WorldWideScience

Sample records for algal toxins origins

  1. Marine algal toxins: origins, health effects, and their increased occurrence

    International Nuclear Information System (INIS)

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence. (Author)

  2. Marine algal toxins: origins, health effects, and their increased occurrence.

    OpenAIRE

    Van Dolah, F M

    2000-01-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in globa...

  3. Algal toxins alter copepod feeding behavior.

    Directory of Open Access Journals (Sweden)

    Jiarong Hong

    Full Text Available Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  4. Algal toxins alter copepod feeding behavior.

    Science.gov (United States)

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A; Waggett, Rebecca J; Place, Allen R

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms) and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods. PMID:22629336

  5. Environmental and Health Effects Associated With Harmful Algal Bloom and Marine Algal Toxins in China

    Institute of Scientific and Technical Information of China (English)

    TIAN YAN; MING-JIANG ZHOU

    2004-01-01

    The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.

  6. Freshwater harmful algal blooms: toxins and children's health.

    Science.gov (United States)

    Weirich, Chelsea A; Miller, Todd R

    2014-01-01

    Massive accumulations of cyanobacteria (a.k.a. "blue-green algae"), known as freshwater harmful algal blooms (FHABs), are a common global occurrence in water bodies used for recreational purposes and drinking water purification. Bloom prevalence is increased due to anthropogenic changes in land use, agricultural activity, and climate change. These photosynthetic bacteria produce a range of toxic secondary metabolites that affect animals and humans at both chronic and acute dosages. Children are especially at risk because of their lower body weight, behavior, and toxic effects on development. Here we review common FHAB toxins, related clinical symptoms, acceptable concentrations in drinking water, case studies of children's and young adults' exposures to FHAB toxins through drinking water and food, methods of environmental and clinical detection in potential cases of intoxication, and best practices for FHAB prevention. PMID:24439026

  7. A neurophysiological method of rapid detection and analysis of marine algal toxins

    DEFF Research Database (Denmark)

    Kerr, DS; Bødtkjer, Donna Briggs; Saba, HI

    1999-01-01

    We have examined the effectiveness of the in vitro rat hippocampal slice preparation as a means of rapidly and specifically detecting the marine algal toxins saxitoxin, brevetoxin, and domoic acid and have identified toxin-specific electrophysiological signatures for each. Brevetoxin (PbTX3, 50-2...

  8. Cephalopods as Vectors of Harmful Algal Bloom Toxins in Marine Food Webs

    OpenAIRE

    Rui Rosa; Pedro Costa; Lopes, Vanessa M.; Ana Rita Lopes

    2013-01-01

    Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic...

  9. Determination of the cyanobacterial toxin cylindrospermopsin in algal food supplements

    OpenAIRE

    H. Liu; Scott, P. M.

    2011-01-01

    For the analysis of blue–green algal food supplements for cylindrospermopsin (CYN), a C18 solid-phase extraction column and a polygraphitized carbon solid-phase extraction column in series was an effective procedure for the clean-up of extracts. Determination of CYN was by liquid chromatography with ultraviolet light detection. At extract spiking levels of CYN equivalent to 25–500 μg g−1, blue–green algal supplement recoveries were in the range 70–90%. CYN was not detected in ten samples of f...

  10. The laboratory mouse in routine food safety testing for marine algal biotoxins and harmful algal bloom toxin research: past, present and future.

    Science.gov (United States)

    Stewart, Ian; McLeod, Catherine

    2014-01-01

    Mouse bioassays have been a mainstay for detecting harmful concentrations of marine algal toxins in shellfish for over 70 years. Routine monitoring involves intraperitoneal injection of shellfish extracts into mice; shellfish contaminated with algal toxins are thus identified by mortality in exposed mice. With the advent of alternative test methods to detect and quantify specific algal toxins has come increasing criticism of enduring use of mouse bioassays for shellfish safety testing. However, the complete replacement of shellfish safety mouse bioassays by chemical, antibody-based, and functional assays has been and will continue to be a gradual process for various reasons, including skills availability and instrument costs for chromatography-based toxin monitoring. Mouse bioassays for shellfish safety testing do not comply with modern standards for laboratory animal welfare, specifically the requirement in published official methods for death as a test outcome. Mouse bioassays for algal biotoxins in shellfish, as well as fundamental algal toxin research endeavors using in vivo models, are amenable to revision and refinement from a humane endpoints perspective. Regulated hypothermia may be a useful and easily acquired nonlethal toxicological endpoint; objective determination of neuromuscular blockade may allow algal neurotoxin testing and research to enter the domain of humane endpoints evaluation. Relinquishing reliance on subjective test endpoints, including death, will likely also deliver collateral improvements in assay variability and sensitivity.

  11. The laboratory mouse in routine food safety testing for marine algal biotoxins and harmful algal bloom toxin research: past, present and future.

    Science.gov (United States)

    Stewart, Ian; McLeod, Catherine

    2014-01-01

    Mouse bioassays have been a mainstay for detecting harmful concentrations of marine algal toxins in shellfish for over 70 years. Routine monitoring involves intraperitoneal injection of shellfish extracts into mice; shellfish contaminated with algal toxins are thus identified by mortality in exposed mice. With the advent of alternative test methods to detect and quantify specific algal toxins has come increasing criticism of enduring use of mouse bioassays for shellfish safety testing. However, the complete replacement of shellfish safety mouse bioassays by chemical, antibody-based, and functional assays has been and will continue to be a gradual process for various reasons, including skills availability and instrument costs for chromatography-based toxin monitoring. Mouse bioassays for shellfish safety testing do not comply with modern standards for laboratory animal welfare, specifically the requirement in published official methods for death as a test outcome. Mouse bioassays for algal biotoxins in shellfish, as well as fundamental algal toxin research endeavors using in vivo models, are amenable to revision and refinement from a humane endpoints perspective. Regulated hypothermia may be a useful and easily acquired nonlethal toxicological endpoint; objective determination of neuromuscular blockade may allow algal neurotoxin testing and research to enter the domain of humane endpoints evaluation. Relinquishing reliance on subjective test endpoints, including death, will likely also deliver collateral improvements in assay variability and sensitivity. PMID:24830147

  12. Toxin content and cytotoxicity of algal dietary supplements

    International Nuclear Information System (INIS)

    Blue-green algae (Spirulina sp., Aphanizomenon flos-aquae) and Chlorella sp. are commercially distributed as organic algae dietary supplements. Cyanobacterial dietary products in particular have raised serious concerns, as they appeared to be contaminated with toxins e.g. microcystins (MCs) and consumers repeatedly reported adverse health effects following consumption of these products. The aim of this study was to determine the toxin contamination and the in vitro cytotoxicity of algae dietary supplement products marketed in Germany. In thirteen products consisting of Aph. flos-aquae, Spirulina and Chlorella or mixtures thereof, MCs, nodularins, saxitoxins, anatoxin-a and cylindrospermopsin were analyzed. Five products tested in an earlier market study were re-analyzed for comparison. Product samples were extracted and analyzed for cytotoxicity in A549 cells as well as for toxin levels by (1) phosphatase inhibition assay (PPIA), (2) Adda-ELISA and (3) LC–MS/MS. In addition, all samples were analyzed by PCR for the presence of the mcyE gene, a part of the microcystin and nodularin synthetase gene cluster. Only Aph. flos-aquae products were tested positive for MCs as well as the presence of mcyE. The contamination levels of the MC-positive samples were ≤ 1 μg MC-LR equivalents g−1 dw. None of the other toxins were found in any of the products. However, extracts from all products were cytotoxic. In light of the findings, the distribution and commercial sale of Aph. flos-aquae products, whether pure or mixed formulations, for human consumption appear highly questionable. -- Highlights: ► Marketed algae dietary supplements were analyzed for toxins. ► Methods: Phosphatase inhibition assay (PPIA), Adda-ELISA, LC-MS/MS. ► Aph. flos-aquae products all tested positive for microcystins. ► Products tested negative for nodularins, saxitoxins, anatoxin-a, cylindrospermopsin. ► Extracts from all products were cytotoxic.

  13. Toxin content and cytotoxicity of algal dietary supplements

    Energy Technology Data Exchange (ETDEWEB)

    Heussner, A.H.; Mazija, L. [Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz (Germany); Fastner, J. [Federal Environmental Agency, Section II 3.3—Drinking-water resources and treatment, Berlin (Germany); Dietrich, D.R., E-mail: daniel.dietrich@uni-konstanz.de [Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz (Germany)

    2012-12-01

    Blue-green algae (Spirulina sp., Aphanizomenon flos-aquae) and Chlorella sp. are commercially distributed as organic algae dietary supplements. Cyanobacterial dietary products in particular have raised serious concerns, as they appeared to be contaminated with toxins e.g. microcystins (MCs) and consumers repeatedly reported adverse health effects following consumption of these products. The aim of this study was to determine the toxin contamination and the in vitro cytotoxicity of algae dietary supplement products marketed in Germany. In thirteen products consisting of Aph. flos-aquae, Spirulina and Chlorella or mixtures thereof, MCs, nodularins, saxitoxins, anatoxin-a and cylindrospermopsin were analyzed. Five products tested in an earlier market study were re-analyzed for comparison. Product samples were extracted and analyzed for cytotoxicity in A549 cells as well as for toxin levels by (1) phosphatase inhibition assay (PPIA), (2) Adda-ELISA and (3) LC–MS/MS. In addition, all samples were analyzed by PCR for the presence of the mcyE gene, a part of the microcystin and nodularin synthetase gene cluster. Only Aph. flos-aquae products were tested positive for MCs as well as the presence of mcyE. The contamination levels of the MC-positive samples were ≤ 1 μg MC-LR equivalents g{sup −1} dw. None of the other toxins were found in any of the products. However, extracts from all products were cytotoxic. In light of the findings, the distribution and commercial sale of Aph. flos-aquae products, whether pure or mixed formulations, for human consumption appear highly questionable. -- Highlights: ► Marketed algae dietary supplements were analyzed for toxins. ► Methods: Phosphatase inhibition assay (PPIA), Adda-ELISA, LC-MS/MS. ► Aph. flos-aquae products all tested positive for microcystins. ► Products tested negative for nodularins, saxitoxins, anatoxin-a, cylindrospermopsin. ► Extracts from all products were cytotoxic.

  14. Cephalopods as Vectors of Harmful Algal Bloom Toxins in Marine Food Webs

    Directory of Open Access Journals (Sweden)

    Rui Rosa

    2013-09-01

    Full Text Available Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB-related toxins in cephalopods (octopods, cuttlefishes and squids. These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers, saxitoxin (and its derivatives and palytoxin (and palytoxin-like compounds and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin in several tissues, but mainly in the digestive gland (DG—the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6% is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs, these organisms accumulate them at the greatest extent in DG >> kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue reaching 971 μg kg−1 and palytoxin reaching 115 μg kg−1 (the regulatory limit for PlTXs is 30 μg kg−1 in shellfish. Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the

  15. Cephalopods as vectors of harmful algal bloom toxins in marine food webs.

    Science.gov (United States)

    Lopes, Vanessa M; Lopes, Ana Rita; Costa, Pedro; Rosa, Rui

    2013-09-01

    Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)--the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG > kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg⁻¹ and palytoxin reaching 115 μg kg⁻¹ (the regulatory limit for PlTXs is 30 μg kg⁻¹ in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the

  16. Concurrent exposure of bottlenose dolphins (Tursiops truncatus to multiple algal toxins in Sarasota Bay, Florida, USA.

    Directory of Open Access Journals (Sweden)

    Michael J Twiner

    Full Text Available Sentinel species such as bottlenose dolphins (Tursiops truncatus can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA, the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA. Over a ten-year study period (2000-2009 we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009 with 36% of all animals testing positive for brevetoxin (n = 118 and 53% positive for DA (n = 83 with several individuals (14% testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001 and eosinophil (p<0.001 counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health.

  17. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    Science.gov (United States)

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  18. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity.

    Directory of Open Access Journals (Sweden)

    Kathi A Lefebvre

    Full Text Available The neurotoxic amino acid, domoic acid (DA, is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  19. Algal Toxin Azaspiracid-1 Induces Early Neuronal Differentiation and Alters Peripherin Isoform Stoichiometry

    Directory of Open Access Journals (Sweden)

    Linda V. Hjørnevik

    2015-12-01

    Full Text Available Azaspiracid-1 is an algal toxin that accumulates in edible mussels, and ingestion may result in human illness as manifested by vomiting and diarrhoea. When injected into mice, it causes neurotoxicological symptoms and death. Although it is well known that azaspiracid-1 is toxic to most cells and cell lines, little is known about its biological target(s. A rat PC12 cell line, commonly used as a model for the peripheral nervous system, was used to study the neurotoxicological effects of azaspiracid-1. Azaspiracid-1 induced differentiation-related morphological changes followed by a latter cell death. The differentiated phenotype showed peripherin-labelled neurite-like processes simultaneously as a specific isoform of peripherin was down-regulated. The precise mechanism behind this down-regulation remains uncertain. However, this study provides new insights into the neurological effects of azaspiracid-1 and into the biological significance of specific isoforms of peripherin.

  20. Rachael Carson Lecture - Algal Toxins in the Deep Blue Sea: an Environmental Concern?

    Science.gov (United States)

    Silver, M. W.; Bargu, S.

    2008-05-01

    Many land plants are known to possess toxins, presumably for grazer deterrence, whereas toxins in marine phytoplankton are a much rarer phenomenon, particularly in open ocean (blue water) environments. Several dozen phytoplankton species, frequently dinoflagellates but also some diatoms, form "harmful algal blooms" nearshore: here their toxins can contaminate filter-feeding shellfish resulting in poisoning "syndromes" when humans consume the tainted shellfish. The present rise in such coastal events is a likely consequence of human activities. In blue water, open ocean environments, the filamentous cyanobacterium Trichodesmium (a blue green alga) is one of the few bloom-forming toxin producers and hosts a consortium of microorganisms that may be partially immune to its toxins. Pseudo-nitzschia, a ubiquitous genus of diatoms recently has been shown to include coastal species that produce domoic acid (DA), a neurotoxin that passes through the food web, sometimes with resulting deaths of marine birds and mammals. Oceanic species of Pseudo-nitzschia also exist but are less well known, and DA has not yet been found in them. Here we review some general features of toxic marine phytoplankton, recent studies on DA in coastal ecosystems and describe some of our findings on blue water Pseudo-nitzschia. We will summarize laboratory experiments that show complex patterns of DA retention and release into the water when Fe is added to coastal Pseudo-nitzschia cultures. In oceanic species, equivalent experiments on cell physiology are limited and the natural species and abundance patterns poorly known. Here we present our recent discovery that DA occurs in oceanic Pseudo-nitzschia and review evidence from the literature that this genus may be preferentially enhanced when iron is added to HNLC (high nutrient, low chlorophyll) waters: areas where nitrogen and phosphorus are not yet depleted, but iron concentrations and phytoplankton biomass are low. The rapid growth of these DA

  1. Detection of Harmful Algal Toxins Using the Radioligand Receptor Binding Assay. A Manual of Methods

    International Nuclear Information System (INIS)

    Marine ecosystems and their resources play major roles in sustaining human population and economic growth in coastal developing countries. These ecosystems are subjected to various natural and human-made threats. Among these are harmful algal blooms (HABs), which are natural phenomena that are increasingly being reported around the globe and responsible for human poisoning through the accumulation of potent toxins in marine food products. The impact of HABs may be aggravated by a limited knowledge of the microalgal species that cause toxic outbreaks, their biology, their diversity, their life cycles, and by poor capabilities for predicting the outbreaks and assessing the degree of HAB toxicity. Other negative factors are the lack of recognition of the disease, the lack of epidemiological data, the lack of adequate and specific treatment and low public awareness. Owing to the profound public health and socioeconomic impact of HABs, many countries have developed and implemented HAB related monitoring programmes and regulatory frameworks. Following a request made by the Philippines during the IAEA General Conference in 1997 to identify possible meaures to address the impacts of HABs, the IAEA initiated related Technical Cooperation projects to assist Member States in strengthening their capacities for prevention, management and mitigation of health and socioeconomic impacts of HABs. Since 1998, the IAEA and the National Oceanic and Atmospheric Administration (NOAA) have undertaken concerted actions to develop and to validate a radioligand based method, the receptor binding assay (RBA). The RBA is now recognized by the AOAC International as an official method for the detection of paralytic shellfish poisoning toxins. Within the IAEA Technical Cooperation programme, the RBA methodology was transferred to over 23 Member States in Africa, Asia, the Pacific region and Latin America. Transfer of knowledge and relevant equipment has enabled the development and strengthening

  2. A shift in the dominant toxin-producing algal species in central California alters phycotoxins in food webs

    Science.gov (United States)

    Jester, R.; Lefebvre, K.; Langlois, G.; Vigilant, V.; Baugh, K.; Silver, M.W.

    2009-01-01

    In California, the toxic algal species of primary concern are the dinoflagellate Alexandrium catenella and members of the pennate diatom genus Pseudo-nitzschia, both producers of potent neurotoxins that are capable of sickening and killing marine life and humans. During the summer of 2004 in Monterey Bay, we observed a change in the taxonomic structure of the phytoplankton community-the typically diatom-dominated community shifted to a red tide, dinoflagellate-dominated community. Here we use a 6-year time series (2000-2006) to show how the abundance of the dominant harmful algal bloom (HAB) species in the Bay up to that point, Pseudo-nitzschia, significantly declined during the dinoflagellate-dominated interval, while two genera of toxic dinoflagellates, Alexandrium and Dinophysis, became the predominant toxin producers. This change represents a shift from a genus of toxin producers that typically dominates the community during a toxic bloom, to HAB taxa that are generally only minor components of the community in a toxic event. This change in the local HAB species was also reflected in the toxins present in higher trophic levels. Despite the small contribution of A. catenella to the overall phytoplankton community, the increase in the presence of this species in Monterey Bay was associated with an increase in the presence of paralytic shellfish poisoning (PSP) toxins in sentinel shellfish and clupeoid fish. This report provides the first evidence that PSP toxins are present in California's pelagic food web, as PSP toxins were detected in both northern anchovies (Engraulis mordax) and Pacific sardines (Sardinops sagax). Another interesting observation from our data is the co-occurrence of DA and PSP toxins in both planktivorous fish and sentinel shellfish. We also provide evidence, based on the statewide biotoxin monitoring program, that this increase in the frequency and abundance of PSP events related to A. catenella occurred not just in Monterey Bay, but also

  3. Nutrients and toxin producing phytoplankton control algal blooms – a spatio-temporal study in a noisy environment

    Indian Academy of Sciences (India)

    Ram Rup Sarkar; Horst Malchow

    2005-12-01

    A phytoplankton-zooplankton prey-predator model has been investigated for temporal, spatial and spatio-temporal dissipative pattern formation in a deterministic and noisy environment, respectively. The overall carrying capacity for the phytoplankton population depends on the nutrient level. The role of nutrient concentrations and toxin producing phytoplankton for controlling the algal blooms has been discussed. The local analysis yields a number of stationary and/or oscillatory regimes and their combinations. Correspondingly interesting is the spatio-temporal behaviour, modelled by stochastic reaction-diffusion equations. The present study also reveals the fact that the rate of toxin production by toxin producing phytoplankton (TPP) plays an important role for controlling oscillations in the plankton system. We also observe that different mortality functions of zooplankton due to TPP have significant influence in controlling oscillations, coexistence, survival or extinction of the zooplankton population. External noise can enhance the survival and spread of zooplankton that would go extinct in the deterministic system due to a high rate of toxin production.

  4. Algal toxins and reverse osmosis desalination operations: Laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid

    KAUST Repository

    Seubert, Erica L.

    2012-12-01

    The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

  5. Algal toxins and reverse osmosis desalination operations: laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid.

    Science.gov (United States)

    Seubert, Erica L; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton H; Caron, David A

    2012-12-01

    The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

  6. Health Risk Assessment of Cyanobacterial (Blue-green Algal Toxins in Drinking Water

    Directory of Open Access Journals (Sweden)

    Andrew R. Humpage

    2005-04-01

    Full Text Available Cyanobacterial toxins have caused human poisoning in the Americas, Europe and Australia. There is accumulating evidence that they are present in treated drinking water supplies when cyanobacterial blooms occur in source waters. With increased population pressure and depleted groundwater reserves, surface water is becoming more used as a raw water source, both from rivers and lakes/reservoirs. Additional nutrients in water which arise from sewage discharge, agricultural run-off or storm water result in overabundance of cyanobacteria, described as a ‘water bloom’. The majority of cyanobacterial water-blooms are of toxic species, producing a diversity of toxins. The most important toxins presenting a risk to the human population are the neurotoxic alkaloids (anatoxins and paralytic shellfish poisons, the cyclic peptide hepatotoxins (microcystins and the cytotoxic alkaloids (cylindrospermopsins. At the present time the only cyanobacteral toxin family that have been internationally assessed for health risk by the WHO are the microcystins, which cause acute liver injury and are active tumour promoters. Based on sub-chronic studies in rodents and pigs, a provisional Guideline Level for drinking water of 1μg/L of microcystin-LR has been determined. This has been adopted in legislation in countries in Europe, South America and Australasia. This may be revised in the light of future teratogenicity, reproductive toxicity and carcinogenicity studies. The other cyanobacterial toxin which has been proposed for detailed health risk assessment is cylindrospermopsin, a cytotoxic compound which has marked genotoxicity, probable mutagenicity, and is a potential carcinogen. This toxin has caused human poisoning from drinking water, and occurs in water supplies in the USA, Europe, Asia, Australia and South America. An initial health risk assessment is presented with a proposed drinking water Guideline Level of 1μg/L. There is a

  7. Algal toxin impairs sea lion memory and hippocampal connectivity, with implications for strandings.

    Science.gov (United States)

    Cook, Peter F; Reichmuth, Colleen; Rouse, Andrew A; Libby, Laura A; Dennison, Sophie E; Carmichael, Owen T; Kruse-Elliott, Kris T; Bloom, Josh; Singh, Baljeet; Fravel, Vanessa A; Barbosa, Lorraine; Stuppino, Jim J; Van Bonn, William G; Gulland, Frances M D; Ranganath, Charan

    2015-12-18

    Domoic acid (DA) is a naturally occurring neurotoxin known to harm marine animals. DA-producing algal blooms are increasing in size and frequency. Although chronic exposure is known to produce brain lesions, the influence of DA toxicosis on behavior in wild animals is unknown. We showed, in a large sample of wild sea lions, that spatial memory deficits are predicted by the extent of right dorsal hippocampal lesions related to natural exposure to DA and that exposure also disrupts hippocampal-thalamic brain networks. Because sea lions are dynamic foragers that rely on flexible navigation, impaired spatial memory may affect survival in the wild.

  8. Toxins

    Science.gov (United States)

    Toxins are substances created by plants and animals that are poisonous to humans. Toxins also include some medicines that are helpful in small doses, but poisonous in large amounts. Most toxins that cause problems ...

  9. A common origin for the bacterial toxin-antitoxin systems parD and ccd, suggested by analyses of toxin/target and toxin/antitoxin interactions.

