Publications by authors named "Chunling Luo"

109 Publications

Novel bacteria capable of degrading phenanthrene in activated sludge revealed by stable-isotope probing coupled with high-throughput sequencing.

Biodegradation 2017 12 27;28(5-6):423-436. Epub 2017 Sep 27.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

The indigenous microorganisms responsible for degrading phenanthrene (PHE) in activated biosludge were identified using DNA-based stable isotope probing. Besides the well-known PHE degraders Burkholderia, Ralstonia, Sinobacteraceae and Arthrobacter, we for the first time linked the taxa Paraburkholderia and Kaistobacter with in situ PHE biodegradation. Analysis of PAH-RHD gene detected in the heavy DNA fraction of C-PHE treatment suggested the mechanisms of horizontal gene transfer or inter-species hybridisation in PAH-RHD gene spread within the microbial community. Additionally, three cultivable PHE degraders, Microbacterium sp. PHE-1, Rhodanobacter sp. PHE-2 and Rhodococcus sp. PHE-3, were isolated from the same activated biosludge. Among them, Rhodanobacter sp. PHE-2 is the first identified strain in its genus with PHE-degrading ability. However, the involvement of these strains in PHE degradation in situ was questionable, due to their limited enrichment in the heavy DNA fraction of C-PHE treatment and lack of PAH-RHD gene found in these isolates. Collectively, our findings provide a deeper understanding of the diversity and functions of indigenous microbes in PHE degradation.
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http://dx.doi.org/10.1007/s10532-017-9806-9DOI Listing
December 2017

Combining Positive Matrix Factorization and Radiocarbon Measurements for Source Apportionment of PM from a National Background Site in North China.

Sci Rep 2017 09 6;7(1):10648. Epub 2017 Sep 6.

Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.

To explore the utility of combining positive matrix factorization (PMF) with radiocarbon (C) measurements for source apportionment, we applied PM data collected for 14 months at a national background station in North China to PMF models. The solutions were compared to C results of four seasonally averaged samples and three outlier samples. Comparing the most readily interpretable PMF solutions and C results revealed that PMF modeling was well able to capture the source patterns of PM with two and three irrelevant source classifications for the seasonal and outlier samples. The contribution of sources that could not be classified as either fossil or non-fossil sources in the PMF solution, and the errors between the modeled and measured concentrations weakened the effectiveness of the comparison. Based on these two factors, we developed an index for selecting the most suitable C measurement samples for combining with the PMF model. Then we examined the potential for coupling PMF modeling and C data with a constrained PMF run using the C data as a priori information. The restricted run could provide a more reliable solution; however, the PMF model must provide a flexible dialog to input the priori restrictions for executing the constraint simulation.
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http://dx.doi.org/10.1038/s41598-017-10762-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5587569PMC
September 2017

Assessing on toxic potency of PM-bound polycyclic aromatic hydrocarbons at a national atmospheric background site in North China.

Sci Total Environ 2018 Jan 1;612:330-338. Epub 2017 Sep 1.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

A total of 76PM samples collected at Tuoji Island from November 2011 to January 2013 were used to analyze 15 congeners of polycyclic aromatic hydrocarbons (∑PAHs) and assess their toxic potency. The average ∑PAHs was 15.34±8.87ngm, ranging from 4.24 to 40.62ngm over the sampling period. BkF, BbF, Phe and BaP were dominant PAH congeners, contributing together 60.64% of the ∑PAH concentration. The highest monthly ∑PAHs concentration was in January 2012, followed by the next January, which was closely four times greater than the lowest level occurred in July 2012. Wheat straw burning was responsible for the high PAH concentrations in June 2012. The averaged BaP toxicity equivalent (TEQ-BaP) concentration was 2.70±1.88ngm over the sampling period. BaP and DaA were the largest contributors, which contributed 58.5% and 14.7% of totals, respectively. The high TEQ-BaP and TEQ-BaP value per unit of ∑PAHs concentration (TEQ-BaP(U)) values occurred in the cold season and the low levels presented in the warm period. The heaviest monthly TEQ-BaP was 5.28±2.84ngm, which appeared in January 2012; the lowest value was 0.86±0.33ngm, which occurred in July 2012. The potential source contribution function (PSCF) showed the occurrence of the high health risk associated with PAHs in the middle of Liaoning and the south of Shandong Peninsula.
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http://dx.doi.org/10.1016/j.scitotenv.2017.08.208DOI Listing
January 2018

The influence of e-waste recycling on the molecular ecological network of soil microbial communities in Pakistan and China.

