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1.
The morphology and toxicity ofPseudo-nitzschia strain PP0201-01, isolated near the estuary of Changjiang (Yangtze) River in Year 2002 and tentatively identified asPseudo-nitzschia pungens, were studied. The strain was identified morphologically asP. pungens using scanning electronic microscope (SEM). The analytical results of LC-PDA (liquid chromatography with photodiode array
detector), LC-MS (liquid chromatography with mass detector), and the toxicity data from mouse bioassay, showed that no domoic
acid was produced by the strain. However, the mechanism of domoic acid production byPseudo-nitzschia species is complicated. More works are needed to assess the toxic species and to evaluate the potential risk of amnesic shellfish
poisoning (ASP) in China.
Supported by the projects of Ministry of Science and Technology (No. 2001CB409704 and No. 2001BA804A20), and the innovation
project of the Institute of Oceanology, CAS (No. 200223107). 相似文献
2.
Study on the coagulation of four species of red tide organisms(Nitzschia pungens,Skeletonema costatum,Prorocentrum minimum and Noctiluca scintillans)with montmorillonite,and the effect ofmontmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagu-late with them is in the order:N.pungens>S.costatum>P.minimum>N.scintillans.Thecoagulation is discussed from the aspects of the structure,shape,size,movement,habit,etc.of differ-ent species and the results are explained theoretically.The experimental results also indicate that the treat-ment of montmorillonite with acid can enhance its coagulating capability.This is due to the fact that Al(OH_2)_6~(+3),exchanged from the clay lattice by hydrogen ion H~+,forms hydroxy-aluminum polymers on thesurface of the montmorillonite.The hydroxy-aluminum polymers positively charge and increase the positivecharacteristic of the clay surface,and also serves as a bridge between adjacent surfaces of particles.Thesetwo functions enhance 相似文献
3.
Shu Yang Xiurong Han Chuansong Zhang Baiye Sun Xiulin Wang Xiaoyong Shi 《中国海洋大学学报(英文版)》2014,13(6):926-934
The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 μg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level(including the nutrient supply from the terrestrial runoffs) was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that diatoms were the main phytoplankton in this area, and Skeletonema costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends: 1) Skeletonema(mainly S. costatum) was dominant throughout the year; and 2) seasonal succession trends were Coscinodiscus(spring) →Chaetoceros(summer and autumn) → Coscinodiscus(winter). The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas: average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950 s-2000 s. 相似文献
4.
Phytoplankton community was investigated in the cage culture area of Daya Bay during a diurnal cycle. Two rainfalls occurred during the course of the experiment and decreased the surface seawater salinity in the aquaculture area. A total of 38 species were identified, of which the dominant species included Pseudo-nitzschia spp. and Skeletonema costatum. Water stratification obstructed the vertical migration of dinoflagellates. Statistical analysis indicated that Synechococcus showed negative relationship with silicate and ammonia, which indicated that Synechococcus adapted to grow at oligotrophic environment. Phytoplankton community structure implied the risk of Pseudo-nitzschia spp. blooms in the aquaculture area of Daya Bay. 相似文献
5.
A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin(CYP) and deltamethrin(DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments. 相似文献
6.
LIU Hui Maeve S. Kelly Dirk A. Campbell DONG Shuanglin ZHU Jianxin WANG Sufeng 《中国海洋大学学报(英文版)》2007,6(2):175-181
A simple method for spiking formulated feed with domoic acid （DA） was developed in this study. DA feed was prepared by mixing 0.15 mL 100 μg mL-1 DA with 0.1 g formulated feed, and drying the mixture at room temperature for 2 h. The prepared DA feed contained 0.19 pg DA per particle. Of the added DA, 46.72% was retained in the feed. Relatively high DA retention （about 50%） was recorded after DA feed was soaked in water for 2h. Exposure to DA feed for 7d did not cause the increase of tissue DA level of adult king scallop （Pecten maximus） significantly in 60 d. The increase of their gonad index after DA exposure was not significantly different from the control. No significant change in DA level was found in spermary, ovary or fertilized eggs after DA exposure. These results indicated that DA excretion may be more efficient than DA accumulation under the current experimental conditions, and the mechanism of domoic acid incorporation in P. maximus may involve intracellular biotransformation. 相似文献
7.
