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Nina Lundholm - One of the best experts on this subject based on the ideXlab platform.
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occurrence of pseudo Nitzschia species and associated domoic acid production along the guangdong coast south china sea
Harmful Algae, 2020Co-Authors: Huan Chang Dong, Nina Lundholm, Sing Tung Teng, Chao WangAbstract:Abstract The diatom genus Pseudo-Nitzschia, which has been associated with amnesic shellfish poisoning events globally, is also one of the key harmful microalga groups in Guangdong coastal waters, off the north coast of the South China Sea. In order to explore the diversity and toxigenic characteristics, Pseudo-Nitzschia isolates were established. Based on a combination of morphological and molecular features, in total 26 different Pseudo-Nitzschia taxa were identified, including two new species, P. uniseriata H.C. Dong & Yang Li and P. yuensis H.C. Dong & Yang Li. Morphologically, P. uniseriata is unique by having striae mainly comprising one row of poroids, which are simple without divided hymen internally, and each poroid containing one, seldom two sectors. Pseudo-Nitzschia yuensis is characterized by having striae comprising one to two rows of poroids. In biseriate striae, the poroids are polygonal and irregularly distributed, and a discontinuous row of poroids may be present in the middle. In uniseriate striae, the poroids usually contain 1–5 sectors. Both taxa are well differentiated from other Pseudo-Nitzschia species in phylogenetic analyses inferred from ITS2 sequence-structure information. Pseudo-Nitzschia uniseriata is sister to P. lineola, whereas P. yuensis forms a group together with P. micropora and P. delicatissima. When comparing ITS2 secondary structure, two hemi-compensatory base change (HCBCs) are found between P. uniseriata and P. lineola. One compensatory base change (CBC) and four HCBCs are found between P. yuensis and P. delicatissima, and there is one CBC and five HCBCs between P. yuensis and P. micropora. The ability of cultured strains to produce particulate DA (pDA) revealed production of pDA in twenty-nine strains belonging to seven species: P. bipertita, P. caciantha, P. cuspidata, P. fraudulenta, P. fukuyoi, P. lundholmiae and P. multiseries. This is the first report of P. bipertita being toxic, with pDA content of 15.6 ± 2.1 fg cell–1. The presence of brine shrimps significantly increased pDA content in P. cuspidata, P. fukuyoi, P. lundholmiae and P. multiseries 1.4 to 7 times, and induced pDA production in P. fraudulenta from below detection limit to 17.5 ± 1.6 fg cell–1. The highest pDA concentration, 4830.5 ± 120.3 fg cell–1, was detected in P. multiseries, a level much lower than previous reports on P. multiseries from North America and Europe. Overall, the cellular toxin levels in Pseudo-Nitzschia spp. were low in Guangdong coastal isolates.
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pseudo Nitzschia Nitzschia and domoic acid new research since 2011
Harmful Algae, 2018Co-Authors: Stephen S Bates, Nina Lundholm, Katherine A Hubbard, Marina Montresor, Chui, Pin LeawAbstract:Abstract Some diatoms of the genera Pseudo-Nitzschia and Nitzschia produce the neurotoxin domoic acid (DA), a compound that caused amnesic shellfish poisoning (ASP) in humans just over 30 years ago (December 1987) in eastern Canada. This review covers new information since two previous reviews in 2012. Nitzschia bizertensis was subsequently discovered to be toxigenic in Tunisian waters. The known distribution of N. navis-varingica has expanded from Vietnam to Malaysia, Indonesia, the Philippines and Australia. Furthermore, 15 new species (and one new variety) of Pseudo-Nitzschia have been discovered, bringing the total to 52. Seven new species were found to produce DA, bringing the total of toxigenic species to 26. We list all Pseudo-Nitzschia species, their ability to produce DA, and show their global distribution. A consequence of the extended distribution and increased number of toxigenic species worldwide is that DA is now found more pervasively in the food web, contaminating new marine organisms (especially marine mammals), affecting their physiology and disrupting ecosystems. Recent findings highlight how zooplankton grazers can induce DA production in Pseudo-Nitzschia and how bacteria interact with Pseudo-Nitzschia. Since 2012, new discoveries have been reported on physiological controls of Pseudo-Nitzschia growth and DA production, its sexual reproduction, and infection by an oomycete parasitoid. Many advances are the result of applying molecular approaches to discovering new species, and to understanding the population genetic structure of Pseudo-Nitzschia and mechanisms used to cope with iron limitation. The availability of genomes from three Pseudo-Nitzschia species, coupled with a comparative transcriptomic approach, has allowed advances in our understanding of the sexual reproduction of Pseudo-Nitzschia, its signaling pathways, its interactions with bacteria, and genes involved in iron and vitamin B12 and B7 metabolism. Although there have been no new confirmed cases of ASP since 1987 because of monitoring efforts, new blooms have occurred. A massive toxic Pseudo-Nitzschia bloom affected the entire west coast of North America during 2015–2016, and was linked to a ‘warm blob’ of ocean water. Other smaller toxic blooms occurred in the Gulf of Mexico and east coast of North America. Knowledge gaps remain, including how and why DA and its isomers are produced, the world distribution of potentially toxigenic Nitzschia species, the prevalence of DA isomers, and molecular markers to discriminate between toxigenic and non-toxigenic species and to discover sexually reproducing populations in the field.