Environ Pollut 2017 Dec 25;231(Pt 1):173-181. Epub 2017 Sep 25.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

Primitive electronic waste (e-waste) recycling releases large amounts of organic pollutants and heavy metals into the environment. As crucial moderators of geochemical cycling processes and pollutant remediation, soil microbes may be affected by these contaminants. We collected soil samples heavily contaminated by e-waste recycling in China and Pakistan, and analyzed the indigenous microbial communities. The results of this work revealed that the microbial community composition and diversity, at both whole and core community levels, were affected significantly by polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and heavy metals (e.g., Cu, Zn, and Pb). The geographical distance showed limited impacts on microbial communities compared with geochemical factors. The constructed ecological network of soil microbial communities illustrated microbial co-occurrence, competition and antagonism across soils, revealing the response of microbes to soil properties and pollutants. Two of the three main modules constructed with core operational taxonomic units (OTUs) were sensitive to nutrition (total organic carbon and total nitrogen) and pollutants. Five key OTUs assigned to Acidobacteria, Proteobacteria, and Nitrospirae in ecological network were identified. This is the first study to report the effects of e-waste pollutants on soil microbial network, providing a deeper understanding of the ecological influence of crude e-waste recycling activities on soil ecological functions.
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http://dx.doi.org/10.1016/j.envpol.2017.08.003DOI Listing
December 2017

Characterisation and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in soils and plants around e-waste dismantling sites in southern China.

Environ Sci Pollut Res Int 2017 Oct 8;24(28):22173-22182. Epub 2017 Aug 8.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

Environmental pollution due to primitive e-waste dismantling activities has been intensively investigated over the last decade in the south-eastern coastal region of China. In the present study, we investigated the distribution and composition of polycyclic aromatic hydrocarbons (PAHs) in soils and plants around e-waste recycling sites in Longtang, Guangdong province, South China. The results indicated that PAH concentrations in rhizosphere soil and non-rhizosphere soil were in the range of 133 to 626 ng/g and 60 to 816 ng/g, respectively, while PAH levels in plant tissue were 96 to 388 ng/g in shoots and 143 to 605 ng/g in roots. PAHs were enriched in rhizosphere soils in comparison with non-rhizosphere soils. The concentrations of PAHs in plant tissues varied greatly among plant cultivars, indicating that the uptake of PAHs by plants is species-dependent. Different profiles of PAHs in the soil and the corresponding plant tissue implied that PAH uptake and translocation by plants were selective.The total daily intakes of PAHs and carcinogenic PAHs through vegetables at the e-waste recycling site were estimated to be 99 and 22 ng/kg/day, respectively, suggesting that potential health risks associated with the consumption of contaminated vegetables should not be ignored.
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http://dx.doi.org/10.1007/s11356-017-9830-7DOI Listing
October 2017

Occurrence and distribution of antibiotics in multiple environmental media of the East River (Dongjiang) catchment, South China.

Environ Sci Pollut Res Int 2017 Apr 1;24(10):9690-9701. Epub 2017 Mar 1.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.

The occurrence and distribution of 11 antibiotics in multiple environmental media including river water, suspended particle, sediment, and soil of the East River catchment, South China, were systematically characterized from multiple spatial (area and point) and temporal (seasonal variation and diurnal variation) scales. The results indicated that six to eight antibiotics were detected in these media. The predominant antibiotics and their concentrations varied with environment media because of the varied contamination sources, physicochemical properties of antibiotics, and media. For their spatial distribution, the river environment including water phase, suspended particles, and sediments showed a similar feature with the rule of C  > C  > C , which may be related to the industrial level and population density. However, the antibiotics in the soils showed a close relationship with the land use types. A diurnal variation of antibiotics at river sections was mainly affected by the tidal change and diurnal domestic sewage discharge feature. Source analysis indicated that domestic sewage was the main source for antibiotic contamination in the river, while irrigation and fertilization using river water and animal wastes were the main reasons for antibiotic contamination in the soils. However, antibiotics may be redistributed in different media in a catchment.
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http://dx.doi.org/10.1007/s11356-017-8664-7DOI Listing
April 2017

Biodegradation of Phenanthrene in Polycyclic Aromatic Hydrocarbon-Contaminated Wastewater Revealed by Coupling Cultivation-Dependent and -Independent Approaches.

Environ Sci Technol 2017 03 28;51(6):3391-3401. Epub 2017 Feb 28.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.

The indigenous microorganisms responsible for degrading phenanthrene (PHE) in polycyclic aromatic hydrocarbons (PAHs)-contaminated wastewater were identified by DNA-based stable isotope probing (DNA-SIP). In addition to the well-known PHE degraders Acinetobacter and Sphingobium, Kouleothrix and Sandaracinobacter were found, for the first time, to be directly responsible for indigenous PHE biodegradation. Additionally, a novel PHE degrader, Acinetobacter tandoii sp. LJ-5, was identified by DNA-SIP and direct cultivation. This is the first report and reference to A. tandoii involved in the bioremediation of PAHs-contaminated water. A PAH-RHD gene involved in PHE metabolism was detected in the heavy fraction of C treatment, but the amplification of PAH-RHD gene failed in A. tandoii LJ-5. Instead, the strain contained catechol 1,2-dioxygenase and the alpha/beta subunits of protocatechuate 3,4-dioxygenase, indicating use of the β-ketoadipate pathway to degrade PHE and related aromatic compounds. These findings add to our current knowledge on microorganisms degrading PHE by combining cultivation-dependent and cultivation-independent approaches and provide deeper insight into the diversity of indigenous PHE-degrading communities.
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http://dx.doi.org/10.1021/acs.est.6b04366DOI Listing
March 2017

SRSF2 Regulates Alternative Splicing to Drive Hepatocellular Carcinoma Development.

