Bioremediation of nitrogen‐containing organic pollutants using phenol‐stimulated activated sludge: performance and microbial community analysis

J of Chemical Tech & Biotech

et al. 2020

Self Cite

BACKGROUND Quinoline is an ubiquitous pollutant widely spread in the environment, which can be eliminated efficiently by microbial degradation. In this study, two quinoline‐degrading Comamonas sp. strains Z1 and Z3 were isolated from activated sludge, and the degradation characteristics and genome annotation were investigated in detail. RESULTS Strain Z1 exhibited a superior capacity for quinoline degradation, which could completely degrade 50–300 mg L−1 quinoline within 8–24 h, whereas strain Z3 required 14–36 h to remove 50–200 mg L−1 quinoline. The suitable pHs for strains Z1 and Z3 were 8.0 and 7.0, respectively, and metal ions such as Mn2+, Ni2+, Cu2+, Co2+ and Hg2+ could greatly inhibit bacterial growth and quinoline degradation. Intermediates of 2‐hydroxyquinoline, 2,8‐dihydroxyquinoline, 8‐hydroxycoumarin, 2,3‐dihydroxyphenylpropionic acids and 2‐hydroxy‐6‐oxonona‐2,4‐diene‐1,9‐dioate were detected by liquid chromatography coupled to Q‐Exactive high‐resolution mass spectrometry. Thus, the biodegradation of quinoline by Comamonas sp. strains possibly proceeded via the 8‐hydroxycoumarin pathway. Genomic sequencing of strains Z1 and Z3 revealed a similar pattern, and a large number of functional genes were predicted to participate in degradation of aromatics. The key genes responsible for quinoline degradation also were identified, such as qor, mhp and bph. Furthermore, quinoline 2‐oxidoreductase (Qor) from strains Z1 and Z3 displayed 47.74%–61.17% similarities with previously reported Qor, which catalyzed the first step of quinoline degradation, and the maximal specific activity in cell‐free extracts of strains Z1 and Z3 was 0.264 and 0.062 U mg protein−1, respectively. CONCLUSION This study should provide efficient microbial resources and useful genomic information for quinoline bioremediation. © 2020 Society of Chemical Industry

Section: Methodsmentioning

confidence: 99%

Comparative characterization and functional genomic analysis of two Comamonas sp. strains for biodegradation of quinoline

J of Chemical Tech & Biotech

et al. 2020

Self Cite

“…Residual indole was determined by high-performance liquid chromatography (HPLC) using Agilent 1290 infinity instruments (Agilent Technology, Santa Clara, CA, USA) equipped with a Hypersil ODS2 column (5 m, 250 × 4.6 mm), which was conducted as described previously. 21 TOC concentrations were measured by Multi N/C 2100 TOC Analyzer (Analytik Jena, Jena, Germany), and nitrogen components (i.e. NO 3 − -N, NO 2 − -N and NH 4 + -N) were determined using standard laboratory methods.…”

Section: Methodsmentioning

confidence: 99%

“…Indole-degrading bacteria were isolated from the activated sludge of sequencing batch reactors (SBRs), which were previously constructed in the lab for bioremediation of nitrogen-containing organic pollutants. 21 Briefly, the activated sludge samples were serially diluted and cultivated on MSM agar plates supplemented with 100 mg L −1 indole. After 3 days of incubation, the colonies were picked out and cultured in MSM with 100 mg L −1 indole.…”

Section: Isolation and Identification Of Indole-degrading Bacteriamentioning

confidence: 99%

“…In our previous study, the SBRs showed good capacity for removal of nitrogen-containing organic pollutants (indole, pyridine and quinoline), and the indigenous bacterial communities played key roles in pollutants removal. 21 Herein, an efficient indole-degrading strain, designated as JW, was isolated from the activated sludge of SBRs. It was a Gram-negative, aerobic and short rod-shaped bacillus with a width of 0.3-0.5 m and length of 0.7-1.0 m ( Fig.…”

Section: Isolation and Identification Of Strain Jwmentioning

confidence: 99%

“…In our previous study, phenol-stimulated activated sludge was constructed for aerobic treatment of nitrogen-containing organic pollutants, and it maintained high efficiency (>99%) for indole removal during long-term operation (90 days). 21 Herein, the activated sludge was used for the screening and isolation of indole-degrading bacterial strains. The indole biodegradation characteristics were investigated and the intermediate metabolites were identified.…”

Section: Introductionmentioning

confidence: 99%

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Biodegradation characteristics and genomic functional analysis of indole‐degrading bacterial strain Acinetobacter sp. JW

Jing

J of Chemical Tech & Biotech

et al. 2018

Self Cite

BACKGROUND Indole, an important type of N‐heterocyclic aromatic compound, is considered a toxic and odorous pollutant in coking and municipal wastewater. For efficient bioremediation of indole‐containing wastewater, an indole‐degrading bacterial strain JW was isolated from activated sludge in this study. The indole biodegradation characteristics and the whole‐genome sequence of strain JW were also determined. RESULTS Strain JW, capable of utilizing indole as the sole carbon and nitrogen source, was identified as Acinetobacter sp. based on 16S rRNA gene sequence analysis. It was able to completely degrade 100 mg L−1 indole within 20 h, and transform organic nitrogen to ammonia (NH4+‐N) and nitrate (NO3−‐N). Meanwhile, strain JW also presented high capacity for indole degradation at a range of initial indole concentrations (25–200 mg L−1) and pH (6.0–8.0). The key metabolites during indole biodegradation were identified by liquid chromatography coupled to Q‐Exactive high resolution mass spectrometry, and included isatin, anthranilate, salicylate, catechol and indigo. The whole‐genome sequence of strain JW revealed the possible functional genes related to indole biodegradation, such as iif genes, ant genes and downstream metabolic genes. Thus, an indole biodegradation mechanism was proposed based on metabolites identification and genomic analysis. CONCLUSION The results suggested that Acinetobacter sp. JW could be a promising biological candidate for bioremediation of indole, and the useful genetic information might enrich our understanding of microbial degradation of indole. © 2018 Society of Chemical Industry

Recent Advance of Atomically Dispersed Dual‐Metal Sites Carbocatalysts: Properties, Synthetic Materials, Catalytic Mechanisms, and Applications in Persulfate‐Based Advanced Oxidation Process

Wei

Cui

et al. 2023

Adv Funct Materials

Recently, atomically dispersed dual‐metal sites carbocatalysts (DMSCs) make a wave in the field of persulfate‐based advanced oxidation processes (PS‐AOPs) in light of their ≈100% atomic utilization efficiency, high density of active sites, and superior catalytic activity. This review aims to provide a state‐of‐the‐art overview on the development of DMSCs for activating PS. Initially, the types and properties of DMSCs are summarized, as well as the role of doping different heteroatoms is discussed. Subsequently, the properties of different carbon carriers and the methods for the synthesis of DMSCs are outlined. After that, the mechanism and application of DMSCs for the activation of PS toward organic contaminants degradation are revealed. Particularly, the mechanism of nonradical pathway is described, and the necessity of coupling DMSCs‐based PS‐AOPs to other processes for practical water treatment is emphasized. Finally, the formidable challenges and future research directions of DMSCs are proposed. This review is expected to provide insight into the preparation of DMSCs in the field of nanomaterials and to broaden the path for their environmental applications.