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Contribution of phytoliths to total biogenic silica volumes in the tropical rivers of Malaysia and associated implications for the marine biogeochemical cycle 被引量:2
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作者 臧家业 刘森 +2 位作者 刘焱光 马永星 冉祥滨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第5期1076-1084,共9页
The contribution of phytoliths to total biogenic silica(BSi) volumes in rivers worldwide,and the associated implications for the biogeochemical cycle,require in-depth study.Based on samples from rivers in Peninsular M... The contribution of phytoliths to total biogenic silica(BSi) volumes in rivers worldwide,and the associated implications for the biogeochemical cycle,require in-depth study.Based on samples from rivers in Peninsular Malaysia,this project investigated the source and characteristics of B Si found in Asian tropical rivers,as well as the process of reverse weathering taking place in these fluvial systems.Results indicated that BSi samples collected in sediments consisted of phytolith,diatom and sponge spicules.Phytoliths,predominantly of the elongate form,comprised 92.8%-98.3% of BSi in the Pahang River.Diatom BSi in this river consisted mainly of pennatae diatoms,but represented a relatively small proportion of the total BSi volume.However,diatom BSi(predominantly of the Centricae form) was more prevalent in the Pontian and Endau Rivers with shares of 68.8% and 79.3% of the total BSi volumes,respectively,than Pahang River.Carbon contents of the BSi particulates ranged from 1.85% to 10.8% with an average of 4.79%.These values are higher than those recorded in other studies to date,and indicate that BSi plays a major role in controlling permanent carbon burial.This study suggests that phytoliths from terrestrial plants are the primary constituents of BSi in the rivers of Peninsular Malaysia,and therefore represent a significant proportion of the coastal silica budget. 展开更多
关键词 biogenic silica PHYTOLITH DIATOM MALAYSIA biogeochemical cycle
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Allelopathic interactions between Prorocentrum micans and Skeletonema costatum or Karenia mikimotoi in laboratory cultures 被引量:6
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作者 冀晓青 韩笑天 +3 位作者 郑立 杨佰娟 俞志明 邹景忠 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期840-848,共9页
Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dino... Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. mieans and high densities of S. costatum inoculated into the same medium, the growth of R rnieans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical(s). Last, a mathematical model was used to simulate growth and interactions between P. micans and S. eostatum and between P. micans and K. mikimotoi in bi-algal cultures. 展开更多
关键词 ALLELOPATHY Prorocentrum micans Skeletonema costatum Karenia mikimotoi bi-algal culture enriched filtrate culture
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Assessment of introduced Kappaphycus (Solieriaceae, Rhodophyta) species relationships in China with molecular markers 被引量:4
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作者 LIU Chenlin HUANG Xiaohang LIU Jianguo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第2期59-65,共7页
Due to morphological plasticity and paucity of diagnostic morphological characters, the taxonomy of Kap- paphycus gets more and more confused with the expanding of commercial cultivation. In this study, the phylogenet... Due to morphological plasticity and paucity of diagnostic morphological characters, the taxonomy of Kap- paphycus gets more and more confused with the expanding of commercial cultivation. In this study, the phylogenetic relationship of 13 strains of introduced Kappaphycus species in China was defined using DNA molecular markers, such as 18S rDNA, rbcL and cox2-cox3 spacer region. The resolutions obtained by three different molecular markers were compared: both cox2--cox3 spacer region and rbcL sequences are eligible in inter- species identification of Kappaphycus, whereas cox2-cox3 spacer region is more variable than rbcL sequence. There is several basepairs' discrepancy among 18S rDNA sequences, while it is 100% identical among both cox2-cox3 spacer region and rbcL sequences of the ten strains of K. alvarezii. We suppose that 18S rDNA sequence can provide more information in biogeography study of Kappaphycus than other two DNA sequences. 展开更多
关键词 18S rDNA cox2-cox3 spacer region molecular marker Kappaphycus rbcL
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The biogenic silica composition, behavior and budget in the Changjiang Estuary 被引量:3