Zheng Guanchao Wu Haiyan Guo Mengmeng Peng Jixing Zhai Yuxiu Tan Zhijun 《中国海洋湖沼学报》2022,40(6):2231-2241
Journal of Oceanology and Limnology - A total of 133 shellfish samples were collected in seven cities of Shandong Province, China, from May to October, 2019. The domoic acid (DA) concentrations... 相似文献
8.
【目的】为开发用于害虫生物防治的细菌杀虫剂,对分离自红树林的一株沙雷氏菌进行鉴定并初步测试其杀虫活性。【方法】采用形态特征比较、细菌理化特性测定和基于16S rDNA序列构建系统发育树对从湛江红树林根际分离的菌株ZJ9进行综合鉴定,采用喂毒法和注射法进行杀虫活性测定。【结果】该菌为黏质沙雷氏菌Serratia marcescens,对草地贪夜蛾3龄幼虫7d校正死亡率为80.21%,且与苏云金芽孢杆菌和隐地杆菌无显著差异,菌体及菌液对大蜡螟老熟幼虫血腔注射24 h死亡率均达100%。【结论】菌株ZJ9为黏质沙雷氏菌,对草地贪夜蛾具有很好杀虫活性,可用作害虫的生物防治资源。 相似文献
9.
A psychrophilic bacterium strain 547 producing cold-adaptive alkaline protease was isolated from the deep sea sediment of Prydz Bay, Antarctica. The organism was identified as a Planomicrobium species by 16S rRNA analysis. The optimal and highest growth temperatures for strain 547 were 15℃ and 30℃, respectively. The extracellular protease was purified by ammonium sulfate precipitation and DEAE cellulose-52 chromatography. The optimal temperature and pH for the activity of the purified enzyme were 35 ℃ and pH 9.0, respectively. The enzyme retained approximately 40% of its activity after 2 h of incubation at 50℃. The enzymatic activity was inhibited by 1 mmol/L phenylmethyl sulfonylfluoride (PMSF) and hydrochloride 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), indicating that it was a serine protease. The presence of Ca2+ and Mn2+ increased the activity of the enzyme. The protease gene with a size of 1 269 bp was cloned from Planomicrobium sp. 547 using primers designed based on the conserved sequences of proteases in GenBank. The Planomicrobium sp. 547 protease contained a domain belonging to the peptidase S8 family, which has a length of 309 amino acid (AA) residues. The alignment and phylogenetic analysis of the AA sequence indicated that the protease belonged to the subtilisin family. 相似文献
10.
Zhang Anqi Liu Honghan Li Chenhong Chen Changping Liang Junrong Sun Lin Gao Yahui 《中国海洋湖沼学报》2022,40(6):2401-2415
Toxic and harmful algal blooms are usually more frequent in mariculture areas due to the abundant trophic conditions. To investigate the relationship between toxic and harmful microalgae and environmental factors, we set up 12 stations near three mariculture regions (Gouqi Island, Sandu Bay, and Dongshan Bay) in the East China Sea. We collected samples from all four seasons starting from May 2020 to March 2021. We identified 199 species belonging to 70 genera, of which 38 species were toxic and harmful, including 24 species of Dinophyceae, 13 species of Bacillariophyceae, and 1 species of Raphidophyceae. The species composition of toxic and harmful microalgae showed a predominance of diatoms in the summer (August), and dinoflagellates in the spring (May), autumn (November), and winter (March). The cell densities of toxic and harmful microalgae were higher in summer (with an average value of 15.34×103 cells/L) than in other seasons, 3.53×103 cells/L in spring, 1.82×103 cells/L in winter, and 1.0×103 cells/L in autumn. Pseudonitzschia pungens, Prorocentrum minimum, Paralia sulcata, and Prorocentrum micans were the dominant species and were available at all 12 stations in the three mariculture areas. We selected 10 toxic and harmful microalgal species with frequency >6 at the survey stations for the redundancy analysis (RDA), and the results show that NO ?3 , water temperature (WT), pH, DO, and NO ?2 were the main factors on distribution of toxic and harmful microalgae. We concluded that the rich nutrient conditions in the East China Sea mariculture areas increased the potential for the risk of toxic and harmful microalgal bloom outbreaks.
