Molecular perspectives and recent advances in microbial remediation of persistent organic pollutants

Abstract

Nutrition and pollution stress stimulate genetic adaptation in microorganisms and assist in evolution of diverse metabolic pathways for their survival on several complex organic compounds. Persistent organic pollutants (POPs) are highly lipophilic in nature and cause adverse effects to the environment and human health by biomagnification through the food chain. Diverse microorganisms, harboring numerous plasmids and catabolic genes, acclimatize to these environmentally unfavorable conditions by gene duplication, mutational drift, hypermutation, and recombination. Genetic aspects of some major POP catabolic genes such as biphenyl dioxygenase (bph), DDT 2,3-dioxygenase, and angular dioxygenase assist in degradation of biphenyl, organochlorine pesticides, and dioxins/furans, respectively. Microbial metagenome constitutes the largest genetic reservoir with miscellaneous enzymatic activities implicated in degradation. To tap the metabolic potential of microorganisms, recent techniques like sequence and function-based screening and substrate-induced gene expression are proficient in tracing out novel catabolic genes from the entire metagenome for utilization in enhanced biodegradation. The major endeavor of today's scientific world is to characterize the exact genetic mechanisms of microbes for bioremediation of these toxic compounds by excavating into the uncultured plethora. This review entails the effect of POPs on the environment and involvement of microbial catabolic genes for their removal with the advanced techniques of bioremediation.

Poaceae with PGPR Bacteria and Arbuscular Mycorrhizae Partnerships as a Model System for Plant Microbiome Manipulation for Phytoremediation of Petroleum Hydrocarbons Contaminated Agricultural Soils

“…These characteristics of increased plant growth by endophyte microorganisms facilitate adaptation to abiotic stress factors and increase the biomass of Oloptum and Pennisetum, making it suitable for phytoremediation. The absorption of TPH by two species of Poaceae is controlled by the hydrophobicity of these organic pollutants [50]. The plant roots before their degradation discreetly absorb hydrophobic complexes by microflora rhizosphere.…”

Bacterial communities in natural versus pesticide‐treated Aphis gossypii populations in North China

“…There were some types that are probably involved in insect resistance to pesticides, such as Acinetobacter, which was isolated from the midgut of a pesticide-resistant H. armigera (Malhotra et al, 2012), and Chryseobacterium isolated from the pyridaben-resistant population of Tetranychus urticae (Yoon et al, 2010). Many pesticides can be degraded by Kocuria, Nocardioides or Pseudonocardia (Bostanian & Akalach, 2006;Chakraborty & Das, 2016;Kumar, Kumar, & Sharma, 2016).…”

Soil Microorganisms and Their Potential in Pesticide Biodegradation; A Review Article

“…Genetic components like the plasmid and transposons were ascertain to have encode enzymes responsible for several pesticides degradation. The isolation and characterization of gene encoding pesticides degradative enzymes as well as novel procedures for isolating and analysis of nucleic acid from microorganisms, would display some distinctive insight into the molecular actions that lead to advance of pesticides degradation phenomena (Chakraborty and Das, 2016). Genetic manipulation offers a technique of engineering microbes to depollute many compounds, including pesticides that may be present in the polluted areas.…”

“…Degradation of pesticide by microorganism involves several forms of enzymes. These approaches are based on several kinds of genes coded with plasmid or chromosomal DNA (Chakraborty and Das, 2016). Pesticide degrading genes in microorganisms have were described to be located on plasmids, transposons or chromosomes of the organism.…”