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作者 RAN Xiangbin LIU Jun +3 位作者 LIU Sen ZANG Jiaye WANG Baodong ZHAO Jun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第1期60-72,共13页
Three comprehensive surveys were performed in the Changjiang(Yangtze River) Estuary(CJE) to understand the biogenic silica(BSi) composition, behavior and budget. It is indicated that the BSi is composed of phyto... Three comprehensive surveys were performed in the Changjiang(Yangtze River) Estuary(CJE) to understand the biogenic silica(BSi) composition, behavior and budget. It is indicated that the BSi is composed of phytoliths,phytoplankton and sponges; phytolith BSi has 16 forms and account for 23% to 83% of the bulk BSi in the maximum turbidity zone. The budget shows that the major exogenous BSi source in the water column of the CJE is the riverine input, accounting for 95% of the total BSi input. Dominant processes that maintain BSi levels in the water column are the primary production(55 Gmol/a) and the subsequent BSi sedimentation(46 Gmol/a); and the BSi pool produced by the primary production represents two point three times the BSi loading of the Changjiang River and 63% of the BSi output, respectively. The net export(26 Gmol/a) of BSi from the CJE to the East China Sea and Yellow Sea roughly equals the riverine BSi loading. The observed total accumulation of BSi is one point seven times larger than the loading of total BSi output, with 53% to 88% of phytolith BSi and their assemblage, indicating that there has already been a "filter" of terrestrial BSi. The reverse weathering in sediments is an important process for the reactive silica removal in the CJE due to authigenic alterations. It is indicated that the phytolith fluxes in the suspended load represent a significant BSi source in the estuary, and the CJE would act as a net BSi sink. 展开更多
关键词 silica cycle DIATOMS PHYTOLITHS BUDGET Changjiang Estuary
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Numerical Simulation of Nutrient and Phytoplankton Dynamics in Guangxi Coastal Bays, China 被引量:2
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作者 QIAO Xudong WANG Baodong +1 位作者 SUN Xia LIANG Shengkang 《Journal of Ocean University of China》 SCIE CAS 2014年第2期338-346,共9页
The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads... The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads and water quality responses, which is crucial for developing eutrophication control strategies, is not well studied. In this study, the riverine fluxes of nutrients were quantified and integrated with nutrient cycling and phytoplankton dynamics by using box models for Guangxi coastal bays. The model concepts and biogeochemical equations were the same; while most model parameters were specific for each bay. The parameters were calibrated with seasonal observations during 2006–2007, and validated with yearly averaged measurements in 2009. The general features of nutrient and phytoplankton dynamics were reproduced, and the models were proved feasible under a wide range of bay conditions. Dissolved inorganic nitrogen was depleted during the spring algal bloom in Zhenzhu Bay and Fangcheng Bay with relatively less nutrient inputs. Phosphorus concentration was high in spring, which decreased then due to continuous phytoplankton consumption. Chlorophyll-a concentration reached its annual maximum in summer, but was the minimum in winter. Eutrophication was characterized by both an increase in nutrient concentrations and phytoplankton biomass in Lianzhou Bay. Either about 80% reduction of nitrogen or 70% reduction of phosphorus was required to control the algal bloom in Lianzhou Bay. Defects of the models were discussed and suggestions to the environmental protection of Guangxi coastal bays were proposed. 展开更多
关键词 ecosystem model NUTRIENT PHYTOPLANKTON seasonal variation coastal bay
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Hydrogen Peroxide Sensor Based on Horseradish Peroxidase Combined with CaCO_3 Microspheres and Gold Nanoparticles 被引量:2
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作者 ZHENG LI JIANG Feng-hua +2 位作者 MA Guang-ran ZHUANG Qian-fen LI Feng 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第5期875-879,共5页