相似文献11.
【目的】通过化学诱导方法从一株海洋真菌Hypocrea lixii中获得多样化的活性小分子化合物。【方法】对菌株在盐酸普鲁卡因的化学诱导作用下进行固体发酵,代谢产物采用硅胶减压柱层析、Sephadex LH-20以及pHPLC等手段分离纯化,对化合物运用NMR、MS等波谱学技术并比对文献进行结构鉴定,采用Ellman比色法及DPPH自由基清除法对化合物进行初步抗乙酰胆碱酯酶(AChE)和抗氧化活性测试。【结果】从海洋真菌Hypocrea lixii在盐酸普鲁卡因诱导下的发酵提取物中分离得到4个异黄酮类化合物,包括6'-O-crotonylgenistin(1)、Genistein(2)、Daidzein(3)和Genistin(4),以及对氨基苯甲酸甲酯(5)、对羟基苯丙酸(6)和胞嘧啶(7),其中化合物1和6为该种中首次报道,化合物5为生物转化来源首次报道,化合物2~4可能源自培养基。在100μmol/L剂量浓度下,化合物1~4对AChE的抑制以及DPPH自由基的清除活性均较弱,化合物5和6显示了相对强的AChE抑制活性,抑制率分别为40%和38%。【结论】盐酸普鲁卡因对该菌次级代谢产生了显著的影响,为深入研究该菌株化学诱导次级代谢产物提供基础。 相似文献
12.
Precise structural identification of phospholipids in the microalga Nitzschia closterium has been established using ultra performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass
spectrometry (UPLC-ESI-Q-TOF-MS) for direct analysis of total lipid extracts. Mass spectrometry was performed in reflective
time-of-flight using electron spraying ionization in negative mode. Phospholipid molecular species identification was based
on the characteristic product ions and neutral loss yielded by different phospholipids under ESI-MS/MS mode. The molecular
species were confirmed by the carboxylate anions produced by phospholipids in negative mode; the regiospecificity of the two
acyl chains was determined from the ratio of sn-1 to sn-2 carboxylate anion abundances. As a result, 18 lipid molecular species were identified for the first time in this microalga,
comprising seven phosphatidylcholines (PC), two phosphatidylethanolamines (PE), two phosphatidylinositols (PI), and seven
phosphatidylglycerols (PG). Lipid standards of PC, PE, PI, and PG were added to the total lipids as internal standards for
semiquantitative analysis, revealing concentrations of phospholipids in this species between 0.09 and 3.37 nmol/mg. This method
can produce a full structural profile of intact phospholipid molecular species and can be used for study of the physiological
and ecological functions of lipids by monitoring their individual changes over time. 相似文献
13.
A harmful algae bloom (HAB) is a dense aggregation of algae in a marine or aquatic environment that can result in significant
environmental problems. To forecast the occurrence of HAB, development of a rapid and precise detection method is urgently
required. In this study, two Skeletonema costatum-like diatoms (SK-1 and SK-2), were identified morphologically under a light microscope, and detected using fluorescent in situ hybridization (FISH). Strain SK-1 was isolated from a frequently HAB affected area of the East China Sea, and strain SK-2
from an aquatic farm in Qingdao, China. Fluorescent DNA probes were designed that were complementary to the ITS sequence (including
5.8S rDNA) of strain SK-1. After hybridization, strong green fluorescence was observed in cells of strain SK-1 under an epifluorescence
microscope; however, no such fluorescence was observed with strain SK-2, which indicates that probes hybridized only the DNA
of the target strain, SK-1, in species-specific manner, and that the two strains do not belong to a same species. This finding
was confirmed by ITS sequence analysis. The FISH technique used in this study was sensitive, simple, and rapid, and is a promising
tool for detecting target HAB species in natural environments. 相似文献
14.