    Directory of Open Access Journals (Sweden)

    Andrew B Smith

    Full Text Available Bacterial toxin-antitoxin (TA systems encode two proteins, a potent inhibitor of cell proliferation (toxin and its specific antidote (antitoxin. Structural data has revealed striking similarities between the two model TA toxins CcdB, a DNA gyrase inhibitor encoded by the ccd system of plasmid F, and Kid, a site-specific endoribonuclease encoded by the parD system of plasmid R1. While a common structural fold seemed at odds with the two clearly different modes of action of these toxins, the possibility of functional crosstalk between the parD and ccd systems, which would further point to their common evolutionary origin, has not been documented. Here, we show that the cleavage of RNA and the inhibition of protein synthesis by the Kid toxin, two activities that are specifically counteracted by its cognate Kis antitoxin, are altered, but not inhibited, by the CcdA antitoxin. In addition, Kis was able to inhibit the stimulation of DNA gyrase-mediated cleavage of DNA by CcdB, albeit less efficiently than CcdA. We further show that physical interactions between the toxins and antitoxins of the different systems do occur and define the stoichiometry of the complexes formed. We found that CcdB did not degrade RNA nor did Kid have any reproducible effect on the tested DNA gyrase activities, suggesting that these toxins evolved to reach different, rather than common, cellular targets.

  10. Algal production of extra and intra-cellular polysaccharides as an adaptive response to the toxin crude extract of Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    El-Sheekh Mostafa

    2012-11-01

    Full Text Available Abstract This is an investigation concerned with studying the possible adaptive response of four different unicellular algae, Anabaena PCC 7120, Oscillatoria angustissima, Scendesmus obliquus and Chlorella vulgaris, to the toxin of Microcystis aeruginosa (Kützing. The effects of four different concentrations, 25, 50, 100 and 200 μg mL-1 of microcystins crude extract of M. aeruginosa, on both intra and extra-cellular polysaccharide levels, in log phase, of the four tested algae were studied. The obtained results showed differential increase in the production levels for both intra and extra-cellular polysaccharides by the tested algae, compared with the control. S. obliquus and C. vulgaris showed a resistance to crude toxin higher than Anabaena PCC 7120 and O. angustissima. The highly production of polysaccharides by green algal species under this toxic stress indicated the involvement of these polysaccharides in protecting the algal cells against toxic species and, reflect the biological behavior of particular algal species to the environmental stresses.

  11. Red and green algal origin of diatom membrane transporters: insights into environmental adaptation and cell evolution.

    Directory of Open Access Journals (Sweden)

    Cheong Xin Chan

    Full Text Available Membrane transporters (MTs facilitate the movement of molecules between cellular compartments. The evolutionary history of these key components of eukaryote genomes remains unclear. Many photosynthetic microbial eukaryotes (e.g., diatoms, haptophytes, and dinoflagellates appear to have undergone serial endosymbiosis and thereby recruited foreign genes through endosymbiotic/horizontal gene transfer (E/HGT. Here we used the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum as models to examine the evolutionary origin of MTs in this important group of marine primary producers. Using phylogenomics, we used 1,014 diatom MTs as query against a broadly sampled protein sequence database that includes novel genome data from the mesophilic red algae Porphyridium cruentum and Calliarthron tuberculosum, and the stramenopile Ectocarpus siliculosus. Our conservative approach resulted in 879 maximum likelihood trees of which 399 genes show a non-lineal history between diatoms and other eukaryotes and prokaryotes (at the bootstrap value ≥70%. Of the eukaryote-derived MTs, 172 (ca. 25% of 697 examined phylogenies have members of both red/green algae as sister groups, with 103 putatively arising from green algae, 19 from red algae, and 50 have an unresolved affiliation to red and/or green algae. We used topology tests to analyze the most convincing cases of non-lineal gene history in which red and/or green algae were nested within stramenopiles. This analysis showed that ca. 6% of all trees (our most conservative estimate support an algal origin of MTs in stramenopiles with the majority derived from green algae. Our findings demonstrate the complex evolutionary history of photosynthetic eukaryotes and indicate a reticulate origin of MT genes in diatoms. We postulate that the algal-derived MTs acquired via E/HGT provided diatoms and other related microbial eukaryotes the ability to persist under conditions of fluctuating ocean chemistry, likely

  12. Algal Production of Extra- and Intra-Cellular Polysaccharides as an Adaptive Response to the Toxin Crude Extract of Microcystis Aeruginosa

    Directory of Open Access Journals (Sweden)

    Mostafa Mohamed El-Sheekh

    2012-11-01

    Full Text Available This is an investigation concerned with studying the possible adaptive response of four different unicellular algae, Anabaena PCC 7120, Oscillatoria angustissima, Scendesmus obliquus and Chlorella vulgaris, to the toxin of Microcystis aeruginosa (Kützing. Theeffects of four different concentrations, 25, 50, 100 and 200 μg mL-1 of microcystins crude extract of M. aeruginosa, on both intra and extra-cellular polysaccharide levels, in log phase,of the four tested algae were studied. The obtained results showed differential increase in the production levels for both intra and extra-cellular polysaccharides by the tested algae,compared with the control. S. obliquus and C. vulgaris showed a resistance to crude toxinhigher than Anabaena PCC 7120 and O. angustissima. The highly production of polysaccharides by green algal species under this toxic stress indicated the involvement of these polysaccharides in protecting the algal cells against toxic species and, reflect thebiological behavior of particular algal species to the environmental stresses.

  13. Cyanobacteria Toxin and Cell Propagation through Seven Lake Erie Treatment Plants during the 2013 Algal Bloom Season - abstract

    Science.gov (United States)

    Over the past five years, Lake Erie has been experiencing harmful algal blooms (HABs) of progressively increasing severity. Cognizant of the potential health and economic impacts, the United States Environmental Protection Agency’s (USEPA’s) Water Supply and Water Resources Divis...

  14. Re-evaluating the green versus red signal in eukaryotes with secondary plastid of red algal origin

    KAUST Repository

    Burki, Fabien

    2012-05-16

    The transition from endosymbiont to organelle in eukaryotic cells involves the transfer of significant numbers of genes to the host genomes, a process known as endosymbiotic gene transfer (EGT). In the case of plastid organelles, EGTs have been shown to leave a footprint in the nuclear genome that can be indicative of ancient photosynthetic activity in present-day plastid-lacking organisms, or even hint at the existence of cryptic plastids. Here,we evaluated the impact of EGTon eukaryote genomes by reanalyzing the recently published EST dataset for Chromera velia, an interesting test case of a photosynthetic alga closely related to apicomplexan parasites. Previously, 513 genes were reported to originate from red and green algae in a 1:1 ratio. In contrast, by manually inspecting newly generated trees indicating putative algal ancestry, we recovered only 51 genes congruent with EGT, of which 23 and 9 were of red and green algal origin, respectively,whereas 19 were ambiguous regarding the algal provenance.Our approach also uncovered 109 genes that branched within a monocot angiosperm clade, most likely representing a contamination. We emphasize the lack of congruence and the subjectivity resulting from independent phylogenomic screens for EGT, which appear to call for extreme caution when drawing conclusions for major evolutionary events. 2012 The Author(s).

  15. Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda).

    Science.gov (United States)

    Händeler, Katharina; Wägele, Heike; Wahrmund, Ute; Rüdinger, Mareike; Knoop, Volker

    2010-11-01

    Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter. PMID:21565106

  16. A contemplation on the secondary origin of green algal and plant plastids

    Directory of Open Access Journals (Sweden)

    Eunsoo Kim

    2014-12-01

    Full Text Available A single origin of plastids and the monophyly of three “primary” plastid-containing groups – the Chloroplastida (or Viridiplantae; green algae+land plants, Rhodophyta, and Glaucophyta – are widely accepted, mainstream hypotheses that form the basis for many comparative evolutionary studies. This “Archaeplastida” hypothesis, however, thus far has not been unambiguously confirmed by phylogenetic studies based on nucleocytoplasmic markers. In view of this as well as other lines of evidence, we suggest the testing of an alternate hypothesis that plastids of the Chloroplastida are of secondary origin. The new hypothesis is in agreement with, or perhaps better explains, existing data, including both the plastidal and nucleocytoplasmic characteristics of the Chloroplastida in comparison to those of other groups.

  17. Algal biotoxins of marine origin: new indications from the European Union.

    Science.gov (United States)

    Poletti, R; Milandri, A; Pompei, M

    2003-09-01

    Marine biotoxins, more or less complex molecules with various origins that can accumulate in the tissues of fish products through the food chain, are reviewed. The EU, aware of the danger incurred in eating certain fish products, has issued a set of hygiene and health directives for the purpose of preventing disease and safeguarding consumer health. In particular, directive 91/492/EEC, of 15 July 1991, lays down the sanitary norms applicable to the production and commercialization of live bivalve molluscs, echinoderms, tunicates and marine gastropods and regulates the whole system involving these products from their origin to consumption. More recently, through Commission Decision dated 15 March 2002 (EC OJ 175/62 of 16.3.2002) the EU has set new standards for the implementation of directive 91/492/EEC with respect to the maximum levels and analysis methods for some marine biotoxins.

  18. The discovery of archaea origin phosphomannomutase in algae based on the algal transcriptome

    Institute of Scientific and Technical Information of China (English)

    FENG Yanjing; CHI Shan; LIU Cui; CHEN Shengping; YU Jun; WANG Xumin; LIU Tao

    2014-01-01

    Phosphomannomutase (PMM;EC 5.4.2.8) is an enzyme that catalyzes the interconversion reaction between mannose-6-phosphate and mannose-1-phosphate. However, its systematic molecular and functional in-vestigations in algae have not hitherto been reported. In this work, with the accomplishment of the 1 000 Plant Project (OneKP) in which more than 218 species of Chromista, including 19 marine phaeophytes, 22 marine rhodophytes, 171 chlorophytes, 5 cryptophytes, 4 haptophytes, and 5 glaucophytes were sequenced, we used a gene analysis method to analyze the PMM gene sequences in algae and confirm the existence of the PMM gene in the transcriptomic sequencing data of Rhodophyta and Ochrophyta. Our results showed that only one type of PMM with four conserved motifs exists in Chromista which is similar to human PMM. Moreover, the phylogenetic tree revealed that algae PMM possibly originated from archaea.

  19. A novel type of light-harvesting antenna protein of red algal origin in algae with secondary plastids

    OpenAIRE

    Sturm, Sabine; Engelken, Johannes; Gruber, Ansgar; Vugrinec, Sascha; G. Kroth, Peter; Adamska, Iwona; Lavaud, Johann

    2013-01-01

    Background: Light, the driving force of photosynthesis, can be harmful when present in excess; therefore, any light harvesting system requires photoprotection. Members of the extended light-harvesting complex (LHC) protein superfamily are involved in light harvesting as well as in photoprotection and are found in the red and green plant lineages, with a complex distribution pattern of subfamilies in the different algal lineages.Results: Here, we demonstrate that the recently discovered "red l...

  20. Cellular vacuoles induced by Mycoplasma pneumoniae CARDS toxin originate from Rab9-associated compartments.

    Directory of Open Access Journals (Sweden)

    Coreen Johnson

    Full Text Available Recently, we identified an ADP-ribosylating and vacuolating cytotoxin in Mycoplasma pneumoniae designated Community Acquired Respiratory Distress Syndrome (CARDS toxin. In this study we show that vacuoles induced by recombinant CARDS (rCARDS toxin are acidic and derive from the endocytic pathway as determined by the uptake of neutral red and the fluid-phase marker, Lucifer yellow, respectively. Also, we demonstrate that the formation of rCARDS toxin-associated cytoplasmic vacuoles is inhibited by the vacuolar ATPase inhibitor, bafilomycin A1, and the ionophore, monensin. To examine the ontogeny of these vacuoles, we analyzed the distribution of endosomal and lysosomal membrane markers during vacuole formation and observed the enrichment of the late endosomal GTPase, Rab9, around rCARDS toxin-induced vacuoles. Immunogold-labeled Rab9 and overexpression of green fluorescent-tagged Rab9 further confirmed vacuolar association. The late endosomal- and lysosomal-associated membrane proteins, LAMP1 and LAMP2, also localized to the vacuolar membranes, while the late endosomal protein, Rab7, and early endosomal markers, Rab5 and EEA1, were excluded. HeLa cells expressing dominant-negative (DN Rab9 exhibited markedly reduced vacuole formation in the presence of rCARDS toxin, in contrast to cells expressing DN-Rab7, highlighting the importance of Rab9 function in rCARDS toxin-induced vacuolation. Our findings reveal the unique Rab9-association with rCARDS toxin-induced vacuoles and its possible relationship to the characteristic histopathology that accompanies M. pneumoniae infection.

  1. Novel Insights on the Dynamics and Consequence of Harmful Algal Blooms in the California Current System: From Parasites as Bloom Control Agents to Human Toxin Exposure

    OpenAIRE

    Mazzillo, Fernanda da Frota Mattos

    2011-01-01

    This dissertation provided novel insights on the dynamics and consequences of harmful algal blooms (HABs) in the California Current System (CCS). Parasitism is described as a biological control agent of harmful dinoflagellate blooms and referred to as a novel factor influencing HAB dynamics in coastal upwelling environments. Chapter 1 documented, for the first time, the presence of Amoebophrya, an endoparasitic dinoflagellate that infects and kills 7 bloom-forming dinoflagellate host species ...

  2. Differences in the toxin profiles of Alexandrium ostenfeldii (Dinophyceae) strains isolated from different geographic origins: Evidence of paralytic toxin, spirolide, and gymnodimine.

    Science.gov (United States)

    Salgado, Pablo; Riobó, Pilar; Rodríguez, Francisco; Franco, José M; Bravo, Isabel

    2015-09-01

    Among toxin-producing dinoflagellates of the genus Alexandrium, Alexandrium ostenfeldii is the only species able to produce paralytic shellfish poisoning (PSP) toxins, spirolides (SPXs) and gymnodimines (GYMs). In this study we characterized and compared three A. ostenfeldii strains isolated from the Baltic, Mediterranean, and southern Chile Seas with respect to their toxin profiles, morphology, and phylogeny. Toxin analyses by HPLC-FD and LC-HRMS revealed differences in the toxin profiles of the three strains. The PSP toxin profiles of the southern Chile and Baltic strains were largely the same and included gonyautoxin (GTX)-3, GTX-2, and saxitoxin (STX), although the total PSP toxin content of the Chilean strain (105.83 ± 72.15 pg cell(-1)) was much higher than that of the Baltic strain (4.04 ± 1.93 pg cell(-1)). However, the Baltic strain was the only strain that expressed detectable amounts of analogues of GYM-A and GYM-B/-C (48.27 ± 26.12 pg GYM-A equivalents cell(-1)). The only toxin expressed by the Mediterranean strain was 13-desmethyl SPX-C (13dMeC; 2.85 ± 4.76 pg cell(-1)). Phylogenetic analysis based on the LSU rRNA showed that the studied strains belonged to distinct molecular clades. The toxin profiles determined in this study provide further evidence of the taxonomic complexity of this species. PMID:26093028

  3. Evolution of an ancient venom: recognition of a novel family of cnidarian toxins and the common evolutionary origin of sodium and potassium neurotoxins in sea anemone.

    Science.gov (United States)

    Jouiaei, Mahdokht; Sunagar, Kartik; Federman Gross, Aya; Scheib, Holger; Alewood, Paul F; Moran, Yehu; Fry, Bryan G

    2015-06-01

    Despite Cnidaria (sea anemones, corals, jellyfish, and hydroids) being the oldest venomous animal lineage, structure-function relationships, phyletic distributions, and the molecular evolutionary regimes of toxins encoded by these intriguing animals are poorly understood. Hence, we have comprehensively elucidated the phylogenetic and molecular evolutionary histories of pharmacologically characterized cnidarian toxin families, including peptide neurotoxins (voltage-gated Na(+) and K(+) channel-targeting toxins: NaTxs and KTxs, respectively), pore-forming toxins (actinoporins, aerolysin-related toxins, and jellyfish toxins), and the newly discovered small cysteine-rich peptides (SCRiPs). We show that despite long evolutionary histories, most cnidarian toxins remain conserved under the strong influence of negative selection-a finding that is in striking contrast to the rapid evolution of toxin families in evolutionarily younger lineages, such as cone snails and advanced snakes. In contrast to the previous suggestions that implicated SCRiPs in the biomineralization process in corals, we demonstrate that they are potent neurotoxins that are likely involved in the envenoming function, and thus represent the first family of neurotoxins from corals. We also demonstrate the common evolutionary origin of type III KTxs and NaTxs in sea anemones. We show that type III KTxs have evolved from NaTxs under the regime of positive selection, and likely represent a unique evolutionary innovation of the Actinioidea lineage. We report a correlation between the accumulation of episodically adaptive sites and the emergence of novel pharmacological activities in this rapidly evolving neurotoxic clade. PMID:25757852

  4. Seasonal and annual dynamics of harmful algae and algal toxins revealed through weekly monitoring at two coastal ocean sites off southern California, USA.

    Science.gov (United States)

    Seubert, Erica L; Gellene, Alyssa G; Howard, Meredith D A; Connell, Paige; Ragan, Matthew; Jones, Burton H; Runyan, Jennifer; Caron, David A

    2013-10-01

    Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach. PMID:23288675

  5. Seasonal and annual dynamics of harmful algae and algal toxins revealed through weekly monitoring at two coastal ocean sites off southern California, USA

    KAUST Repository

    Seubert, Erica L.

    2013-01-04

    Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach. © 2012 Springer-Verlag Berlin Heidelberg.

  6. Prevalence of genes for enterotoxins, toxic shock syndrome toxin 1 and exfoliative toxin among clinical isolates of Staphylococcus pseudintermedius from canine origin.

    Science.gov (United States)

    Yoon, Jang W; Lee, Gi-Jong; Lee, So-Young; Park, Chul; Yoo, Jong-Hyun; Park, Hee-Myung

    2010-10-01

    A total of 74 Staphylococcus pseudintermedius strains were isolated from the 99 clinical cases of canine pyoderma or chronic otitis in our veterinary teaching hospital during May 2006-February 2008. In this study, we examined the genetic distribution of staphylococcal pyogenic toxins such as staphylococcal enterotoxins A (sea), B (seb), C (sec), D (sed), E (see), and toxic shock syndrome toxin 1 (tst) as well as the previously characterized S. intermedius exfoliative toxin (siet) among those isolates. The polymerase chain reaction analyses with the toxin gene-specific primers revealed that 18 (24.3%) of 74 S. pseudintermedius isolates carried the sec genes, but none of the sea, seb, sed, see and tst genes. Further DNA sequencing analysis of the amplified sec genes revealed that they all belonged to the canine type C staphylococcal enterotoxin (SEC(canine) ) whose superantigenic activity has been demonstrated. In addition to the sec(canine) genes, our polymerase chain reaction results showed that all the 74 isolates carried the siet gene. Since both SEC(canine) and SIET toxins are known to be biologically active, it would be interesting to investigate how those toxins are involved in the pathogenesis of the canine diseases by S. pseudintermedius such as pyoderma or chronic otitis.

  7. Adaptive eukaryote-to-eukaryote lateral gene transfer: stress-related genes of algal origin in the closest unicellular relatives of animals.

    Science.gov (United States)

    Nedelcu, A M; Miles, I H; Fagir, A M; Karol, K

    2008-11-01

    In addition to mutation, gene duplication and recombination, the transfer of genetic material between unrelated species is now regarded as a potentially significant player in the shaping of extant genomes and the evolution and diversification of life. Although this is probably true for prokaryotes, the extent of such genetic exchanges in eukaryotes (especially eukaryote-to-eukaryote transfers) is more controversial and the selective advantage and evolutionary impact of such events are less documented. A laterally transferred gene could either be added to the gene complement of the recipient or replace the recipient's homologue; whereas gene replacements can be either adaptive or stochastic, gene additions are most likely adaptive. Here, we report the finding of four stress-related genes (two ascorbate peroxidase and two metacaspase genes) of algal origin in the closest unicellular relatives of animals, the choanoflagellates. At least three of these sequences represent additions to the choanoflagellate gene complement, which is consistent with these transfers being adaptive. We suggest that these laterally acquired sequences could have provided the primitive choanoflagellates with additional or more efficient means to cope with stress, especially in relation to adapting to freshwater environments and/or sessile or colonial lifestyles. PMID:18717747

  8. Algal biofuels.

    Science.gov (United States)

    Razeghifard, Reza

    2013-11-01

    The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented.

  9. Microplate receptor assays: tools for monitoring seafood toxins

    International Nuclear Information System (INIS)

    Global increase in toxic algal blooms and the resultant increase in the incidence of human illness, many seafood monitoring program have been established worldwide to determine the presence of algal toxins, and one of the standard method of detection for algal toxins is the mouse bioassay. Receptor assay are appropriate for those toxin classes that interact with membrane receptors including the voltage dependent sodium channel and the glutamate receptor and most of algal toxins in seafood occur that possess different toxic potencies and are present in contaminated seafood. Receptor assays are particularly applicable for measuring total toxic potency since, within a toxin class, all congeners bind to the same receptor and relative binding affinities correlate well with their relative toxic potencies

  10. Toxins Best Paper Award 2015

    OpenAIRE

    Tesh, Vernon L.

    2015-01-01

    In order to recognize outstanding papers related to biotoxins and toxinology that have been published in Toxins, the Editorial Board established an annual “Toxins Best Paper Award”. We are pleased to announce the first “Toxins Best Paper Award” for 2015. Nominations were selected by the Editorial Board members, with all papers published in 2011 eligible for consideration. Reviews and original research articles were evaluated separately. Following review and voting by the Toxins Best Paper Awa...

  11. Extended evaluation of polymeric and lipophilic sorbents for passive sampling of marine toxins

    OpenAIRE

    Zendong, Zita; Herrenknecht, Christine; Abadie, Eric; Brissard, Charline; Tixier, Celine; Mondeguer, Florence; Sechet, Veronique; Amzil, Zouher; Hess, Philipp

    2014-01-01

    Marine biotoxins are algal metabolites that can accumulate in fish or shellfish and render these foodstuffs unfit for human consumption. These toxins, released into seawater during algal occurrences, can be monitored through passive sampling. Acetone, methanol and isopropanol were evaluated for their efficiency in extracting toxins from algal biomass. Isopropanol was chosen for further experiments thanks to a slightly higher recovery and no artifact formation. Comparison of Oasis HLB, Strata-...

  12. Optimizing production of asperolide A, a potential anti-tumor tetranorditerpenoid originally produced by the algal-derived endophytic fungus Aspergillus wentii EN-48

    Science.gov (United States)

    Xu, Rui; Li, Xiaoming; Xu, Gangming; Wang, Bingui

    2016-07-01

    The marine algal-derived endophytic fungus Aspergillus wentii EN-48 produces the potential anti-tumor agent asperolide A, a tetranorlabdane diterpenoid active against lung cancer. However, the fermentation yield of asperolide A was very low and only produced in static cultures. Static fermentation conditions of A. wentii EN-48 were optimized employing response surface methodology to enhance the production of asperolide A. The optimized conditions resulted in a 13.9-fold yield enhancement, which matched the predicted value, and the optimized conditions were successfully used in scale-up fermentation for the production of asperolide A. Exogenous addition of plant hormones (especially 10 μmol/L methyl jasmonate) stimulated asperolide A production. To our knowledge, this is first optimized production of an asperolide by a marine-derived fungus. The optimization is Effective and valuable to supply material for further anti-tumor mechanism studies and preclinical evaluation of asperolide A and other norditerpenoids.