Direct electrochemistry and electrocatalysis of horseradish peroxidase(HRP) were achieved by entrapping the enzyme between CaCO3 microspheres and gold nanoparticles through forming sandwich configuration (CaCO3-HRP... Direct electrochemistry and electrocatalysis of horseradish peroxidase(HRP) were achieved by entrapping the enzyme between CaCO3 microspheres and gold nanoparticles through forming sandwich configuration (CaCO3-HRP-AuNPs). Polyanion, poly(styrene sulfonate)(PSS), was hybrid with CaCO3 microspheres to increase the surface negative charges for binding with HRP through electrostatic interaction. After the bioconjugate CaCO3 PSS-HRP was entrapped in chitosan based sol-gel(CS-GPTMS) film, HRP was encapsulated by in situ formation of an outer layer of AuNPs through electrochemical reduction of HAuCl4. The composite film containing AuNPs, CaCO3-PSS-HRP bioconjugates and CS-GPTMS can provide favorable microenvironment for HRP to perform direct electron transfer at glassy carbon electrode(GCE). HRP retained its bioelectrocatalytic activity and lead to sensitive and fast amperometric response for the determination of H2O2. H2O2 could be detected in a very wide linear range from 5.0×10-6 mol/L to 7.1×10-2 mol/L. The sandwich configuration of CaCO3-biomolecules-AuNPs could serve as a versatile platform for enzyme immobilization and biosensing. 展开更多
关键词 Direct electrochemistry Horseradish peroxidase(HRP) CaCO3 microsphere Chitosan based sol-gel
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Preparation of Spherical Silica-supported Biosorbent for Copper Ions Removal in Wastewater Based on Sol-gel Reaction and Simple Treatment with Sodium Hydroxide 被引量:1
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作者 ZHENG Li JIANG Feng-hua +2 位作者 DONG Ping-jun ZHUANG Qian-fen LI Feng 2 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2010年第3期355-359,共5页
A new and effective strategy was proposed for preparing new organic-inorganic composite biosorbent with spherical silica as supporting core and chitosan(CS)-based hybrid layer as shell based on sol-gel reaction and ... A new and effective strategy was proposed for preparing new organic-inorganic composite biosorbent with spherical silica as supporting core and chitosan(CS)-based hybrid layer as shell based on sol-gel reaction and simple treatment with sodium hydroxide(NaOH). The coating layer was covalently bound on the supporting silica through polysaccharide incorporated sol-gel process starting from CS and inorganic precursor γ-glycidoxypropyltrimethoxysiloxane(GPTMS). GPTMS had epoxide groups and cross-linked amine groups of CS to avoid its acidic solubilization. The composite biosorbent had coarse surface due to the wet phase-inversion by treating in NaOH solution. The prepared biosorbent could be used in treating electric plating wastewater. 展开更多
关键词 CHITOSAN Sodium hydroxide BIOSORPTION Waste treatment
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Photosynthetic physiologies of phytoplankton in the eastern equatorial Indian Ocean during the spring inter-monsoon 被引量:1
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作者 Chao Yuan Zongjun Xu +3 位作者 Xuelei Zhang Qinsheng Wei Huiwu Wang Zongling Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第6期83-91,共9页
Phytoplankton physiologies are dynamic and have sensitive responses to the ambient environment. In this paper, we examine photosynthetic physiologies of phytoplankton communities with Phyto-PAM in the eastern equatori... Phytoplankton physiologies are dynamic and have sensitive responses to the ambient environment. In this paper, we examine photosynthetic physiologies of phytoplankton communities with Phyto-PAM in the eastern equatorial Indian Ocean during the spring inter-monsoon. Environmental parameters were measured to investigate the coupling between phytoplankton photosynthetic physiologies and their habitats. During the cruise, the water column was highly stratified. The mixed layer extended to about 75 m and was characterized by high temperature (>28°C) and low nutrient level. The Fv/Fm values and chlorophyll a (Chl a) concentrations were lower at the surface, as consequences of nutrient depletion and photo-inhibition. Subsurface Chl a maximum (SCM) occurred between 75 and 100 m, and had the highest Fv/Fm values. The formation of SCM was a balance between nutrient availability and light limitation. The SCM may contribute significantly to pelagic food web and primary production in the water column. Phytoplankton in different layers encountered different light, trophic and hydrographic dynamics and evolved distinct photosynthetic characteristics. Despite of co-limitation of nutrient limitation and photo-inhibition, phytoplankton in the surface layer showed their acclimation to high irradiance, had lower light utilization efficiencies (α: 0.061±0.032) and could exploit a wide range of light irradiance. Whereas, phytoplankton in the SCM layers presented the highest light utilization efficiencies (α: 0.146±0.48), which guaranteed higher photosynthetic capacities under low light level. These results provide insights into phytoplankton photo-adaption strategies in this less explored region. 展开更多
