Isolation and characterization of indigenous bacterial assemblage for biodegradation of persistent herbicides in the soil

Mariam Zameer; Usaal Tahir; Sana Khalid; Nureen Zahra; Abid Sarwar; Tariq Aziz; Ahsan Saidal; Majid Alhomrani; Abdulhakeem S. Alamri; Anas S. Dablool; Manal Y. Sameeh; Amal A. Mohamed; Amnah Alharbi

doi:10.18388/abp.2020_6563

Mariam Zameer Institute of Molecular Biology and Biotechnology, The University of Lahore, 54000, Punjab Pakistan
Usaal Tahir Institute of Molecular Biology and Biotechnology, The University of Lahore, 54000, Punjab Pakistan
Sana Khalid College of Earth and Environmental Sciences, University of the Punjab, Lahore, 54000, Punjab Pakistan
Nureen Zahra Institute of Molecular Biology and Biotechnology, The University of Lahore, 54000, Punjab Pakistan
Abid Sarwar Food and Biotechnology Research Center, PCSIR Labs Complex Lahore 54600, Punjab Pakistan
Tariq Aziz Institute of Basic Medical Sciences Khyber Medical University Peshawar 25120, Pakistan
Ahsan Saidal Institute of Basic Medical Sciences Khyber Medical University Peshawar 25120, Pakistan
Majid Alhomrani Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
Abdulhakeem S. Alamri Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
Anas S. Dablool Department of Public Health, Health Sciences College Al-Leith, Umm Al-Qura University, Makkah, Saudi Arabia, 24382, Saudi Arabia
Manal Y. Sameeh Chemistry Department, Al-Leith University College, Umm Al-Qura University, Makkah 24831, Saudi Arabia
Amal A. Mohamed Chemistry Department, Al-Leith University College, Umm Al-Qura University, Makkah 24831, Saudi Arabia
Amnah Alharbi Department of Biochemistry, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia

DOI: https://doi.org/10.18388/abp.2020_6563

Abstract

Abstract: Extensive pesticides (herbicides) use is negatively disturbing the environment and humans. Pesticide bioremediation with eco-friendly techniques bears prime importance. This study aimed to isolate and characterize three different herbicides (metribuzin, clodinafop- propargyl, MCPA (2-methyl, 4 chlorophenoxyacetic acids) and Bromoxynil) degrading bacterial strains from agricultural fields of Punjab University, Pakistan. Among the 12 bacterial isolates, 5 were metribuzin degrading, 3 were clodinafop propargyl degrading and, 4 were MCPA and Bromoxynil degrading bacteria. Morphological, microscopic, and molecular characterization revealed that the majority of these bacterial strains were gram-negative and belonged to Bacillus and Pseudomonas genera. The isolates A6, B3, and C1 were subjected to respective herbicide degradation and the data was confirmed through GC-MS analysis. The effect of herbicide concentrations, pH, and temperature on bacterial growth was determined at OD600. The strain A6 degraded 14.8% metribuzin out of the provided concentration of 50 ppm by following the deamination pathway. While the isolates B3 and C1 degraded 23.2% and 33.9% clodinafop, MCPA and bromo-xynil, respectively, at a spiking concentration of 50ppm. The clodinafop, MCPA and Bromoxynil were metabolized into less toxic products i.e., dicarboxylic acids and 2-methyl phenol respectively, and metabolized via decarboxylation and dehalogenation mechanism. The present study evaluates the herbicides degrading bacterial strains that could potentially be used for bioremediation of agricultural contaminated sites.