  13. Toxins Best Paper Award 2015

    Directory of Open Access Journals (Sweden)

    Vernon L. Tesh

    2015-03-01

    Full Text Available In order to recognize outstanding papers related to biotoxins and toxinology that have been published in Toxins, the Editorial Board established an annual “Toxins Best Paper Award”. We are pleased to announce the first “Toxins Best Paper Award” for 2015. Nominations were selected by the Editorial Board members, with all papers published in 2011 eligible for consideration. Reviews and original research articles were evaluated separately. Following review and voting by the Toxins Best Paper Award Committee, the following three papers have won Toxins Best Paper Awards for 2015:[...

  14. Irish Marine Institute biotoxin, phytoplankton and remote sensing data for Harmful Algal Event monitoring Identification Information (NODC Accession 0000668)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The presence of harmful algal species, which produce toxins, pose a significant threat to public health and coastal aquaculture activities. For example, estimated...

  15. Harmful Algal Blooms (HABs)

    Science.gov (United States)

    ... Topics Eighth Annual National Conference on Health Communication, Marketing & Media August 19-21, 2014 Atlanta, GA Harmful Algal Blooms Recommend on Facebook Tweet Share Compartir On this Page What's the ...

  16. Harmful algal blooms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.R.; PrabhaDevi; DeSouza, L.; Verlecar, X.N.; Naik, C.G.

    as harmful algal bloom. Bloom formation is a natural process and it enhances biological productivity, but turns worrisome when caused by toxic species, leading to massive fish mortalities and hazards to human health. Incidences of'red tide' are increasing...

  17. Algal Supply System Design - Harmonized Version

    Energy Technology Data Exchange (ETDEWEB)

    Jared Abodeely; Daniel Stevens; Allison Ray; Debor

    2013-03-01

    The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.

  18. Novel one-step centrifugal sensor system for the detection of cyanobacterial toxin microcystin-LR

    OpenAIRE

    Fitzgerald, Jenny; Maguire, Ivan; Heery, Brendan; Murphy, Caroline; Nwankire, Charles; O'Kennedy, Richard; Regan, Fiona

    2015-01-01

    Globally, the most prevalent cyanobacterial toxins, in blooms from fresh and brackish waters, are the cyclic peptide toxins of the microcystin family. The need for on-site algal-toxin monitoring has become increasingly urgent due to the amplified demand for fresh-water and for safe, ‘toxin-free’ shellfish and fish stocks. Along with routine testing of shellfish stocks for biotoxins including microcystin, the EU also require routine monitoring for the presence of the causative ...

  19. Method for detecting biological toxins

    Energy Technology Data Exchange (ETDEWEB)

    Ligler, F.S.; Campbell, J.R.

    1992-01-01

    Biological toxins are indirectly detected by using polymerase chain reaction to amplify unique nucleic acid sequences coding for the toxins or enzymes unique to toxin synthesis. Buffer, primers coding for the unique nucleic acid sequences and an amplifying enzyme are added to a sample suspected of containing the toxin. The mixture is then cycled thermally to exponentially amplify any of these unique nucleic acid sequences present in the sample. The amplified sequences can be detected by various means, including fluorescence. Detection of the amplified sequences is indicative of the presence of toxin in the original sample. By using more than one set of labeled primers, the method can be used to simultaneously detect several toxins in a sample.

  20. Endogenous viral elements in algal genomes

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; YU Jun; WU Shuangxiu; LIU Tao; SUN Jing; CHI Shan; LIU Cui; LI Xingang; YIN Jinlong; WANG Xumin

    2014-01-01

    Endogenous viral elements (EVEs) are host-genomic fragments originated from viral genomes. They have been found universally in animal and plant genomes. Here we carried out a systematic screening and analy-sis of EVEs in algal genomes and found that EVEs commonly exist in algal genomes. We classified the EVE fragments into three categories according to the length of EVE fragments. Due to the probability of sequence similarity by chance, we ignored the potential function of medium-length EVE fragments. However, long-length EVE fragments probably had capability to encode protein domains or even entire proteins, and some short-length EVE fragments had high similarity with host's siRNA sequences and possibly served functions of small RNAs. Therefore, short and long EVE fragments might provide regulomic and proteomic novelty to the host's metabolism and adaptation. We also found several EVE fragments shared by more than 3 algal genomes. By phylogenetic analysis of the shared EVEs and their corresponding species, we found that the integration of viral fragments into host genomes was an ancient event, possibly before the divergence of Chlorophytes and Ochrophytes. Our findings show that there is a frequent genetic flow from viruses to algal genomes. Moreover, study on algal EVEs shed light on the virus-host interaction in large timescale and could also help us understand the balance of marine ecosystems.

  1. Pertussis toxin

    Energy Technology Data Exchange (ETDEWEB)

    Sekura, R.D.; Moss, J.; Vaughan, M.

    1985-01-01

    This book contains 13 selections. Some of the titles are: Genetic and Functional Studies of Pertussis Toxin Substrates; Effect of Pertussis Toxin on the Hormonal Responsiveness of Different Tissues; Extracellular Adenylate Cyclase of Bordetella pertussis; and GTP-Regulatory Proteins are Introcellular Messagers: A Model for Hormone Action.

  2. Polyamine toxins

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Jensen, Lars S; Vogensen, Stine B

    2005-01-01

    Polyamine toxins, isolated from spiders and wasps, have been used as pharmacological tools for the study of ionotropic receptors, but their use have so far been hampered by their lack of selectivity. In this mini-review, we describe how careful synthetic modification of native polyamine toxins have...

  3. Cyanobacteria Toxin and Cell Propagation through Lake Erie Treatment Facilities - proceedings

    Science.gov (United States)

    Harmful algal blooms (HABs), and their associated toxins, in fresh water lakes and reservoirs are drawing the attention of utilities and state regulators nation-wide. Recognizing the potential health and economic consequences, the US Environmental Protection Agency, in partnersh...

  4. [Algal biotoxins in Dialysis Water: a risk not managed].

    Science.gov (United States)

    Ferrante, Margherita; Zuccarello, Pietro; Garufi, Angela; Cristaldi, Antonio; Oliveri Conti, Gea

    2016-01-01

    A literature review was performed to retrieve updated information on the quality of dialysis water, with a focus on the emerging problem of the presence of algal toxins (microcystins) produced by cyanobacteria. Current legislation was examined as well as studies conducted to date in different geographic areas. In this article, the authors present review results along with recommendations to operators and managers of dialysis units, for preventing possible risks for patients. PMID:27077559

  5. Botulinum toxin.

    OpenAIRE

    Savardekar Preeti

    1989-01-01

    Botulinum toxin, one of the most poisonous biological substances known, is a neurotoxin produced by the bacterium Clostridium botulinum. C. botulinum elaborates eight antigenically distinguishable exotoxins (A, B, C 1 , C 2 , D, E, F and G). All serotypes interfere with neural transmission by blocking the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. The weakness induced by injection with botulinum toxin A usually lasts about...

  6. Novel method for the detection of cyanobacterial toxin microcystin-LR using a centrifugal microfluidic (Lab-On-A-Disc) sensing system

    OpenAIRE

    Maguire, Ivan; Fitzgerald, Jenny; Heery, Brendan; Murphy, Caroline; Nwankire, Charles; O'Kennedy, Richard; Ducree, Jens; Regan, Fiona

    2015-01-01

    Globally, the most prevalent cyanobacterial toxins, in blooms from fresh and brackish waters, are the cyclic peptide toxins of the microcystin family. The need for on-site algal-toxin monitoring has become increasingly urgent due to the amplified demand for fresh-water and for safe, ‘toxinfree’ shellfish and fish stocks. Along with routine testing of shellfish stocks for biotoxins including microcystin, the EU also require routine monitoring for the presence of the causative algal species. He...

  7. Algal MIPs, high diversity and conserved motifs

    Directory of Open Access Journals (Sweden)

    Johanson Urban

    2011-04-01

    Full Text Available Abstract Background Major intrinsic proteins (MIPs also named aquaporins form channels facilitating the passive transport of water and other small polar molecules across membranes. MIPs are particularly abundant and diverse in terrestrial plants but little is known about their evolutionary history. In an attempt to investigate the origin of the plant MIP subfamilies, genomes of chlorophyte algae, the sister group of charophyte algae and land plants, were searched for MIP encoding genes. Results A total of 22 MIPs were identified in the nine analysed genomes and phylogenetic analyses classified them into seven subfamilies. Two of these, Plasma membrane Intrinsic Proteins (PIPs and GlpF-like Intrinsic Proteins (GIPs, are also present in land plants and divergence dating support a common origin of these algal and land plant MIPs, predating the evolution of terrestrial plants. The subfamilies unique to algae were named MIPA to MIPE to facilitate the use of a common nomenclature for plant MIPs reflecting phylogenetically stable groups. All of the investigated genomes contained at least one MIP gene but only a few species encoded MIPs belonging to more than one subfamily. Conclusions Our results suggest that at least two of the seven subfamilies found in land plants were present already in an algal ancestor. The total variation of MIPs and the number of different subfamilies in chlorophyte algae is likely to be even higher than that found in land plants. Our analyses indicate that genetic exchanges between several of the algal subfamilies have occurred. The PIP1 and PIP2 groups and the Ca2+ gating appear to be specific to land plants whereas the pH gating is a more ancient characteristic shared by all PIPs. Further studies are needed to discern the function of the algal specific subfamilies MIPA-E and to fully understand the evolutionary relationship of algal and terrestrial plant MIPs.

  8. Algal functional annotation tool

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes

  9. Use of biosensors for the detection of marine toxins

    OpenAIRE

    McPartlin, Daniel A.; Lochhead, Michael J.; Connell, Laurie B.; Doucette, Gregory J.; O'Kennedy, Richard J.

    2016-01-01

    Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndrom...

  10. Botulinum toxin

    Directory of Open Access Journals (Sweden)

    Nigam P

    2010-01-01

    Full Text Available Botulinum toxin, one of the most poisonous biological substances known, is a neurotoxin produced by the bacterium Clostridium botulinum. C. botulinum elaborates eight antigenically distinguishable exotoxins (A, B, C 1 , C 2 , D, E, F and G. All serotypes interfere with neural transmission by blocking the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. The weakness induced by injection with botulinum toxin A usually lasts about three months. Botulinum toxins now play a very significant role in the management of a wide variety of medical conditions, especially strabismus and focal dystonias, hemifacial spasm, and various spastic movement disorders, headaches, hypersalivation, hyperhidrosis, and some chronic conditions that respond only partially to medical treatment. The list of possible new indications is rapidly expanding. The cosmetological applications include correction of lines, creases and wrinkling all over the face, chin, neck, and chest to dermatological applications such as hyperhidrosis. Injections with botulinum toxin are generally well tolerated and side effects are few. A precise knowledge and understanding of the functional anatomy of the mimetic muscles is absolutely necessary to correctly use botulinum toxins in clinical practice.

  11. National Algal Biofuels Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, John [Dept. of Energy (DOE), Washington DC (United States); Sarisky-Reed, Valerie [Dept. of Energy (DOE), Washington DC (United States)

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  12. Origins.

    Science.gov (United States)

    Online-Offline, 1999

    1999-01-01

    Provides an annotated list of resources dealing with the theme of origins of life, the universe, and traditions. Includes Web sites, videos, books, audio materials, and magazines with appropriate grade levels and/or subject disciplines indicated; professional resources; and learning activities. (LRW)

  13. Advanced Algal Systems Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Research and development (R&D) on advanced algal biofuels and bioproducts presents an opportunity to sustainably expand biomass resource potential in the United States. The Bioenergy Technologies Office’s (BETO’s) Advanced Algal Systems Program is carrying out a long-term, applied R&D strategy to lower the costs of algal biofuel production by working with partners to develop revolutionary technologies and conduct crosscutting analyses to better understand the potential

  14. Effect of Antibiotic Treatment on Toxin Production by Alexandrium tamarense

    Institute of Scientific and Technical Information of China (English)

    CHANG-HAI WANG; YI-YUN WANG; YING-YING SUN; XIAN-TANG XIE

    2003-01-01

    Objective Impact of the presence of bacteria associated with a marine dinoflagellate,Alexandrium tamarense CI01, on the growth and toxin production of the algae in batch culture was investigated. Methods Pronounced changes in the activities of the algal culture were observed when the culture was treated with different doses of a mixture of penicillin and streptomycin.Results In the presence of antibiotics at the initial concentration of 100 u/mL in culture medium,both algal growth and toxin yield increased markedly. When the concentration of antibiotics was increased to 500 u/mL, the microalgal growth was inhibited, but resumed in a few days to eventually reach the same level of growth and toxin production as at the lower dose of the antibiotics. When the antibiotics were present at a concentration of 1000 u/mL, the algal growth was inhibited permanently.Conclusions The results indicate that antibiotics can enhance algal growth and toxin production not only through their inhibition of the growth and hence competition for nutrients, but also through their effects on the physiology of the algae.

  15. Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

    Science.gov (United States)

    Rosen, Barry H.; Ann St. Amand

    2015-01-01

    Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

  16. In situ passive solid-phase adsorption of micro-algal biotoxins as a monitoring tool.

    Science.gov (United States)

    MacKenzie, Lincoln A

    2010-06-01

    Laboratory and field studies of the passive solid-phase adsorption toxin tracking (SPATT) method have been carried out around the world. A wide range of marine micro-algal toxins have been detected and the potential of the method to provide reliable, sensitive, time-integrated sampling to monitor the occurrence of toxic algal bloom events has been demonstrated. The method has several important advantages over current phytoplankton and shellfish monitoring methods. Trials of various adsorption substrates have been carried out and the best candidates have been selected for the lipophilic marine biotoxin groups; however, research continues to locate suitable substrates for the more polar water-soluble compounds such as domoic acid and the saxitoxins. The technique has also been successfully applied to the detection of a range of freshwater cyanobacterial toxins.

  17. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.

    2015-03-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  18. Algal functional annotation tool

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, D. [UCLA; Casero, D. [UCLA; Cokus, S. J. [UCLA; Merchant, S. S. [UCLA; Pellegrini, M. [UCLA

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  19. Why do we study animal toxins?

    Science.gov (United States)

    Zhang, Yun

    2015-07-18

    Venom (toxins) is an important trait evolved along the evolutionary tree of animals. Our knowledges on venoms, such as their origins and loss, the biological relevance and the coevolutionary patterns with other organisms are greatly helpful in understanding many fundamental biological questions, i.e., the environmental adaptation and survival competition, the evolution shaped development and balance of venoms, and the sophisticated correlations among venom, immunity, body power, intelligence, their genetic basis, inherent association, as well as the cost-benefit and trade-offs of biological economy. Lethal animal envenomation can be found worldwide. However, from foe to friend, toxin studies have led lots of important discoveries and exciting avenues in deciphering and fighting human diseases, including the works awarded the Nobel Prize and lots of key clinic therapeutics. According to our survey, so far, only less than 0.1% of the toxins of the venomous animals in China have been explored. We emphasize on the similarities shared by venom and immune systems, as well as the studies of toxin knowledge-based physiological toxin-like proteins/peptides (TLPs). We propose the natural pairing hypothesis. Evolution links toxins with humans. Our mission is to find out the right natural pairings and interactions of our body elements with toxins, and with endogenous toxin-like molecules. Although, in nature, toxins may endanger human lives, but from a philosophical point of view, knowing them well is an effective way to better understand ourselves. So, this is why we study toxins. PMID:26228472

  20. Botox (Botulinum Toxin)

    Science.gov (United States)

    ... and rashes clinical tools newsletter | contact Share | Botox (Botulinum Toxin) A A A BEFORE: Crow's feet before Botox ... wrinkles. One such procedure involves the use of botulinum toxin injections. Botulinum toxin is produced by the fermentation ...

  1. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  2. Algal Bloom: Boon or Bane?

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    Algal blooms occur in response to nutrient deplete or replete conditions. Nitrogen fixing forms proliferate under oligotrophic conditions when nutrient levels are low. Replete conditions in response to upwelling creates the most biologically...

  3. Fueling Future with Algal Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-07-05

    Algae constitute a major component of fundamental eukaryotic diversity, play profound roles in the carbon cycle, and are prominent candidates for biofuel production. The US Department of Energy Joint Genome Institute (JGI) is leading the world in algal genome sequencing (http://jgi.doe.gov/Algae) and contributes of the algal genome projects worldwide (GOLD database, 2012). The sequenced algal genomes offer catalogs of genes, networks, and pathways. The sequenced first of its kind genomes of a haptophyte E.huxleyii, chlorarachniophyte B.natans, and cryptophyte G.theta fill the gaps in the eukaryotic tree of life and carry unique genes and pathways as well as molecular fossils of secondary endosymbiosis. Natural adaptation to conditions critical for industrial production is encoded in algal genomes, for example, growth of A.anophagefferens at very high cell densities during the harmful algae blooms or a global distribution across diverse environments of E.huxleyii, able to live on sparse nutrients due to its expanded pan-genome. Communications and signaling pathways can be derived from simple symbiotic systems like lichens or complex marine algae metagenomes. Collectively these datasets derived from algal genomics contribute to building a comprehensive parts list essential for algal biofuel development.

  4. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  5. Identifying Historical Occurrences of HABs Using Sedimentary Algal Pigments

    Science.gov (United States)

    Smoak, J. M.; Waters, M. N.

    2008-12-01

    Algal blooms are a common feature of many coastal areas. Under some environmental conditions, these develop into Harmful Algal Blooms (HABs) and present an environmental hazard and a health risk for humans and wildlife due to toxin production. While monitoring programs track the development of contemporary HABs, data are lacking for historical blooms. We use sedimentary algal pigments to identify the occurrence of Karenia Brevis (Florida Red Tide) in sediment cores collected from mangrove environments along the west coast of Florida. Karenia Brevis has a unique pigment, gyroxanthin-diester, that is routinely used to identify red tide in the water column. Gyroxanthin-diester and other carotenoid pigments associated with red tide taxa are analyzed using HPLC techniques. Identification of gyroxanthan-diester is based on comparison with HPLC analysis of gyroxanthin standard, a monoculture sample of K. Brevis and with published spectra of Gyroxanthin-diester in water samples. We track the timing of the K. Brevis using Pb-210 dating models which allows an examination over the last 100 years.

  6. Harmful Algal in Banyuasin Coastal Waters, South Sumatera

    Directory of Open Access Journals (Sweden)

    Riris Aryawati

    2016-09-01

    Full Text Available Phytoplankton have important as food-chain major component and primary production of marine environment. However, high abundance of phytoplankton could give harmful effects toward water ecosystem. Moreover, they could produce toxic substances that will be accumulated within their consumer. This accumulation could be dangerous for human or animals.This research were aimed to determine and calculatespecies of harmful algae in Banyuasin coastal waters. The study was conducted on April, June, August, October and December of 2013, and in February 2014, at ten stations. Phytoplankton samples were taken vertically using plankton nets. In the form of cone-shaped with a diameter of 30 cm, length 100 cm and mesh size 30 μm.The result showed that there are 35 genera of phytoplankton. That have been found and consisted of four groups; Bacillariophyceae, Dinophyceae, Cyanophyceae and Chlorophyceae. 13 species were identified as Harmful Algal (Chaetoceros, Coscinodiscus, Nitzschia, Skeletonema, Thalassiosira, Alexandrium, Ceratium, Dinophysis, Noctiluca, Protoperidinium, Prorocentrum, Anabaena dan Oscillatoria, with seven of them were known for having toxin (Nitzschia, Alexandrium, Dinophysis, Protoperidinium Prorocentrum, Anabaena and Oscillatoria. Monitoring result showed that the highest number of species of potential harmful algal blooms (HABs occured in June and the highest abundance occured in August, especially Chaetoceros and Skeletonema.How to CiteAryawati, R., Bengen, D. G., Prartono, T., & Zulkifli, H. (2016. Harmful Algal in Banyuasin Coastal Waters, South Sumatera. Biosaintifika: Journal of Biology & Biology Education, 8(2, 231-239.

  7. Algal culture studies for CELSS

    Science.gov (United States)

    Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

    1987-01-01

    Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

  8. Evaluation of Harmful Algal Bloom Outreach Activities

    Directory of Open Access Journals (Sweden)

    Richard Weisman

    2007-12-01

    Full Text Available With an apparent increase of harmful algal blooms (HABs worldwide,healthcare providers, public health personnel and coastal managers are struggling toprovide scientifically-based appropriately-targeted HAB outreach and education. Since1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year freeAquatic Toxins Hotline (1-888-232-8635 available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-relatedillness among callers are reported to the Florida Health Department. This pilot studyevaluated an automated call processing menu system that allows callers to access bilingualHAB information, and to speak directly with a trained Poison Information Specialist. Themajority (68% of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.

  9. Immunotoxins: The Role of the Toxin

    Directory of Open Access Journals (Sweden)

    David FitzGerald

    2013-08-01

    Full Text Available Immunotoxins are antibody-toxin bifunctional molecules that rely on intracellular toxin action to kill target cells. Target specificity is determined via the binding attributes of the chosen antibody. Mostly, but not exclusively, immunotoxins are purpose-built to kill cancer cells as part of novel treatment approaches. Other applications for immunotoxins include immune regulation and the treatment of viral or parasitic diseases. Here we discuss the utility of protein toxins, of both bacterial and plant origin, joined to antibodies for targeting cancer cells. Finally, while clinical goals are focused on the development of novel cancer treatments, much has been learned about toxin action and intracellular pathways. Thus toxins are considered both medicines for treating human disease and probes of cellular function.

  10. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The biogenic stabilisation of intertidal estuarine sediments by epipelic diatom films and the macrophyte Vaucheria was studied at three sites on the Severn Estuary. The cohesive strength meter (CSM) was developed to measure surface critical shear stress with varied algal density. A number of techniques have been used to determine the general in situ erodibility of cohesive estuarine sediments. The measurements of sediment shear strength and critical erosion velocity were investigated. Field experiments were undertaken to investigate the effect of algae on binding sediments, and a predictive method for the assessment of sediment stabilisation by algal binding was developed. (author)

  11. Identification of euglenophycin--a toxin found in certain euglenoids.

    Science.gov (United States)

    Zimba, Paul V; Moeller, Peter D; Beauchesne, Kevin; Lane, Hannah E; Triemer, Richard E

    2010-01-01

    Currently cyanoprokaryotic algae, diatoms, haptophytes, dinoflagellates, euglenoids, and rhaphidophytes are known to produce algal toxins. A previous study by the authors reported euglenoid algae producing toxin(s) in aquaculture ponds, with confirmation based on positive fish bioassays following exposure to the isolated clonal algal cultures. Toxicity was observed in euglenoid culture isolates obtained from the pond as well as a clonal, culture collection taxon. Here we provide conclusive evidence for euglenoid toxin production, including HPLC/MS, MS/MS, and NMR analyses of a clonal (non-axenic) isolate of Euglena sanguinea grown in batch culture. Following wet chemical serial fractionation, toxic activity was identified in both the methanol and hexane extracts. These extracts were then purified using HPLC. Bioassay-guided HPLC fractionation of these two extracts demonstrated that a single class of toxic compounds, identical in mass and similar in molecular structure, was produced by this organism. The toxic compounds exhibited a maximal UV absorbance at 238nm and gave diagnostic mass peaks at 306 (MH(+)) and 288 (MH(+)-H(2)O). Unambiguous molecular structural determination was carried out by high field NMR analysis operating in 1- and 2-dimensions. Though a predominant isomer represented the bulk of the toxin, several stereo- and structural isomers were evidenced by NMR, and HPLC/MS. This compound is an alkaloid similar in structure to fire ant venom. The compound exhibits ichthyotoxic, herbicidal and anticancer activity at low ppm to ppb dosages. PMID:19615398

  12. Algal taxonomy forum: Algal Taxonomist, Let Serendipity Reign!

    Science.gov (United States)

    Druehl, Louis

    2013-04-01

    The publication of a mini-review by Olivier De Clerck et al. in this issue of the Journal of Phycology presented an opportunity to open a dialogue on challenges faced by contemporary algal taxonomists. The Editorial Office solicited the following two additional contributions in response to De Clerck et al.'s paper; the responses were edited solely for clarity, space and format.

