•Three efficient aryl-OPFRs-degrading bacterial consortia were enriched from China.•These consortia exhibited excellent environmental adaptation (15–40 ℃, pH 5.0–12.0).•Strain Rhodococcus sp. YC-JH2 ...could utilize TPhP as sole carbon source for growth.•Strain Sphingopyxis sp. YC-JH3 could efficiently degrade TPhP (96.2% within 7 days).
Three bacterial consortia, named YC-SY1, YC-BJ1 and YC-GZ1, were enriched from different areas of China. Bacterial consortia YC-SY1, YC-BJ1 and YC-GZ1 could efficiently degrade triphenyl phosphate (TPhP) (100 mg/L) by approximately 79.4%, 99.8% and 99.6%, tricresyl phosphate (TCrP) by 90.6%, 91.9% and 96.3%, respectively, within 4 days. And they could retain high degrading efficiency under a broad range of temperature (15–40 ℃), pH (6.0–10.0) and salinity (0–4%). A total of 10 bacterial isolates were selected and investigated their degradation capacity. Among these isolates, two were significantly superior to the others. Strain Rhodococcus sp. YC-JH2 could utilize TPhP (50 mg/L) as sole carbon source for growth with 37.36% degradation within 7 days. Strain Sphingopyxis sp. YC-JH3 could efficiently degrade 96.2% of TPhP (50 mg/L) within 7 days, except that no cell growth was observed. Combined with 16S diversity analysis, our results suggest that the effective components of three bacterial consortia responsible for TPhP and TCrP degradation were almost the same, that is, bacteria capable of degrading TPhP and TCrP are limited, in this study, the most efficient component is Sphingopyxis. This study provides abundant microorganism sources for research on organophosphorus flame retardants (OPFRs) metabolism and bioremediation towards OPFRs-contaminated environments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Geomorphic evolution was studied based on geomorphic indices and field surveys.•Geomorphic parameters reveal obvious relationships with tectonic activity.•Geomorphic evolution is ...controlled by northeastward extrusion of the Qinghai-Tibetan Plateau.•The southwestern Ordos Block undergoes strong northwestward tectonic tilting.
The Qianhe River Basin is located at the convergence zone of the northeastern margin of the Tibetan Plateau (NETP), the Ordos Block and the Qinling Mountains. A tectonic geomorphology study of the Qianhe River is significant for providing a deeper understanding of the tectonic transition between the NETP and the Ordos Block and the dynamic relationship of these three tectonic units. Based on Advanced Spaceborne Thermal Emission and Reflection global digital elevation model (ASTER-GDEM) data and geographic information system (GIS) techniques, four tectonic geomorphic indices, the hypsometric integral (HI), stream length-gradient (SL), drainage basin asymmetry (AF), and drainage basin shape (BS), were calculated and analyzed. Geologic evidence from field surveys, deformation measurements, and fault slip rate estimates was also obtained to further discuss the tectonic activity and tectonic geomorphic evolution model. Through analytical comparisons, we proposed that the variations in the applied geomorphic index values were not significantly affected by climate and lithology but indicated variations in related tectonic activity. The geomorphic index value analysis suggested relatively strong tectonic activity in Liupanshan Mountain and Longshan Mountain and northwestward tectonic tilting of the southwest margin of the Ordos Block. The actual mechanisms responsible for the observed variations in the Qianhe River Basin are the rapid uplift and northeastward extrusion of the Qinghai-Tibetan Plateau and the local tilting uplift of the southwestern Ordos Block.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the Cenozoic, fault‐related basins, including the Wei River, Lingbao and Linfen basins, developed on the southeast margin of the Ordos Block. Based on the latest drilling data and previous ...research results, this article analysed the evolutionary processes, temporal and spatial relationships and tectonic background of these basins, and obtained the following results: (a) The Wei River Basin and the Lingbao Basin belong to a unified basin, which formed in the Palaeocene and developed gradually from east to west. (b) The Linfen Basin formed in the late Miocene and developed gradually from southwest to northeast. (c) The evolution of the basin systems was dominated by the westward subduction of the Pacific Plate in the Palaeogene and then by a combination effects of the subduction of the Pacific Plate and the uplift of the Tibetan Plateau. (d) The so‐called Fen‐Wei Graben is not supported by the different geological evolutionary histories of the Wei River Basin and the Linfen Basin.