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Induction of domoic acid production in diatoms-Types of grazers and diatoms are important.
Harmful Algae, 2018Co-Authors: Nina Lundholm, Bernd Krock, Torkel Gissel Nielsen, Sylke Wohlrab, Uwe John, Jette Skov, Jinfeng Cheng, Marina Pančić, Kristie Rigby, Erik SelanderAbstract:Abstract Grazers can induce toxin (domoic acid, DA) production in diatoms. The toxic response has been observed in two species of Pseudo-Nitzschia and was induced by Calanus copepods. In this study, interactions between diatoms and copepods were further explored using different species of diatoms and copepods. All herbivorous copepods induced toxin production, whereas exposure to carnivorous copepods did not. In line with this, increasing the number of herbivorous copepods resulted in even higher toxin production. The induced response is thus only elicited by copepods that pose a real threat to the responding cells, which supports that the induced toxin production in diatoms evolved as an inducible defense. The cellular toxin content in Pseudo-Nitzschia was positively correlated to the concentration of a group of specific polar lipids called copepodamides that are excreted by the copepods. This suggests that copepodamides are the chemical cues responsible for triggering the toxin production. Carnivorous copepods were found to produce less or no copepodamides. Among the diatoms exposed to grazing herbivorous copepods, only two of six species of Pseudo-Nitzschia and none of the Nitzschia or Fragilariopsis strains responded by producing DA, indicating that not all Pseudo-Nitzschia species/strains are able to produce DA, and that different diatom species might have different strategies for coping with grazing pressure. Growth rate was negatively correlated to cellular domoic acid content indicating an allocation cost associated with toxin production. Long-term grazing experiments showed higher mortality rates of grazers fed toxic diatoms, supporting the hypothesis that DA production is an induced defense mechanism.
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pseudo Nitzschia simulans sp nov bacillariophyceae the first domoic acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-Nitzschia simulans sp. nov. (Bacillariophyceae), the first domoic acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
Zhijun Tan - One of the best experts on this subject based on the ideXlab platform.
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pseudo Nitzschia simulans sp nov bacillariophyceae the first domoic acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-Nitzschia simulans sp. nov. (Bacillariophyceae), the first domoic acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
Sing Tung Teng - One of the best experts on this subject based on the ideXlab platform.
