EXISTENCE OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) DEGRADING BACTERIA IN COAL SAMPLES.

This study is conducted to isolate polycyclic aromatic hydrocarbons (PAHs) degrading bacteria from coal samples of an opencast coalmine. In this study five PAHs degrading bacteria were isolated on minimal salt medium (MSM) that priory enriched with a PAHs compound, phenanthrene. Lytic zone formations on MSM agar during culture growth also confirmed the PAHs degradation. Microscope assisted methods revealed the nature of cell type and Gram reaction type of the isolates as two are Gram-positive and three are Gram-negative and all are rod shaped bacteria. The isolates screened for their ability to grow on MSM broth that supplemented with three test PAHs compounds phenanthrene, anthracene or pyrene as sole source of carbon. In this assay, the isolates exhibited good range of growth on the tested three PAHs. Under morphological characterization and biochemical characterization the isolates recorded significant differentiation. Production of different enzymes on specific media determined as per standard protocols for the bacteria. Finally, the isolates characterized at molecular level by sequencing 16S rDNA genes. The isolated bacteria identified by the compilation of morphological, biochemical and molecular characterization data as Bacillus thuringiensis KMM1, Achromobacter xylosoxidans KMM2, Bacillus cereus KMM3, Alcaligenes faecalis KMM4 and Brevibacillus laterosporus KMM5.