Degradation of Acephate and Its Intermediate Methamidophos: Mechanisms and Biochemical Pathways

Front. Bioeng. Biotechnol.

Pang

et al. 2021

Self Cite

176

Global environmental contamination with a complex mixture of xenobiotics has become a major environmental issue worldwide. Many xenobiotic compounds severely impact the environment due to their high toxicity, prolonged persistence, and limited biodegradability. Microbial-assisted degradation of xenobiotic compounds is considered to be the most effective and beneficial approach. Microorganisms have remarkable catabolic potential, with genes, enzymes, and degradation pathways implicated in the process of biodegradation. A number of microbes, including Alcaligenes, Cellulosimicrobium, Microbacterium, Micrococcus, Methanospirillum, Aeromonas, Sphingobium, Flavobacterium, Rhodococcus, Aspergillus, Penecillium, Trichoderma, Streptomyces, Rhodotorula, Candida, and Aureobasidium, have been isolated and characterized, and have shown exceptional biodegradation potential for a variety of xenobiotic contaminants from soil/water environments. Microorganisms potentially utilize xenobiotic contaminants as carbon or nitrogen sources to sustain their growth and metabolic activities. Diverse microbial populations survive in harsh contaminated environments, exhibiting a significant biodegradation potential to degrade and transform pollutants. However, the study of such microbial populations requires a more advanced and multifaceted approach. Currently, multiple advanced approaches, including metagenomics, proteomics, transcriptomics, and metabolomics, are successfully employed for the characterization of pollutant-degrading microorganisms, their metabolic machinery, novel proteins, and catabolic genes involved in the degradation process. These technologies are highly sophisticated, and efficient for obtaining information about the genetic diversity and community structures of microorganisms. Advanced molecular technologies used for the characterization of complex microbial communities give an in-depth understanding of their structural and functional aspects, and help to resolve issues related to the biodegradation potential of microorganisms. This review article discusses the biodegradation potential of microorganisms and provides insights into recent advances and omics approaches employed for the specific characterization of xenobiotic-degrading microorganisms from contaminated environments.

Section: Bioremediation Potential Of Microorganisms For Xenobiotic Comentioning

confidence: 99%

Recent Advanced Technologies for the Characterization of Xenobiotic-Degrading Microorganisms and Microbial Communities

Mishra

Front. Bioeng. Biotechnol.

Pang

et al. 2021

Self Cite

176

“…Many different enzymatic processes are involved in biodegradation by microorganisms, including hydroxylation, demethylation, dechlorination, and oxidation (Liu et al, 2020;Bhatt et al, 2021e). Different biodegradation processes are associated with different enzymes, such as hydrolases, esterases, dehydrogenases, laccases, and lignin peroxidases (Maqbool et al, 2016;Lin et al, 2020;Mishra et al, 2020). The reported enzymes involved in the initial degradation of PUHs are amidohydrolases or amidases, which are summarized in Table 3, and a phylogenetic tree (amino acid sequences) of the key initial hydrolytic enzymes is shown in Figure 4.…”

Section: Functional Enzymes and Genes Involved In Diuron Degradationmentioning

confidence: 99%

“…Bioaugmentation is considered an efficient way to remediate DUR-polluted sites by introducing specific degrading microorganisms ( Cycoń et al, 2017 ; Arora et al, 2018 ; Feng et al, 2020 ; Lin et al, 2020 ). Although a considerable number of DUR-degrading microorganisms have been isolated, identified, and characterized and their metabolic mechanisms have been elucidated, their ability to remediate DUR-contaminated environmental matrices, such as water, soil, and subsurface material, remains a major challenge ( Huang et al, 2017 ).…”

Section: Preventive Bioremediation Using Diuron-degrading Microorganismsmentioning

confidence: 99%

Emerging Strategies for the Bioremediation of the Phenylurea Herbicide Diuron

Zhang

et al. 2021

Front. Microbiol.

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Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.

“…The biodegradation of imidacloprid by different types of bacteria was first reported in 2007 [114], when it was shown that the Leifsonia strain PC-21 co-metabolized imidacloprid and degraded 37-58% of 25 g•L −1 of imidacloprid in a trypsin solution containing 1 g•L −1 succinic acid and d-glucose in 3 weeks at 27 • C [114]. The increasing use of potentially dangerous chemicals in agriculture has led to increased concern for the environment and public health, but the use of biological control strategies is a risk-free and economically viable approach [115][116][117][118][119]. Soil organic matter is the main adsorption medium of imidacloprid, and the microorganisms in the soil can effectively degrade imidacloprid.…”

Section: Degradation Of Imidacloprid By Microbial Strainsmentioning

confidence: 99%

Insights into the Toxicity and Degradation Mechanisms of Imidacloprid Via Physicochemical and Microbial Approaches

Pang

Zhang

et al. 2020

Toxics

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Imidacloprid is a neonicotinoid insecticide that has been widely used to control insect pests in agricultural fields for decades. It shows insecticidal activity mainly by blocking the normal conduction of the central nervous system in insects. However, in recent years, imidacloprid has been reported to be an emerging contaminant in all parts of the world, and has different toxic effects on a variety of non-target organisms, including human beings, due to its large-scale use. Hence, the removal of imidacloprid from the ecosystem has received widespread attention. Different remediation approaches have been studied to eliminate imidacloprid residues from the environment, such as oxidation, hydrolysis, adsorption, ultrasound, illumination, and biodegradation. In nature, microbial degradation is one of the most important processes controlling the fate of and transformation from imidacloprid use, and from an environmental point of view, it is the most promising means, as it is the most effective, least hazardous, and most environmentally friendly. To date, several imidacloprid-degrading microbes, including Bacillus, Pseudoxanthomonas, Mycobacterium, Rhizobium, Rhodococcus, and Stenotrophomonas, have been characterized for biodegradation. In addition, previous studies have found that many insects and microorganisms have developed resistance genes to and degradation enzymes of imidacloprid. Furthermore, the metabolites and degradation pathways of imidacloprid have been reported. However, reviews of the toxicity and degradation mechanisms of imidacloprid are rare. In this review, the toxicity and degradation mechanisms of imidacloprid are summarized in order to provide a theoretical and practical basis for the remediation of imidacloprid-contaminated environments.