ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING, PHENOL- AND CATECHOL-DEGRADING PSEUDOMONAS PUTIDA STRAIN AMR-12 IN SOILS
FROM EGYPT
M. ABD. ABDEL-MONGY 1, M. S. SHUKOR 2, S. HUSSEIN 3, A. P. K. LING 4*, N. A. SHAMAAN 5, M. Y. SHUKOR 2, 6 1. Sadat City University, Genetic Engineering and Biotechnology Institute, Microbial Biotechnology Department, Egypt
2. Snoc International Sdn Bhd, Lot 343, Jalan 7/16 Kawasan Perindustrian Nilai 7, Inland Port, 71800, Negeri Sembilan, Malaysia
3. Malaysian Nuclear Agency, Agrotechnology and Bioscience Division, Bangi, Malaysia
4. International Medical University, Department of Applied Biomedical Science and Biotechnology, 57000 Kuala Lumpur, Malaysia
5. Islamic Science University of Malaysia, Faculty of Medicine and Health Sciences, 55100 Kuala Lumpur, Malaysia
6. Universiti Putra Malaysia, Faculty of Biotechnology and Biomolecular Sciences, Department of Biochemistry, UPM 43400 Serdang, Selangor, Malaysia
*Corresponding author: anna_ling@imu.edu.my
Sites contaminated with both heavy metals and organic xenobiotic pollutants warrants the effective use of either a multitude of bacterial degraders or bacteria having the capacity to detoxify numerous toxicants simultaneously. A molybdenum-reducing bacterium with the capacity to degrade phenolics is reported. Molybdenum (sodium molybdate) reduction was optimum between pH 6.0 and 7.0 and between 20 and 30 °C. The most suitable electron donor was glucose. A narrow range of phosphate concentrations between 5.0 and 7.5 mM was required for optimal reduction, while molybdate between 20 and 30 mM were needed for optimal reduction. The scanning absorption spectrum of the molybdenum blue produced indicated that Mo-blue is a reduced phosphomolybdate. Molybdenum reduction was inhibited by the heavy metals mercury, silver and chromium. Biochemical analysis identified the bacterium as Pseudomonas putida strain Amr-12. Phenol and phenolics cannot support molybdenum reduction. However, the bacterium was able to grow on the phenolic compounds (phenol and catechol) with observable lag periods. Maximum growth on phenol and catechol occurred around the concentrations of 600 mgâL-1. The ability of this bacterium to detoxify molybdenum and grown on toxic phenolic makes this bacterium an important tool for bioremediation.