Wenjun Han Jingyan Gu Qiujie Yan Jungang Li Zhihong Wu Qianqun Gu Yuezhong Li 《中国海洋大学学报(英文版)》2012,11(3):375-382
Bacteria of the genus Flammeovirga can digest complex polysaccharides (CPs), but no details have been reported regarding the CP depolymerases of these bacteria. MY04, an agarolytic marine bacterium isolated from coastal sediments, has been identified as a new member of the genus Flammeovirga. The MY04 strain is able to utilize multiple CPs as a sole carbon source and grows well on agarose, mannan, or xylan. This strain produces high concentrations of extracellular proteins (490 mg L-1 ± 18.2 mg L-1 liquid culture) that exhibit efficient and extensive degradation activities on various polysaccharides, especially agarose. These proteins have an activity of 310 U mg-1 ± 9.6 U mg-1 proteins. The extracellular agarase system (EAS) in the crude extracellular enzymes contains at least four agarose depolymerases, which are with molecular masses of approximately 30-70 kDa. The EAS is stable at a wide range of pH values (6.0-11.0), temperatures (0-50℃), and sodium chloride (NaCl) concentrations (0- 0.9 mol L-1). Two major degradation products generated from agarose by the EAS are identified to be neoagarotetraose and neoagarohexaose, suggesting that β-agarases are the major constituents of the MY04 EAS. These results suggest that the Flammeovirga strain MY04 and its polysac-charide-degradation system hold great promise in industrial applications. 相似文献
15.
Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands,East China Sea 总被引：1，自引：0，他引：1
A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identifi ed, and D. caudat a was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×10 2 cells/L in surface water and 1.25×10 2 cells/L in bottom water(10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid(OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit(20 μg OA eq./100 g meat). Ten out of fi fteen wild samples(66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat(more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities(80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July. 相似文献
16.
【目的】综述重金属元素镉Cd和铜Cu对海洋浮游植物的毒性效应研究,总结重金属对海洋浮游植物的毒性作用机制,为开展重金属对海洋浮游植物毒害机理的深入研究提供借鉴。【方法】以毒理实验中常用的重金属镉和铜为代表,总结了重金属对海洋浮游植物毒理研究的常用测试指标,归纳了重金属对海洋浮游植物光合作用、抗氧化系统等方面的毒性作用机制。【结果】重金属对海洋浮游植物毒性作用机制概括为:1)重金属替换与其结构相似的作为酶辅助因子的金属元素,使浮游植物体内某些酶失活;2)重金属直接或间接诱导活性氧的产生,使浮游植物受到氧化胁迫;3)重金属与生物大分子中的某些基团亲和性高而结合,阻断相关的生理生化过程。【结论】重金属的毒性效应因浮游植物种类不同而有所差异,今后相关研究中需更加关注重金属在多种海洋浮游植物共存环境下的毒性效应及机制,将有助于全面系统地理解重金属对海洋浮游植物的致毒机理。 相似文献
17.
