Biodegradation of Benzo(a)pyrene by Marine Denitrifying Bacteria

Abstract

This research presented the successfully ability of denitrifying bacteria for degradation of benzo(a)pyrene , a five fused ring of polycyclic aromatic hydrocarbons. The experiments were started from the collection of marine sediments from Chonburi province, Thailand. Then, these sediments were screened for the existing of denitrifying bacteria by nitrate reduction ability to alpha-naphthylamine. The result found that 8 isolations of denitrifying bacteria were achieved from total of 40 bacterial isolations screened from 23 of marine sediments. These selected denitrifying bacteria were further applied to degrade of 200 ppm of initially concentration of benzo(a)pyrene contamination in liquid media. The remediation process was incubated under the anoxic condition for more than 50 days. The result showed the complete biodegradation of benzo(a)pyrene by denitrification process within 45 days. Finally, the obtained denitrifying bacteria isolations were genetically identified by 16 s RNA and result was indicated that one of them was Bacillus subtilis specie.