关键词 FV/FM rapid light curves PHOTOSYNTHETIC physiologies eastern EQUATORIAL INDIAN Ocean
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Degradation potential and diversity of oil-degrading bacteria isolated from the sediments of the Jiaozhou Bay, China 被引量:1
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作者 Wei Gao Xiangxing Gao +10 位作者 Tiezhu Mi Bin Han Yiran Zhang Xinzi Li Xiaofei Yin Chengjun Sun Qian Li Zhisong Cui Xiao Luan Zhigang Yu Li Zheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第6期54-64,共11页
A great deal of oil contaminated the shoreline by the Qingdao oil pipeline explosion in 2013. The four oildegrading consortia were enriched from sediment samples with crude oil as sole carbon and energy sources. The b... A great deal of oil contaminated the shoreline by the Qingdao oil pipeline explosion in 2013. The four oildegrading consortia were enriched from sediment samples with crude oil as sole carbon and energy sources. The biodiversity and community analysis showed that the Luteibacter, Parvibaculum and a genus belonging to Alcanivoracaceae were found predominant bacteria in the four consortia, which belonged to Proteobacteria. Nine strains exhibiting distinct 16S rRNA gene sequences were isolated from the consortia. These strains were identified to eight genera based on 16S rRNA gene sequences. Five of the nine strains degraded more than 30% of the crude oil in two weeks by gravimetric method. From the analysis of GC-MS, most of the isolated strains tended to degrade n-alkanes rather than PAHs. Five strains showed high degrading ability of the total n-alkanes. Only Strain D2 showed great PAHs degrading ability and the degrading rates ranged from 34.9% to 77.5%. The sequencing analysis of the oil-degrading consortia confirmed that the genus of Alcanivorax was one of the dominant bacteria in Consortia A and E and Strain E4 might be one of the dominant bacteria. The strains obtained in this study demonstrated the potential for oil bioremediation in oil-contaminated beach ecosystems. 展开更多
关键词 oil SPILL BIODEGRADATION microbial CONSORTIUM DOMINANT bacteria
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Scanning electron microscopy coupled with energydispersive X-ray spectrometry for quick detection of sulfuroxidizing bacteria in environmental water samples 被引量:1
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作者 SUN Chengjun JIANG Fenghua +5 位作者 GAO Wei LI Xiaoyun YU Yanzhen YIN Xiaofei WANG Yong DING Haibing 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第1期185-191,共7页
Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not mee... Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples. 展开更多
关键词 sulfur bacteria energy-dispersive X-ray spectrometry scanning electron microscopy bacteria detection environmental water samples 16S rRNA sequencing
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The study of the adductor muscle-shell interface structure in three Mollusc species 被引量:1
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作者 ZHU Yaoyao SUN Chengjun +4 位作者 SONG Yingfei JIANG Fenghua YIN Xiaofei TANG Min DING Haibing 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第8期57-64,共8页
The adductor muscle scar(AMS) is the fixation point of adductor muscle to the shell. It is an important organicinorganic interface and stress distribution area. Despite recent advances, our understanding of the stru... The adductor muscle scar(AMS) is the fixation point of adductor muscle to the shell. It is an important organicinorganic interface and stress distribution area. Despite recent advances, our understanding of the structure and composition of the AMS remain limited. Here, we report study on the AMS of three bivalves: Mytilus coruscus,Chlamys farreri and Ruditapes philippinarum. Results showed that there were significant differences among their AMS structures. Both M. coruscus and C. farreri were found to have a columnar layer above the nacreous platelet shell structure at the AMS and this layer was more organized in M. coruscus. There was no distinguishable twolayer structure in R. philippinarum. Atomic force microscopy(AFM) and Fourier transform infrared spectroscopy(FT-IR) results showed that the AMS was much smoother than the nacreous inner shell in all the three species and the AMS had minor different compositions from the nacreous shell layer. SDS-PAGE(sodium dodecyl-sulfate polyacrylamide gel electophoresis) study of the proteins isolated from the interface indicated that there was a 70 k Da protein which seemed to be specifically located to the highly organized columnar AMS structure in Mytilus coruscus. Further analysis of this protein showed it contained high level of Asx(Asp+Asn), Glx(Glu+Gln) and Gly.The special structure and composition of the AMS might play important roles in the stability, adhesion and function at this stress distribution site. 展开更多