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Phthalic acid esters (PAEs), which are widespread environmental contaminants, can be efficiently biodegraded, mediated by enzymes such as hydrolases. Despite great advances in the characterization of ...PAE hydrolases, which are the most important enzymes in the process of PAE degradation, their molecular catalytic mechanism has rarely been systematically investigated. Acinetobacter sp. LUNF3, which was isolated from contaminated soil in this study, demonstrated excellent PAE degradation at 30 °C and pH 5.0–11.0. After sequencing and annotating the complete genome, the gene dphAN1, encoding a novel putative PAE hydrolase, was identified with the conserved motifs catalytic triad (Ser201-Asp295-His325) and oxyanion hole (H127GGG130). DphAN1 can hydrolyze DEP (diethyl phthalate), DBP (dibutyl phthalate) and BBP (benzyl butyl phthalate). The high activity of DphAN1 was observed under a wide range of temperature (10–40 °C) and pH (6.0–9.0). Moreover, the metal ions (Fe2+, Mn2+, Cr2+ and Fe3+) and surfactant TritonX-100 significantly activated DphAN1, indicating a high adaptability and tolerance of DphAN1 to these chemicals. Molecular docking revealed the catalytic triad, oxyanion hole and other residues involved in binding DBP. The mutation of these residues reduced the activity of DphAN1, confirming their interaction with DBP. These results shed light on the catalytic mechanism of DphAN1 and may contribute to protein structural modification to improve catalytic efficiency in environment remediation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Despites lots of characterized microorganisms that are capable of degrading phthalic acid esters (PAEs), there are few isolated strains with high activity towards PAEs under a broad range of ...environmental conditions. In this study,
sp. YC-JH1 had advantages over its counterparts in terms of di(2-ethylhexyl) phthalate (DEHP) degradation performance. It possessed an excellent degradation ability in the range of 20⁻50 °C, pH 5.0⁻12.0, or 0⁻8% NaCl with the optimal degradation condition 40 °C and pH 10.0. Therefore, strain YC-JH1 appeared suitable for bioremediation application at various conditions. Metabolites analysis revealed that DEHP was sequentially hydrolyzed by strain YC-JH1 to mono(2-ethylhexyl) phthalate (MEHP) and phthalic acid (PA). The hydrolase MphG1 from strain YC-JH1 hydrolyzed monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-n-hexyl phthalate (MHP), and MEHP to PA. According to molecular docking and molecular dynamics simulation between MphG1 and monoalkyl phthalates (MAPs), some key residues were detected, including the catalytic triad (S125-H291-D259) and the residues R126 and F54 potentially binding substrates. The mutation of these residues accounted for the reduced activity. Together, the mechanism of MphG1 catalyzing MAPs was elucidated, and would shed insights into catalytic mechanism of more hydrolases.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The Earth's climate had undergone a global transition around 4–3 Ma, from warm to cool. The western Wei River Basin, its late Cenozoic tectonic evolution was mainly controlled by the expansion of the ...Tibetan Plateau, is affected by both Monsoon climate and Westerlies circulation. A set of lacustrine sediments between 4.2 and 3.6 Ma with clearly sedimentary rhythm are good materials for studying the palaeoclimate/palaeoenvironment changes and exploring the contained tectonic implications.
We present a high‐resolution grain‐sized, magnetic susceptible, and carbonate content records from the palaeolake sediments at the global climate transition interval (4.2–3.6 Ma) in the western Wei River Basin. The abrupt changes of climate indicators at about 4.14–4.16 Ma, which is a regional response to global cooling, indicate that both westerly and monsoonal circulations were enhanced and should be attributed to global cooling rather than the uplift of TibetanPlateau. From 4.14 to 3.6 Ma, the climate represented stepwise strengthening or weakening with frequent fluctuations on the millennium scale and extreme dry events at 3.77–3.80 Ma. Combined with regional geological environment and palaeoclimate evolution data, the palaeolake that rapidly receded at 3.6 Ma provides evidence for the understanding the major climatic and environmental changes produced by the uplift of the Tibetan Plateau in western Wei River Basin and surrounding areas.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Earthworms are an important ecological group, especially in agricultural regions in Northeast China. However, fewer studies focus on this group of organisms compared with other faunal groups. Here, ...we sequenced 15 new mitogenomes of Aporrectodea tuberculata Eisen, 1874, A. trapezoides Duges, 1828, Eisenia nordenskioldi Eisen, 1878 and Drawida ghilarovi Gates, 1969 in Northeast China using a high-throughput sequencing platform. These incomplete linear and double-stranded mitogenomes vary from 14,998 bp to 16,123 bp in size and include 37 genes and a putative control region. Intraspecific genetic divergence was quantified in the lumbricid species, and a control region in D. ghilarovi was reported for the first time by comparison to the mitogenomes of the congeners. Phylogenetic analysis based on coding genes and ribosomal DNA datasets using BI and ML inferences showed the non-monophyly of Aporrectodea and polyphyly of E. nordenskioldi. Future works should examine the taxonomy, phylogeny and population genetics not only of Lumbricidae but also the other earthworm families on the global scale using mitogenomic and nuclear data.