Biotransformation of pyrene in soil in the presence of earthworm Eisenia fetida

Pyrene, a toxic four benzene ring polycyclic aromatic hydrocarbons (PAHs) that persists in the environment, is highly resistant to degradation. Hence, this study aims to investigate the pyrene degradation by the combination of earthworm (Eisenia fetida) and some microbes in the soil. The artificially contaminated soil (200 g) was prepared in a container box by the addition of pyrene and combined with the addition of the earthworms and some microbes. The results showed that no mortality of earthworms in all soil conditions. The largest amount of pyrene (68.7%) was removed by earthworm microbes in the unsterilized soil. Twelve enzymes were produced such as peroxidase, laccase, invertase, glucosidase, phosphatase, phytase, urease, hydrolase, chitinase, nitrogenase, aminopeptidase, and arylsulfatase. The combination of earthworm and microbes transformed pyrene to protocatechuic acid via pyrene-4,5-dione, phenanthrene-4,5-dicarboxylic acid, and phenanthrene-4-carboxylic acid. But, these compounds were not confirmed in our extract.