  13. Sentinel Animals in a One Health Approach to Harmful Cyanobacterial and Algal Blooms

    OpenAIRE

    Backer, Lorraine C.; Melissa Miller

    2016-01-01

    People, domestic animals, and wildlife are all exposed to numerous environmental threats, including harmful algal blooms (HABs). However, because animals exhibit wide variations in diet, land use and biology, they are often more frequently or heavily exposed to HAB toxins than are people occupying the same habitat, making them sentinels for human exposures. Historically, we have taken advantage of unique physiological characteristics of animals, such as the sensitivity of canaries to carbon m...

  14. Paralytic shellfish poison algal biotoxins: Sardinia report 2002-2011 and non-compliance management

    OpenAIRE

    Giuseppa Lorenzoni; Igor Arras; Giovanna Sanna; Pietro Delogu; Alessandro Mudadu; Antonio Piras; Antonio Mura; Edoardo Marongiu; Sebastiano Virgilio

    2013-01-01

    Several microalgae of the genus Alexandrium (Alexandrium minutum and Alexandrium catenelle) can produce an algal biotoxin, the paralytic shellfish poison (PSP) that can be accumulated in the shellfish edible tissues making them hazardous to the consumer’s health. In this paper we report i) the results of PSP toxins survey carried out by mouse bioassays (mouse test AOAC 958.08) on 7457 samples of bivalve molluscs farmed in Sardinia and in other European countries and marketed in Sardinia...

  15. Botulinum toxin injection - larynx

    Science.gov (United States)

    Injection laryngoplasty; Botox-larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography-guided botulinum toxin treatment; Percutaneous indirect laryngoscopy-guided botulinum toxin Treatment; ...

  16. *CYANOBACTERIA AND THEIR TOXINS

    Science.gov (United States)

    Cyanobacteria, or blue-green algae, are naturally-occurring contaminants of surface waters worldwide. These photosynthesizing prokaryotes thrive in warm, shallow, nutrient-rich waters. Many produce potent toxins as secondary metabolites. Cyanobacteria toxins have been document...

  17. Stool C. difficile toxin

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003590.htm Stool C. difficile toxin To use the sharing features on this page, please enable JavaScript. The stool C. difficile toxin test detects harmful substances produced by ...

  18. Transcriptome sequencing of essential marine brown and red algal species in China and its significance in algal biology and phylogeny

    Institute of Scientific and Technical Information of China (English)

    WU Shuangxiu; YU Jun; SUN Jing; CHI Shan; WANG Liang; WANG Xumin; LIU Cui; LI Xingang; YIN Jinlong; LIU Tao

    2014-01-01

    Most phaeophytes (brown algae) and rhodophytes (red algae) dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important resources for industries such as food, medicine and materials due to their unique metabolisms and me-tabolites. However, many fundamental questions surrounding their origins, early diversification, taxonomy, and special metabolisms remain unsolved because of poor molecular bases in brown and red algal study. As part of the 1 000 Plant Project, the marine macroalgal transcriptomes of 19 Phaeophyceae species and 21 Rhodophyta species from China's coast were sequenced, covering a total of 2 phyla, 3 classes, 11 orders, and 19 families. An average of 2 Gb per sample and a total 87.3 Gb of RNA-seq raw data were generated. Approxi-mately 15 000 to 25 000 unigenes for each brown algal sample and 5 000 to 10 000 unigenes for each red algal sample were annotated and analyzed. The annotation results showed obvious differences in gene expres-sion and genome characteristics between red algae and brown algae;these differences could even be seen between multicellular and unicellular red algae. The results elucidate some fundamental questions about the phylogenetic taxonomy within phaeophytes and rhodophytes, and also reveal many novel metabolic pathways. These pathways include algal CO2 fixation and particular carbohydrate metabolisms, and related gene/gene family characteristics and evolution in brown and red algae. These findings build on known algal genetic information and significantly improve our understanding of algal biology, biodiversity, evolution, and potential utilization of these marine algae.

  19. Multiplex biotoxin surface plasmon resonance method for marine biotoxins in algal and seawater samples.

    Science.gov (United States)

    McNamee, Sara E; Elliott, Christopher T; Delahaut, Philippe; Campbell, Katrina

    2013-10-01

    A multiplex surface plasmon resonance (SPR) biosensor method for the detection of paralytic shellfish poisoning (PSP) toxins, okadaic acid (and analogues) and domoic acid was developed. This method was compared to enzyme-linked immunosorbent assay (ELISA) methods. Seawater samples (n=256) from around Europe were collected by the consortia of an EU project MIcroarrays for the Detection of Toxic Algae (MIDTAL) and evaluated using each method. A simple sample preparation procedure was developed which involved lysing and releasing the toxins from the algal cells with glass beads followed by centrifugation and filtering the extract before testing for marine biotoxins by both multi-SPR and ELISA. Method detection limits based on IC20 values for PSP, okadaic acid and domoic acid toxins were 0.82, 0.36 and 1.66 ng/ml, respectively, for the prototype multiplex SPR biosensor. Evaluation by SPR for seawater samples has shown that 47, 59 and 61 % of total seawater samples tested positive (result greater than the IC20) for PSP, okadaic acid (and analogues) and domoic acid toxins, respectively. Toxic samples were received mainly from Spain and Ireland. This work has demonstrated the potential of multiplex analysis for marine biotoxins in algal and seawater samples with results available for 24 samples within a 7 h period for three groups of key marine biotoxins. Multiplex immunological methods could therefore be used as early warning monitoring tools for a variety of marine biotoxins in seawater samples.

  20. Multiplex biotoxin surface plasmon resonance method for marine biotoxins in algal and seawater samples.

    Science.gov (United States)

    McNamee, Sara E; Elliott, Christopher T; Delahaut, Philippe; Campbell, Katrina

    2013-10-01

    A multiplex surface plasmon resonance (SPR) biosensor method for the detection of paralytic shellfish poisoning (PSP) toxins, okadaic acid (and analogues) and domoic acid was developed. This method was compared to enzyme-linked immunosorbent assay (ELISA) methods. Seawater samples (n=256) from around Europe were collected by the consortia of an EU project MIcroarrays for the Detection of Toxic Algae (MIDTAL) and evaluated using each method. A simple sample preparation procedure was developed which involved lysing and releasing the toxins from the algal cells with glass beads followed by centrifugation and filtering the extract before testing for marine biotoxins by both multi-SPR and ELISA. Method detection limits based on IC20 values for PSP, okadaic acid and domoic acid toxins were 0.82, 0.36 and 1.66 ng/ml, respectively, for the prototype multiplex SPR biosensor. Evaluation by SPR for seawater samples has shown that 47, 59 and 61 % of total seawater samples tested positive (result greater than the IC20) for PSP, okadaic acid (and analogues) and domoic acid toxins, respectively. Toxic samples were received mainly from Spain and Ireland. This work has demonstrated the potential of multiplex analysis for marine biotoxins in algal and seawater samples with results available for 24 samples within a 7 h period for three groups of key marine biotoxins. Multiplex immunological methods could therefore be used as early warning monitoring tools for a variety of marine biotoxins in seawater samples. PMID:23250726

  1. Bioterrorism: toxins as weapons.

    Science.gov (United States)

    Anderson, Peter D

    2012-04-01

    The potential for biological weapons to be used in terrorism is a real possibility. Biological weapons include infectious agents and toxins. Toxins are poisons produced by living organisms. Toxins relevant to bioterrorism include ricin, botulinum, Clostridium perfrigens epsilson toxin, conotoxins, shigatoxins, saxitoxins, tetrodotoxins, mycotoxins, and nicotine. Toxins have properties of biological and chemical weapons. Unlike pathogens, toxins do not produce an infection. Ricin causes multiorgan toxicity by blocking protein synthesis. Botulinum blocks acetylcholine in the peripheral nervous system leading to muscle paralysis. Epsilon toxin damages cell membranes. Conotoxins block potassium and sodium channels in neurons. Shigatoxins inhibit protein synthesis and induce apoptosis. Saxitoxin and tetrodotoxin inhibit sodium channels in neurons. Mycotoxins include aflatoxins and trichothecenes. Aflatoxins are carcinogens. Trichothecenes inhibit protein and nucleic acid synthesis. Nicotine produces numerous nicotinic effects in the nervous system.

  2. Virulence profiles of Shiga toxin-producing Escherichia coli and other potentially diarrheagenic E.coli of bovine origin, in Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    M.A. Pizarro

    2013-12-01

    Full Text Available This study described a group of strains obtained from a slaughter house in Mendoza, in terms of their pathogenic factors, serotype, antibiotype and molecular profile. Ninety one rectal swabs and one hundred eight plating samples taken from carcasses of healthy cattle intended for meat consumption were analyzed. Both the swab and the plate samples were processed to analyze the samples for the presence of virulence genes by PCR: stx1, stx2, eae and astA. The Stx positive strains were confirmed by citotoxicity assay in Vero cells. The isolates were subsequently investigated for their O:H serotype, antimicrobial susceptibility and molecular profile by Random Amplification of Polymorphic DNA (RAPD. Twelve E.coli strains were identified by their pathogenicity. Nine were from fecal origin and three from carcasses. Three strains carried the stx1 gene, three the stx2 gene, two carried eae and four the astA gene. The detected serotypes were: O172:H-; O150:H8; O91:H21; O178:H19 and O2:H5. The strains showed a similarity around 70% by RAPD. Some of the E.coli strains belonged to serogroups known for certain life-threatening diseases in humans. Their presence in carcasses indicates the high probability of bacterial spread during slaughter and processing.

  3. Methods for removing contaminants from algal oil

    Energy Technology Data Exchange (ETDEWEB)

    Lupton, Francis Stephen

    2016-09-27

    Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

  4. [Intoxication of botulinum toxin].

    Science.gov (United States)

    Chudzicka, Aleksandra

    2015-09-01

    Botulinum toxin is an egzotoxin produced by Gram positive bacteria Clostridium botulinum. It is among the most potent toxins known. The 3 main clinical presentations of botulism are as follows: foodborne botulism, infant botulism and wound botulism. The main symptom of intoxication is flat muscles paralysis. The treatment is supportive care and administration of antitoxin. In prevention the correct preparing of canned food is most important. Botulinum toxin is accepted as a biological weapon.

  5. Evidence for production of paralytic shellfish toxins by bacteria associated with Alexandrium spp. (Dinophyta) in culture

    OpenAIRE

    Gallacher, S.; Flynn, Kevin J.; Franco, José M.; Brueggemann, E. E. (Ernst); Hines, H.B. (Harry)

    1997-01-01

    A substantial proportion of bacteria from five Alexandrium cultures originally isolated from various countries produced sodium channel blocking (SCB) toxins, as ascertained by mouse neuroblastoma assay. The quantities of SCB toxins produced by bacteria and dinoflagellates were noted, and the limitations in comparing the toxicities of these two organisms are discussed. The chemical nature of the SCB toxins in selected bacterial isolates was determined as paralytic shellfish toxins by pre- and ...

  6. Diarrhetic Shellfish Toxins and Other Lipophilic Toxins of Human Health Concern in Washington State

    Directory of Open Access Journals (Sweden)

    Bich-Thuy L. Eberhart

    2013-05-01

    Full Text Available The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay State Park, Washington State, USA, demonstrated the need to monitor diarrhetic shellfish toxins (DSTs in Washington State for the protection of human health. Following these cases of diarrhetic shellfish poisoning, monitoring for DSTs in Washington State became formalized in 2012, guided by routine monitoring of Dinophysis species by the SoundToxins program in Puget Sound and the Olympic Region Harmful Algal Bloom (ORHAB partnership on the outer Washington State coast. Here we show that the DSTs at concentrations above the guidance level of 16 μg okadaic acid (OA + dinophysistoxins (DTXs/100 g shellfish tissue were widespread in sentinel mussels throughout Puget Sound in summer 2012 and included harvest closures of California mussel, varnish clam, manila clam and Pacific oyster. Concentrations of toxins in Pacific oyster and manila clam were often at least half those measured in blue mussels at the same site. The primary toxin isomer in shellfish and plankton samples was dinophysistoxin-1 (DTX-1 with D. acuminata as the primary Dinophysis species. Other lipophilic toxins in shellfish were pectenotoxin-2 (PTX-2 and yessotoxin (YTX with azaspiracid-2 (AZA-2 also measured in phytoplankton samples. Okadaic acid, azaspiracid-1 (AZA-1 and azaspiracid-3 (AZA-3 were all below the levels of detection by liquid chromatography tandem mass spectrometry (LC-MS/MS. A shellfish closure at Ruby Beach, Washington, was the first ever noted on the Washington State Pacific coast due to DSTs. The greater than average Fraser River flow during the summers of 2011 and 2012 may have provided an environment conducive to dinoflagellates and played a role in the prevalence of toxigenic Dinophysis in Puget Sound.

  7. Reporter Gene Assay for Detection of Shellfish Toxins

    Institute of Scientific and Technical Information of China (English)

    WEI-DONG YANG; MIN-YI WU; JIE-SHENG LIU; XI-CHUN PENG; HONG-YE LI

    2009-01-01

    Objective To explore the potential reporter gene assay for the detection of sodium channel-specific toxins in shellfish as an alternative for screening harmful algal bloom (HAB) toxins, considering the fact that the existing methods including HPLC and bioassay are inappropriate for identifying HAB toxins which poses a serious problem on human health and shellfish industry. Methods A reporter plasmid pEGFP-c-fos containing c-fos promoter and EGFP was constructed and transfected into T24 cells using LipofectAMINE 2000. Positive transfectants were screened by G418 to produce a pEGFP-c-fos-T24 cell line. After addition of increasing neurotoxic shellfish poison (NSP) or GTX2,3, primary components of paralytic shellfish poison (PSP), changes in expression of EGFP in the cell line were observed under a laser scanning confocal microscope and quantified with Image-pro Plus software. Results Dose-dependent changes in the intensity of green fluorescence were observed for NSP in a range from 0 to 10 ng/mL and for GTX 2,3 from 0 to 16 ng/mL. Conclusion pEGFP-c-fos-T24 can be applied in detecting HAB toxins, and cell-based assay can be used as an alternative for screening sodium channel-specific HAB toxins.

  8. Detection of marine toxins, brevetoxin-3 and saxitoxin, in seawater using neuronal networks.

    Science.gov (United States)

    Kulagina, Nadezhda V; Mikulski, Christina M; Gray, Samuel; Ma, Wu; Doucette, Gregory J; Ramsdell, John S; Pancrazio, Joseph J

    2006-01-15

    There is a need for assay systems that can detect known and unanticipated neurotoxins associated with harmful algal blooms. The present work describes our attempt to monitor the presence of brevetoxin-3 (PbTx-3) and saxitoxin (STX) in a seawater matrix using the neuronal network biosensor (NNB). The NNB relies on cultured mammalian neurons grown over microelectrode arrays, where the inherent bioelectrical activity of the network manifested as extracellular action potentials can be monitored noninvasively. Spinal cord neuronal networks were prepared from embryonic mice and the mean spike rate across the network was analyzed before and during exposure to the toxins. Extracellular action potentials from the network are highly sensitive not only to purified STX and PbTx-3, but also when in combination with matrixes such as natural seawater and algal growth medium. Detection limits for STX and PbTx-3, respectively, are 0.031 and 0.33 nM in recording buffer and 0.076 and 0.48 nM in the presence of 25-fold-diluted seawater. Our results demonstrated that neuronal networks could be used for analysis of Alexandrium fundyense (STX-producer) and Karenia brevis (PbTx-producer) algal samples lysed directly in the seawater-based growth medium and appropriately diluted with HEPES-buffered recording medium. The cultured network responded by changes in mean spike rate to the presence of STX-or PbTx-producing algae but not to the samples of two non-STX and non-PbTx isolates of the same algal genera. This work provides evidence that the NNB has the capacity to rapidly detect toxins associated with cells of toxic algal species or as dissolved forms present in seawater and hasthe potential for monitoring toxin levels during harmful algal blooms. PMID:16468405

  9. Understanding malarial toxins.

    Science.gov (United States)

    Starkl Renar, Katarina; Iskra, Jernej; Križaj, Igor

    2016-09-01

    Recognized since antiquity, malaria is one of the most infamous and widespread infectious diseases in humans and, although the death rate during the last century has been diminishing, it still accounts for more than a half million deaths annually. It is caused by the Plasmodium parasite and typical symptoms include fever, shivering, headache, diaphoresis and nausea, all resulting from an excessive inflammatory response induced by malarial toxins released into the victim's bloodstream. These toxins are hemozoin and glycosylphosphatidylinositols. The former is the final product of the parasite's detoxification of haeme, a by-product of haemoglobin catabolism, while the latter anchor proteins to the Plasmodium cell surface or occur as free molecules. Currently, only two groups of antimalarial toxin drugs exist on the market, quinolines and artemisinins. As we describe, they both target biosynthesis of hemozoin. Other substances, currently in various phases of clinical trials, are directed towards biosynthesis of glycosylphosphatidylinositol, formation of hemozoin, or attenuation of the inflammatory response of the patient. Among the innovative approaches to alleviating the effects of malarial toxins, is the development of antimalarial toxin vaccines. In this review the most important lessons learned from the use of treatments directed against the action of malarial toxins in antimalarial therapy are emphasized and the most relevant and promising directions for future research in obtaining novel antimalarial agents acting on malarial toxins are discussed.

  10. Understanding malarial toxins.

    Science.gov (United States)

    Starkl Renar, Katarina; Iskra, Jernej; Križaj, Igor

    2016-09-01

    Recognized since antiquity, malaria is one of the most infamous and widespread infectious diseases in humans and, although the death rate during the last century has been diminishing, it still accounts for more than a half million deaths annually. It is caused by the Plasmodium parasite and typical symptoms include fever, shivering, headache, diaphoresis and nausea, all resulting from an excessive inflammatory response induced by malarial toxins released into the victim's bloodstream. These toxins are hemozoin and glycosylphosphatidylinositols. The former is the final product of the parasite's detoxification of haeme, a by-product of haemoglobin catabolism, while the latter anchor proteins to the Plasmodium cell surface or occur as free molecules. Currently, only two groups of antimalarial toxin drugs exist on the market, quinolines and artemisinins. As we describe, they both target biosynthesis of hemozoin. Other substances, currently in various phases of clinical trials, are directed towards biosynthesis of glycosylphosphatidylinositol, formation of hemozoin, or attenuation of the inflammatory response of the patient. Among the innovative approaches to alleviating the effects of malarial toxins, is the development of antimalarial toxin vaccines. In this review the most important lessons learned from the use of treatments directed against the action of malarial toxins in antimalarial therapy are emphasized and the most relevant and promising directions for future research in obtaining novel antimalarial agents acting on malarial toxins are discussed. PMID:27353131

  11. Extended evaluation of polymeric and lipophilic sorbents for passive sampling of marine toxins.

    Science.gov (United States)

    Zendong, Zita; Herrenknecht, Christine; Abadie, Eric; Brissard, Charline; Tixier, Céline; Mondeguer, Florence; Séchet, Véronique; Amzil, Zouher; Hess, Philipp

    2014-12-01

    Marine biotoxins are algal metabolites that can accumulate in fish or shellfish and render these foodstuffs unfit for human consumption. These toxins, released into seawater during algal occurrences, can be monitored through passive sampling. Acetone, methanol and isopropanol were evaluated for their efficiency in extracting toxins from algal biomass. Isopropanol was chosen for further experiments thanks to a slightly higher recovery and no artifact formation. Comparison of Oasis HLB, Strata-X, BondElut C18 and HP-20 sorbent materials in SPE-mode led to the choice of Oasis HLB, HP-20 and Strata-X. These three sorbents were separately exposed as passive samplers for 24 h to seawater spiked with algal extracts containing known amounts of okadaic acid (OA), azaspiracids (AZAs), pinnatoxin-G (PnTX-G), 13-desmethyl spirolide-C (SPX1) and palytoxins (PlTXs). Low density polyethylene (LDPE) and silicone rubber (PDMS) strips were tested in parallel on similar mixtures of spiked natural seawater for 24 h. These strips gave significantly lower recoveries than the polymeric sorbents. Irrespective of the toxin group, the adsorption rate of toxins on HP-20 was slower than on Oasis HLB and Strata-X. However, HP-20 and Strata-X gave somewhat higher recoveries after 24 h exposure. Irrespective of the sorbent tested, recoveries were generally highest for cyclic imines and OA group toxins, slightly lower for AZAs, and the lowest for palytoxins. Trials in re-circulated closed tanks with mussels exposed to Vulcanodinium rugosum or Prorocentrum lima allowed for further evaluation of passive samplers. In these experiments with different sorbent materials competing for toxins in the same container, Strata-X accumulated toxins faster than Oasis HLB, and HP-20, and to higher levels. The deployment of these three sorbents at Ingril French Mediterranean lagoon to detect PnTX-G in the water column showed accumulation of higher levels on HP-20 and Oasis HLB compared to Strata-X. This study

  12. Approaches to monitoring, control and management of harmful algal blooms (HABs)

    OpenAIRE

    Anderson, Donald M.

    2009-01-01

    Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called “red tides”). These phenomena are caused by blooms of microscopic algae. Some of these algae are toxic, and can lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life, typically as a result of the transfer of toxins through the food web. Sometimes the direct release of toxic compounds can be lethal to marine animals. Non-toxic HABs cause damage to ecosys...

  13. Exploring the Utilization of Complex Algal Communities to Address Algal Pond Crash and Increase Annual Biomass Production for Algal Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Cyd E. [Dept. of Energy (DOE), Washington DC (United States).

    2014-03-25

    This white paper briefly reviews the research literature exploring complex algal communities as a means of increasing algal biomass production via increased tolerance, resilience, and resistance to a variety of abiotic and biotic perturbations occurring within harvesting timescales. This paper identifies what data are available and whether more research utilizing complex communities is needed to explore the potential of complex algal community stability (CACS) approach as a plausible means to increase biomass yields regardless of ecological context and resulting in decreased algal-based fuel prices by reducing operations costs. By reviewing the literature for what we do and do not know, in terms of CACS methodologies, this report will provide guidance for future research addressing pond crash phenomena.

  14. Staphylococcus aureus toxins.

    Science.gov (United States)

    Otto, Michael

    2014-02-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions.