关键词 mollusc shell adductor muscle-shell interface shell protein shell microstructure
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Biomarker responses in the bivalve Chlamys farreri to the water-soluble fraction of crude oil
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作者 蒋凤华 张丽 +2 位作者 杨佰娟 郑立 孙承君 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第4期853-861,共9页
To investigate the effect of the water soluble fraction of crude oil(WSF) on marine bivalves, the scallop C hlamys farreri was exposed to three WSF concentrations(0.18 mg/L, 0.32 mg/L, and 0.51 mg/L, respectively) in ... To investigate the effect of the water soluble fraction of crude oil(WSF) on marine bivalves, the scallop C hlamys farreri was exposed to three WSF concentrations(0.18 mg/L, 0.32 mg/L, and 0.51 mg/L, respectively) in seawater. Petroleum hydrocarbon contents in scallops and a suite of enzymes [7-Ethoxyresorufin-O-deethylase(EROD), aryl hydrocarbon hydroxylase(AHH), glutathione S-transferase(GST), and glutathione peroxidase(GPx)] in gills and digestive glands were monitored over 10 days. The results revealed that WSF affected the activity of the four enzymes in the gills and digestive glands. EROD activity in the gills was significantly induced in most individuals of the three test groups, while in the digestive gland it was significantly induced in the low-concentration group within 4 days but was inhibited in the middle- and high-concentration groups on days 1, 4, and 10. AHH activity in the gills of all treatment groups was significantly induced on day 1. In the digestive gland, AHH activity was induced in most individuals from the treatment groups. In all treatment groups, GST activity was significantly inhibited from days 2 to 10 in the gills and was induced after day 4 in the digestive gland. GPx activity in the gills was significantly inhibited throughout the exposure period in all treatment groups. There was no overall significant difference in GPx activity in the digestive gland between the control and treatment groups. Our results also revealed that petroleum hydrocarbon concentrations in the tissues increased linearly with exposure time. EROD activity in the digestive gland and GST and GPx activity in the gill tissue were negatively correlated with petroleum hydrocarbon body burden. These enzymes play important roles in detoxification and can act as potential biomarkers for monitoring petroleum hydrocarbon contaminants in the marine environment. 展开更多
关键词 crude oil water soluble fraction (WSF) Chlamysfarreri biomarkers DETOXIFICATION
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Phosphorus speciation,transformation and benthic processes with implications for environmental impacts in the aquaculture area of Rushan Bay
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作者 Yao Feng Jun Liu +4 位作者 Aijun Zhang Yibin Wang Lu Wang Zongqing Lv Xiangbin Ran 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第8期99-112,共14页
Phosphorus(P)is an essential nutrient for many organisms in the ocean,which plays a central role in the stability of ecosystems and the evolution of the environment.The distribution,occurrence and source-sink process ... Phosphorus(P)is an essential nutrient for many organisms in the ocean,which plays a central role in the stability of ecosystems and the evolution of the environment.The distribution,occurrence and source-sink process of P in offshore waters are highly influenced by mariculture activities.P transformation in water-sediment system is the key process in P cycling,however,the mechanism is poorly documented in the coastal sea which is influenced by human activities.Based on the comprehensive surveys in the adjacent waters outside Rushan Bay in May,July and August 2014 and February 2015,the form and transformation of P in the suspended particulate matter(SPM)and surface sediment were analyzed.The results showed that contents of total P,authigenic P and organic P of SPM increased with the increase in distance from the shoreline off Rushan Bay,and the detrital-P decreased.The partition coefficient of P between water and SPM was related to the chemical activity of different forms of P,and a higher reactivity of inorganic P associated with SPM was observed.Hypoxia induced by mariculture changes the distribution and morphological composition of P in SPM and sediment in this typical aquaculture area,which can result in a conversion of sink to source of P in the sediment,thereby having a significant impact on the regional nutrient budget and associated with eutrophication. 展开更多