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occurrence of pseudo Nitzschia species and associated domoic acid production along the guangdong coast south china sea
Harmful Algae, 2020Co-Authors: Huan Chang Dong, Nina Lundholm, Sing Tung Teng, Chao WangAbstract:Abstract The diatom genus Pseudo-Nitzschia, which has been associated with amnesic shellfish poisoning events globally, is also one of the key harmful microalga groups in Guangdong coastal waters, off the north coast of the South China Sea. In order to explore the diversity and toxigenic characteristics, Pseudo-Nitzschia isolates were established. Based on a combination of morphological and molecular features, in total 26 different Pseudo-Nitzschia taxa were identified, including two new species, P. uniseriata H.C. Dong & Yang Li and P. yuensis H.C. Dong & Yang Li. Morphologically, P. uniseriata is unique by having striae mainly comprising one row of poroids, which are simple without divided hymen internally, and each poroid containing one, seldom two sectors. Pseudo-Nitzschia yuensis is characterized by having striae comprising one to two rows of poroids. In biseriate striae, the poroids are polygonal and irregularly distributed, and a discontinuous row of poroids may be present in the middle. In uniseriate striae, the poroids usually contain 1–5 sectors. Both taxa are well differentiated from other Pseudo-Nitzschia species in phylogenetic analyses inferred from ITS2 sequence-structure information. Pseudo-Nitzschia uniseriata is sister to P. lineola, whereas P. yuensis forms a group together with P. micropora and P. delicatissima. When comparing ITS2 secondary structure, two hemi-compensatory base change (HCBCs) are found between P. uniseriata and P. lineola. One compensatory base change (CBC) and four HCBCs are found between P. yuensis and P. delicatissima, and there is one CBC and five HCBCs between P. yuensis and P. micropora. The ability of cultured strains to produce particulate DA (pDA) revealed production of pDA in twenty-nine strains belonging to seven species: P. bipertita, P. caciantha, P. cuspidata, P. fraudulenta, P. fukuyoi, P. lundholmiae and P. multiseries. This is the first report of P. bipertita being toxic, with pDA content of 15.6 ± 2.1 fg cell–1. The presence of brine shrimps significantly increased pDA content in P. cuspidata, P. fukuyoi, P. lundholmiae and P. multiseries 1.4 to 7 times, and induced pDA production in P. fraudulenta from below detection limit to 17.5 ± 1.6 fg cell–1. The highest pDA concentration, 4830.5 ± 120.3 fg cell–1, was detected in P. multiseries, a level much lower than previous reports on P. multiseries from North America and Europe. Overall, the cellular toxin levels in Pseudo-Nitzschia spp. were low in Guangdong coastal isolates.
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pseudo Nitzschia simulans sp nov bacillariophyceae the first domoic acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-Nitzschia simulans sp. nov. (Bacillariophyceae), the first domoic acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
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The genus Pseudo-Nitzschia (Bacillariophyceae) in Malaysia, including new records and a key to species inferred from morphology-based phylogeny. Botanica Marina
2013Co-Authors: Sing Tung Teng, Hong Chang Lim, Chui, Pin Leaw, Po, Teen LimAbstract:in Malaysia, including new records and a key to species inferred from morphology-based phylogeny Abstract: Species of the diatom Pseudo-Nitzschia are known to produce domoic acid that is responsible for amnesic shellfish poisoning (ASP). To investigate the potential risk of ASP and species occurrence of toxic or potentially toxic Pseudo-Nitzschia in Malaysian waters, plankton samples were collected from 17 locations. Samples were examined through transmission electron microscopy. Species of Pseudo-Nitzschia were identified on the basis of the frustule morphology and morphometric measurements. Twenty-two well-described species were recorded, of which 14 are new records for Malaysia. A new morphotype, closely resembling species in the pseudodelicatissima complex, was also discovered. The morphotype differs from other species in the complex by its lower densities of fibulae and striae. Nine of the species have previously been asso-ciated with ASP events worldwide. Our study recorded for the first time high species richness of Pseudo-Nitzschia in the confined coasts of Malaysia. In addition, we performed a morphology-based phylogeny and proposed a key to Pseudo-Nitzschia species, with a special emphasis on the poroid structure of the striae, to aid in species identification
Astrid Schnetzer - One of the best experts on this subject based on the ideXlab platform.
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a decade and a half of pseudo Nitzschia spp and domoic acid along the coast of southern california
Harmful Algae, 2018Co-Authors: Jayme Smith, Astrid Schnetzer, Burton H Jones, Paige E Connell, Richard Evans, Alyssa G Gellene, Meredith D A Howard, Susan Kaveggia, Lauren Palmer, Bridget N SeegersAbstract:Blooms of the marine diatom genus Pseudo-Nitzschia that produce the neurotoxin domoic acid have been documented with regularity along the coast of southern California since 2003, with the occurrence of the toxin in shellfish tissue predating information on domoic acid in the particulate fraction in this region. Domoic acid concentrations in the phytoplankton inhabiting waters off southern California during 2003, 2006, 2007, 2011 and 2017 were comparable to some of the highest values that have been recorded in the literature. Blooms of Pseudo-Nitzschia have exhibited strong seasonality, with toxin appearing predominantly in the spring. Year-to-year variability of particulate toxin has been considerable, and observations during 2003, 2006, 2007, 2011 and again in 2017 linked domoic acid in the diets of marine mammals and seabirds to mass mortality events among these animals. This work reviews information collected during the past 15 years documenting the phenology and magnitude of Pseudo-Nitzschia abundances and domoic acid within the Southern California Bight. The general oceanographic factors leading to blooms of Pseudo-Nitzschia and outbreaks of domoic acid in this region are clear, but subtle factors controlling spatial and interannual variability in bloom magnitude and toxin production remain elusive.