  15. Recent Advances in Algal Genetic Tool Development

    Energy Technology Data Exchange (ETDEWEB)

    R. Dahlin, Lukas; T. Guarnieri, Michael

    2016-06-24

    The goal of achieving cost-effective biofuels and bioproducts derived from algal biomass will require improvements along the entire value chain, including identification of robust, high-productivity strains and development of advanced genetic tools. Though there have been modest advances in development of genetic systems for the model alga Chlamydomonas reinhardtii, progress in development of algal genetic tools, especially as applied to non-model algae, has generally lagged behind that of more commonly utilized laboratory and industrial microbes. This is in part due to the complex organellar structure of algae, including robust cell walls and intricate compartmentalization of target loci, as well as prevalent gene silencing mechanisms, which hinder facile utilization of conventional genetic engineering tools and methodologies. However, recent progress in global tool development has opened the door for implementation of strain-engineering strategies in industrially-relevant algal strains. Here, we review recent advances in algal genetic tool development and applications in eukaryotic microalgae.

  16. Uptake, transfer and elimination kinetics of paralytic shellfish toxins in common octopus (Octopus vulgaris).

    Science.gov (United States)

    Lopes, Vanessa M; Baptista, Miguel; Repolho, Tiago; Rosa, Rui; Costa, Pedro Reis

    2014-01-01

    Marine phycotoxins derived from harmful algal blooms are known to be associated with mass mortalities in the higher trophic levels of marine food webs. Bivalve mollusks and planktivorous fish are the most studied vectors of marine phycotoxins. However, field surveys recently showed that cephalopod mollusks also constitute potential vectors of toxins. Thus, here we determine, for the first time, the time course of accumulation and depuration of paralytic shellfish toxins (PSTs) in the common octopus (Octopus vulgaris). Concomitantly, the underlying kinetics of toxin transfer between tissue compartments was also calculated. Naturally contaminated clams were used to orally expose the octopus to PSTs during 6 days. Afterwards, octopus specimens were fed with non-contaminated shellfish during 10 days of depuration period. Toxins reached the highest concentrations in the digestive gland surpassing the levels in the kidney by three orders of magnitude. PSTs were not detected in any other tissue analyzed. Net accumulation efficiencies of 42% for GTX5, 36% for dcSTX and 23% for C1+2 were calculated for the digestive gland. These compounds were the most abundant toxins in both digestive gland and the contaminated shellfish diet. The small differences in relative abundance of each toxin observed between the prey and the cephalopod predator indicates low conversion rates of these toxins. The depuration period was better described using an exponential decay model comprising a single compartment - the entire viscera. It is worth noting that since octopuses' excretion and depuration rates are low, the digestive gland is able to accumulate very high toxin concentrations for long periods of time. Therefore, the present study clearly shows that O. vulgaris is a high-potential vector of PSTs during and even after the occurrence of these toxic algal blooms.

  17. Direct conversion of algal biomass to biofuel

    Science.gov (United States)

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  18. Molecular characterization of harmful algal species

    OpenAIRE

    Stacca, Daniela

    2014-01-01

    The main purpose of the research activities carried out in this thesis was to give contributions to ecological studies on potentially harmful algal species (HAS) present in Sardinia’s aquatic environments through the application of biomolecular techniques. In Sardinia, as well as globally in the world, the reports of blooms caused by HAS (Harmful Algal Blooms, HABs) have increased in recent decades, requiring specific studies and investigations. The identification of the species invo...

  19. Algal and fungal diversity in Antarctic lichens.

    Science.gov (United States)

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident. PMID:25105247

  20. Sterol phylogenesis and algal evolution

    Energy Technology Data Exchange (ETDEWEB)

    Nes, W.D.; Norton, R.A.; Crumley, F.G. (Richard B. Russell Research Center, Athens, GA (USA)); Madigan, S.J.; Katz, E.R. (State Univ. of New York at Stony Brook (USA))

    1990-10-01

    The stereochemistry of several sterol precursors and end products synthesized by two fungal-like microorganisms Prototheca wickerhamii (I) and Dictyostelium discoideum (II) have been determined by chromatographic (TLC, GLC, and HPLC) and spectral (UV, MS, and {sup 1}H NMR) methods. From I and II the following sterols were isolated from the cells: cycloartenol, cyclolaudenol, 24(28)-methylenecy-cloartanol, ergosterol, protothecasterol, 4{alpha}-methylergostanol, 4{alpha}-methylclionastanol, clionastanol, 24{beta}-ethylcholesta-8,22-enol, and dictyosterol. In addition, the mechanism of C-24 methylation was investigated in both organisms by feeding to I (2-{sup 3}H)lanosterol, (2-{sup 3}H)cycloartenol, (24{sup 3}H)lanosterol, and (methyl-{sup 2}H{sub 3})methionine and by feeding to II (methyl-{sup 2}H{sub 3})methionine. The results demonstrate that the 24{beta} configuration is formed by different alkylation routes in I and II. The authors conclude that Prototheca is an apoplastic Chlorella (i.e., an alga) and that Dictyostelium as well as the other soil amoebae that synthesize cycloartenol evolved from algal rather than fungal ancestors.

  1. Towards developing algal synthetic biology.

    Science.gov (United States)

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems.

  2. Towards developing algal synthetic biology.

    Science.gov (United States)

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems. PMID:27284033

  3. Targeted silencing of anthrax toxin receptors protects against anthrax toxins.

    Science.gov (United States)

    Arévalo, Maria T; Navarro, Ashley; Arico, Chenoa D; Li, Junwei; Alkhatib, Omar; Chen, Shan; Diaz-Arévalo, Diana; Zeng, Mingtao

    2014-05-30

    Anthrax spores can be aerosolized and dispersed as a bioweapon. Current postexposure treatments are inadequate at later stages of infection, when high levels of anthrax toxins are present. Anthrax toxins enter cells via two identified anthrax toxin receptors: tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). We hypothesized that host cells would be protected from anthrax toxins if anthrax toxin receptor expression was effectively silenced using RNA interference (RNAi) technology. Thus, anthrax toxin receptors in mouse and human macrophages were silenced using targeted siRNAs or blocked with specific antibody prior to challenge with anthrax lethal toxin. Viability assays were used to assess protection in macrophages treated with specific siRNA or antibody as compared with untreated cells. Silencing CMG2 using targeted siRNAs provided almost complete protection against anthrax lethal toxin-induced cytotoxicity and death in murine and human macrophages. The same results were obtained by prebinding cells with specific antibody prior to treatment with anthrax lethal toxin. In addition, TEM8-targeted siRNAs also offered significant protection against lethal toxin in human macrophage-like cells. Furthermore, silencing CMG2, TEM8, or both receptors in combination was also protective against MEK2 cleavage by lethal toxin or adenylyl cyclase activity by edema toxin in human kidney cells. Thus, anthrax toxin receptor-targeted RNAi has the potential to be developed as a life-saving, postexposure therapy against anthrax.

  4. Immunoassays and Biosensors for the Detection of Cyanobacterial Toxins in Water

    Directory of Open Access Journals (Sweden)

    Michael G. Weller

    2013-11-01

    Full Text Available Algal blooms are a frequent phenomenon in nearly all kinds of fresh water. Global warming and eutrophication by waste water, air pollution and fertilizers seem to lead to an increased frequency of occurrence. Many cyanobacteria produce hazardous and quite persistent toxins, which can contaminate the respective water bodies. This may limit the use of the raw water for many purposes. The purification of the contaminated water might be quite costly, which makes a continuous and large scale treatment economically unfeasible in many cases. Due to the obvious risks of algal toxins, an online or mobile detection method would be highly desirable. Several biosensor systems have been presented in the literature for this purpose. In this review, their mode of operation, performance and general suitability for the intended purpose will be described and critically discussed. Finally, an outlook on current developments and future prospects will be given.

  5. Stability of toxin gene proportion in red-pigmented populations of the cyanobacterium Planktothrix during 29 years of re-oligotrophication of Lake Zürich

    OpenAIRE

    Ostermaier Veronika; Schanz Ferdinand; Köster Oliver; Kurmayer Rainer

    2012-01-01

    Abstract Background Harmful algal blooms deteriorate the services of aquatic ecosystems. They are often formed by cyanobacteria composed of genotypes able to produce a certain toxin, for example, the hepatotoxin microcystin (MC), but also of nontoxic genotypes that either carry mutations in the genes encoding toxin synthesis or that lost those genes during evolution. In general, cyanobacterial blooms are favored by eutrophication. Very little is known about the stability of the toxic/nontoxic...

  6. An analytical perspective on detection, screening, and confirmation in phycology, with particular reference to toxins and toxin-producing species.

    Science.gov (United States)

    de la Iglesia, Pablo; Fernández-Tejedor, Margarita; Trobajo, Rosa; Diogène, Jorge

    2013-12-01

    Knowledge concerning the ability of microalgae to produce metabolites of interest such as toxins or high-value secondary metabolites requires exhaustive details to be supplied on how the research was conducted. These should include the microalgal species and strain characterization, the culture conditions, the cell density, and physiological state at the time of harvesting, the harvesting method, the sample pre-treatment protocol, and the subsequent instrumental analytical separation/detection system. In this comment, we discuss issues that affect algal research from an analytical chemistry perspective, particularly (i) the need to specify detection capabilities of the entire method (i.e., limits of detection or threshold detection levels), which we illustrate in relation to classification of a species or strain as being "toxin producing" or "non-toxin producing"; and (ii) the requirements that have to be satisfied to confirm a microalgal species (new or not) as a producer of a particular chemical of interest for phycologists, which again we illustrate in relation to toxins. A successful collaboration among phycologists and analytical chemists will only be achieved as a result of a synergistic collaboration between the two disciplines, with a reciprocal understanding at least at a background level.

  7. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  8. Metatranscriptome profiling of a harmful algal bloom.

    Science.gov (United States)

    Cooper, Endymion D; Bentlage, Bastian; Gibbons, Theodore R; Bachvaroff, Tsvetan R; Delwiche, Charles F

    2014-07-01

    Metagenomic methods provide a powerful means to investigate complex ecological phenomena. Developed originally for study of Bacteria and Archaea, the application of these methods to eukaryotic microorganisms is yet to be fully realized. Most prior environmental molecular studies of eukaryotes have relied heavily on PCR amplification with eukaryote-specific primers. Here we apply high throughput short-read sequencing of poly-A selected RNA to capture the metatranscriptome of an estuarine dinoflagellate bloom. To validate the metatranscriptome assembly process we simulated metatranscriptomic datasets using short-read sequencing data from clonal cultures of four algae of varying phylogenetic distance. We find that the proportion of chimeric transcripts reconstructed from community transcriptome sequencing is low, suggesting that metatranscriptomic sequencing can be used to accurately reconstruct the transcripts expressed by bloom-forming communities of eukaryotes. To further validate the bloom metatransciptome assembly we compared it to a transcriptomic assembly from a cultured, clonal isolate of the dominant bloom-causing alga and found that the two assemblies are highly similar. Eukaryote-wide phylogenetic analyses reveal the taxonomic composition of the bloom community, which is comprised of several dinoflagellates, ciliates, animals, and fungi. The assembled metatranscriptome reveals the functional genomic composition of a metabolically active community. Highlighting the potential power of these methods, we found that relative transcript abundance patterns suggest that the dominant dinoflagellate might be expressing toxin biosynthesis related genes at a higher level in the presence of competitors, predators and prey compared to it growing in monoculture. PMID:25484636

  9. Why do we study animal toxins?

    OpenAIRE

    Zhang, Yun

    2015-01-01

    Venom (toxins) is an important trait evolved along the evolutionary tree of animals. Our knowledges on venoms, such as their origins and loss, the biological relevance and the coevolutionary patterns with other organisms are greatly helpful in understanding many fundamental biological questions, i.e., the environmental adaptation and survival competition, the evolution shaped development and balance of venoms, and the sophisticated correlations among venom, immunity, body power, intelligence,...

  10. Quantifying Phycocyanin Concentration in Cyanobacterial Algal Blooms from Remote Sensing Reflectance-A Quasi Analytical Approach

    Science.gov (United States)

    Mishra, S.; Mishra, D. R.; Tucker, C.

    2011-12-01

    Cyanobacterial harmful algal blooms (CHAB) are notorious for depleting dissolved oxygen level, producing various toxins, causing threats to aquatic life, altering the food-web dynamics and the overall ecosystem functioning in inland lakes, estuaries, and coastal waters. Most of these algal blooms produce various toxins that can damage cells, tissues and even cause mortality of living organisms. Frequent monitoring of water quality in a synoptic scale has been possible by the virtue of remote sensing techniques. In this research, we present a novel technique to monitor CHAB using remote sensing reflectance products. We have modified a multi-band quasi analytical algorithm that determines phytoplankton absorption coefficients from above surface remote sensing reflectance measurements using an inversion method. In situ hyperspectral remote sensing reflectance data were collected from several highly turbid and productive aquaculture ponds. A novel technique was developed to further decompose the phytoplankton absorption coefficients at 620 nm and obtain phycocyanin absorption coefficient at the same wavelength. An empirical relationship was established between phycocyanin absorption coefficients at 620 nm and measured phycocyanin concentrations. Model calibration showed strong relationship between phycocyanin absorption coefficients and phycocyanin pigment concentration (r2=0.94). Validation of the model in a separate dataset produced a root mean squared error of 167 mg m-3 (phycocyanin range: 26-1012 mg m-3). Results demonstrate that the new approach will be suitable for quantifying phycocyanin concentration in cyanobacteria dominated turbid productive waters. Band architecture of the model matches with the band configuration of the Medium Resolution Imaging Spectrometer (MERIS) and assures that MERIS reflectance products can be used to quantify phycocyanin in cyanobacterial harmful algal blooms in optically complex waters.

  11. Algal Biology Toolbox Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-08-01

    DOE-EERE's Bioenergy Technologies Office (BETO) works to accelerate the development of a sustainable, cost-competitive, advanced biofuel industry that can strengthen U.S. energy security, environmental quality, and economic vitality, through research, development, and demonstration projects in partnership with industry, academia, and national laboratory partners. BETO’s Advanced Algal Systems Program (also called the Algae Program) has a long-term applied research and development (R&D) strategy to increase the yields and lower the costs of algal biofuels. The team works with partners to develop new technologies, to integrate technologies at commercially relevant scales, and to conduct crosscutting analyses to better understand the potential and challenges of the algal biofuels industry. Research has indicated that this industry is capable of producing billions of gallons of renewable diesel, gasoline, and jet fuels annually. R&D activities are integrated with BETO’s longstanding effort to accelerate the commercialization of lignocellulosic biofuels.

  12. Algal Biology Toolbox Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-08-09

    BETO works to accelerate the development of a sustainable, cost-competitive, advanced biofuel industry that can strengthen U.S. energy security, environmental quality, and economic vitality, through research, development, and demonstration projects in partnership with industry, academia, and national laboratory partners. BETO’s Advanced Algal Systems Program (also called the Algae Program) has a long-term applied research and development (R&D) strategy to increase the yields and lower the costs of algal biofuels. The team works with partners to develop new technologies, to integrate technologies at commercially relevant scales, and to conduct crosscutting analyses to bet- ter understand the potential and challenges of the algal biofuels industry. Research has indicated that this industry is capable of producing billions of gallons of renewable diesel, gasoline, and jet fuels annually. R&D activities are integrated with BETO’s longstanding effort to accelerate the commercialization of lignocellulosic biofuels.

  13. Botulinum Toxin Therapy

    Science.gov (United States)

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ... toxin therapy public SPOT Skin Cancer™ Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ...

  14. Algal recycling enhances algal productivity and settleability in Pediastrum boryanum pure cultures.

    Science.gov (United States)

    Park, Jason B K; Craggs, Rupert J; Shilton, Andy N

    2015-12-15

    Recycling a portion of gravity harvested algae (i.e. algae and associated bacteria biomass) has been shown to improve both algal biomass productivity and harvest efficiency by maintaining the dominance of a rapidly-settleable colonial alga, Pediastrum boryanum in both pilot-scale wastewater treatment High Rate Algal Ponds (HRAP) and outdoor mesocosms. While algal recycling did not change the relative proportions of algae and bacteria in the HRAP culture, the contribution of the wastewater bacteria to the improved algal biomass productivity and settleability with the recycling was not certain and still required investigation. P. boryanum was therefore isolated from the HRAP and grown in pure culture on synthetic wastewater growth media under laboratory conditions. The influence of recycling on the productivity and settleability of the pure P. boryanum culture was then determined without wastewater bacteria present. Six 1 L P. boryanum cultures were grown over 30 days in a laboratory growth chamber simulating New Zealand summer conditions either with (Pr) or without (Pc) recycling of 10% of gravity harvested algae. The cultures with recycling (Pr) had higher algal productivity than the controls (Pc) when the cultures were operated at both 4 and 3 d hydraulic retention times by 11% and 38% respectively. Furthermore, algal recycling also improved 1 h settleability from ∼60% to ∼85% by increasing the average P. boryanum colony size due to the extended mean cell residence time and promoted formation of large algal bio-flocs (>500 μm diameter). These results demonstrate that the presence of wastewater bacteria was not necessary to improve algal productivity and settleability with algal recycling.

  15. [Protein toxins of Staphylococcus aureus].

    Science.gov (United States)

    Shamsutdinov, A F; Tiurin, Iu A

    2014-01-01

    Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.

  16. Algal biofuels: key issues, sustainability and life cycle assessment

    DEFF Research Database (Denmark)

    Singh, Anoop; Olsen, Stig Irving

    2011-01-01

    capital investment. The harvested algal biomass and its extracts can be efficiently converted to different biofuels such as bioethanol, biodiesel, biogas and biohydrogen by implementation of various process technologies. Comprehensive life cycle assessments (LCA) of algal biofuels illustrating...

  17. A Harmful Algal Bloom of Karenia brevis in the Northeastern Gulf of Mexico as Revealed by MODIS and VIIRS: A Comparison

    OpenAIRE

    Chuanmin Hu; Barnes, Brian B.; Lin Qi; Corcoran, Alina A.

    2015-01-01

    The most recent Visible Infrared Imager Radiometer Suite (VIIRS) is not equipped with a spectral band to detect solar-stimulated phytoplankton fluorescence. The lack of such a band may affect the ability of VIIRS to detect and quantify harmful algal blooms (HABs) in coastal waters rich in colored dissolved organic matter (CDOM) because of the overlap of CDOM and chlorophyll absorption within the blue-green spectrum. A recent HAB dominated by the toxin-producing dinoflagellate Karenia brevis i...

  18. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  19. Botulinum Toxin and Gastrointestinal Tract Disorders: Panacea, Placebo, or Pathway to the Future?

    OpenAIRE

    Lacy, Brian E.; Weiser, Kirsten; Kennedy, Abigail

    2008-01-01

    The history of botulinum toxin is fascinating. First recognized as the cause of botulism nearly 200 years ago, it was originally feared as a deadly poison. Over the last 30 years, however, botulinum toxin has been transformed into a readily available medication used to treat a variety of medical disorders. Interest in the use of botulinum toxin has been particularly strong for patients with spastic smooth muscle disorders of the gastrointestinal tract. Patients with achalasia, diffuse esophag...

  20. Marine mimivirus relatives are probably large algal viruses

    Directory of Open Access Journals (Sweden)

    Claverie Jean-Michel

    2008-01-01

    Full Text Available Abstract Background Acanthamoeba polyphaga mimivirus is the largest known ds-DNA virus and its 1.2 Mb-genome sequence has revealed many unique features. Mimivirus occupies an independent lineage among eukaryotic viruses and its known hosts include only species from the Acanthamoeba genus. The existence of mimivirus relatives was first suggested by the analysis of the Sargasso Sea metagenomic data. Results We now further demonstrate the presence of numerous "mimivirus-like" sequences using a larger marine metagenomic data set. We also show that the DNA polymerase sequences from three algal viruses (CeV01, PpV01, PoV01 infecting different marine algal species (Chrysochromulina ericina, Phaeocystis pouchetii, Pyramimonas orientalis are very closely related to their homolog in mimivirus. Conclusion Our results suggest that the numerous mimivirus-related sequences identified in marine environments are likely to originate from diverse large DNA viruses infecting phytoplankton. Micro-algae thus constitute a new category of potential hosts in which to look for new species of Mimiviridae.

  1. Simultaneous screening for lipophilic and hydrophilic toxins in marine harmful algae using a serially coupled reversed-phase and hydrophilic interaction liquid chromatography separation system with high-resolution mass spectrometry.

    Science.gov (United States)

    Chen, Junhui; Gao, Liyuan; Li, Zhaoyong; Wang, Shuai; Li, Jingxi; Cao, Wei; Sun, Chengjun; Zheng, Li; Wang, Xiaoru

    2016-03-31

    The presence of toxins in harmful algal blooms (HABs) poses considerable concerns because of their potential adverse effects on ecological environments and human health. When marine HABs occur, efficient screening and identification of toxins in different kinds of HAB algae remains a challenge. In this study, the applicability of serial coupling of reversed-phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) combined with high resolution mass spectrometry (HR-MS) for the simultaneous screening and identification of various kinds of known lipophilic and hydrophilic toxins in HAB algae was investigated for the first time. Ultrasound-assisted extraction (UAE) was explored to extract both lipophilic and hydrophilic toxins in algae simultaneously. As in most cases, toxin standards were not available; therefore, an identification procedure based on accurate mass data and chromatographic behavior was proposed. According to this procedure, eight known lipophilic toxins and 11 hydrophilic toxins were successfully detected in a single injection, and the proposed method was validated. Satisfactory sensitivity, repeatability (RSD <14.87%) and recovery (89.4-105.8%) of the method were achieved. A major advantage of the proposed method is that it can almost detect members of all eight groups of marine algal toxins in a single run. Using this method, several known toxins in different marine toxigenic algae including Alexandrium tamarense, Alexandrium minutum and Prorocentrum lima were successfully observed and identified. This work demonstrates that RPLC/HILIC-HR-MS combined with an accurate mass list of known marine algal toxins may be used as a powerful tool for screening of different classes of known toxins in marine harmful algae. PMID:26965334

  2. Algal blooms and Membrane Based Desalination Technology

    NARCIS (Netherlands)

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational pro

  3. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    2015-01-01

    Recently, high-quality data were published on the algal growth inhibition caused by 50 non-polar narcotic compounds, of which 39 were liquid compounds with defined water solubility. In the present study, the toxicity data for these liquids were applied to challenge the chemical activity range for...

  4. Isolation, purification and spectrometric analysis of PSP toxins from moraxella sp., a bacterium associated with a toxic dinoflagellate

    Energy Technology Data Exchange (ETDEWEB)

    Boyce, S.D.; Doucette, G.J.

    1994-12-31

    Paralytic shellfish poisoning (PSP) is a seafood intoxication syndrome caused by the injestion of shellfish contaminated with toxins produced by algae known as dinoflagellates. The PSP toxins, saxitoxin and its derivatives, act to block voltage-dependent sodium channels and can cause paralysis and even death at higher doses. It is well documented that bacteria coexist with many harmful or toxic algal species, though the exact nature of the association in relation to toxin production is unknown. Recently, the bacterium Moraxella sp. was isolated from the PSP toxin producing dinoflagellate Alexandrium tamarense. Through HPLC analysis and saxitoxin receptor binding assays performed on crude bacterial extracts, it appears that Moraxella sp. is capable of producing saxitoxin and several of its derivatives. However, physical confirmation (e.g. mass spectrometry) of these results is still needed.