关键词 phosphorus speciation TRANSFORMATION benthic process AQUACULTURE Rushan Bay
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Degradation of lipids in seasonal hypoxic seawater under different oxygen saturation
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作者 HE Yunhong SUN Chengjun +2 位作者 LI Wenjuan YANG Gui-Peng DING Haibing 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第5期1570-1585,共16页
The hypoxic phenomena of seawater have been found in the Changjiang esturay and its adjacent area for several decades. To study organic matter degradation in seasonal hypoxic seawater, series of stimulated incubation ... The hypoxic phenomena of seawater have been found in the Changjiang esturay and its adjacent area for several decades. To study organic matter degradation in seasonal hypoxic seawater, series of stimulated incubation experiments with S keletonema costatum in seawater under different oxygen saturations were conducted. By tracking variations of lipids originated from the alga, time-dependent concentrations of neutral lipids(hexadecanol, otctadecanol, cholesterol, brassicasterol and phytol) and fatty acids(12:0, 14:0, 16:0, 16:1, 18:0, 18:1(9), 20:5 and 22:6) were obtained during three month of incubation. The results indicate that residence time, oxygen saturation, bacterial community and the structure of lipids were key factors controlling preservation and degradation of lipids in seawater. The degradation rate constants calculated from multi-G model showed that under same oxygen saturation, algal fatty acid degraded faster than neutral lipids, and unsaturated fatty acids degraded faster than saturated fatty acids. Our new discovery showed that degradation rate constant had linear positive correlation with oxygen saturation of seawater, indicating the critical role of oxygen on degradation of algal lipids in hypoxic seawater. The results of this study will be helpful to understand organic carbon cycling in seawater and marine environment more deeply. Future field experiments and investigation should be conducted tracking control factors, especially the role of oxygen saturation on organic matter degradation in natural environment. 展开更多
关键词 organic matter degradation seasonal hypoxia LIPIDS fatty acids the Changjiang River estuary
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Vertical variations and composition of dissolved free amino acid in the seawater of the Yap Trench in the western Pacific Ocean
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作者 Jiaohong NIU Chengjun SUN +7 位作者 Bo YANG Lei XIE Fenghua JIANG Wei CAO Yan CHEN Haibing DING Yuhuan HUANG Xianchi GAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期118-137,共20页
The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column der... The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column derivatization of o-phthalaldehyde.Results show that the average concentration of DFAA in the study area was 0.47±0.36μmol/L.In different sampling stations,the concentrations of DFAA with water depth showed complex variation patterns.At the sediment-seawater interface,the concentrations of DFAA in the western side of the trench were obviously higher than that in its eastern side.In the study area,there were no significant correlations between the concentrations of DFAA and the environmental parameters such as concentrations of chlorophyll a(Chl a),dissolved oxygen(DO),pH,and dissolved inorganic nitrogen(DIN),indicating that the concentrations of DFAA in seawater of the trench are affected by many factors,such as photosynthesis,respiration,temperature,pressure,illumination,and circulation.The dominant DFAA are similar in different water layers of sampling stations,including aspartic acid(Asp),glutamic acid(Glu),glycine(Gly),and serine(Ser).The composition of different amino acids,and the relative abundance of acidic,basic,and neutral amino acids might be related to the sources and consumption of various amino acids.Nine pairs of amino acids in the DFAA showed significantly positive relationship by correlation matrix analysis,suggesting that they might share similar biogeochemical processes.The degradation index(DI)of the DFAA in seawater of the Yap Trench could reflect the degradation,source,and freshness of DFAA in the trench to some extents.This is a preliminary study of amino acids from sea surface to hadal zone in the ocean,more works shall be done in different trenches to reveal their biogeochemical characte ristics in extreme marine environme nts. 展开更多
关键词 dissolved free amino acid(DFAA) Yap Trench "Jiaolong"submersible ABYSS hadal zone degradation Index(DI)
