African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12191

Full Length Research Paper

Behavioral response of resistant and sensitive Pseudomonas aeruginosa S22 isolated from Sohag Governorate, Egypt to cadmium stress

El-Sayed, M. Soltan1, Rehab, M. Mohamed1 and Ahmed, A. Shoreit2*
1Sohag University, Faculty of Science, Botany Department, Egypt. 2Assiut University, Faculty of Science, Botany Department, Egypt.
Email: [email protected]

  •  Accepted: 21 March 2008
  •  Published: 18 July 2008

Abstract

A total of 62 Pseudomonas isolates were selected from a contaminated site at Sohag district and tested for their resistance tto cadmium metal. Isolate no. 22 was found to be the most resistant one and has a plasmid with molecular wt27.491 Kbp. The minimal inhibition concentrations (MIC) for the resistant (R) and adopted sensitive (S) isolates were 1.0 and 0.119 mmol L-1, respectively. The growth, protein content and maximum specific growth rate (k) decreased with increasing concentrations of heavy metal. The generation time (T) increased with the addition of divalent cations (Fe2+, Mg2+ and Ca2+) plus cadmium. Under cadmium stress, three proteins of high molecular weights (208, 78 and 33.5 KD) were lost while one protein with low molecular weight (2.5 KD) was induced. LPS profile was modified under stress of CdCl2. Absence of bands in region I, which represents the O-specific antigen, and region II (core-oligosaccharide linked to lipid A) were recorded at high concentrations of CdCl2.

Key words: Pseudomonas aeruginosa, cadmium stress, heavy metal resistance.