About this Research Topic
Polycyclic aromatic hydrocarbons (PAHs) are a large and diverse group of organic, hydrocarbon molecules with two or more fused benzene rings in linear, angular or cluster formation. These environmental pollutants have either anthropogenic origin, like oil spillage or automobile exhaust, or are produced naturally by e.g. forest fires. The high molecular weight PAHs (composed of four or more aromatic rings) are reported to be very potent carcinogens and mutagens, toxic to human health; and their removal from the environment is therefore essential. This can be carried out through different remediation processes, such as chemical oxidation, photocatalytic oxidation, volatilization and sedimentation, or bioremediation using microorganisms.
Various bacterial genera, for instance Pseudomonas, Serratia, Bacillus, Burkholderia, or Ralstonia, are known to metabolize PAHs. The advantage of using bioremediation for PAHs degradation is the degradation of complex organic compounds to simple molecules, such as organic acids or carbon dioxide, which can be incorporated into the natural biogeochemical cycles or utilized by the microorganisms.
Concerning the effects of PAHs contamination on human’s health and environment, there is undeniably an urgent need of effective and sustainable technologies that may substantiate on-site remediation of PAHs. Their biodegradation is carried out by applying selected microorganism, or consortium of microorganisms on the contaminated site.
Numerous current approaches in genomic, transcriptomic and metabolomics studies have strengthened the concepts of microbial genetics and metabolite modelling for hydrocarbons biodegradation. Recent technologies, such as Next Generation Sequencing (NGS) or Stable Isotope Probing (SIP) have enriched our knowledge of the microbial, functional and metabolic diversity involved in the degradation of hydrocarbons in soil/water, and the effect bioaugmentation might have on the native community of microbes. Furthermore, the research on the contribution of uncultured microbial communities to the PAH biodegradation is of great significance, as these may play an important role in this process.
We hope this Research Topic to be useful for the environmental biotechnologists and microbiologists who are working on analysing the consequences of PAH pollution and finding solutions for the environments which are highly contaminated by PAHs.
We welcome papers addressing different aspects of strategies for PAH biodegradation, the merits of existing technologies and improvements in efficiency. Authors are invited to submit original research articles, reviews or opinion papers. The themes covered in this Research Topic include the following:
1. Role of aerobic/anaerobic bacteria, archaebacteria and fungi in catabolism / co-metabolism of high molecular weight PAHs.
2. Molecular mechanisms of microbial high molecular weight PAH degradation; bioavailability, genetics, pathways, enzymes, and their application.
3. Biodegradation of high molecular weight PAHs in soil and marine / freshwater environments, specifically in water columns and sediments.
4. Functional gene analysis and dynamics of microbial communities associated with high molecular weight PAH contaminated environments.
5. Engineering strategies to construct efficient high molecular weight PAH degraders.
All submitted manuscripts should present a clear hypothesis; merely descriptive papers will be considered out of scope.
Keywords: Polyaromatic hydrocarbons, dioxygenases, microbial degradation, phytoremediation, bioaugmentation, pathways, microbiome
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.