Cancer Res 2017 03 12;77(5):1168-1178. Epub 2017 Jan 12.

Institute for Nutritional Sciences, Chinese Academy of Sciences, Shanghai, China.

Aberrant RNA splicing is recognized to contribute to cancer pathogenesis, but the underlying mechanisms remain mainly obscure. Here, we report that the splicing factor SRSF2 is upregulated frequently in human hepatocellular carcinoma (HCC), where this event is associated with poor prognosis in patients. RNA-seq and other molecular analyses were used to identify SRSF2-regulated alternative splicing events. SRSF2 binding within an alternative exon was associated with its inclusion in the RNA, whereas SRSF2 binding in a flanking constitutive exon was associated with exclusion of the alternative exon. Notably, cancer-associated splice variants upregulated by SRSF2 in clinical specimens of HCC were found to be crucial for pathogenesis and progression in hepatoma cells, where SRSF2 expression increased cell proliferation and tumorigenic potential by controlling expression of these variants. Our findings identify SRSF2 as a key regulator of RNA splicing dysregulation in cancer, with possible clinical implications as a candidate prognostic factor in patients with HCC. .
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http://dx.doi.org/10.1158/0008-5472.CAN-16-1919DOI Listing
March 2017

Atmospheric deposition of PBDEs and DPs in Dongjiang River Basin, South China.

Environ Sci Pollut Res Int 2017 Feb 30;24(4):3882-3889. Epub 2016 Nov 30.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

The atmospheric deposition fluxes of polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DPs) in Dongjiang River Basin of the Pearl River Delta in South China were investigated during winter and summer, respectively. The total deposition fluxes varied from 4.74 to 27.0 ng/m/day for PBDEs and 8.77 to 206 ng/m/day for DPs, respectively. The fractions of anti-DP to the total DPs (f ) varied from 0.28 to 0.63 (mean = 0.43 ± 0.06), i.e., generally lower than those in commercial products, which might be attributed to the different environmental fates of the two isomers. Significant seasonal and spatial variations of PBDEs and DPs were observed. The deposition fluxes in summer were generally higher than those in winter, which may be due to the relatively high temperature and rainfall in summer under the influence of prevailing subtropical monsoon climate. Moreover, high deposition fluxes of PBDEs and DPs in urban areas and significant urban/rural gradient implied that local industrial activities in the urban areas were primary sources, which were further confirmed by the results of principal component analysis. The highest deposition of PBDE and DP fluxes was found at different sampling sites, suggesting PBDEs and DPs may be derived from different industries or products.
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http://dx.doi.org/10.1007/s11356-016-8082-2DOI Listing
February 2017

Characterisation of the phenanthrene degradation-related genes and degrading ability of a newly isolated copper-tolerant bacterium.

Environ Pollut 2017 Jan 23;220(Pt B):1059-1067. Epub 2016 Nov 23.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address:

A copper-tolerant phenanthrene (PHE)-degrading bacterium, strain Sphingobium sp. PHE-1, was newly isolated from the activated sludge in a wastewater treatment plant. Two key genes, ahdA1b-1 encoding polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHDɑ) and xyLE encoding catechol-2,3-dioxygenase (C23O), involved in the PHE metabolism by strain PHE-1 were identified. The PAH-RHD gene cluster showed 96% identity with the same cluster of Sphingomonas sp. P2. Our results indicated the induced transcription of xylE and ahdA1b-1 genes by PHE, simultaneously promoted by Cu(II). For the first time, high concentration of Cu(II) is found to encourage the expression of PAH-RHDɑ and C23O genes during PHE degradation. Applying Sphingomonas PHE-1 in PHE-contaminated soils for bioaugmentation, the abundance of xylE gene was increased by the planting of ryegrass and the presence of Cu(II), which, in turn, benefited ryegrass growth. The best performance of PHE degradation and the highest abundance of xylE genes occurred in PHE-copper co-contaminated soils planted with ryegrass.
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http://dx.doi.org/10.1016/j.envpol.2016.11.037DOI Listing
January 2017

Factors influencing the atmospheric concentrations of PCBs at an abandoned e-waste recycling site in South China.

Sci Total Environ 2017 Feb 10;578:34-39. Epub 2016 Nov 10.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

The diurnal atmospheric concentrations of polychlorinated biphenyls (PCBs) were investigated at an abandoned e-waste recycling site in South China during winter and summer. Total PCB concentrations during winter and summer were 27.6-212 and 368-1704pg/m in the particulate phase and 270-697 and 3000-15,500pg/m in the gaseous phase, respectively. Both gaseous and particulate PCB concentrations and compositions exhibited significant difference between winter and summer samples, but no diurnal variations during the measurement period. The correlation analysis between PCB concentrations and meteorological conditions, including atmospheric temperature, humidity, and mixing layer height, suggested that the seasonal variability of atmospheric PCB concentrations was strongly temperature-dependent, while the diurnal variability was probably source-dependent. The temperature-driven variations can also be proved by the significant linear correlation between ln P and 1/T in the Clausius-Clapeyron plot. Although government has implemented controls to reduce e-waste pollution, both the relatively high concentrations of PCBs and the diurnal variation in the air suggested that emissions from occasional e-waste recycling activities may still exist in this recycling area. These results underline the importance of continuing e-waste recycling site management long after abandonment.
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http://dx.doi.org/10.1016/j.scitotenv.2016.08.131DOI Listing
February 2017

Exploring the Influence of Environmental Factors on Bacterial Communities within the Rhizosphere of the Cu-tolerant plant, Elsholtzia splendens.

Sci Rep 2016 10 26;6:36302. Epub 2016 Oct 26.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

Bacterial communities of rhizospheric soils play an important role in the tolerance and uptake of metal-tolerant/hyperaccumulating plants to metals, e.g. the Cu-tolerant Elsholtzia splendens native to China. In this work, pyrosequencing of the bacterial 16S rRNA gene was firstly applied to investigate the rhizospheric bacterial community of E. splendens grown at Cu contaminated sites. The 47 phyla including 11 dominant phyla (>1%) in E. splendens rhizosphere were presented. The effects of Cu and other environmental factors (total organic carbon, total nitrogen and pH) on the rhizospheric bacterial community were studied comprehensively. The phyla abundances were affected by the environmental factors to different extent, and we found pH, instead of Cu concentration, influenced UniFrac distance significantly and was identified as the most important environmental factor affecting bacterial community. In addition, the influence of environmental factors on gene profiles was explored according to the predicted metagenomes obtained by PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states). Our study illustrates a view about Cu-tolerant E. splendens rhizospheric bacterial communities (composition, diversity and gene profiles) and their influencing factors, giving a hand for the understanding on bacterial community is formed and affected in rhizosphere.
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http://dx.doi.org/10.1038/srep36302DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5080579PMC
October 2016

The Abandoned E-Waste Recycling Site Continued to Act As a Significant Source of Polychlorinated Biphenyls: An in Situ Assessment Using Fugacity Samplers.

Environ Sci Technol 2016 08 28;50(16):8623-30. Epub 2016 Jul 28.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.

The recycling of e-waste has attracted significant attention due to emissions of polychlorinated biphenyls (PCBs) and other contaminants into the environment. We measured PCB concentrations in surface soils, air equilibrated with the soil, and air at 1.5-m height using a fugacity sampler in an abandoned electronic waste (e-waste) recycling site in South China. The total concentrations of PCBs in the soils were 39.8-940 ng/g, whereas the concentrations in air equilibrated with the soil and air at 1.5 m height were 487-8280 pg/m(3) and 287-7380 pg/m(3), respectively. The PCB concentrations displayed seasonal variation; they were higher in winter in the soils and higher in summer in the air, indicating that the emission of PCBs from the soil was enhanced during hot seasons for the relatively high temperature or additional sources, especially for low-chlorinated PCBs. We compared two methods (traditional fugacity model and fugacity sampler) for assessing the soil-air partition coefficients (Ksa) and the fugacity fractions of PCBs. The results suggested that the fugacity sampler provided more instructive and practical estimation on Ksa values and trends in air-soil exchange, especially for low-chlorinated PCBs. The abandoned e-waste burning site still acted as a significant source of PCBs many years after the prohibition on open burning.
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http://dx.doi.org/10.1021/acs.est.6b01620DOI Listing
August 2016

Plant selective uptake of halogenated flame retardants at an e-waste recycling site in southern China.

Environ Pollut 2016 Jul 2;214:705-712. Epub 2016 May 2.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

The concentrations and homolog patterns of halogenated flame retardants (HFRs) in vegetables grown at an e-waste contaminated site were investigated. Polybrominated diphenyl ethers (PBDEs) were the dominant HFRs in vegetable tissues, with concentrations ranging from 10.3 to 164 ng g(-1) and 1.16-107 ng g(-1) in shoots and roots, respectively, followed by novel brominated flame retardants (NBFRs) and dechlorane plus (DPs). This is an indication that PBDE contamination in vegetables grown around e-waste recycling sites may pose a risk to the local terrestrial ecosystem and residents. In addition, this is the first report on the concentrations and compositions of NBFRs in vegetables around e-waste recycling sites. The HFRs concentrations in vegetables varied greatly with the vegetable species, with the highest concentrations observed in Brassica oleracea var. capitata. Root concentration factors (RCF) decreased with increasing log Kow of HFRs, which indicated that the uptake of HFRs was controlled mainly by log Kow. Dissimilar HFRs profiles in shoots and roots suggested that the uptake and translocation of HFRs by plants were selective, with lower halogenated congeners prone to accumulation in vegetable tissues. Positive relationships between PBDEs and their substitutes were observed in vegetable tissues, suggesting that the replacement of PBDEs by NBFRs has not resulted in an obvious transition in plants within the study area.
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http://dx.doi.org/10.1016/j.envpol.2016.04.071DOI Listing
July 2016

Liver-Specific Deletion of SRSF2 Caused Acute Liver Failure and Early Death in Mice.

Mol Cell Biol 2016 06 16;36(11):1628-38. Epub 2016 May 16.

Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China

The liver performs a variety of unique functions critical for metabolic homeostasis. Here, we show that mice lacking the splicing factor SRSF2 but not SRSF1 in hepatocytes have severe liver pathology and biochemical abnormalities. Histological analyses revealed generalized hepatitis with the presence of ballooned hepatocytes and evidence of fibrosis. Molecular analysis demonstrated that SRSF2 governs splicing of multiple genes involved in the stress-induced cell death pathway in the liver. More importantly, SRSF2 also functions as a potent transcription activator, required for efficient expression of transcription factors mainly responsible for energy homeostasis and bile acid metabolism in the liver. Consistent with the effects of SRSF2 in gene regulation, accumulation of total cholesterol and bile acids was prominently observed in the mutant liver, followed by enhanced generation of reactive oxygen species and increased endoplasmic reticulum stress, as revealed by biochemical and ultrastructural analyses. Taking these observations together, inactivation of SRSF2 in liver caused dysregulated splicing events and hepatic metabolic disorders, which trigger endoplasmic reticulum stress, oxidative stress, and finally liver failure.
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http://dx.doi.org/10.1128/MCB.01071-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4959313PMC
June 2016

Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil.

J Hazard Mater 2016 May 11;308:50-7. Epub 2016 Jan 11.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually (13)C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota.
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http://dx.doi.org/10.1016/j.jhazmat.2016.01.009DOI Listing
May 2016

Could Uptake and Acropetal Translocation of PBDEs by Corn Be Enhanced Following Cu Exposure? Evidence from a Root Damage Experiment.

Environ Sci Technol 2016 Jan 31;50(2):856-63. Epub 2015 Dec 31.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.

Cocontamination by heavy metals and persistent organic pollutants (POPs) is ubiquitous in the environment. Fate of POPs within soil/water-plant system is a significant concern and an area where much uncertainty still exists when plants suffered cotoxicity from POPs and metals. This study investigated the fate of polybrominated diphenyl ethers (PBDEs) when copper (Cu) was present within the soil/water-plant system using pot and hydroponic experiments. The presence of Cu was found to induce damage to the root cell membranes of corn (Zea mays L. cv. Nongda 108) with increasing concentration in both shoots and roots. The PBDE congeners BDE209 and BDE47 in shoots were also enhanced with the increasing electrolytic leakage from root, attributed to Cu damage, and the highest shoot BDE209 and BDE47 levels were observed under the highest Cu dosage. In addition, positive correlations were observed between the PBDE content of corn shoots and the electrolytic leakage of corn roots. These results indicated that within a defective root system, more PBDEs will penetrate the roots and are acropetally translocated in the shoots. The potential ecological risk associated with the translocation and accumulation of POPs into plant shoots needs careful reconsideration in media cocontaminated with metals and POPs, whereas often ignored or underestimated in environmental risk assessments.
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http://dx.doi.org/10.1021/acs.est.5b04030DOI Listing
January 2016

Characterization of Cu(II) and Cd(II) resistance mechanisms in Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and their potential application in the bioremediation of heavy metal-phenanthrene co-contaminated sites.

Environ Sci Pollut Res Int 2016 Apr 15;23(7):6861-72. Epub 2015 Dec 15.

College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.

Soil that is co-contaminated with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) is difficult to bioremediate due to the ability of toxic metals to inhibit PAH degradation by bacteria. We demonstrated the resistance mechanisms to Cu(II) and Cd(II) of two newly isolated strains of Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and further tested their potential application in the bioremediation of HM-phenanthrene (PhA) co-contaminated sites. The PHE-SPH and PHE-OCH strains tolerated 4.63 and 4.34 mM Cu(II) and also showed tolerance to 0.48 and 1.52 mM Cd(II), respectively. Diverse resistance patterns were detected between the two strains. In PHE-OCH cells, the maximum accumulation of Cu(II) occurred in the cell wall, while the maximum accumulation was in the cytoplasm of PHE-SPH cells. This resulted in a sudden suppression of growth in PHE-OCH and a gradual inhibition in PHE-SPH as the concentration of Cu(II) increased. Organic acid production was markedly higher in PHE-OCH than in PHE-SPH, which may also have a role in the resistance mechanisms, and contributes to the higher Cd(II) tolerance of PHE-OCH. The factors involved in the absorption of Cu(II) or Cd(II) in PHE-SPH and PHE-OCH were identified as proteins and carbohydrates by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, both strains showed the ability to efficiently degrade PhA and maintained this high degradation efficiency under HM stress. The high tolerance to HMs and the PhA degradation capacity make Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH excellent candidate organisms for the bioremediation of HM-PhA co-contaminated sites.
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http://dx.doi.org/10.1007/s11356-015-5926-0DOI Listing
April 2016

SRSF10 Plays a Role in Myoblast Differentiation and Glucose Production via Regulation of Alternative Splicing.

Cell Rep 2015 Nov 12;13(8):1647-57. Epub 2015 Nov 12.

Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China. Electronic address:

Alternative splicing is a major mechanism of controlling gene expression and protein diversity in higher eukaryotes. We report that the splicing factor SRSF10 functions during striated muscle development, myoblast differentiation, and glucose production both in cells and in mice. A combination of RNA-sequencing and molecular analysis allowed us to identify muscle-specific splicing events controlled by SRSF10 that are critically involved in striated muscle development. Inclusion of alternative exons 16 and 17 of Lrrfip1 is a muscle-specific event that is activated by SRSF10 and essential for myoblast differentiation. On the other hand, in mouse primary hepatocytes, PGC1α is a key target of SRSF10 that regulates glucose production by fasting. SRSF10 represses inclusion of PGC1α exon 7a and facilitates the production of functional protein. The results highlight the biological significance of SRSF10 and regulated alternative splicing in vivo.
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http://dx.doi.org/10.1016/j.celrep.2015.10.038DOI Listing
November 2015

Distributions and compositions of old and emerging flame retardants in the rhizosphere and non-rhizosphere soil in an e-waste contaminated area of South China.

Environ Pollut 2016 Jan;208(Pt B):619-25

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

We investigated rhizosphere effects on the distributions and compositions of polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DPs) in rhizosphere soils (RS) and non-rhizosphere soils (NRS) in an e-waste recycling area in South China. The concentrations of PBDEs, NBFRs, and DPs ranged from 13.9 to 351, 11.6 to 70.8, and 0.64 to 8.74 ng g(-1) in RS and 7.56 to 127, 8.98 to 144, and 0.38 to 8.45 ng g(-1) in NRS, respectively. BDE-209 and DBDPE were the dominant congeners of PBDEs and NBFRs, respectively. PBDEs, NBFRs, and DPs were more enriched in RS than NRS in most vegetables species. Further analysis suggested that the differentiation of the rhizosphere effect on halogenated flame retardants (HFRs) was not solely controlled by the octanol-water coefficients. This difference was also reflected by the correlations between total organic carbon (TOC) and PBDEs, NBFRs, or DPs, which indicated that organic carbon was a more pivotal controlling factor for PBDEs and DPs than for NBFRs in soil. We also found significant positive correlations between PBDEs and their replacement products, which indicated a similar emission pattern and environmental behaviour.
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http://dx.doi.org/10.1016/j.envpol.2015.10.038DOI Listing
January 2016

High-resolution ghost imaging experiments with cosh-Gaussian modulated incoherent sources.

J Opt Soc Am A Opt Image Sci Vis 2015 Mar;32(3):482-5

We experimentally demonstrate that ghost imaging (GI) quality can be significantly improved by modulating the incoherent Gaussian sources with hyperbolic cosine functions. In our experiments, a source with desired cosh-Gaussian intensity distribution can be generated by a programmable spatial light modulator, and is used in the GI setup to obtain high quality ghost images. The influences of the hyperbolic cosine parameter on the point-spread function and the GI quality have been investigated experimentally and interpreted theoretically. Our experimental results show that the resolution of ghost images can be obviously enhanced with cosh-Gaussian modulated incoherent sources. The kind of source-shaping technique proposed in this paper is a high-efficiency method to improve the GI quality and may be very useful for the GI applications.
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http://dx.doi.org/10.1364/JOSAA.32.000482DOI Listing
March 2015

The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils.

J Hazard Mater 2016 Jan 24;301:35-45. Epub 2015 Aug 24.

Lancaster Environment Centre, Lancaster University, Lancaster LA1 2YW, UK. Electronic address:

The ecological effect of earthworms on the fate of soil pentachlorophenol (PCP) differs with species. This study addressed the roles and mechanisms by which two earthworm species (epigeic Eisenia fetida and endogeic Amynthas robustus E. Perrier) affect the soil microbial community and enzyme activity during the bioremediation of PCP-contaminated soils. A. robustus removed more soil PCP than did E. foetida. A. robustus improved nitrogen utilisation efficiency and soil oxidation more than did E. foetida, whereas the latter promoted the organic matter cycle in the soil. Both earthworm species significantly increased the amount of cultivable bacteria and actinomyces in soils, enhancing the utilisation rate of the carbon source (i.e. carbohydrates, carboxyl acids, and amino acids) and improving the richness and evenness of the soil microbial community. Additionally, earthworm treatment optimized the soil microbial community and increased the amount of the PCP-4-monooxygenase gene. Phylogenic classification revealed stimulation of indigenous PCP bacterial degraders, as assigned to the families Flavobacteriaceae, Pseudomonadaceae and Sphingobacteriacea, by both earthworms. A. robustus and E. foetida specifically promoted Comamonadaceae and Moraxellaceae PCP degraders, respectively.
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http://dx.doi.org/10.1016/j.jhazmat.2015.08.034DOI Listing
January 2016

Identification of benzo[a]pyrene-metabolizing bacteria in forest soils by using DNA-based stable-isotope probing.

Appl Environ Microbiol 2015 Nov 7;81(21):7368-76. Epub 2015 Aug 7.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.

DNA-based stable-isotope probing (DNA-SIP) was used in this study to investigate the uncultivated bacteria with benzo[a]pyrene (BaP) metabolism capacities in two Chinese forest soils (Mt. Maoer in Heilongjiang Province and Mt. Baicaowa in Hubei Province). We characterized three different phylotypes with responsibility for BaP degradation, none of which were previously reported as BaP-degrading microorganisms by SIP. In Mt. Maoer soil microcosms, the putative BaP degraders were classified as belonging to the genus Terrimonas (family Chitinophagaceae, order Sphingobacteriales), whereas Burkholderia spp. were the key BaP degraders in Mt. Baicaowa soils. The addition of metabolic salicylate significantly increased BaP degradation efficiency in Mt. Maoer soils, and the BaP-metabolizing bacteria shifted to the microorganisms in the family Oxalobacteraceae (genus unclassified). Meanwhile, salicylate addition did not change either BaP degradation or putative BaP degraders in Mt. Baicaowa. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD) genes were amplified, sequenced, and quantified in the DNA-SIP (13)C heavy fraction to further confirm the BaP metabolism. By illuminating the microbial diversity and salicylate additive effects on BaP degradation across different soils, the results increased our understanding of BaP natural attenuation and provided a possible approach to enhance the bioremediation of BaP-contaminated soils.
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http://dx.doi.org/10.1128/AEM.01983-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592850PMC
November 2015

Simultaneous enhanced removal of Cu, PCBs, and PBDEs by corn from e-waste-contaminated soil using the biodegradable chelant EDDS.

Environ Sci Pollut Res Int 2015 Nov 17;22(22):18203-10. Epub 2015 Jul 17.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

We evaluated the influence of the biodegradable chelant ethylenediamine disuccinic acid (EDDS) on plant uptake of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and Cu by corn from electronic waste (e-waste)-contaminated soil. The highest concentration and highest total uptake of Cu in corn were observed in the treatment with 5 mM EDDS, which resulted in a 4-fold increase of the Cu translocation factor (C(shoot)/C(root)) compared to the control. The concentrations of PCBs and PBDEs in shoots and roots increased with increasing application rates of EDDS, and 1.58- and 1.32-fold average increases in the concentrations of PCBs and PBDEs, respectively, were observed in shoots in the EDDS treatments. A significant positive correlation was observed between shoot Cu and shoot PCBs and PBDEs. We speculate that PCBs and PBDEs were activated by the EDDS-triggered dissolved organic carbon (DOC) and then indiscriminately taken up by roots and translocated to shoots following damage to the roots mainly by the increased extractable Cu resulting from the EDDS application.
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http://dx.doi.org/10.1007/s11356-015-5045-yDOI Listing
November 2015

Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing.

PLoS One 2015 22;10(6):e0130846. Epub 2015 Jun 22.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP). The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP) results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130846PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4476716PMC
March 2016

Permeability of Plant Young Root Endodermis to Cu Ions and Cu-Citrate Complexes in Corn and Soybean.

Int J Phytoremediation 2015 ;17(9):822-34

a College of Life Sciences, Nanjing Agricultural University , Nanjing , China.

The non-selective apoplastic passage of Cu and Cu-citrate complexes into the root stele of monocotyledonous corn and dicotyledonous soybean was investigated using an inorganic-salt-precipitation technique. Either Cu ions or Cu-citrate complexes were drawn into root through the apoplast from the root growth medium, and K4[Fe(CN)6] was subsequently perfused through xylem vessels or the entire root cross section. Based on microscopic identification of the reddish-brown precipitates of copper ferrocyanide in the cell walls of the xylem of corn and soybean roots, Cu(2+) passed through the endodermal barrier into the xylem of both species. When the solution containing 200 μM CuSO4 and 400 μM sodium citrate (containing 199.98 μM Cu-citrate, 0.02 μM Cu(2+)) was drawn via differential pressure gradients into the root xylem while being perfused with K4[Fe(CN)6] through the entire root cross-section, reddish-brown precipitates were observed in the walls of the stele of soybean, but not corn root. However, when a CuSO4 solution containing 0.02 or 0.2 μM free Cu(2+) was used, no reddish-brown precipitates were detected in the stele of either of the two plants. Results indicated that endodermis was permeable to Cu-citrate complexes in primary roots of soybean, but not corn. The permeability of the endodermal barrier to the Cu-citrate complex may vary between dicotyledonous and monocotyledonous plants, which has considerable implications for chelant-enhanced phytoextraction.
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http://dx.doi.org/10.1080/15226514.2014.981241DOI Listing
August 2016

Assessment of amendments for the immobilization of Cu in soils containing EDDS leachates.

Environ Sci Pollut Res Int 2015 Nov 17;22(21):16525-34. Epub 2015 Jun 17.

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

In this study, the effectiveness of six soil amendments (ferrihydrite, manganese dioxide, gibbsite, calcium carbonate, biochar, and organic fertilizer) was investigated to assess the feasibility of minimizing possible environmental contaminant leaching during S,S-ethylenediaminedisuccinic acid (EDDS)-enhanced phytoextraction process based on 0.01-M CaCl2 extraction. Results showed that the application of EDDS could significantly increase Cu concentrations in the leaching solution. Compared with control, incorporation of six amendments (excluding organic fertilizer) significantly decreased CaCl2-extractable Cu concentrations in both soils. When EDDS-containing solutions leached from the soil columns (mimicking the upper soil layers) were added to soils with different amendments (mimicking the subsoil), CaCl2-extractable Cu in the soils amended with ferrihydrite, manganese dioxide, gibbsite, and calcium carbonate was significantly lower than that in the control soil (no amendments) and remained relatively constant during the first 14 days. Incorporation of biochar or organic fertilizer had no positive effect on the immobilization of Cu in EDDS leachates in soils. After 14 days, CaCl2-extractable Cu concentration decreased rapidly in soils incorporated with various amendments. Integrating soil washing with biodegradable chelating agents or chelant-enhanced phytoextraction and immobilization of heavy metals in subsoil could be used to rapidly reduce the concentration of bioavailable metal fractions in the upper soil layers and minimize environmental risks of secondary pollution.
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http://dx.doi.org/10.1007/s11356-015-4840-9DOI Listing
November 2015

The key microorganisms for anaerobic degradation of pentachlorophenol in paddy soil as revealed by stable isotope probing.

J Hazard Mater 2015 Nov 30;298:252-60. Epub 2015 May 30.

Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China.

Pentachlorophenol (PCP) is a common residual persistent pesticide in paddy soil and has resulted in harmful effect on soil ecosystem. The anaerobic microbial transformation of PCP, therefore, has been received much attentions, especially the functional microbial communities for the reductive transformation. However, the key functional microorganisms for PCP mineralization in the paddy soil still remain unknown. In this work, DNA-based stable isotope probing (SIP) was applied to explore the key microorganisms responsible for PCP mineralization in paddy soil. The SIP results indicated that the dominant bacteria responsible for PCP biodegradation belonged to the genus Dechloromonas of the class β-Proteobacteria. In addition, the increased production of (13)CH4 and (13)CO2 indicated that the addition of lactate enhanced the rate of biodegradation and mineralization of PCP. Two archaea classified as the genera of Methanosaeta and Methanocella of class Methanobacteria were enriched in the heavy fraction when with lactate, whereas no archaea was detected in the absence of lactate. These findings provide direct evidence for the species of bacteria and archaea responsible for anaerobic PCP or its breakdown products mineralization and reveal a new insight into the microorganisms linked with PCP degradation in paddy soil.
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http://dx.doi.org/10.1016/j.jhazmat.2015.05.049DOI Listing
November 2015

Characterization of the exchange of PBDEs in a subtropical paddy field of China: A significant inputs of PBDEs via air-foliage exchange.

Environ Pollut 2015 Oct 17;205:1-7. Epub 2015 May 17.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

Rice and the distinctive cultivation practices employed in rice growth can significantly influence the environmental fate of polybrominated diphenyl ethers (PBDEs) in a paddy field. We studied variations in PBDE concentrations in multiple compartments of a paddy field in the suburban area of Guangzhou, South China, including air, soil, water, and rice tissues. The input/output fluxes of air-surface and air-foliage exchange, atmospheric deposition and water input during different rice growth stages were measured simultaneously. Air-foliage and air-water diffusion exchanges were the key processes controlling inputs and outputs of PBDEs in paddy fields, respectively, whereas atmospheric deposition dominated inputs of higher brominated PBDEs. The high input of PBDEs via air-foliage exchange suggested that vegetation can significantly increase the air-to-field transport of PBDEs in ecosystems. The annual input of PBDEs in all paddy fields in Guangdong Province was estimated to be 22.1 kg.
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http://dx.doi.org/10.1016/j.envpol.2015.05.016DOI Listing
October 2015

Polychlorinated naphthalenes (PCNs) in Chinese forest soil: Will combustion become a major source?

Environ Pollut 2015 Sep 14;204:124-32. Epub 2015 May 14.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address:

We collected O- and A-horizon soil samples in 26 Chinese mountainous forests to investigate the content, spatial pattern, and potential sources of polychlorinated naphthalenes (PCNs). Spatial patterns were influenced mainly by the approximation to sources and soil organic contents. High concentrations often occurred close to populated or industrialized areas. Combustion-related activities contributed to PCN pollution. Relatively high proportions of CN-73 in northern China may be attributed to coke consumption, while CN-51 could be an indicator of biomass burning in Southwest China. There are evidences that PCNs may largely derived from unintentional production. If uncontrolled, UP-PCN (unintentionally produced PCNs) emissions could increase with industrial development. The abnormally high concentrations at Gongga and Changbai Mountains appear to be associated with the high efficient of forest filter of atmospheric contaminants at these densely forested sites. We question whether this is caused by ecotones between forests, and raise additional questions for future analyses.
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http://dx.doi.org/10.1016/j.envpol.2015.04.014DOI Listing
September 2015
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