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marine snow formation by the toxin producing diatom pseudo Nitzschia australis
Harmful Algae, 2017Co-Authors: Astrid Schnetzer, Adrian Marchetti, Robert H Lampe, Claudia R Beniteznelson, Christopher L Osburn, Avery O TattersAbstract:Abstract The formation of marine snow (MS) by the toxic diatom Pseudo-nitschia australis was simulated using a roller table experiment. Concentrations of particulate and dissolved domoic acid (pDA and dDA) differed significantly among exponential phase and MS formation under simulated near surface conditions (16 °C/12:12-dark:light cycle) and also differed compared to subsequent particle decomposition at 4 °C in the dark, mimicking conditions in deeper waters. Particulate DA was first detected at the onset of exponential growth, reached maximum levels associated with MS aggregates (1.21 ± 0.24 ng mL−1) and declined at an average loss rate of ∼1.2% pDA day−1 during particle decomposition. Dissolved DA concentrations increased throughout the experiment and reached a maximum of ∼20 ng mL−1 at final sampling on day 88. The succession by P. australis from active growth to aggregation resulted in increasing MS toxicity and based on DA loading of particles and known in situ sinking speeds, a significant amount of toxin could have easily reached the deeper ocean or seafloor. MS formation was further associated with significant dDA accumulation at a ratio of pDA: dDA: cumulative dDA of approximately 1:10:100. Overall, this study confirms that MS functions as a major vector for toxin flux to depth, that Pseudo-Nitzschia-derived aggregates should be considered ‘toxic snow’ for MS-associated organisms, and that effects of MS toxicity on interactions with aggregate-associated microbes and zooplankton consumers warrant further consideration.
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blooms of pseudo Nitzschia and domoic acid in the san pedro channel and los angeles harbor areas of the southern california bight 2003 2004
Harmful Algae, 2007Co-Authors: Astrid Schnetzer, Peter E. Miller, Rebecca A Schaffner, Beth Stauffer, Burton H Jones, Stephen B Weisberg, Paul M Digiacomo, William M Berelson, David A CaronAbstract:Abundances of Pseudo-Nitzschia spp. and concentrations of particulate domoic acid (DA) were determined in the Southern California Bight (SCB) along the coasts of Los Angeles and Orange Counties during spring and summer of 2003 and 2004. At least 1500 km2 were affected by a toxic event in May/June of 2003 when some of the highest particulate DA concentrations reported for US coastal waters were measured inside the Los Angeles harbor (12.7 μg DA L−1). Particulate DA levels were an order of magnitude lower in spring of 2004 (February and March), but DA concentrations per cell at several sampling stations during 2004 exceeded previously reported maxima for natural populations of Pseudo-Nitzschia (mean = 24 pg DA cell−1, range = 0–117 pg DA cell−1). Pseudo-Nitzschia australis dominated the Pseudo-Nitzschia assemblage in spring 2004. Overall, DA-poisoning was implicated in >1400 mammal stranding incidents within the SCB during 2003 and 2004. Ancillary physical and chemical data obtained during our regional surveys in 2004 revealed that Pseudo-Nitzschia abundances, particulate DA and cellular DA concentrations were inversely correlated with concentrations of silicic acid, nitrogen and phosphate, and to specific nutrient ratios. Particulate DA was detected in sediment traps deployed at 550 and 800 m depth during spring of 2004 (0.29–7.6 μg DA (g sediment dry weight)−1). The highest DA concentration in the traps was measured within 1 week of dramatic decreases in the abundances of Pseudo-Nitzschia in surface waters. To our knowledge these are the deepest sediment trap collections from which DA has been detected. Sinking of the spring Pseudo-Nitzschia bloom may constitute a potentially important link between DA production in surface waters and benthic communities in the coastal ocean near Los Angeles. Our study indicates that toxic blooms of Pseudo-Nitzschia are a recurring phenomenon along one of the most densely populated coastal stretches of the SCB and that the severity and magnitude of these events can be comparable to or greater than these events in other geographical regions affected by domoic acid.
Chun Xiu Huang - One of the best experts on this subject based on the ideXlab platform.
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pseudo Nitzschia simulans sp nov bacillariophyceae the first domoic acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-Nitzschia simulans sp. nov. (Bacillariophyceae), the first domoic acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-Nitzschia has attracted attention because of production of the toxin, domoic acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-Nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-Nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-Nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-Nitzschia species, represent a new species, Pseudo-Nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