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Phylogenetic analysis and in vitro culture of mosses fromthe Antarctic Fildes Peninsula
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作者 LIU Shenghao ZHANG Zhaohui +4 位作者 WANG Nengfei CONG Bailin ZHANG Pengying LIN Xuezheng HUANG Xiaohang 《Advances in Polar Science》 2014年第2期97-104,共8页
Molecular genetic techniques have proven very useful for initial analysis of the extent of genetic variation and dispersal in several Antarctic moss species. In the present study, the small subunit ribosomal RNA (SSU... Molecular genetic techniques have proven very useful for initial analysis of the extent of genetic variation and dispersal in several Antarctic moss species. In the present study, the small subunit ribosomal RNA (SSU rDNA) and internal transcribed spacers of the nuclear ribosomal DNA (ITS rDNA) were sequenced in nine individuals of different mosses from the Fildes Peninsula of Antarctica. Sequence alignment showed that the extreme environment tended to increase the genetic diversity of Antarctic mosses. In addition, in our phylogenetic analysis, one previously unidentified Antarctic moss species was characterized by comparison with SSU and ITS rDNA sequences of known moss species. Moreover, the optimal culture medium and conditions for surface explant sterilization and protonemata induction in tissue culture of Pohlia nutans were investigated. The successful establishment of a tissue culture protocol together with the phylogenetic analysis of Antarctic mosses will provide technological support to establish an effective resource regeneration method for discovering new functional genes and gaining novel insights into the mechanisms of stress acclimation. 展开更多
关键词 phylogenetic tree tissue culture protonemata formation Pohlia nutans
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Land-Sea Interactions in Punta China(Baja California,Mexico):Addressing Anthropic and Natural Disturbances in a Retrospective Context
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作者 Guillermo Torres-Moye Anamaria Escofet 《Journal of Environmental Protection》 2014年第16期1520-1530,共11页
In extensive SCUBA-diving surveys of kelp forests along 350 km of the Baja California peninsula coastline from the US-México borderline to Sacramento Reef, benthic species richness has been satisfactorily explain... In extensive SCUBA-diving surveys of kelp forests along 350 km of the Baja California peninsula coastline from the US-México borderline to Sacramento Reef, benthic species richness has been satisfactorily explained by environmental structural features such as bottom rugosity. However, values at Punta China embayment (PCE) departed significantly from the model whereas the adjacent Santo Tomás cove (STC) did not. In addition, in August 20, 2011, visibility was under 1 m at PCE and over 10 m at STC;these conditions presumably reflect the influence of the limestone extraction industry located on land. In order to investigate the case allowing for temporal comparisons, we set a regional research scenario similar to a 1993 pioneer study, comprising PCE and two contrasting sites (STC to the North, and San José embayment, SJE, to the South). Land and sea side were addressed separately, and a 1950-2012 time-span period was set in order to perform the analysis of retrospective data. Our results suggest that the current scenario results from the combined influence of a local, anthropic and chronic land-based disturbance represented by the progressive expansion of limestone extraction industry, and the episodic influence of a natural, large scale and acute disturbance represented by the 1982-83 and 1997-98 El Nino events. The influence of both driving forces, however, is not necessarily equally distributed in space, yielding a regional mosaic of natural and social conditions. Our results confirm and expand previous knowledge in the area, and may contribute to?future basic and applied research. 展开更多
关键词 Mexican Pacific Embayments Mining Industry El Nino Events Kelp Beds Safari Method
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In vitro iron enrichment experiments in the Prydz Bay, the Southern Ocean: A test of the iron hypothesis 被引量:2
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作者 SUN Song PU XinMing ZHANG YongShan 《Science China Earth Sciences》 SCIE EI CAS 2009年第9期1426-1435,共10页
