Aerobic and Anaerobic Bacterial and Fungal Degradation of Pyrene: Mechanism Pathway Including Biochemical Reaction and Catabolic Genes

Abstract

Microbial biodegradation is one of the acceptable technologies to remediate and control the pollution by polycyclic aromatic hydrocarbon (PAH). Several bacteria, fungi, and cyanobacteria strains have been isolated and used for bioremediation purpose. This review paper is intended to provide key information on the various steps and actors involved in the bacterial and fungal aerobic and anaerobic degradation of pyrene, a high molecular weight PAH, including catabolic genes and enzymes, in order to expand our understanding on pyrene degradation. The aerobic degradation pathway by Mycobacterium vanbaalenii PRY-1 and Mycobactetrium sp. KMS and the anaerobic one, by the facultative bacteria anaerobe Pseudomonas sp. JP1 and Klebsiella sp. LZ6 are reviewed and presented, to describe the complete and integrated degradation mechanism pathway of pyrene. The different microbial strains with the ability to degrade pyrene are listed, and the degradation of pyrene by consortium is also discussed. The future studies on the anaerobic degradation of pyrene would be a great initiative to understand and address the degradation mechanism pathway, since, although some strains are identified to degrade pyrene in reduced or total absence of oxygen, the degradation pathway of more than 90% remains unclear and incomplete. Additionally, the present review recommends the use of the combination of various strains of anaerobic fungi and a fungi consortium and anaerobic bacteria to achieve maximum efficiency of the pyrene biodegradation mechanism.

Bioremediation of Soil from Petroleum Contamination

“…Alkanes having short (C5-C9) carbon chains are often toxic, since they can dissolve microbial cell membranes; hence, they are metabolized by a limited number of bacterial and fungal species, including yeast [89,112]. The concurrent presence of microbes enhances the biodegradation [116][117][118].…”

A Review on Bacterial Degradation of Benzo[a]pyrene and Its Impact on Environmental Health

“…These PAHs pollutants harm our lives and, some have less beneficial effects on the environment and human health (Jong-Su et al 2009). PAHs are used as raw materials for the manufacture of all hydrocarbons which generate toxic environmental pollutants due to natural and anthropogenic activities (Elyamine et al 2021). Millions of tonnes of hydrocarbon products spill into soil and water bodies due to oil spills and vehicle emissions (Stogiannidis and Laane 2015) and the major amount of oil spill sites have hazardous conditions for human health and the environment.…”

“…Biological, chemical, and physical remediation are used for decontamination of benzo [a]pyrene, and one of the best methods for microbial degradation, is bioremediation, the most cost-effective and eco-friendly method (Jong-Su et al 2009;Wang et al 2018). Breakdown of benzo[a]pyrene, is a mineralization and conversion process and various aerobic and anaerobic bacteria species contribute to this process (Elyamine et al 2021). Multiple microorganisms and their species have been discovered, which have degraded highly stable and waste polycyclic hydrocarbons.…”

“…In biodegradation mechanisms, enzyme attacks on benzo[a]pyrene rings in the presence of oxygen molecules are called aerobic metabolism. As a first step, the dioxygenase-enzyme helps catabolize oxidation of arenes (organic molecules made from C, H, atoms) which occur in an aerobic environment bacterial metabolic activity to concern for cisdihydrodiols, catechol(Elyamine et al 2021), that is an early product (cis-dihydrodiols, catechol) formed by the aerobic bacterial system. This pathway indicates major middle intermediates such as sodium succinate, salicylate, and catechols, which go through intermediates of the tricarboxylic acid (TCA) cycle, in the meta-cleavage pathway, dioxygenase enzyme secretes by bacteria and enzyme attacks on the ortho position of benzo[a]pyrene and intradiol and extradiol product produced during ring cleavage of aromatic compounds(Pimviriyakul et al 2020).…”

MOLECULAR CHARACTERISATION OF BACTERIA MONOOXYGENASE AND DEHYDROGENASE GENES INVOLVED IN PAHs REMEDIATION

“…Aerobic bioconversion/degradation of PAHs is made possible by oxygenase-mediated metabolism (monooxygenase or dioxygenase enzymes). The first step in the aerobic bacterial degradation of PAHs in the environment is the hydroxylation of an aromatic benzene ring through a dioxygenase, forming cis-dihydrodiol that is rearomatized to a diol intermediate by the action of a dehydrogenase (Elyamine et al, 2021;Okolafor & Ekhaise, 2022;Srivastava & Kumar, 2019). Secondly, the diol intermediates are immediately cleaved by intradiol or extradiol ring-cleaving dioxygenases through either an ortho-cleavage or meta-cleavage pathway, resulting in intermediates of catechols which are converted to TCA cycle intermediates (Pérez-Pantoja et al, 2019;Phale et al, 2020).…”