Researchers identify fungus for pyrene remediation

New Delhi: Researchers at the Council of Scientific & Industrial Research-Indian Institute of Petroleum (CSIR-IIP), Dehradun, have identified a fungus capable of removing toxic, recalcitrant, and carcinogenic polycyclic aromatic hydrocarbons (PAHs) from the environment.

The rapid pace of economic development and industrialisation has resulted in the release of several PAHs into the environment. The PAHs are ubiquitous environmental pollutants originating from multiple sources, including combustion of petrogenic fossil fuels, and incomplete incineration of municipal wastes and biomass.

Pyrene, possessing four benzene rings, belongs to the highly toxic class of PAHs, with carcinogenic and mutagenic properties. It gets lodged into the environmental matrices like soil, water and atmosphere, resulting in widespread environmental pollution, necessitating adequate remediation of contaminated environmental matrices.

The researchers at IIP identified a white-rot fungus Trametes maxima IIPLC-32 which has the potential to cause microbial degradation of pyrene. According to researchers, growing on dead plants, this fungus causes pyrene degradation using special enzymes.

The researchers used gas chromatographic-mass spectrometer and serotome analysis for their study. Gas chromatographic-mass spectrometric identification of prominent metabolites helped determine the pyrene degradation pathway. As found by researchers, the pyrene concentration decreased by 79.8 percent, 65.37 percent and 56.37 percent within 16 days from the initial levels of 10 mg per litre, 25 mg per litre and 50 mg per litre, respectively. The serotome analysis revealed the presence of 81 extracellular proteins. Knowledge of serotome analysis in pyrene degradation helped understand the degradation mechanism of pyrene.

“The rapid pace of economic development and industrialisation has resulted in an increased level of pollution in the environment. To combat this pollution, resources are already present in the environment, which must be appropriately tapped by us,” said Anjan Ray, Director, CSIR-IIP.

It may be noted that among the pollutants found in the soil, many PAHs are also present. The fungus identified by the researchers can cause microbial degradation, thereby improving the soil quality. “This fungus acts to decrease the pollution level of the soil,” says Pankaj Kanaujia, a member of the research team.

As revealed by the study, the fungus T.maxima may prove to be helpful in the remediation of especially pyrene. The recommendation from the study is that T.maxima IIPLC-32 can be tried in the future for the bioremediation of PAH-contaminated aquatic environments.

The study has been published in the peer-reviewed, Environmental Science and Pollution Research journal.

Besides Anjan Ray, other research team members included Arfin Imam, Sunil Kumar Suman, Bhanu Prasad Vempatapa, Deependra Tripathi and Pankaj K. Kanaujia. 

(India Science Wire)