In "high nitrate, low chlorophyll" (HNLC) ocean regions, iron has been typically regarded as the limiting factor for phytoplankton production. This "iron hypothesis" needs to be tested in various o... In "high nitrate, low chlorophyll" (HNLC) ocean regions, iron has been typically regarded as the limiting factor for phytoplankton production. This "iron hypothesis" needs to be tested in various oceanic environments to understand the role of iron in marine biological and biogeochemical processes. In this paper, three in vitro iron enrichment experiments were performed in Prydz Bay and at the Polar Front north of the Ross Sea, to study the role of iron on phytoplankton production. At the Polar Front of Ross Sea, iron addition significantly (P<0.05, Student's t-test) stimulated phytoplankton growth. In Prydz Bay, however, both the iron treatments and the controls showed rapid phytoplankton growth, and no significant effect (P>0.05, Student's t-test) as a consequence of iron addition was observed. These results confirmed the limiting role of iron in the Ross Sea and indicated that iron was not the primary factor limiting phytoplankton growth in Prydz Bay. Because the light environment for phytoplankton was enhanced in experimental bottles, light was assumed to be responsible for the rapid growth of phytoplankton in all treatments and to be the limiting factor controlling field phytoplankton growth in Prydz Bay. During the incubation experiments, nutrient consumption ratios also changed with the physiological status and the growth phases of phytoplankton cells. When phytoplankton growth was stimulated by iron addition, N was the first and Si was the last nutrient which absorption enhanced. The Si/N and Si/P consumption ratios of phytoplankton in the stationary and decay phases were significantly higher than those of rapidly growing phytoplankton. These findings were helpful for studies of the ma- rine ecosystem and biogeochemistry in Prydz Bay, and were also valuable for biogeochemical studies of carbon and nutrients in various marine environments. 展开更多
关键词 IRON LIMITATION IRON HYPOTHESIS Southern Ocean PRYDZ Bay NUTRIENT consumption ratio
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Interactions between natural biofilm,substratum surface wettability,and mussel plantigrade settlement
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作者 YANG JinLong GUO XingPan +4 位作者 DING DeWen GAO Wei HUANG DaoFen CHEN YuRu LIANG Xiao 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第2期382-390,共9页
Mytilus galloprovincialis is a major fouling organism in the inter-tidal zone.However,the interactions between M.galloprovincialis plantigrade settlement,biofilm characteristics,and surface wettability remains unknown... Mytilus galloprovincialis is a major fouling organism in the inter-tidal zone.However,the interactions between M.galloprovincialis plantigrade settlement,biofilm characteristics,and surface wettability remains unknown.Here,we examined M.galloprovincialis plantigrade settlement responses to marine biofilms(BFs)on surfaces of varying wettability.No significant difference in mussel settlement was observed on young BFs(7 d)on surfaces of differing wettability;while settlement decreased on older BFs(14,21,and 28 d)formed on low compared to high wettability surfaces.Surface wettability affected BF characteristics.The standardized harmonic mean and water contact angles values were not correlated with diatom density and chlorophyll a concentration,but were correlated with bacterial density,dry weight,and thickness.Denaturing gradient gel electrophoresis revealed that bacterial community structure differed on BFs on surfaces of varying wettability.Thus,surface wettability affects biofilm characteristics,and the subsequent changes in BF characteristics may be responsible for the variation in biofilm-inducing activity of M.galloprovincialis plantigrade settlement. 展开更多
关键词 Mytilus galloprovincialis Plantigrade settlement Biofilms Surface wettability Bacterial community
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耐盐碱解磷菌Bacillus sp.DYS211对土壤磷溶解和植物生长的促进作用
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作者 Wei Wang Xiaodan Sun +5 位作者 Wenhao Huang Xiaoting Men Shijie Yi Fengrong Zheng Zhaohui Zhang Zongling Wang 《Journal of Plant Ecology》 SCIE CSCD 2023年第6期172-184,共13页
土壤全磷含量高而速效磷含量不足严重制约盐碱地区磷的高效利用。虽然耐盐碱解磷菌可以溶解不溶性磷,但很少有研究关注其在植物生长中的应用。我们从盐碱地区鸟粪中分离到一株解磷菌,鉴定命名为Bacillus sp.DYS211,并对其生长特性和耐... 土壤全磷含量高而速效磷含量不足严重制约盐碱地区磷的高效利用。虽然耐盐碱解磷菌可以溶解不溶性磷,但很少有研究关注其在植物生长中的应用。我们从盐碱地区鸟粪中分离到一株解磷菌,鉴定命名为Bacillus sp.DYS211,并对其生长特性和耐盐碱能力进行了测定。为研究解磷菌对植物种子萌发和生长的影响,在盐地碱蓬中进行解磷菌添加的盆栽试验。该解磷菌菌株在培养前12 h生长迅速,48 h时溶磷量最大,达到258.22 mg L^(−1)。耐盐碱性和解磷能力试验表明,DYS211倾向于溶解无机磷,为嗜盐菌,在1%–8%盐度条件下具有良好的解磷效果(有效磷含量>150 mg L^(−1))。在葡萄糖和蔗糖(C源)以及硫酸铵、硝酸铵和酵母浸膏粉(N源)中均表现出较好的解磷能力。在促生长试验中,该解磷菌对种子萌发有促进作用,特别是在高盐胁迫下,促进率为8.33%。在盐碱条件下,解磷菌均能显著提高盐地碱蓬的株高和生物量(最高可达3倍),且高盐胁迫下茎粗增加。该菌株表现出在盐碱地区植被恢复中的潜力。 展开更多
关键词 有效磷 解磷菌 盐地碱蓬(Suaeda salsa) 种子萌发 植物生物量
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