Bioremediation of a pentacyclic PAH, Dibenz(a,h)Anthracene- A long road to trip with bacteria, fungi, autotrophic eukaryotes and surprises

Dibenz(a,h)Anthracene (DBahA), classified as a probable human carcinogen (B2) is the first Poly Aromatic Hydrocarbons (PAH) to be chemically purified and used for cancer-based studies. Till date, only 30 papers focus on the bioremediation aspects of DBahA out of more than 200 research publications for each of the other 15 priority PAHs. Thus, the review raises an alarm and calls for efficient bioremediation strategies for considerable elimination of this compound from the environment. This article reviews and segregates the available papers on DBahA bioremoval from the beginning till date into bacteria, fungi and plant mediated remediation and offers suggestions for the most competent and cost-effective modes to bio-remove DBahA from the environment. One of the proficient ways to get rid of this PAH could with the use of biosurfactant-enriched bacterial consortium in DBahA polluted environment, which is given considerable importance here. Among the bacterial and fungal microbiomes, unquestionably the former are the beneficiaries which utilize the breakdown products of this PAH metabolized by the latter. Nevertheless, the use of plant communities for efficient DBahA utilization through fibrous root system is also discussed at length. The current status of DBahA as reflected by the publications at https://www.ncbi.nlm.nih.gov and recommendations among the explored groups [bacterial/fungal/plant communities] for better DBahA elimination are pointed out. Finally, the review emphasizes the pros and cons of all the methodologies used for selective/combinatorial removal of DBahA and present the domain to the researchers to carry forward by incorporating their individual ideas. (C) 2018 Published by Elsevier Ltd.