  5. Emergent Toxins in North Atlantic Temperate Waters: A Challenge for Monitoring Programs and Legislation

    Directory of Open Access Journals (Sweden)

    Marisa Silva

    2015-03-01

    Full Text Available Harmful Algal Blooms (HAB are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

  6. Lipophilic Toxins in Butrinti Lagoon Mussels and their Relation with Potentially Toxic Dinoflagellates

    Directory of Open Access Journals (Sweden)

    MARSELA BREGAJ

    2014-12-01

    Full Text Available Diarrheic Shellfish Poisoning (DSP is a gastrointestinal illness. It is caused by the consumption of contaminated shellfish. These toxins are produced by the planktonic algae (mainly dinoflagellates. The aim of the current study was to evaluate the presence of potential toxic phytoplankton species and marine biotoxins like DSP in Butrinti Lagoon and to analyze the relationship between toxin levels and abundance of possible causative phytoplankton species. Samples were collected in Butrinti Lagoon, known for the cultivation of the, Mytilus galloprovicialis and fishing. During January 2011 until December 2012 were analyzed 126 samples of M. galloprovincialis for the presence of lipophilic toxins and dinoflagellates potentially toxic. The toxins were extracted from shellfish tissue using acetone, followed by extraction with dichloromethane and methanol. The final residue is dissolve in 1% (v/v Tween 60. 19.84% of samples analyzed shown positive results for the presence of toxins that cause DSP with higher concentration of limit sets in EC Regulation No. 853/2004. The presence of different dinoflagellates was observed in the samples during that period in level 120cell/L - 920 cell/L, like Gonyaulax spinifera, Dinophysis sacculus, Dinophysis acuminata, that are known to produce algal toxins, including DSP.

  7. Sustainability of algal biofuel production using integrated renewable energy park (IREP) and algal biorefinery approach

    International Nuclear Information System (INIS)

    Algal biomass can provide viable third generation feedstock for liquid transportation fuel. However, for a mature commercial industry to develop, sustainability as well as technological and economic issues pertinent to algal biofuel sector must be addressed first. This viewpoint focuses on three integrated approaches laid out to meet these challenges. Firstly, an integrated algal biorefinery for sequential biomass processing for multiple high-value products is delineated to bring in the financial sustainability to the algal biofuel production units. Secondly, an integrated renewable energy park (IREP) approach is proposed for amalgamating various renewable energy industries established in different locations. This would aid in synergistic and efficient electricity and liquid biofuel production with zero net carbon emissions while obviating numerous sustainability issues such as productive usage of agricultural land, water, and fossil fuel usage. A 'renewable energy corridor' rich in multiple energy sources needed for algal biofuel production for deploying IREPs in the United States is also illustrated. Finally, the integration of various industries with algal biofuel sector can bring a multitude of sustainable deliverables to society, such as renewable supply of cheap protein supplements, health products and aquafeed ingredients. The benefits, challenges, and policy needs of the IREP approach are also discussed.

  8. Efficacy of T-2 toxin detoxifying agent in broiler chickens

    Directory of Open Access Journals (Sweden)

    Nešić V.

    2012-01-01

    Full Text Available This investigation was conducted in order to investigate the efficacy of the detoxifying agent Mycofix® Plus (MP in the prevention and/or alleviation in vivo adverse effects of T-2 toxin in broilers. In addition, the adsorbing potential of MP was estimated in vitro. Mean degradation levels of T-2 toxin with MP in vitro, as measured by HPTLC, varied from 26.06 to 31.02 % and the adsorption ability was elevated in acidic environment (pH 3. In vivo trial was performed on 160 one day old "Ross" broiler chicks and lasted for 21 days. Birds were divided into 4 equal groups as follows: Group 1 - negative control; Group 2 - positive control - 2 ppm T-2 toxin; Group 3 - 2 ppm T-2 toxin+2 kg/t MP; Group 4 - 2 kg/t MP. Broilers fed the diet containing 2 mg/kg of T-2 toxin without MP developed typical T-2 toxicosis. Birds that were fed the diet containing both T-2 and MP had better performances and no oral ulcerations as the dominant sign of T-2 toxicosis were observed. Histopathological examination of tissues originating from birds fed the diet containing T-2 toxin revealed degenerative changes in the oral and small intestine mucosa, necroses of enterocytes and hepatocytes, as well as depletion of lymphocytes in the bursa Fabricii. Immunohistochemical examination also revealed negative effects of T-2 toxin on cells proliferation in intestineal and bile duct mucosa, as well as on lymphocytes from bursa Fabricii. The macroscopic and microscopic structure of the liver, intestine and bursa Fabricii of broilers fed a diet containing T-2 toxin and MP was mostly preserved. Cutaneous basophile hypersensitivity reaction was weaker in broilers fed mixtures containing 2 mg/kg T-2 toxin.

  9. Toxins and drug discovery.

    Science.gov (United States)

    Harvey, Alan L

    2014-12-15

    Components from venoms have stimulated many drug discovery projects, with some notable successes. These are briefly reviewed, from captopril to ziconotide. However, there have been many more disappointments on the road from toxin discovery to approval of a new medicine. Drug discovery and development is an inherently risky business, and the main causes of failure during development programmes are outlined in order to highlight steps that might be taken to increase the chances of success with toxin-based drug discovery. These include having a clear focus on unmet therapeutic needs, concentrating on targets that are well-validated in terms of their relevance to the disease in question, making use of phenotypic screening rather than molecular-based assays, and working with development partners with the resources required for the long and expensive development process. PMID:25448391

  10. Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems?

    Science.gov (United States)

    Brooks, Bryan W; Lazorchak, James M; Howard, Meredith D A; Johnson, Mari-Vaughn V; Morton, Steve L; Perkins, Dawn A K; Reavie, Euan D; Scott, Geoffrey I; Smith, Stephanie A; Steevens, Jeffery A

    2016-01-01

    In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration of HABs in inland waters are poorly understood across spatiotemporal scales and differentially engaged among states, tribes, and territories. Harmful algal bloom impacts are not as predictable as those from conventional chemical contaminants, for which water quality assessment and management programs were primarily developed, because interactions among multiple natural and anthropogenic factors determine the likelihood and severity to which a HAB will occur in a specific water body. These forcing factors can also affect toxin production. Beyond site-specific water quality degradation caused directly by HABs, the presence of HAB toxins can negatively influence routine surface water quality monitoring, assessment, and management practices. Harmful algal blooms present significant challenges for achieving water quality protection and restoration goals when these toxins confound interpretation of monitoring results and environmental quality standards implementation efforts for other chemicals and stressors. Whether HABs presently represent the greatest threat to inland water quality is debatable, though in inland waters of developed countries they typically cause more severe acute impacts to environmental quality than conventional chemical contamination events. The authors identify several timely research needs. Environmental toxicology, environmental chemistry, and risk-assessment expertise must interface with ecologists, engineers, and public health practitioners to engage the complexities of HAB assessment and management, to address the forcing factors for HAB formation, and

  11. Effects of algal-produced neurotoxins on metabolic activity in telencephalon, optic tectum and cerebellum of Atlantic salmon (Salmo salar)

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Marit Jorgensen [Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo (Norway); Horsberg, Tor Einar [Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo (Norway)], E-mail: tor.e.horsberg@veths.no

    2007-11-30

    Neurotoxins from algal blooms have been reported to cause mortality in a variety of species, including sea birds, sea mammals and fish. Farmed fish cannot escape harmful algal blooms and their potential toxins, thus they are more vulnerable for exposure than wild stocks. Sublethal doses of the toxins are likely to affect fish behaviour and may impair cognitive abilities. In the present study, changes in the metabolic activity in different parts of the Atlantic salmon (Salmo salar) brain involved in central integration and cognition were investigated after exposure to sublethal doses of three algal-produced neurotoxins; saxitoxin (STX), brevetoxin (BTX) and domoic acid (DA). Fish were randomly selected to four groups for i.p. injection of saline (control) or one of the neurotoxins STX (10 {mu}g STX/kg bw), BTX (68 {mu}g BTX/kg bw) or DA (6 mg DA/kg bw). In addition, {sup 14}C-2-deoxyglucose was i.m. injected to measure brain metabolic activity by autoradiography. The three regions investigated were telencephalon (Tel), optic tectum (OT) and cerebellum (Ce). There were no differences in the metabolic activity after STX and BTX exposure compared to the control in these regions. However, a clear increase was observed after DA exposure. When the subregions with the highest metabolic rate were pseudocoloured in the three brain regions, the three toxins caused distinct differences in the respective patterns of metabolic activation. Fish exposed to STX displayed similar patterns as the control fish, whereas fish exposed to BTX and DA showed highest metabolic activity in subregions different from the control group. All three neurotoxins affected subregions that are believed to be involved in cognitive abilities in fish.

  12. Neurotoxic potential and cellular uptake of T-2 toxin in human astrocytes in primary culture.

    Science.gov (United States)

    Weidner, Maria; Lenczyk, Marlies; Schwerdt, Gerald; Gekle, Michael; Humpf, Hans-Ulrich

    2013-03-18

    The trichothecene mycotoxin T-2 toxin, which is produced by fungi of the Fusarium species, is a worldwide occurring contaminant of cereal based food and feed. The cytotoxic properties of T-2 toxin are already well described with apoptosis being a major mechanism of action in various cell lines as well as in primary cells of different origin. However, only few data on neurotoxic properties of T-2 toxin are reported so far, but in vivo studies showed different effects of T-2 toxin on behavior as well as on levels of brain amines in animals. To further investigate the cytotoxic properties of T-2 toxin on cells derived from brain tissue, normal human astrocytes in primary culture (NHA) were used in this study. Besides studies of cytotoxicity, apoptosis (caspase-3-activation, Annexin V) and necrosis (LDH-release), the cellular uptake and metabolism of T-2 toxin in NHA was analyzed and compared to the uptake in an established human cell line (HT-29). The results show that human astrocytes were highly sensitive to the cytotoxic properties of T-2 toxin, and apoptosis, induced at low concentrations, was identified for the first time as the mechanism of toxic action in NHA. Furthermore, a strong accumulation of T-2 toxin in NHA and HT-29 cells was detected, and T-2 toxin was subjected to metabolism leading to HT-2 toxin, a commonly found metabolite after T-2 toxin incubation in both cell types. This formation seems to occur within the cells since incubations of T-2 toxin with cell depleted culture medium did not lead to any degradation of the parent toxin. The results of this study emphasize the neurotoxic potential of T-2 toxin in human astrocytes at low concentrations after short incubation times. PMID:23363530

  13. Clostridium difficile binary toxin CDT

    OpenAIRE

    Gerding, Dale N.; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

    2013-01-01

    Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylatio...

  14. Coupling of algal biofuel production with wastewater.

    Science.gov (United States)

    Bhatt, Neha Chamoli; Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.

  15. Bioactive substances in marine phytoplankton: salinity effects on growth and toxin production of the dinophyte Alexandrium ostenfeldii

    OpenAIRE

    Martens, Helge

    2014-01-01

    Alexandrium ostenfeldii is one of the most intensely studied toxic dinophyta in the world’s oceans and coastal waters. Its toxins are highly potent neurotoxins and causatives of food intoxications by contaminated sea food. In the last few years harmful algal blooms (HAB) of A. ostenfeldii have become a recurrent phenomenon in coastal waters. In 2012 such a dense bloom occurred in the Ouwerkerkse Kreek. This creek system in The Netherlands is discharging water in the Oosterschelde estuary, a l...

  16. A review on algal biofuel production

    Institute of Scientific and Technical Information of China (English)

    WANG Ling; ZHU jing

    2016-01-01

    Culturing of microalgae has be established as an alternative feedstock for biofuel production due to their fast growth rate and ability to accumulate high quantity of lipid and carbohydrate respectively. However, using this bioresource is still limited duo to low productivity and higher cultivation cost. Genetic and metabolic engineering,photobioreactors play significant role in algal biomass production. Hence, this review is focused on these, aiming at providing useful informations.

  17. Algal blooms and Membrane Based Desalination Technology

    OpenAIRE

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in seawater reverse osmosis (SWRO) plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of the plant to avoid irreversible fouling...

  18. Energy balance of algal biogas production

    OpenAIRE

    Milledge, J.J.; Heaven, S.

    2014-01-01

    A mechanistic energy balance model was successfully developed for the production of biogas from the anaerobic digestion of micro-algal biomass from raceways. The energy balance model was used to consider the energetic viability of a number of production scenarios, and to identify the most critical parameters affecting net energy production. The output of the model demonstrated that no single method of harvesting studied (centrifugation, settlement or flocculation), produced a sufficiently gr...

  19. Comparisons of native Shiga toxins (Stxs type 1 and 2 with chimeric toxins indicate that the source of the binding subunit dictates degree of toxicity.

    Directory of Open Access Journals (Sweden)

    Lisa M Russo

    Full Text Available Shiga toxin (Stx-producing E. coli (STEC cause food-borne outbreaks of hemorrhagic colitis. The main virulence factor expressed by STEC, Stx, is an AB5 toxin that has two antigenically distinct forms, Stx1a and Stx2a. Although Stx1a and Stx2a bind to the same receptor, globotriaosylceramide (Gb3, Stx2a is more potent than Stx1a in mice, whereas Stx1a is more cytotoxic than Stx2a in cell culture. In this study, we used chimeric toxins to ask what the relative contribution of individual Stx subunits is to the differential toxicity of Stx1a and Stx2a in vitro and in vivo. Chimeric stx1/stx2 operons were generated by PCR such that the coding regions for the A2 and B subunits of one toxin were combined with the coding region for the A1 subunit of the heterologous toxin. The toxicities of purified Stx1a, Stx2a, and the chimeric Stxs were determined on Vero and HCT-8 cell lines, while polarized HCT-8 cell monolayers grown on permeable supports were used to follow toxin translocation. In all in vitro assays, the activity of the chimeric toxin correlated with that of the parental toxin from which the B subunit originated. The origin of the native B subunit also dictated the 50% lethal dose of toxin after intraperitoneal intoxication of mice; however, the chimeric Stxs exhibited reduced oral toxicity and pH stability compared to Stx1a and Stx2a. Taken together, these data support the hypothesis that the differential toxicity of the chimeric toxins for cells and mice is determined by the origin of the B subunit.

  20. Requirements for anthrax toxin entry into cells

    OpenAIRE

    Ryan, Patricia Lynn

    2010-01-01

    Bacillus anthracis secretes a harmful exotoxin called anthrax toxin. Anthrax toxin has deleterious effects on several host cell types and is a significant contributor to anthrax pathogenesis. Toxin-deleted strains of B. anthracis are highly attenuated and many of the symptoms of anthrax can be replicated with anthrax toxin alone. Anthrax toxin is an AB-type toxin with two catalytic A moieties. PA, the B moiety, is responsible for receptor binding, pore formation and translocation of the catal...

  1. Shiga Toxin Detection Methods : A Short Review

    OpenAIRE

    Guerrero, Y. Castaño; González-Aguilar, G.

    2013-01-01

    The Shiga toxins comprise a family of related protein toxins secreted by certain types of bacteria. Shigella dysenteriae, some strain of Escherichia coli and other bacterias can express toxins which caused serious complication during the infection. Shiga toxin and the closely related Shiga-like toxins represent a group of very similar cytotoxins that may play an important role in diarrheal disease and hemolytic-uremic syndrome. The outbreaks caused by this toxin raised serious public health c...

  2. Effects of co-existing microalgae and grazers on the production of hemolytic toxins in Karenia mikimotoi

    Science.gov (United States)

    Yang, Weidong; Zhang, Naisheng; Cui, Weimin; Xu, Yanyan; Li, Hongye; Liu, Jiesheng

    2011-11-01

    Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography. In addition, we evaluated the effect of co-occuring algae ( Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongolica on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinoflagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.

  3. Effects of co-existing microalgae and grazers on the production of hemolytic toxins in Karenia mikimotoi

    Institute of Scientific and Technical Information of China (English)

    YANG Weidong; ZHANG Naisheng; CUI Weimin; XU Yanyan; LI Hongye; LIU Jiesheng

    2011-01-01

    Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world.The hemolytic substances produced by K.mikimotoi are thought to cause mortality in fishes and invertebrates.We evaluated the composition of the hemolytic toxin produced by K.mikimotoi cultured in the laboratory using thin-layer chromatography.In addition,we evaluated the effect of co-occuring algae (Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongolica on hemolytic toxin production in K.mikimotoi.The hemolytic toxins from K.mikimotoi were a mixture of 2 liposaccharides and I lipid.Waterbome clues from P.donghaiense and A.tamarense inhibited the growth of K.mikimotoi but increased the production of hemolytic toxins.Conversely,K.mikimotoi strongly inhibited the growth of caged P.donghaiense and A.tamarense.In addition,the ingestion of K.mikimotoi by M.mongolica induced the production of hemolytic toxins in K.mikimotoi.Taken together,our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances.K.mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity.The production of hemolytic toxins in dinoflagellates was not only dependent on resource availability,but also on the risk of predation.Hemolytic toxins likely play an important role as chemical deterrents secreted by K.mikimotoi.

  4. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish

    Directory of Open Access Journals (Sweden)

    Christopher Elliott

    2011-01-01

    Full Text Available Paralytic shellfish poisoning (PSP is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20–300 ng/mL, incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis.

  5. Progress in Understanding Harmful Algal Blooms: Paradigm Shifts and New Technologies for Research, Monitoring, and Management

    Science.gov (United States)

    Anderson, Donald M.; Cembella, Allan D.; Hallegraeff, Gustaaf M.

    2012-01-01

    The public health, tourism, fisheries, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past few decades. This has led to heightened scientific and regulatory attention, and the development of many new technologies and approaches for research and management. This, in turn, is leading to significant paradigm shifts with regard to, e.g., our interpretation of the phytoplankton species concept (strain variation), the dogma of their apparent cosmopolitanism, the role of bacteria and zooplankton grazing in HABs, and our approaches to investigating the ecological and genetic basis for the production of toxins and allelochemicals. Increasingly, eutrophication and climate change are viewed and managed as multifactorial environmental stressors that will further challenge managers of coastal resources and those responsible for protecting human health. Here we review HAB science with an eye toward new concepts and approaches, emphasizing, where possible, the unexpected yet promising new directions that research has taken in this diverse field.

  6. Sentinel Animals in a One Health Approach to Harmful Cyanobacterial and Algal Blooms

    Directory of Open Access Journals (Sweden)

    Lorraine C. Backer

    2016-04-01

    Full Text Available People, domestic animals, and wildlife are all exposed to numerous environmental threats, including harmful algal blooms (HABs. However, because animals exhibit wide variations in diet, land use and biology, they are often more frequently or heavily exposed to HAB toxins than are people occupying the same habitat, making them sentinels for human exposures. Historically, we have taken advantage of unique physiological characteristics of animals, such as the sensitivity of canaries to carbon monoxide, to more quickly recognize threats and help protect human health. As HAB events become more severe and widespread worldwide, exposure and health outcome data for animals can be extremely helpful to predict, prevent, and evaluate human exposures and health outcomes. Applying a One Health approach to investigation of HABs means that lessons learned from animal sentinels can be applied to protect people, animals and our shared environment.

  7. Paralytic shellfish poison algal biotoxins: Sardinia report 2002-2011 and non-compliance management

    Directory of Open Access Journals (Sweden)

    Giuseppa Lorenzoni

    2013-09-01

    Full Text Available Several microalgae of the genus Alexandrium (Alexandrium minutum and Alexandrium catenelle can produce an algal biotoxin, the paralytic shellfish poison (PSP that can be accumulated in the shellfish edible tissues making them hazardous to the consumer’s health. In this paper we report i the results of PSP toxins survey carried out by mouse bioassays (mouse test AOAC 958.08 on 7457 samples of bivalve molluscs farmed in Sardinia and in other European countries and marketed in Sardinia region from 2002 to 2011, and ii the management of positive cases. Based on our experience it is very important to strictly apply the planned activities in order to prevent any risk and to protect the consumer’s and producer’s health.

  8. Algal Toxins in Upper Klamath Lake, Oregon: Linking Water Quality to Juvenile Sucker Health

    Science.gov (United States)

    VanderKooi, S.P.; Burdick, S.M.; Echols, K.R.; Ottinger, C.A.; Rosen, B.H.; Wood, T.M.

    2010-01-01

    As the lead science agency for the Department of Interior, the U.S. Geological Survey is actively involved in resource issues in the Klamath River basin. Activities include research projects on endangered Lost River and shortnose suckers, threatened coho salmon, groundwater resources, seasonal runoff forecasting, water quality in Upper Klamath Lake and the Klamath River, nutrient cycling in wetlands, and assessment of land idling programs to reduce water consumption. Many of these studies are collaborations with various partners including Department of Interior agencies, Indian Tribes, and State agencies.

  9. Algal taxonomy: a road to nowhere?

    Science.gov (United States)

    De Clerck, Olivier; Guiry, Michael D; Leliaert, Frederik; Samyn, Yves; Verbruggen, Heroen

    2013-04-01

    The widespread view of taxonomy as an essentially retrogressive and outmoded science unable to cope with the current biodiversity crisis stimulated us to analyze the current status of cataloguing global algal diversity. Contrary to this largely pessimistic belief, species description rates of algae through time and trends in the number of active taxonomists, as revealed by the web resource AlgaeBase, show a much more positive picture. More species than ever before are being described by a large community of algal taxonomists. The lack of any decline in the rate at which new species and genera are described, however, is indicative of the large proportion of undiscovered diversity and bears heavily on any prediction of global algal species diversity and the time needed to catalogue it. The saturation of accumulation curves of higher taxa (family, order, and classes) on the other hand suggest that at these taxonomic levels most diversity has been discovered. This reasonably positive picture does not imply that algal taxonomy does not face serious challenges in the near future. The observed levels of cryptic diversity in algae, combined with the shift in methods used to characterize them, have resulted in a rampant uncertainty about the status of many older species. As a consequence, there is a tendency in phycology to move gradually away from traditional names to a more informal system whereby clade-, specimen- or strain-based identifiers are used to communicate biological information. Whether these informal names for species-level clades represent a temporary situation stimulated by the lag between species discovery and formal description, or an incipient alternative or parallel taxonomy, will be largely determined by how well we manage to integrate historical collections into modern taxonomic research. Additionally, there is a pressing need for a consensus about the organizational framework to manage the information about algal species names. An eventual strategy

  10. Harmful algal blooms: a case study in two mesotrophic drinking water supply reservoirs in South Carolina

    Science.gov (United States)

    Journey, Celeste A.; Beaulieu, Karen M.; Knight, Rodney R.; Graham, Jennifer L.; Arrington, Jane M.; West, Rebecca; Westcott, John; Bradley, Paul M.

    2010-01-01

    Algal blooms can be harmful and a nuisance in a variety of aquatic ecosystems, including reservoirs and lakes. Cyanobacterial(blue-green algae) harmful algal blooms are notorious for producing both taste-and-odor compounds and potent toxins that may affect human health. Taste–and-odor episodes are aesthetic problems often caused by cyanobacterial-produced organic compounds (geosmin and methylisoborneol) and are common in reservoirs and lakes used as source water supplies. The occurrences of these taste-and-odor compounds and toxins (like microcystin) can be sporadic and vary in intensity both spatially and temporally. Recent publications by the U.S. Geological Survey address this complexity and provide protocols for cyanotoxin and taste-and-odor sampling programs. A case study conducted by the U.S. Geological Survey, in cooperation with Spartanburg Water, monitored two mesotrophic reservoirs that serve as public drinking water supplies in South Carolina. Study objectives were (1) to identify spatial and temporal occurrence of the taste-and-odor compound geosmin and the cyanotoxin microcystin and (2) to assess the associated limnological conditions before, during, and after these occurrences. Temporal and spatial occurrence of geosmin and microcystin were highly variable from 2007 to 2009. The highest geosmin concentrations tended to occur in the spring. Microcystin tended to occur in the late summer and early fall, but occurrence was rare and well below World Health Organization guidelines for finished drinking water and recreational activities. No current U.S. Environmental Protection Agency standards are applicable to cyanotoxins in drinking or ambient water. In general, elevated geosmin and microcystin concentrations were the result of complex interactions between cyanobacterial ⬚community composition, nutrient availability, water clarity, hydraulic residence time, and stratification.