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In the study of global change, the relationship between the Holocene climatic disaster events and the rise and fall of ancient civilization is of considerable significance to a profound understanding ...of civilization evolution and human‐land harmony. During the geological survey in the western Wei River Basin, a debris‐flow event that would have destroyed an archaeological site was uncovered in the Holocene loesson the south bank of the Qian River. They were studied by field observations and laboratory analysis, including magnetic susceptibility, particle size distribution, carbonate content determination, and AMS14C dating. The debris‐flow event was dated at about 3702 BP to 4084 cal BP by using the AMS14C in combination with archaeological artefacts age determination. Mingling with cultural layer, whole pig bones, and covering ash pit and cellars, the debris flow incident was linked to the site destruction. Combined with the global climate background at about 4000 a BP, the palaeo‐floods records in the Wei River Basin, and the regional palaeo‐earthquakes, we infer that the debris‐flow was triggered by large earthquake and heavy rainfall and was a regional hydrological response to the 4.0 ka global climate event. Moreover, the debris‐flow incident and its resulting archaeological site ruin have essential scientific significance for exploring the climate environment evolution, the ancient civilization evolvement, and the human‐land relationship development in the Wei River Basin and surrounding area.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid ester (AOPP) herbicide, was widely used and had led to detrimental environmental effects. For finding the ...QPE-degrading bacteria and promoting the biodegradation of QPE, a series of studies were carried out.
A QPE-degrading bacterial strain YC-XJ1 was isolated from desert soil and identified as Methylobacterium populi, which could degrade QPE with methanol by cometabolism. Ninety-seven percent of QPE (50 mg/L) could be degraded within 72 h under optimum biodegradation condition of 35°C and pH 8.0. The maximum degradation rate of QPE was 1.4 mg/L/h, and the strain YC-XJ1 exhibited some certain salinity tolerance. Two novel metabolites, 2-hydroxy-6-chloroquinoxaline and quinoxaline, were found by high-performance liquid chromatography/mass spectroscopy analysis. The metabolic pathway of QPE was predicted. The catalytic efficiency of strain YC-XJ1 toward different AOPPs herbicides in descending order was as follows: haloxyfop-p-methyl ≈ diclofop-methyl ≈ fluazifop-p-butyl > clodinafop-propargyl > cyhalofop-butyl > quizalofop-p-ethyl > fenoxaprop-p-ethyl > propaquizafop > quizalofop-p-tefuryl. The genome of strain YC-XJ1 was sequenced using a combination of PacBio RS II and Illumina platforms. According to the annotation result, one α/β hydrolase gene was selected and named qpeh1, for which QPE-degrading function has obtained validation. Based on the phylogenetic analysis and multiple sequence alignment with other QPE-degrading esterases reported previously, the QPEH1 was clustered with esterase family V.
M. populi YC-XJ1 could degrade QPE with a novel pathway, and the qpeh1 gene was identified as one of QPE-degrading esterase gene.How to cite: Li X, Wang J, Wu W, et al. Co-metabolic biodegradation of quizalofop-p-ethyl by Methylobacterium populi YC-XJ1 and identification of QPEH1 esterase. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.05.003.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Biodegradation is a reliable approach for efficiently eliminating persistent pollutants such as chlorpyrifos. Despite many bacteria or fungi isolated from contaminated environment and capable of ...degrading chlorpyrifos, limited enzymes responsible for its degradation have been identified, let alone the catalytic mechanism of the enzymes.
In present study, the gene cpd encoding a chlorpyrifos hydrolase was cloned by analysis of genomic sequence of Paracoccus sp. TRP. Phylogenetic analysis and BLAST indicated that CPD was a novel member of organophosphate hydrolases. The purified CPD enzyme, with conserved catalytic triad (Ser155-Asp251-His281) and motif Gly-Asp-Ser-Ala-Gly, was significantly inhibited by PMSF, a serine modifier. Molecular docking between CPD and chlorpyrifos showed that Ser155 was adjacent to chlorpyrifos, which indicated that Ser155 may be the active amino acid involved in chlorpyrifos degradation. This speculation was confirmed by site-directed mutagenesis of Ser155Ala accounting for the decreased activity of CPD towards chlorpyrifos. According to the key role of Ser155 in chlorpyrifos degradation and molecular docking conformation, the nucleophilic catalytic mechanism for chlorpyrifos degradation by CPD was proposed.
The novel enzyme CPD was capable of hydrolyze chlorpyrifos and Ser155 played key role during degradation of chlorpyrifos.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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