Dataset Information

Enhanced dechlorination and biodegradation of 2-chloroaniline by a 2-aminoanthraquinone-graphene oxide composite under anaerobic conditions.

ABSTRACT: The effect of a 2-aminoanthraquinone-graphene oxide (AQ-GO) composite on the anaerobic dechlorination and degradation of chloroanilines by an enriched bacterial consortium was investigated. The results showed that the maximal degradation efficiency of 20?mg/L 2-chloroaniline (2-CA) reached 91.4% at a dose of 20?mg/L AQ-GO in 30 d. Moreover, the pseudo-first-order rate constant of 2-CA degradation in the AQ-GO-mediated system was 2.9-fold higher than those in AQ- and GO-mediated systems alone. During this process, a synergetic effect between AQ and GO was observed, which was attributed to the increased intracellular and extracellular electron transfer pathways. GC-MS analysis showed that 2-CA could be degraded to hexanoic acid and ultimately mineralized to CO₂. Illumina MiSeq sequencing revealed that additional AQ-GO significantly increased the relative abundance of Firmicutes. Further analysis showed that the populations of the genera Oscillospira, unclassified Lactobacillales, unclassified Veillonellaceae and Ruminococcus exhibited positive correlations with the rate constant of 2-CA degradation and the dehydrogenase activity of bacterial consortium. These findings indicated that AQ-GO promoted the enrichment of functional bacteria and increased the bacterial activity, resulting in the enhanced dechlorination and degradation of 2-chloroaniline.

SUBMITTER: Lu H

PROVIDER: S-EPMC6710426 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Enhanced dechlorination and biodegradation of 2-chloroaniline by a 2-aminoanthraquinone-graphene oxide composite under anaerobic conditions.

Lu Hong H Zhang Tiantian T Zhou Yang Y Zhou Jiti J Wang Jing J Wang Xiaolei X

Scientific reports 20190826 1

The effect of a 2-aminoanthraquinone-graphene oxide (AQ-GO) composite on the anaerobic dechlorination and degradation of chloroanilines by an enriched bacterial consortium was investigated. The results showed that the maximal degradation efficiency of 20 mg/L 2-chloroaniline (2-CA) reached 91.4% at a dose of 20 mg/L AQ-GO in 30 d. Moreover, the pseudo-first-order rate constant of 2-CA degradation in the AQ-GO-mediated system was 2.9-fold higher than those in AQ- and GO-mediated systems alone. Du ...[more]

PMID: 31451740

Similar Datasets

Project description:Anaerobic biodegradation of aromatic compounds under sulfate-reducing conditions is important to marine sediments. Sulfate respiration by a single bacterial strain and syntrophic metabolism by a syntrophic bacterial consortium are primary strategies for sulfate-dependent biodegradation of aromatic compounds. The objective of this study was to investigate the potential of conductive iron oxides to facilitate the degradation of aromatic compounds under sulfate-reducing conditions in marine sediments, using benzoate as a model aromatic compound. Here, in anaerobic incubations of sediments from the Pearl River Estuary, the addition of hematite or magnetite (20 mM as Fe atom) enhanced the rates of sulfate-dependent benzoate degradation by 81.8 and 91.5%, respectively, compared with control incubations without iron oxides. Further experiments demonstrated that the rate of sulfate-dependent benzoate degradation accelerated with increased magnetite concentration (5, 10, and 20 mM). The detection of acetate as an intermediate product implied syntrophic benzoate degradation pathway, which was also supported by the abundance of putative acetate- or/and H2-utilizing sulfate reducers from microbial community analysis. Microbial reduction of iron oxides under sulfate-reducing conditions only accounted for 2-11% of electrons produced by benzoate oxidation, thus the stimulatory effect of conductive iron oxides on sulfate-dependent benzoate degradation was not mainly due to an increased pool of terminal electron acceptors. The enhanced rates of syntrophic benzoate degradation by the presence of conductive iron oxides probably resulted from the establishment of a direct interspecies electron transfer (DIET) between syntrophic partners. In the presence of magnetite, Bacteroidetes and Desulfobulbaceae with potential function of extracellular electron transfer might be involved in syntrophic benzoate degradation. Results from this study will contribute to the development of new strategies for in situ bioremediation of anaerobic sediments contaminated with aromatic compounds, and provide a new perspective for the natural attenuation of aromatic compounds in iron-rich marine sediments.

