Published: 23 November 2011

Abstract

 

XJ-25, a strain with strong antioxidant activity was isolated from sand biological soil crusts in Gurban Tonggut Desert, Xinjiang, China. Strain XJ-25 is closely related to Bacillus simplex through the 16s rDNA sequencing combined with morphological, physiological and biochemical analysis. The medium for optimal antioxidant activity was NB with 1.5 g/Lglucose. Based on the kinetic assay, antioxidant activity began at early exponential growth phases; maximum activity was reached at the stationary phase. Scavenging effects on 2, 2-Diphenyl-1-picrylhydrazyl (DPPH), the hydroxyl and superoxide radicals, T-AOC capacity and protection against lipid damage were evaluated. The main antioxidant compounds were in the extracellular secreted supernatant of XJ-25. The active compounds were very stable at a pH range of 2 to 12, and temperature from 40 to 121°C, as well as in some organic solvents. Thin layer chromatography assay by DPPH scavenging assay showed two active spots with a Rf values of 0.35 and 0.47, and both of them were ninhydrin positive.

 

Key words: Antioxidant activity, Bacillus simplex, TLC, bacteria, sand soil biological crusts.