  11. Algal-bacterial interactions in metal contaminated floodplain sediments

    Energy Technology Data Exchange (ETDEWEB)

    Boivin, M.E.Y. [National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Department of Animal Ecology, IES, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Greve, G.D. [National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Department of Animal Ecology, IES, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Garcia-Meza, J.V. [Department of Aquatic Ecology and Ecotoxicology, IBED, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands); Massieux, B. [Netherlands Institute of Ecology, Centre for Limnology, Rijkstraatweg 6, 3631 AC Nieuwersluis (Netherlands); Sprenger, W. [Department of Aquatic Ecology and Ecotoxicology, IBED, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands); Kraak, M.H.S. [Department of Aquatic Ecology and Ecotoxicology, IBED, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands)]. E-mail: castella@science.uva.nl; Breure, A.M. [National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Rutgers, M. [National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Admiraal, W. [Department of Aquatic Ecology and Ecotoxicology, IBED, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands)

    2007-02-15

    The aim of the present study was to investigate algal-bacterial interactions in a gradient of metal contaminated natural sediments. By means of multivariate techniques, we related the genetic structure (denaturing gradient gel electrophoresis, DGGE) and the physiological structure (community-level physiological profiling, CLPP) of the bacterial communities to the species composition of the algal communities and to the abiotic environmental variables, including metal contamination. The results revealed that genetic and physiological structure of the bacterial communities correlated with the species composition of the algal community, but hardly to the level of metal pollution. This must be interpreted as an indication for a strong and species-specific linkage of algal and bacterial species in floodplain sediments. Metals were, however, not proven to affect either the algal or the bacterial communities of the Dutch river floodplains. - Algal and bacterial communities in floodplain sediments are interlinked, but are not affected by metal pollution.

  12. Algal Bloom in Aquatic Ecosystems-an Overview

    Directory of Open Access Journals (Sweden)

    M. Ghorbani

    2014-04-01

    Full Text Available Algae play an important role in all aquatic ecosystems by providing all living organisms of water bodies with preliminary nutrients and energy required. However, abnormal and excessive algal growth so-called algal bloom would be detrimental as much. Given the importance of algae in aquatic environment as well as their sensitivity to environmental changes, algal measurements are of key components of water quality monitoring programs. The algal blooms could include a variety of adverse impacts on environmental, social, cultural and economic environments. The present study is an overview on the algal growth, its mechanisms and mitigating strategies in aquatic ecosystems whereas in spite of the growing knowledge of human being of ecological, physiological, and functional conditions of eutrophication, a systematic understanding of algal blooms is still lacking.

  13. Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake

    Directory of Open Access Journals (Sweden)

    Yung-Sung Cheng

    2008-06-01

    Full Text Available We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses, but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L in the water and (<0.1 ng/m3 in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L. Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.

  14. Available Resources for Algal Biofuel Development in China

    OpenAIRE

    Li Chen; Changle Pang; Zhenhong Yuan; Shunni Zhu; Zhongming Wang; Shuhao Huo; Renjie Dong

    2011-01-01

    Microalgal biofuel research in China has made noticeable progress, and algae cultivation for biofuel production is considered to be an important contribution to Greenhouse Gas (GHG) mitigation and energy security. In this paper, the algal biofuel potentiality in China was reviewed from the points of view of algal biodiversity, algal culture collection, GHGs (especially CO 2 ) mitigation, and the availability of the required sunlight, wastewater and land resources. The cultivation of microalga...

  15. The ins and outs of algal metal transport

    OpenAIRE

    Blaby-Haas, Crysten E.; Merchant, Sabeeha S

    2012-01-01

    Metal transporters are a central component in the interaction of algae with their environment. They represent the first line of defense to cellular perturbations in metal concentration, and by analyzing algal metal transporter repertoires, we gain insight into a fundamental aspect of algal biology. The ability of individual algae to thrive in environments with unique geochemistry, compared to non-algal species commonly used as reference organisms for metal homeostasis, provides an opportunity...

  16. The quantitative real-time PCR applications in the monitoring of marine harmful algal bloom (HAB) species.

    Science.gov (United States)

    Penna, Antonella; Antonella, Penna; Galluzzi, Luca; Luca, Galluzzi

    2013-10-01

    In the last decade, various molecular methods (e.g., fluorescent hybridization assay, sandwich hybridization assay, automatized biosensor detection, real-time PCR assay) have been developed and implemented for accurate and specific identification and estimation of marine toxic microalgal species. This review focuses on the recent quantitative real-time PCR (qrt-PCR) technology developed for the control and monitoring of the most important taxonomic phytoplankton groups producing biotoxins with relevant negative impact on human health, the marine environment, and related economic activities. The high specificity and sensitivity of the qrt-PCR methods determined by the adequate choice of the genomic target gene, nucleic acid purification protocol, quantification through the standard curve, and type of chemical detection method make them highly efficient and therefore applicable to harmful algal bloom phenomena. Recent development of qrt-PCR-based assays using the target gene of toxins, such as saxitoxin compounds, has allowed more precise quantification of toxigenic species (i.e., Alexandrium catenella) abundance. These studies focus only on toxin-producing species in the marine environment. Therefore, qrt-PCR technology seems to offer the advantages of understanding the ecology of harmful algal bloom species and facilitating the management of their outbreaks.

  17. Daphnia magna negatively affected by chronic exposure to purified Cry-toxins.

    Science.gov (United States)

    Bøhn, Thomas; Rover, Carina Macagnan; Semenchuk, Philipp Robert

    2016-05-01

    Cry-toxin genes originating from Bacillus thuringiensis are inserted into genetically modified (GM) plants, often called Bt-plants, to provide insect resistance to pests. Significant amounts of Bt-plant residues, and thus Cry-toxins, will be shed to soil and aquatic environments. We exposed Daphnia magna to purified Cry1Ab and Cry2Aa toxins for the full life-span of the animals. We used single toxins in different doses and combinations of toxins and Roundup(®), another potential stressor on the rise in agricultural ecosystems. Animals exposed to 4.5 mg/L (ppm) of Cry1Ab, Cry2Aa and the combination of both showed markedly higher mortality, smaller body size and very low juvenile production compared to controls. Animals exposed to 0.75 mg/L also showed a tendency towards increased mortality but with increased early fecundity compared to the controls. Roundup(®) stimulated animals to strong early reproductive output at the cost of later rapid mortality. We conclude that i) purified Cry-toxins in high concentrations are toxic to D. magna, indicating alternative modes-of-action for these Cry-toxins; ii) Cry-toxins act in combination, indicating that 'stacked events' may have stronger effects on non-target organisms; iii) further studies need to be done on combinatorial effects of multiple Cry-toxins and herbicides that co-occur in the environment. PMID:26993955

  18. Addressing the challenges for sustainable production of algal biofuels: I. Algal strains and nutrient supply.

    Science.gov (United States)

    Abdelaziz, Ahmed E M; Leite, Gustavo B; Hallenbeck, Patrick C

    2013-01-01

    Microalgae hold promise for the production of sustainable replacement of fossil fuels due to their high growth rates, ability to grow on non-arable land and their high content, under the proper conditions, of high energy compounds that can be relatively easily chemically converted to fuels using existing technology. However, projected large-scale algal production raises a number of sustainability concerns concerning land use, net energy return, water use and nutrient supply. The state-of-the-art of algal production of biofuels is presented with emphasis on some possible avenues to provide answers to the sustainability questions that have been raised. Here, issues concerning algal strains and supply of nutrients for large-scale production are discussed. Since sustainability concerns necessitate the use of wastewaters for supply of bulk nutrients, emphasis is placed on the composition and suitability of different wastewater streams. At the same time, algal cultivation has proven useful in waste treatment processes, and thus this aspect is also treated in some detail. PMID:24350435

  19. Food toxin detection with atomic force microscope

    Science.gov (United States)

    Externally introduced toxins or internal spoilage correlated pathogens and their metabolites are all potential sources of food toxins. To prevent and protect unsafe food, many food toxin detection techniques have been developed to detect various toxins for quality control. Although several routine m...

  20. Algal Attributes: An Autecological Classification of Algal Taxa Collected by the National Water-Quality Assessment Program

    Science.gov (United States)

    Porter, Stephen D.

    2008-01-01

    Algae are excellent indicators of water-quality conditions, notably nutrient and organic enrichment, and also are indicators of major ion, dissolved oxygen, and pH concentrations and stream microhabitat conditions. The autecology, or physiological optima and tolerance, of algal species for various water-quality contaminants and conditions is relatively well understood for certain groups of freshwater algae, notably diatoms. However, applications of autecological information for water-quality assessments have been limited because of challenges associated with compiling autecological literature from disparate sources, tracking name changes for a large number of algal species, and creating an autecological data base from which algal-indicator metrics can be calculated. A comprehensive summary of algal autecological attributes for North American streams and rivers does not exist. This report describes a large, digital data file containing 28,182 records for 5,939 algal taxa, generally species or variety, collected by the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. The data file includes 37 algal attributes classified by over 100 algal-indicator codes or metrics that can be calculated easily with readily available software. Algal attributes include qualitative classifications based on European and North American autecological literature, and semi-quantitative, weighted-average regression approaches for estimating optima using regional and national NAWQA data. Applications of algal metrics in water-quality assessments are discussed and national quartile distributions of metric scores are shown for selected indicator metrics.

  1. Shiga Toxin Producing Escherichia coli.

    Science.gov (United States)

    Bryan, Allen; Youngster, Ilan; McAdam, Alexander J

    2015-06-01

    Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli.

  2. Detection of extracellular toxin(s) produced by Vibrio vulnificus.

    OpenAIRE

    Kreger, A; Lockwood, D.

    1981-01-01

    Conditions are described for the production, in high titers, a heat-labile, antigenic, extracellular toxin(s) by Vibrio vulnificus, a recently recognized human pathogen. Bacteriologically sterile culture filtrate preparations obtained from mid-logarithmic-phase cultures of the bacterium possessed cytolytic activity against mammalian erythrocytes, cytotoxic activity for Chinese hamster ovary cells, vascular permeability factor activity in guinea pig skin, and lethal activity for mice. The spec...

  3. Chemical Diversity, Origin, and Analysis of Phycotoxins

    DEFF Research Database (Denmark)

    Rasmussen, Silas Anselm; Andersen, Aaron John Christian; Andersen, Nikolaj Gedsted;

    2016-01-01

    Microalgae, particularly those from the lineage Dinoflagellata, are very well-known for their ability to produce phycotoxins that may accumulate in the marine food chain and eventually cause poisoning in humans. This includes toxins accumulating in shellfish, such as saxitoxin, okadaic acid......, yessotoxins, azaspiracids, brevetoxins, and pinnatoxins. Other toxins, such as ciguatoxins and maitotoxins, accumulate in fish, where, as is the case for the latter compounds, they can be metabolized to even more toxic metabolites. On the other hand, much less is known about the chemical nature of compounds...... complex natural compounds known to mankind, with chemical structures that show no resemblance to what has been characterized from plants, fungi, or bacteria. In addition, it will summarize algal species known to be related to fish-killing blooms, but from which ichthyotoxins are yet to be characterized....

  4. Mechanical algal disruption for efficient biodiesel extraction

    Science.gov (United States)

    Krehbiel, Joel David

    Biodiesel from algae provides several benefits over current biodiesel feedstocks, but the energy requirements of processing algae into a useable fuel are currently so high as to be prohibitive. One route to improving this is via disruption of the cells prior to lipid extraction, which can significantly increase energy recovery. Unfortunately, several obvious disruption techniques require more energy than can be gained. This dissertation examines the use of microbubbles to improve mechanical disruption of algal cells using experimental, theoretical, and computational methods. New laboratory experiments show that effective ultrasonic disruption of algae is achieved by adding microbubbles to an algal solution. The configuration studied flows the solution through a tube and insonifies a small section with a high-pressure ultrasound wave. Previous biomedical research has shown effective cell membrane damage on animal cells with similar methods, but the present research is the first to extend such study to algal cells. Results indicate that disruption increases with peak negative pressure between 1.90 and 3.07 MPa and with microbubble concentration up to 12.5 x 107 bubbles/ml. Energy estimates of this process suggest that it requires only one-fourth the currently most-efficient laboratory-scale disruption process. Estimates of the radius near each bubble that causes disruption (i.e. the disruption radius) suggest that it increases with peak negative pressure and is near 9--20 microm for all cases tested. It is anticipated that these procedures can be designed for better efficiency and efficacy, which will be facilitated by identifying the root mechanisms of the bubble-induced disruption. We therefore examine whether bubble expansion alone creates sufficient cell deformation for cell rupture. The spherically-symmetric Marmottant model for bubble dynamics allows estimation of the flow regime under experimental conditions. Bubble expansion is modeled as a point source of

  5. Benthic algal communities : recovery from experimental acidification

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.A.; Findlay, D.L.; Kasian, S.E.M. [Fisheries and Oceans Canada, Winnipeg, MB (Canada). Freshwater Inst.; Baulch, H.M. [Fisheries and Oceans Canada, Winnipeg, MB (Canada); Trent Univ., Peterborough, ON (Canada); Armstrong, L.M. [Ducks Unlimited Canada, Stonewall, MB (Canada). Inst. for Wetland and Waterfowl Research; McNicol, D.K. [Canadian Wildlife Service, Ottawa, ON (Canada); Vinebrooke, R.D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

    2009-11-15

    This study evaluated the hypothesis that chemical recovery promotes the rapid recovery of benthic algal communities in formerly acidified lakes. The study was conducted at an experimental lake in Ontario over a 10 year period of pH recovery that followed a 10 year period of experimental acidification from a pH of 6.7 to 4.5. A reference lake in the region was also studied to account for regional changes during the study period. Changes in the epilithon on rock surfaces included lower cyanobacterial biomass following the acidification as well as increases in diatoms and greens. Acidification-induced increases in respiration prevented epilithic metabolic recovery. Prior declines in photosynthesis were reversed. Blooms of metaphytic filamentous green algae with a higher pH occurred during the recovery period. The recovery of many aggregate functional and taxonomic properties lagged behind reductions in acidity. Incomplete chemical recovery and the absence of functionally important biota were attributed to incomplete algal recovery at the lake. 59 refs., 2 tabs., 8 figs.

  6. Use of biosensors for the detection of marine toxins.

    Science.gov (United States)

    McPartlin, Daniel A; Lochhead, Michael J; Connell, Laurie B; Doucette, Gregory J; O'Kennedy, Richard J

    2016-06-30

    Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact.

  7. Use of biosensors for the detection of marine toxins.

    Science.gov (United States)

    McPartlin, Daniel A; Lochhead, Michael J; Connell, Laurie B; Doucette, Gregory J; O'Kennedy, Richard J

    2016-06-30

    Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact. PMID:27365035

  8. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Biddy, M.; Jones, S.

    2013-03-01

    This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.

  9. Mechanical algal disruption for efficient biodiesel extraction

    Science.gov (United States)

    Krehbiel, Joel David

    Biodiesel from algae provides several benefits over current biodiesel feedstocks, but the energy requirements of processing algae into a useable fuel are currently so high as to be prohibitive. One route to improving this is via disruption of the cells prior to lipid extraction, which can significantly increase energy recovery. Unfortunately, several obvious disruption techniques require more energy than can be gained. This dissertation examines the use of microbubbles to improve mechanical disruption of algal cells using experimental, theoretical, and computational methods. New laboratory experiments show that effective ultrasonic disruption of algae is achieved by adding microbubbles to an algal solution. The configuration studied flows the solution through a tube and insonifies a small section with a high-pressure ultrasound wave. Previous biomedical research has shown effective cell membrane damage on animal cells with similar methods, but the present research is the first to extend such study to algal cells. Results indicate that disruption increases with peak negative pressure between 1.90 and 3.07 MPa and with microbubble concentration up to 12.5 x 107 bubbles/ml. Energy estimates of this process suggest that it requires only one-fourth the currently most-efficient laboratory-scale disruption process. Estimates of the radius near each bubble that causes disruption (i.e. the disruption radius) suggest that it increases with peak negative pressure and is near 9--20 microm for all cases tested. It is anticipated that these procedures can be designed for better efficiency and efficacy, which will be facilitated by identifying the root mechanisms of the bubble-induced disruption. We therefore examine whether bubble expansion alone creates sufficient cell deformation for cell rupture. The spherically-symmetric Marmottant model for bubble dynamics allows estimation of the flow regime under experimental conditions. Bubble expansion is modeled as a point source of

  10. Uniform algal growth in photobioreactors using surface scatterers

    Science.gov (United States)

    Ahsan, Syed S.; Pereyra, Brandon; Erickson, David

    2014-03-01

    Cultures of algae, such as cyanobacteria, are a promising source of renewable energy. However, algal growth is highly dependent on light intensity and standard photobioreactors do a poor job of distributing light uniformly for algal utilization due to shading effects in dense algal cultures. Engineered scattering schemes are already employed in current slab-waveguide technologies, like edge-lit LEDs. Stacking such slab-waveguides that uniformly distribute light could potentially yield photobioreactors to overcome the shading effect and grow extremely high densities of algal cultures that would lower monetary and energetic costs. Here, we characterize and design a scattering scheme for specific application within photobioreactors which employs a gradient distribution of surface scatterers with uniform lateral scattering intensity. This uniform scattering scheme is shown to be superior for algal cultivation.

  11. Stability of the intra- and extracellular toxins of Prymnesium parvum using a microalgal bioassay

    DEFF Research Database (Denmark)

    Blossom, Hannah Eva; Andersen, Nikolaj Gedsted; Rasmussen, Silas Anselm;

    2014-01-01

    Prymnesium parvum produces a variety of toxic compounds, which affect other algae, grazers and organisms at higher trophic levels. Here we provide the method for development of a sensitive algal bioassay using a microalgal target, Teleaulax acuta, to measure strain variability in P. parvum toxicity......, as well as the temporal stability of both the intracellular and the extracellular lytic compounds of P. parvum. We show high strain variation in toxicities after 3h incubation with LC50s ranging from 24 to 223×103cellsml−1. Most importantly we prove the necessity of testing physico-chemical properties...... of P. parvum toxins before attempting to isolate and characterize them. The extracellular toxin in the supernatant is highly unstable, and it loses significant lytic effects after 3 days despite storage at −20°C and after only 24h stored at 4°C. However, when stored at −80°C, lytic activity is more...

  12. Detection of surface algal blooms using the newly developed algorithm surface algal bloom index (SABI)

    Science.gov (United States)

    Alawadi, Fahad

    2010-10-01

    Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HABs involved and the environmental conditions, if their concentration rises above a critical threshold, it can impact the flora and fauna of the aquatic habitat through the introduction of the so called "red tide" phenomenon. The estimation of chlorophyll concentration is derived from quantifying the spectral relationship between the blue and the green bands reflected from the water column. This spectral relationship is employed in the standard ocean colour chlorophyll-a (Chlor-a) product, but is incapable of detecting certain macro-algal species that float near to or at the water surface in the form of dense filaments or mats. The ability to accurately identify algal formations that sometimes appear as oil spill look-alikes in satellite imagery, contributes towards the reduction of false-positive incidents arising from oil spill monitoring operations. Such algal formations that occur in relatively high concentrations may experience, as in land vegetation, what is known as the "red-edge" effect. This phenomena occurs at the highest reflectance slope between the maximum absorption in the red due to the surrounding ocean water and the maximum reflectance in the infra-red due to the photosynthetic pigments present in the surface algae. A new algorithm termed the surface algal bloom index (SABI), has been proposed to delineate the spatial distributions of floating micro-algal species like for example cyanobacteria or exposed inter-tidal vegetation like seagrass. This algorithm was

  13. Antibody-based biological toxin detection

    Energy Technology Data Exchange (ETDEWEB)

    Menking, D.E.; Goode, M.T. [Army Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD (United States)

    1995-12-01

    Fiber optic evanescent fluorosensors are under investigation in our laboratory for the study of drug-receptor interactions for detection of threat agents and antibody-antigen interactions for detection of biological toxins. In a direct competition assay, antibodies against Cholera toxin, Staphylococcus Enterotoxin B or ricin were noncovalently immobilized on quartz fibers and probed with fluorescein isothiocyanate (FITC) - labeled toxins. In the indirect competition assay, Cholera toxin or Botulinum toxoid A was immobilized onto the fiber, followed by incubation in an antiserum or partially purified anti-toxin IgG. These were then probed with FITC-anti-IgG antibodies. Unlabeled toxins competed with labeled toxins or anti-toxin IgG in a dose dependent manner and the detection of the toxins was in the nanomolar range.

  14. Targeted Toxins in Brain Tumor Therapy

    Directory of Open Access Journals (Sweden)

    Walter A. Hall

    2010-11-01

    Full Text Available Targeted toxins, also known as immunotoxins or cytotoxins, are recombinant molecules that specifically bind to cell surface receptors that are overexpressed in cancer and the toxin component kills the cell. These recombinant proteins consist of a specific antibody or ligand coupled to a protein toxin. The targeted toxins bind to a surface antigen or receptor overexpressed in tumors, such as the epidermal growth factor receptor or interleukin-13 receptor. The toxin part of the molecule in all clinically used toxins is modified from bacterial or plant toxins, fused to an antibody or carrier ligand. Targeted toxins are very effective against cancer cells resistant to radiation and chemotherapy. They are far more potent than any known chemotherapy drug. Targeted toxins have shown an acceptable profile of toxicity and safety in early clinical studies and have demonstrated evidence of a tumor response. Currently, clinical trials with some targeted toxins are complete and the final results are pending. This review summarizes the characteristics of targeted toxins and the key findings of the important clinical studies with targeted toxins in malignant brain tumor patients. Obstacles to successful treatment of malignant brain tumors include poor penetration into tumor masses, the immune response to the toxin component and cancer heterogeneity. Strategies to overcome these limitations are being pursued in the current generation of targeted toxins.

  15. Yessotoxins, a Group of Marine Polyether Toxins: an Overview

    Directory of Open Access Journals (Sweden)

    José J. Fernández

    2008-05-01

    Full Text Available Yessotoxin (YTX is a marine polyether toxin that was first isolated in 1986 from the scallop Patinopecten yessoensis. Subsequently, it was reported that YTX is produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. YTXs have been associated with diarrhetic shellfish poisoning (DSP because they are often simultaneously extracted with DSP toxins, and give positive results when tested in the conventional mouse bioassay for DSP toxins. However, recent evidence suggests that YTXs should be excluded from the DSP toxins group, because unlike okadaic acid (OA and dinophyisistoxin-1 (DTX-1, YTXs do not cause either diarrhea or inhibition of protein phosphatases . In spite of the increasing number of molecular studies focused on the toxicity of YTX, the precise mechanism of action is currently unknown. Since the discovery of YTX, almost forty new analogues isolated from both mussels and dinoflagellates have been characterized by NMR or LC-MS/MS techniques. These studies indicate a wide variability in the profile and the relative abundance of YTXs in both, bivalves and dinoflagellates. This review covers current knowledge on the origin, producer organisms and vectors, chemical structures, metabolism, biosynthetic origin, toxicological properties, potential risks to human health and advances in detection methods of YTXs.

