Abstract

This study was carried out to isolate and identify indigenous bacteria associated with pesticides heavily contaminated soil in Sudan. The samples were collected from pesticides contaminated soil in different locations. The predominant bacterial isolates were then purified by subculturing on selective media. Seven isolates were selected based on their capability to degrade pesticides and three of them having the highest performance in biodegradation of frequently reported pesticide contaminants were subject to identification by molecular tools using 16S rDNA gene sequence analysis. Amplification of 16S rDNA gene was done from genomic DNA and sequenced. Construction of phylogenetic tree was done after aligning of multiple sequences. The results reveal that the three bacterial isolates are Bacillus cereus ATCC 14579, Bacillus subtilis subsp. inaquosorum KCTC 13429 and Bacillus safensis FO-36b. This is the first record of pesticides biodegradation by B. safensis FO-36b which can be considered as a novel contribution in this field. Since these strains were found effective and are living naturally in an environment heavily contaminated with pesticides, therefore, they might have potential in removing pesticides from contaminated soils, especially soils of pesticide stores and dumping sites in developing countries.

Key words: Bacillus, gene sequencing, pesticides-polluted soil, Sudan.