Cadmium(Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem,affecting the phytoplankton community and primary productivity.In this study,we identified the toxicity threshold of Cd for phytoplankton under seawater conditions of the coastal East China Sea(ECS) through both laboratory and in situ mesocosm incubation experiments.The mesocosm experiment showed that Cd in low concentration(0.003 μg per μg chl a) was conducive to the growth of natural community and increased chl a productivity.In high concentration(0.03 μg per μg chl a) Cd acted as an inhibiting factor which decreased the total chl a productivity.The diatom community was found to be more sensitive to Cd toxicity than dinoflagellate,as the low concentration Cd showed toxicity to diatom but enhanced dinoflagellate growth.We noticed that the soluble Cd estimated from atmosphere deposition to the coastal ECS was below the toxicity threshold and the Cd deposition might promote phytoplankton growth in this region.In our laboratory experiments,adding Cd,similar to aerosol deposition,stimulated the growth of both dominant algal species Prorocentrum donghaiense Lu(dinoflagellate) and Skeletonema costatum(diatom).Adding Cd on a higher level inhibited the growth of both the species,but Skeletonema costatum seemed obviously more sensitive to toxicity.This indicates the potential impact of atmospheric deposition Cd on phytoplankton community succession in the ECS. 相似文献
18.
Geng Huixia Sun Hongxiao Liu Chao Kong Fanzhou Zhang Qingchun Yan Tian Yu Rencheng 《中国海洋湖沼学报》2022,40(6):2218-2230
Lipophilic marine toxins (LMTs) produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers. Phytoplankton and shellfish samples were collected from coastal waters of Weihai in Shandong Peninsula, China in autumn, 2020, and screened for lipophilic marine toxins and their potential producers using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and high throughput sequencing of partial DNA (V4 region of the 18S rRNA gene) extracted from phytoplankton. Pectenotoxin-2 (PTX2), trace amounts of azaspiracid (AZA1 or AZA40), and 13-desmethyl spirolide C (13-DesMe-C) were detected in phytoplankton samples, while PTX2 and gymnodimine (GYM) were detected in shellfish samples. The toxin content in shellfish samples was much lower than the regulatory limit or values reported previously. Results suggest that lipophilic marine toxins should have low risk in coastal waters of Weihai in autumn. Based on the data of high throughput sequencing, the OTUs were assigned to 5 identified species of Alexandrium, including A. ostenfeldii capable of producing 13-DesMe-C and GYM. Two OTUs were found closely related to the toxic species in genus Dinophysis, but it is impossible to assign them to any identified species due to the low resolving power of the V4 region for Dinophysis. The OTUs could not be assigned to any identified species in the genus Azadinium, suggesting the existence of unidentified species in this region.
相似文献19.
高效液相色谱法检测水产品中的孔雀石绿和结晶紫 总被引：3，自引：0，他引：3
样品中的孔雀石绿、结晶紫经试剂盒提取,浓缩后用经固相萃取柱净化、硼氢化钾还原、反向色谱柱分离,使用荧光检测器检测,孔雀石绿、结晶紫的加标回收率在76.1%～92.5%之间,相对标准偏差1.9%～5.8%,检出限均为0.5μg/kg。结果表明:该方法检测孔雀石绿(MG)、结晶紫(GV)处理简单,灵敏度高,节省时间,可用于大量样品的快速分析。 相似文献
20.
《中国海洋大学学报(英文版)》2016,(2)
The information of trophic relationship is important for studying the Southern Ocean ecosystems.In this study,three dominant krill species,Euphausia superba,Thysanoessa macrura and Euphausia crystallorophias,were collected from Prydz Bay,Antarctica,during austral summer of 2009/2010.The composition of fatty acids in these species was studied.E.superba and T.macrura showed a similar fatty acid composition which was dominated by C14:0,C16:0,EPA(eicosapentenoic acid) and DHA(decosahexenoic acid) while E.crystallorophias showed higher contents of C18:1(n-9),C18:1(n-7),DHA and EPA than the former two.Higher fatty acid ratios of C18:1(n-9)/18:1(n-7),PUFA(polyunsaturated fatty acid)/SFA(saturated fatty acid),and 18PUFA/16 PUFA indicated that E.crystallorophias should be classified as a typical omnivore with a higher trophic position compared with E.superba and T.macrura. 相似文献