Project description:Cell proliferation is achieved by numerous enzyme reactions. Temperature governs the activity of each enzyme, which overall determines the optimal growth temperature. Synthesizing useful chemicals and fuels utilizes only part of the metabolic pathways, especially the central metabolic pathways such as glycolysis and TCA cycle to metabolize glucose. However, the optimal temperature for the activity of the central metabolic pathways is inconclusive whether it is correlated with the optimal temperature for cell proliferation. Here, we found that Corynebacterium glutamicum wild type increased the metabolic activity to consume glucose under anaerobic (oxygen deprived) conditions at 42.5ºC, in which the cell hardly grows under aerobic conditions. Glucose consumption rate was increased by 24% at 42.5ºC compared to that at the optimal growth temperature of 30.0ºC. Transcriptional analysis showed that gapX gene encoding glycelaldehydre-3-phosphate dehydrogenase, glucokinase gene, and a gene involved in glucose uptake were upregulated at 42.5ºC. Production of fermentative lactate was increased by 69% than that at 30.0ºC, whereas succinate production was decreased by 13%. In addition to several glycolytic enzymes, the activity of pyruvate kinase was increased with increasing the temperature, whereas the activity of phosphoenolpyruvate carboxylase in anapleotic pathway leading to succinate synthesis was decreased. However, a metabolically engineered succinate over-producing strain, in which lactate production was shut off and pyruvate carboxylase encoding gene in another anapleotic pathway was overexpressed, produced 34% higher succinate at 42.5ºC than that at 30.0ºC with increased glucose consumption. This study provides the evidence that the optimal reaction temperature for production of fermentative products can be set beyond upper limit of growth temperature in C. glutamicum, and hence it could be applicable for producing various chemicals and fuels in C. glutamicum under anaerobic conditions and non-growing cell reactions in other microorganisms.

Project description:Creation of an innovative composite photocatalyst, to advance its performance, has attracted researchers to the field of photocatalysis. In this article, a new photocatalyst based on polyaniline/reduced graphene oxide (PANI/RGO) composites has been prepared via the in situ oxidative polymerization method employing RGO as a template. For thermoelectric applications, though a higher percentage (50 wt %) of RGO has been used, for photocatalytic activity, lesser percentages (2, 5, and 8 wt %) of RGO in the composite have given a significant outcome. Furthermore, photoluminescence (PL) spectra, time-resolved fluorescence spectra, and Brunauer-Emmett-Teller surface area analyses confirmed the improved photocatalytic mechanism. PANI/RGO composites under visible light irradiation exhibit amazingly improved activity toward the degradation of cationic and anionic dyes in comparison with pristine PANI or RGO. Here, a PANI/RGO composite, with 5 wt % RGO(PG2), has emerged as the best combination with the degradation percentages of 99.68, 99.35, and 98.73 for malachite green, rhodamine B, and congo red within 15, 30, and 40 min, respectively. Experimental findings show that the introduction of RGO can relieve the agglomeration of PANI nanoparticles and enhance the light absorption of the materials due to an increased surface area. Moreover, the PG2 composite also showed excellent photocatalytic activity to reduce noxious Cr(VI). The effective removal of Cr(VI) up to 94.7% at pH 2 was observed within only 15 min. With the help of the active species trapping experiment, a plausible mechanism for the photocatalytic degradation has been proposed. The heightened activity of the as-synthesized composite compared to that of neat PANI or RGO was generally because of high concentrations of •OH radicals and partly of •O2 - and holes (h+) as concluded from the nitroblue tetrazolium probe test and photoluminescence experiment. It is hoped that the exceptional photocatalytic performance of our work makes the conducting polymer-based composite an effective alternative in wastewater treatment for industrial applications.

Dataset Information

Enhanced dechlorination and biodegradation of 2-chloroaniline by a 2-aminoanthraquinone-graphene oxide composite under anaerobic conditions.

Publications

Enhanced dechlorination and biodegradation of 2-chloroaniline by a 2-aminoanthraquinone-graphene oxide composite under anaerobic conditions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure