The Experts below are selected from a list of 17316 Experts worldwide ranked by ideXlab platform
Ping Zheng - One of the best experts on this subject based on the ideXlab platform.
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ecological success of the nitrosopumilus and nitrosospira clusters in the Intertidal Zone
Microbial Ecology, 2019Co-Authors: Shuai Liu, Weiling Yang, Jiaqi Wang, Huan Liu, Ping ZhengAbstract:The Intertidal Zone is an important buffer and a nitrogen sink between land and sea. Ammonia oxidation is the rate-limiting step of nitrification, conducted by ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). However, it remains a debatable issue regarding dominant ammonia oxidizers in this region, and environmental factors driving their spatiotemporal niche differentiation have yet to be identified. In this study, Intertidal and subtidal Zones of Zhoushan Islands were selected for seasonal sampling. Ammonia-oxidizing activity, quantitative PCR, and 454 high-throughput sequencing were performed to study the nitrification potential, abundance, and community structure of ammonia-oxidizing archaea and bacteria. AOA and AOB amoA abundance (107–108amoA gene copies/g dry weight sediment) varied spatiotemporally independently of environmental factors. AOA surpassed AOB in most samples, driven by sediment temperature, moisture, and total nitrogen. The diversity of both AOA and AOB differed spatiotemporally. The Nitrosopumilus and Nitrosospira clusters accounted for an absolutely dominant percentage of AOA (> 99%) and AOB (> 99%) respectively, indicating a negligible contribution of other clusters to ammonia oxidation. However, there was no significant correlation between nitrification potential and the abundance of AOA or AOB. Overall, the present study showed that AOA dominated over AOB spatiotemporally in the Intertidal Zone of Zhoushan Islands due to fluctuations in environmental factors, and the Nitrosopumilus and Nitrosospira clusters ecologically succeeded in the Intertidal Zone of Zhoushan Islands.
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spatial temporal pattern of sulfate dependent anaerobic methane oxidation in an Intertidal Zone of the east china sea
Applied and Environmental Microbiology, 2019Co-Authors: Jiaqi Wang, Chaoyang Cai, Miaolian Hua, Junren Wang, Hongrui Yang, Haifeng Qian, Ping ZhengAbstract:ABSTRACT Methane is a primary greenhouse gas which is responsible for global warming. The sulfate-dependent anaerobic methane oxidation (S-AOM) process catalyzed by anaerobic methanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB) is a vital link connecting the global carbon and sulfur cycles, and it is considered to be the overriding methane sink in marine ecosystem. However, there have been few studies regarding the role of S-AOM process and the distribution of ANME archaea in Intertidal ecosystem. The Intertidal Zone is a buffer Zone between sea and land and plays an important role in global geochemical cycle. In the present study, the abundance, potential methane oxidation rate, and community structure of ANME archaea in the Intertidal Zone were studied by quantitative PCR, stable isotope tracing method and high-throughput sequencing. The results showed that the potential S-AOM activity ranged from 0 to 0.77 nmol 13CO2 g−1 (dry sediment) day−1. The copy number of 16S rRNA gene of ANME archaea reached 106 ∼ 107 copies g−1 (dry sediment). The average contribution of S-AOM to total anaerobic methane oxidation was up to 34.5%, while denitrifying anaerobic methane oxidation accounted for the rest, which implied that S-AOM process was an essential methane sink that cannot be overlooked in Intertidal ecosystem. The simulated column experiments also indicated that ANME archaea were sensitive to oxygen and preferred anaerobic environmental conditions. This study will help us gain a better understanding of the global carbon-sulfur cycle and greenhouse gas emission reduction and introduce a new perspective into the enrichment of ANME archaea. IMPORTANCE The sulfate-dependent anaerobic methane oxidation (S-AOM) process catalyzed by anaerobic methanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB) is a vital link connecting the global carbon and sulfur cycles. We conducted a research into the spatial-temporal pattern of S-AOM process and the distribution of ANME archaea in coastal sediments collected from the Intertidal Zone. The results implied that S-AOM process was a methane sink that cannot be overlooked in the Intertidal ecosystem. We also found that ANME archaea were sensitive to oxygen and preferred anaerobic environmental conditions. This study will help us gain a better understanding of the global carbon-sulfur cycle and greenhouse gas emission reduction and introduce a new perspective into the enrichment of ANME archaea.
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Denitrifying Anaerobic Methane Oxidation: A Previously Overlooked Methane Sink in Intertidal Zone
Environmental science & technology, 2018Co-Authors: Wang Jiaqi, Chaoyang Cai, Li Yufen, Miaolian Hua, Junren Wang, Hongrui Yang, Ping ZhengAbstract:The Intertidal Zone is an open ecosystem rich in organic matter and plays an important role in global biogeochemical cycles. It was previously considered that methane was mainly removed by sulfate-dependent anaerobic methane oxidation (sulfate-AOM) process in marine ecosystems while other anaerobic methane oxidation processes were ignored. Recent researches have demonstrated that denitrifying anaerobic methane oxidation (DAMO), consisting of nitrite-dependent anaerobic methane oxidation (nitrite-AOM) and nitrate-dependent anaerobic methane oxidation (nitrate-AOM), can also oxidize methane. In this work, the community structure, quantity and potential methane oxidizing rate of DAMO archaea and bacteria in the Intertidal Zone were studied by high-throughput sequencing, qPCR and stable isotope tracing method. The results showed that nitrate-AOM and nitrite-AOM were both active in the Intertidal Zone and showed approximate methane oxidation rates. The copy number of 16S rRNA gene of DAMO archaea and DAMO bacteria were 104 ∼ 105 copies g-1 (dry sediment), whereas NC10 bacteria were slightly higher. The contribution rate of DAMO process to total anaerobic methane removal in the Intertidal Zone reached 65.6% ∼ 100%, which indicates that DAMO process is an important methane sink in Intertidal ecosystem. Laboratory incubations also indicated that DAMO archaea were more sensitive to oxygen and preferred a more anoxic environment. These results help us draw a more complete picture of methane and nitrogen cycles in natural habitats.
Dangyu Zhang - One of the best experts on this subject based on the ideXlab platform.
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impacts of burial by sediment on decomposition and heavy metal concentrations of suaeda salsa in Intertidal Zone of the yellow river estuary china
Marine Pollution Bulletin, 2017Co-Authors: Dangyu Zhang, Xingyun Hu, Liping TianAbstract:Three one-off burial treatments were designed in Intertidal Zone of the Yellow River estuary to determine the effects of sediment burial on decomposition and heavy metal levels of Suaeda salsa. Sediment burial showed significant effect on decomposition rate of S. salsa. With increasing burial depth, Cu, Zn, Cd and Co levels generally increased, while Cr and Mn levels decreased. Except for Zn, Mn, Cd and Co, stocks of Pb, Cr, Cu, Ni and V in S. salsa among burials were greatly different. The S. salsa in three burials was particular efficient in binding V and Co and releasing Pb, Zn and Cd, and, with increasing burial depth, stocks of Cr, Cu, Ni and Mn shifted from accumulation to release. In future, the eco-toxic risk of Pb, Cr, Cu, Zn, Ni, Mn and Cd exposure might be serious as the strong burial episodes occurred in S. salsa marsh.
Weiguo Zhang - One of the best experts on this subject based on the ideXlab platform.
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Synchrotron micro-scale study of trace metal transport and distribution in Spartina alterniflora root system in Yangtze River Intertidal Zone
2020Co-Authors: Huan Feng, Weiguo Zhang, Wenliang Liu, Yu Qian, Jun Wang, Jia-jun Wang, Christopher Eng, Chang-jun Liu, Keith W JonesAbstract:Abstract This study is focused on micro-scale measurement of metal (Ca, Cl, Fe, K, Mn, Cu, Pb, and Zn) distributions in Spartina alterniflora root system. The root samples were collected in the Yangtze River Intertidal Zone in July 2013. Sync h r o t r o n X -r a y f l u o r e s c e n c e ( X R F ) , c o m p u t e d microtomography (CMT), and X-ray absorption near-edge structure (XANES) techniques, which provide micro-meter scale analytical resolution, were applied to this study. Although it was found that the metals of interest were distributed in both epidermis and vascular tissue with the varying concentrations, the results showed that Fe plaque was mainly distributed in the root epidermis. Other metals (e.g., Cu, Mn, Pb, and Zn) were correlated with Fe in the epidermis possibly due to scavenge by Fe plaque. Relatively high metal concentrations were observed in the root hair tip. This micro-scale investigation provides insights of understanding the metal uptake and spatial distribution as well as the function of Fe plaque governing metal transport in the root system
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heavy metal contamination in surface sediments of yangtze river Intertidal Zone an assessment from different indexes
Environmental Pollution, 2009Co-Authors: Weiguo Zhang, Huan Feng, Jinna Chang, Jianguo Qu, Hongxia Xie, Lizhong YuAbstract:Abstract Surface sediments (0–5 cm) from 59 stations within the Yangtze River Intertidal Zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg −1 dry weight): Al, 40,803–97,213; Fe, 20,538–49,627; Cd, 0.12–0.75; Cr, 36.9–173; Cu, 6.87–49.7; Mn, 413–1,112; Ni, 17.6–48.0; Pb, 18.3–44.1; and Zn, 47.6–154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes ( I geo ) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn.
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lead pb isotopes as a tracer of pb origin in yangtze river Intertidal Zone
Chemical Geology, 2008Co-Authors: Weiguo Zhang, Huan Feng, Jinna ChangAbstract:Abstract In order to investigate the source of Pb within the Yangtze River Intertidal Zone, studying Pb isotope ratios is a likely approach because the ratios of these Pb isotopes can be used to identify the natural or anthropogenic origin of Pb. In this study, a total of 59 surface sediment samples ( 204 Pb, 206 Pb, 207 Pb and 208 Pb) and found that the total Pb concentrations varied from 18.3 to 44.1 mg kg − 1 with an average concentration of 27.3 mg kg − 1 . The observed Pb isotope ratios, excluding one station near Shanghai Pudong Airport which is significantly influenced by anthropogenic sources, varied from 18.459 to 18.750 for 206 Pb/ 204 Pb, 15.628 to 15.728 for 207 Pb/ 204 Pb, and 38.715 to 39.213 for 208 Pb/ 204 Pb. This study shows that Pb found within the Yangtze River Intertidal Zone sediments was mainly from the catchment in the Yangtze River watershed. Significant Pb pollution was not discerned in the Yangtze River Intertidal Zone. However, Pb contamination in some localized areas was suggested by Pb enrichment factor (EF).
Jinna Chang - One of the best experts on this subject based on the ideXlab platform.
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heavy metal contamination in surface sediments of yangtze river Intertidal Zone an assessment from different indexes
Environmental Pollution, 2009Co-Authors: Weiguo Zhang, Huan Feng, Jinna Chang, Jianguo Qu, Hongxia Xie, Lizhong YuAbstract:Abstract Surface sediments (0–5 cm) from 59 stations within the Yangtze River Intertidal Zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg −1 dry weight): Al, 40,803–97,213; Fe, 20,538–49,627; Cd, 0.12–0.75; Cr, 36.9–173; Cu, 6.87–49.7; Mn, 413–1,112; Ni, 17.6–48.0; Pb, 18.3–44.1; and Zn, 47.6–154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes ( I geo ) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn.
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lead pb isotopes as a tracer of pb origin in yangtze river Intertidal Zone
Chemical Geology, 2008Co-Authors: Weiguo Zhang, Huan Feng, Jinna ChangAbstract:Abstract In order to investigate the source of Pb within the Yangtze River Intertidal Zone, studying Pb isotope ratios is a likely approach because the ratios of these Pb isotopes can be used to identify the natural or anthropogenic origin of Pb. In this study, a total of 59 surface sediment samples ( 204 Pb, 206 Pb, 207 Pb and 208 Pb) and found that the total Pb concentrations varied from 18.3 to 44.1 mg kg − 1 with an average concentration of 27.3 mg kg − 1 . The observed Pb isotope ratios, excluding one station near Shanghai Pudong Airport which is significantly influenced by anthropogenic sources, varied from 18.459 to 18.750 for 206 Pb/ 204 Pb, 15.628 to 15.728 for 207 Pb/ 204 Pb, and 38.715 to 39.213 for 208 Pb/ 204 Pb. This study shows that Pb found within the Yangtze River Intertidal Zone sediments was mainly from the catchment in the Yangtze River watershed. Significant Pb pollution was not discerned in the Yangtze River Intertidal Zone. However, Pb contamination in some localized areas was suggested by Pb enrichment factor (EF).
Liping Tian - One of the best experts on this subject based on the ideXlab platform.
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impacts of burial by sediment on decomposition and heavy metal concentrations of suaeda salsa in Intertidal Zone of the yellow river estuary china
Marine Pollution Bulletin, 2017Co-Authors: Dangyu Zhang, Xingyun Hu, Liping TianAbstract:Three one-off burial treatments were designed in Intertidal Zone of the Yellow River estuary to determine the effects of sediment burial on decomposition and heavy metal levels of Suaeda salsa. Sediment burial showed significant effect on decomposition rate of S. salsa. With increasing burial depth, Cu, Zn, Cd and Co levels generally increased, while Cr and Mn levels decreased. Except for Zn, Mn, Cd and Co, stocks of Pb, Cr, Cu, Ni and V in S. salsa among burials were greatly different. The S. salsa in three burials was particular efficient in binding V and Co and releasing Pb, Zn and Cd, and, with increasing burial depth, stocks of Cr, Cu, Ni and Mn shifted from accumulation to release. In future, the eco-toxic risk of Pb, Cr, Cu, Zn, Ni, Mn and Cd exposure might be serious as the strong burial episodes occurred in S. salsa marsh.
