Microbial Degradation of Naphthalene and Substituted Naphthalenes: Metabolic Diversity and Genomic Insight for Bioremediation

Abstract

Low molecular weight polycyclic aromatic hydrocarbons (PAHs) like naphthalene and substituted naphthalenes (methylnaphthalene, naphthoic acids, 1-naphthyl N-methylcarbamate, etc.) are used in various industries and exhibit genotoxic, mutagenic, and/or carcinogenic effects on living organisms. These synthetic organic compounds (SOCs) or xenobiotics are considered as priority pollutants that pose a critical environmental and public health concern worldwide. The extent of anthropogenic activities like emissions from coal gasification, petroleum refining, motor vehicle exhaust, and agricultural applications determine the concentration, fate, and transport of these ubiquitous and recalcitrant compounds. Besides physicochemical methods for cleanup/removal, a green and eco-friendly technology like bioremediation, using microbes with the ability to degrade SOCs completely or convert to non-toxic by-products, has been a safe, cost-effective, and promising alternative. Various bacterial species from soil flora belonging to Proteobacteria (Pseudomonas, Pseudoxanthomonas, Comamonas, Burkholderia, and Novosphingobium), Firmicutes (Bacillus and Paenibacillus), and Actinobacteria (Rhodococcus and Arthrobacter) displayed the ability to degrade various SOCs. Metabolic studies, genomic and metagenomics analyses have aided our understanding of the catabolic complexity and diversity present in these simple life forms which can be further applied for efficient biodegradation. The prolonged persistence of PAHs has led to the evolution of new degradative phenotypes through horizontal gene transfer using genetic elements like plasmids, transposons, phages, genomic islands, and integrative conjugative elements. Systems biology and genetic engineering of either specific isolates or mock community (consortia) might achieve complete, rapid, and efficient bioremediation of these PAHs through synergistic actions. In this review, we highlight various metabolic routes and diversity, genetic makeup and diversity, and cellular responses/adaptations by naphthalene and substituted naphthalene-degrading bacteria. This will provide insights into the ecological aspects of field application and strain optimization for efficient bioremediation.

Eco‐physiological portrait of a novel Pseudomonas sp. CSV86: an ideal host/candidate for metabolic engineering and bioremediation

“…and related taxa ( Burkholderia , Sphingomonas , Acinetobacter ). These metabolic pathways have been found to be under the control of substrate‐specific regulatory mechanisms (Phale et al ., 2019; Phale et al ., 2020, Mohapatra and Phale, 2021). Therefore, a thorough metabolic, genomic and eco‐physiological understanding is imperative for designing appropriate strategies for remediation of such contaminants for better sustainability.…”

Plant Growth-Promoting Microbe Mediated Uptake of Essential Nutrients (Fe, P, K) for Crop Stress Management: Microbe–Soil–Plant Continuum

“…and their metabolic complexity and physiology (what are they doing?) (Mohapatra and Phale, 2021 interactions (such as pollutant degradation, bioremediation) within the population and with plant host(s) (Kanaly and Harayama, 2000;Olanrewaju et al, 2019). The PGP microbial communities belong to broad phylogenetic lineages, i.e., Bacteria, Archaea, Algae, and other Eukaryotes (filamentous fungi, yeast, protozoans), but bacterial members are significantly important (Figure 1A, Lugtenberg and Kamilova, 2009;Verma et al, 2019b;Khatoon et al, 2020…”

Investigating the degradation behavior of Cypermethrin (CYP) and Chlorpyrifos (CPP) in peach orchard soils using organic/inorganic amendments

“…Anwar et al (2011) investigated residues (0.031 mg kg −1 ) in peach fruits in Nawab Shah, Sindh, and Shah et al (2011) reported concentration of CYP (1.86 mg kg −1 ) in alkaline soils. Various organic and inorganic amendments were applied to biodegrade different group’s pesticides for various fruits crops ( Mohapatra and Phale, 2021 , Aioub et al, 2019 , Mukherjee, 2009 ). Different studies showed that combined application of organic and inorganic amendments were effective to reduce residual effect of CYP.…”

“…Significant reduction of CPP concentration in soil was observed after 45 days of all tested treatments except soil amended with urea. Various organic and inorganic amendments were successfully applied to biodegrade different groups (organochlorine and organophosphate) pesticides in soil ( Mohapatra and Phale, 2021 , Aioub et al, 2019 , Mukherjee, 2009 ). Combined application of organic and inorganic amendments were remarkably useful to decrease residual consequence of CPP.…”