  16. Physical Water Quality and Algal Density for Remediation of Algal Blooms in Tropical Shallow Eutrophic Reservoir

    OpenAIRE

    Gurminder Kaur Sardool Singh; Perumal Kuppan; Goto, Masafumi; Sugiura, Norio; Megat Johari Megat Mohd Noor; Zaini Ujang

    2013-01-01

    This study is on physical water quality data with regards to algal bloom occurrence in a shallow eutrophic reservoir in Malaysia. Some of the important physical parameters emphasized for future remedial studies for the Semberong Dam, a tropical reservoir, are dissolved oxygen, temperature and light intensity. The use of Planktothrix culture as a dominant algae or a mixed culture with a spike of this dominant algae is suggested for remedial study. Other influencing factors for consideration ar...

  17. Extreme Algal Bloom Detection with MERIS

    Science.gov (United States)

    Amin, R.; Gilerson, A.; Gould, R.; Arnone, R.; Ahmed, S.

    2009-05-01

    Harmful Algal Blooms (HAB's) are a major concern all over the world due to their negative impacts on the marine environment, human health, and the economy. Their detection from space still remains a challenge particularly in turbid coastal waters. In this study we propose a simple reflectance band difference approach for use with Medium Resolution Imaging Spectrometer (MERIS) data to detect intense plankton blooms. For convenience we label this approach as the Extreme Bloom Index (EBI) which is defined as EBI = Rrs (709) - Rrs (665). Our initial analysis shows that this band difference approach has some advantages over the band ratio approaches, particularly in reducing errors due to imperfect atmospheric corrections. We also do a comparison between the proposed EBI technique and the Maximum Chlorophyll Index (MCI) Gower technique. Our preliminary result shows that both the EBI and MCI indeces detect intense plankton blooms, however, MCI is more vulnerable in highly scattering waters, giving more positive false alarms than EBI.

  18. Harmful Algal Bloom Research in China

    Institute of Scientific and Technical Information of China (English)

    Su Jilan; Zhou Mingjiang

    2001-01-01

    Proliferations of harmful algae in coastal waters, i.e., harmful algal blooms (HABs), popularly known as "red tides," have attracted the concern of governments and scientists worldwide. In recent years, HABs have occurred in China with increasing frequency and scope. These outbreaks have seriously affected the economy along the coast through fish kills, heavy losses in aquaculture, threats to human health, and other effects detrimental to the marine ecosystem. Therefore, it is important to pay special attention to the ecology and oceanography studies related to the outbreak of HABs. Only through the combination of the advancement of such knowledge with the strengthening of the monitoring network can we develop a HAB warning system for the sustainable development of the coastal economy.

  19. Staphylococcus aureus in vitro secretion of alpha toxin (hla) correlates with the affiliation to clonal complexes.

    Science.gov (United States)

    Monecke, Stefan; Müller, Elke; Büchler, Joseph; Stieber, Bettina; Ehricht, Ralf

    2014-01-01

    The alpha toxin of Staphylococcus aureus is a pore forming toxin that penetrates host cell membranes causing osmotic swelling, rupture, lysis and subsequently cell death. Haemolysin alpha is toxic to a wide range of different mammalian cells; i.e., neurotoxic, dermonecrotic, haemolytic, and it can cause lethality in a wide variety of animals. In this study, the in vitro alpha toxin production of 648 previously genotyped isolates of S. aureus was measured quantitatively using antibody microarrays. Isolates originated from medical and veterinary settings and were selected in order to represent diverse clonal complexes and defined clinical conditions. Generally, the production of alpha toxin in vitro is related to the clonal complex affiliation. For clonal complexes CC22, CC30, CC45, CC479, CC705 and others, invariably no alpha toxin production was noted under the given in vitro conditions, while others, such as CC1, CC5, CC8, CC15 or CC96 secreted variable or high levels of alpha toxin. There was no correlation between alpha toxin yield and clinical course of the disease, or between alpha toxin yield and host species.

  20. Staphylococcus aureus in vitro secretion of alpha toxin (hla correlates with the affiliation to clonal complexes.

    Directory of Open Access Journals (Sweden)

    Stefan Monecke

    Full Text Available The alpha toxin of Staphylococcus aureus is a pore forming toxin that penetrates host cell membranes causing osmotic swelling, rupture, lysis and subsequently cell death. Haemolysin alpha is toxic to a wide range of different mammalian cells; i.e., neurotoxic, dermonecrotic, haemolytic, and it can cause lethality in a wide variety of animals. In this study, the in vitro alpha toxin production of 648 previously genotyped isolates of S. aureus was measured quantitatively using antibody microarrays. Isolates originated from medical and veterinary settings and were selected in order to represent diverse clonal complexes and defined clinical conditions. Generally, the production of alpha toxin in vitro is related to the clonal complex affiliation. For clonal complexes CC22, CC30, CC45, CC479, CC705 and others, invariably no alpha toxin production was noted under the given in vitro conditions, while others, such as CC1, CC5, CC8, CC15 or CC96 secreted variable or high levels of alpha toxin. There was no correlation between alpha toxin yield and clinical course of the disease, or between alpha toxin yield and host species.

  1. Development of Certified Reference Materials for Diarrhetic Shellfish Poisoning Toxins, Part 1: Calibration Solutions.

    Science.gov (United States)

    Beach, Daniel G; Crain, Sheila; Lewis, Nancy; LeBlanc, Patricia; Hardstaff, William R; Perez, Ruth A; Giddings, Sabrina D; Martinez-Farina, Camilo F; Stefanova, Roumiana; Burton, Ian W; Kilcoyne, Jane; Melanson, Jeremy E; Quilliam, Michael A; McCarron, Pearse

    2016-09-01

    Okadaic acid (OA) and its analogs dinophysistoxins-1 (DTX1) and -2 (DTX2) are lipophilic polyethers produced by marine dinoflagellates. These toxins accumulate in shellfish and cause diarrhetic shellfish poisoning (DSP) in humans. Regulatory testing of shellfish is essential to safeguard public health and for international trade. Certified reference materials (CRMs) play a key role in analytical monitoring programs. This paper presents an overview of the interdisciplinary work that went into the planning, production, and certification of calibration-solution CRMs for OA, DTX1, and DTX2. OA and DTX1 were isolated from large-scale algal cultures and DTX2 from naturally contaminated mussels. Toxins were isolated by a combination of extraction and chromatographic steps with processes adapted to suit the source and concentration of each toxin. New 19-epi-DSP toxin analogs were identified as minor impurities. Once OA, DTX1, and DTX2 were established to be of suitable purity, solutions were prepared and dispensed into flame-sealed glass ampoules. Certification measurements were carried out using quantitative NMR spectroscopy and LC-tandem MS. Traceability of measurements was established through certified external standards of established purity. Uncertainties were assigned following standards and guidelines from the International Organization for Standardization, with components from the measurement, stability, and homogeneity studies being propagated into final combined uncertainties. PMID:27524810

  2. Botulinum Toxin Injections: A Treatment for Muscle Spasms

    Science.gov (United States)

    ... A Treatment for Muscle Spasms What is botulinum toxin? Botulinum toxin is a protein that helps stop muscle ... won't have any harmful effects from the toxin. Botulinum toxin has been used safely for a number ...

  3. Production of biofuel using molluscan pseudofeces derived from algal cells

    Science.gov (United States)

    Das, Keshav C.; Chinnasamy, Senthil; Shelton, James; Wilde, Susan B.; Haynie, Rebecca S.; Herrin, James A.

    2012-08-28

    Embodiments of the present disclosure provide for novel strategies to harvest algal lipids using mollusks which after feeding algae from the growth medium can convert algal lipids into their biomass or excrete lipids in their pseudofeces which makes algae harvesting energy efficient and cost effective. The bioconverter, filter-feeding mollusks and their pseudofeces can be harvested and converted to biocrude using an advanced thermochemical liquefaction technology. Methods, systems, and materials are disclosed for the harvest and isolation of algal lipids from the mollusks, molluscan feces and molluscan pseudofeces.

  4. Available Resources for Algal Biofuel Development in China

    Directory of Open Access Journals (Sweden)

    Li Chen

    2011-08-01

    Full Text Available Microalgal biofuel research in China has made noticeable progress, and algae cultivation for biofuel production is considered to be an important contribution to Greenhouse Gas (GHG mitigation and energy security. In this paper, the algal biofuel potentiality in China was reviewed from the points of view of algal biodiversity, algal culture collection, GHGs (especially CO2 mitigation, and the availability of the required sunlight, wastewater and land resources. The cultivation of microalgae utilizing power plants gas with large amounts of CO2 and wastewaters from urban households, industry and animal husbandry are suitable for large scale production in China. Land is hardly a limitation for algae cultivation.

  5. Proterozoic microfossils revealing the time of algal divergences

    Science.gov (United States)

    Moczydlowska-Vidal, Malgorzata

    2010-05-01

    Proterozoic microfossils revealing the time of algal divergences Małgorzata Moczydłowska-Vidal Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, SE 752 36 Uppsala, Sweden (malgo.vidal@pal.uu.se) Morphological and reproductive features and cell wall ultrastructure and biochemistry of Proterozoic acritarchs are used to determine their affinity to modern algae. The first appearance datum of these microbiota is traced to infer a minimum age of the divergence of the algal classes to which they may belong. The chronological appearance of microfossils that represent phycoma-like and zygotic cysts and vegetative cells and/or aplanospores, respectively interpreted as prasinophyceaen and chlorophyceaen microalgae, is related to the Viridiplantae phylogeny. These divergence times differ from molecular clock estimates, and the palaeontological evidence suggests that they are older. The best examples of unicellular, organic-walled microfossils (acritarchs) from the Mesoproterozoic to Early Ordovician are reviewed to demonstrate features, which are indicative of their affinity to photosynthetic microalgae. The first indication that a microfossil may be algal is a decay- and acid-resistant cell wall, which reflects its biochemistry and ultrastructure, and probably indicates the ability to protect a resting/reproductive cyst. The biopolymers synthesized in the cell walls of algae and in land plants ("plant cells"), such as sporopollenin/algaenan, are diagnostic for photosynthetic taxa and were inherited from early unicellular ancestors. These preservable cell walls are resistant to acetolysis, hydrolysis and acids, and show diagnostic ultrastructures such as the trilaminar sheath structure (TLS). "Plant cell" walls differ in terms of chemical compounds, which give high preservation potential, from fungal and animal cell walls. Fungal and animal cells are fossilized only by syngenetic permineralization, whereas "plant cells" are fossilized as body

  6. Sodium Channel Inhibiting Marine Toxins

    Science.gov (United States)

    Llewellyn, Lyndon E.

    Saxitoxin (STX), tetrodotoxin (TTX) and their many chemical relatives are part of our daily lives. From killing people who eat seafood containing these toxins, to being valuable research tools unveiling the invisible structures of their pharmacological receptor, their global impact is beyond measure. The pharmacological receptor for these toxins is the voltage-gated sodium channel which transports Na ions between the exterior to the interior of cells. The two structurally divergent families of STX and TTX analogues bind at the same location on these Na channels to stop the flow of ions. This can affect nerves, muscles and biological senses of most animals. It is through these and other toxins that we have developed much of our fundamental understanding of the Na channel and its part in generating action potentials in excitable cells.

  7. Clostridium difficile and C. difficile Toxin Testing

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Clostridium difficile and C. difficile Toxin Testing Share this page: ... C. diff; C diff antigen; GDH Formal name: Clostridium difficile Culture; C. difficile Toxin, A and B; C. ...

  8. Toxin synergism in snake venoms

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard

    2016-01-01

    Synergism between venom toxins exists for a range of snake species. Synergism can be derived from both intermolecular interactions and supramolecular interactions between venom components, and can be the result of toxins targeting the same protein, biochemical pathway or physiological process. Few...... simple systematic tools and methods for determining the presence of synergism exist, but include co-administration of venom components and assessment of Accumulated Toxicity Scores. A better understanding of how to investigate synergism in snake venoms may help unravel strategies for developing novel...

  9. Toxin yet not toxic: Botulinum toxin in dentistry.

    Science.gov (United States)

    Archana, M S

    2016-04-01

    Paracelsus contrasted poisons from nonpoisons, stating that "All things are poisons, and there is nothing that is harmless; the dose alone decides that something is a poison". Living organisms, such as plants, animals, and microorganisms, constitute a huge source of pharmaceutically useful medicines and toxins. Depending on their source, toxins can be categorized as phytotoxins, mycotoxins, or zootoxins, which include venoms and bacterial toxins. Any toxin can be harmful or beneficial. Within the last 100 years, the perception of botulinum neurotoxin (BTX) has evolved from that of a poison to a versatile clinical agent with various uses. BTX plays a key role in the management of many orofacial and dental disorders. Its indications are rapidly expanding, with ongoing trials for further applications. However, despite its clinical use, what BTX specifically does in each condition is still not clear. The main aim of this review is to describe some of the unclear aspects of this potentially useful agent, with a focus on the current research in dentistry. PMID:27486290

  10. Airborne Monitoring of Harmful Algal Blooms over Lake Erie

    Science.gov (United States)

    Tokars, Roger; Lekki, John

    2013-01-01

    The Hyperspectral Imager mounted to an aircraft was used to develop a remote sensing capability to detect the pigment Phycocyanin, an indicator of Microcystis, in low concentration as an early indicator of harmful algal bloom prediction.

  11. Algal Biofuels R&D at NREL (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2012-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  12. Raceways-based production of algal crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Chisti, Yusuf [Massey Univ., Palmerston North (New Zealand). School of Engineering

    2013-11-01

    Raceway ponds, or 'high-rate algal ponds', of various configurations have been used to treat wastewater since the 1950s. They are also known as Oswald ponds after their inventor W. J. Oswald. Large-scale outdoor culture of microalgae and cyanobacteria in raceways is well established (Terry and Raymond 1985; Oswald 1988; Borowitzka and Borowitzka 1989; Becker 1994; Lee 1997; Molina Grima 1999; Pulz 2001; Borowitzka 2005; Spolaore et al. 2006). Raceway culture is used commercially in the United States, Thailand, China, Israel and elsewhere, mostly to produce algae for relatively high-value applications. This chapter is focused on raceways typically used in the production of algal biomass and not in the treatment of wastewater. The engineering design, operation and performance characteristics of raceways are discussed. The biomass productivity of the raceways is assessed in relation to limits imposed by algal biology. The economics of algal oil production in raceways are discussed. (orig.)

  13. Impacts of algal blooms removal by chitosan-modified soils on zooplankton community in Taihu Lake,China

    Institute of Scientific and Technical Information of China (English)

    Jiajia Ni; Yuhe Yu; Weisong Feng; Qingyun Yan; Gang pan; Bo Yang; Xiang Zhang; Xuemei Li

    2010-01-01

    It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology,especially removing algal blooms,because algae were the major primary producer in algal lakes.The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study.Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE).A total of 44 zooplankton taxa (23 protozoa,17 rotifers,3 copepoda and 1 cladocera) were detected by microscope checkup,and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616,63 bands amplified by primers Fung-G-C and NS1) were detected by PCR-DGGE.The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites,and DGGE profiles could represent the biologic diversity.The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually.In addition,the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.

  14. SxtA and sxtG Gene Expression and Toxin Production in the Mediterranean Alexandrium minutum (Dinophyceae

    Directory of Open Access Journals (Sweden)

    Federico Perini

    2014-10-01

    Full Text Available The dinoflagellate Alexandrium minutum is known for the production of potent neurotoxins affecting the health of human seafood consumers via paralytic shellfish poisoning (PSP. The aim of this study was to investigate the relationship between the toxin content and the expression level of the genes involved in paralytic shellfish toxin (PST production. The algal cultures were grown both in standard f/2 medium and in phosphorus/nitrogen limitation. In our study, LC-HRMS analyses of PST profile and content in different Mediterranean A. minutum strains confirmed that this species was able to synthesize mainly the saxitoxin analogues Gonyautoxin-1 (GTX1 and Gonyautoxin-4 (GTX4. The average cellular toxin content varied among different strains, and between growth phases, highlighting a decreasing trend from exponential to stationary phase in all culture conditions tested. The absolute quantities of intracellular sxtA1 and sxtG mRNA were not correlated with the amount of intracellular toxins in the analysed A. minutum suggesting that the production of toxins may be regulated by post-transcriptional mechanisms and/or by the concerted actions of alternative genes belonging to the PST biosynthesis gene cluster. Therefore, it is likely that the sxtA1 and sxtG gene expression could not reflect the PST accumulation in the Mediterranean A. minutum populations under the examined standard and nutrient limiting conditions.

  15. Association of toxin-producing Clostridium botulinum with the macroalga Cladophora in the Great Lakes.

    Science.gov (United States)

    Chun, Chan Lan; Ochsner, Urs; Byappanahalli, Muruleedhara N; Whitman, Richard L; Tepp, William H; Lin, Guangyun; Johnson, Eric A; Peller, Julie; Sadowsky, Michael J

    2013-03-19

    Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism

  16. Association of toxin-producing Clostridium botulinum with the macroalga Cladophora in the Great Lakes

    Science.gov (United States)

    Chun, Chan Lan; Ochsner, Urs; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Tepp, William H.; Lin, Guangyun; Johnson, Eric A.; Peller, Julie; Sadowsky, Michael J.

    2013-01-01

    Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15 000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism

  17. 2016 National Algal Biofuels Technology Review Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Algae-based biofuels and bioproducts offer great promise in contributing to the U.S. Department of Energy (DOE) Bioenergy Technologies Office’s (BETO’s) vision of a thriving and sustainable bioeconomy fueled by innovative technologies. The state of technology for producing algal biofuels continues to mature with ongoing investment by DOE and the private sector, but additional research, development, and demonstration (RD&D) is needed to achieve widespread deployment of affordable, scalable, and sustainable algal biofuels.

  18. Oligotrophic Bacteria Enhance Algal Growth under Iron-Deficient Conditions

    OpenAIRE

    Keshtacher-Liebso..., E.; Hadar, Y; Chen, Y.

    1995-01-01

    A Halomonas sp., a marine halophilic and oligotrophic bacterium, was grown on exudates of Dunaliella bardawil. The bacteria increased the solubility of Fe, thereby enhancing its availability to the algae. As a result, the algal growth rate increased. Because of these syntrophic relations, growth of the marine alga D. bardawil was facilitated at Fe levels that would otherwise induce Fe deficiency and inhibit algal growth.

  19. Harmful algal research and response: A human dimensions strategy

    OpenAIRE

    2006-01-01

    Harmful Algal Research and Response: A Human Dimensions Strategy (HARR-HD) justifies and guides a coordinated national commitment to human dimensions research critical to prevent and respond to impacts of harmful algal blooms (HABs). Beyond HABs, it serves as a framework for developing hu-man dimensions research as a cross-cutting priority of ecosystem science supporting coastal and ocean management, including hazard research and mitigation planning. Measuring and promoting commu-nity resilie...

  20. Both, toxin A and toxin B, are important in Clostridium difficile infection

    OpenAIRE

    Kuehne, Sarah A; Cartman, Stephen T; Minton, Nigel P.

    2011-01-01

    The bacterium Clostridium difficile is the leading cause of healthcare associated diarrhoea in the developed world and thus presents a major financial burden. The main virulence factors of C. difficile are two large toxins, A and B. Over the years there has been some debate over the respective roles and importance of these two toxins. To address this, we recently constructed stable toxin mutants of C. difficile and found that they were virulent if either toxin A or toxin B was functional. Thi...

  1. Algal Turf Scrubbers: Cleaning Water While Capturing Solar Energy

    International Nuclear Information System (INIS)

    Algal Turfs and Algal Turf Scrubbers (ATS) Algal Turfs are bio diverse communities of unicellular to filamentous algae of all major algal phyla. Algal Turf Scrubbers (ATS) are bioengineered ecosystems dominated by algal turfs. They clean water to very high quality, and remove CO2 from the atmosphere by capturing solar energy at rates 10 times that of agriculture and 50 times that of forestry. ATS was invented at the Smithsonian Institution, by scientist, Walter Adey in the 1980s as a tool for controlling water quality in highly diverse model ecosystems. The technology received extensive R and D for aqua cultural, municipal, and industrial water cleaning by Dr. Adey, using venture capital, through the 1990s. Later, Hydro Mentia, Inc., of Ocala, Florida, engineered ATS to landscape scale of 20-50 Mgpd (it is important to note that this is a modular system, capable of expanding to any size.) A 2005 independent study of ATS, by the South Florida Water Management District and the IFAS Institute of the University of Florida, certified ATS as 5-100 times more cost efficient at removing nutrients from Everglades canal waters than the next competitor, the STA, a managed marsh system. ATS and STA were the final contestants in a 15-year study of nine technologies, and ATS was the only technology that created a use able byproduct.

  2. Algal biofuels: key issues, sustainability and life cycle assessment

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; Irving Olsen, S.

    2011-05-15

    In recent years research activities are intensively focused on renewable fuels in order to fulfill the increasing energy demand and to reduce the fossil fuels consumption and external oil dependency either in order to provide local energetic resources and or as a means for reducing greenhouse gases (GHG) emissions to reduce the climate change effects. Among the various renewable energy sources algal biofuels is a very promising source of biomass as algae sequester huge quantities of carbon from atmosphere and are very efficient in utilizing the nutrients from the industrial effluent and municipal wastewater. Algae capture CO{sub 2} from atmosphere and industrial flue gases and transform it in to organic biomass that can be used for the production of biofuels. Like other biomass, algal biomass is also a carbon neutral source for the production of bioenergy. Therefore cultivation of algal biomass provides dual benefits; while being able to utilize nutrients in waste water thus reducing impacts on inland waters it produce biomass for the production of biofuels. However, reaching commercial scale production of algal biofuels is difficult. The main drawbacks include the harvesting of dry biomass and higher capital investment. The harvested algal biomass and its extracts can be efficiently converted to different biofuels such as bioethanol, biodiesel, biogas and biohydrogen by implementation of various process technologies. Comprehensive life cycle assessments (LCA) of algal biofuels illustrating environmental benefits and impacts can be a tool for policy decisions and for technology development. (Author)

  3. Benthic algal vegetation in Isfjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    Stein Fredriksen

    2015-08-01

    Full Text Available Benthic algal vegetation was investigated at 10 sites in Isfjorden, Svalbard. Five sites were visited during summer 2010 and five during summer 2012. Both the littoral and sublittoral vegetation were sampled, the littoral by hand-picking and use of a throwable rake and the sublittoral using a triangular dredge. A total of 88 different taxa were registered, comprising 17 Chlorophyta, 40 Ochrophyta, 30 Rhodophyta and the Xantophyceae Vaucheria sp. The green algae Ulvaria splendens (Ruprecht Vinogradova was recorded in Svalbard for the first time. Most of the sites consisted of hard bottom substrate, but one site, Kapp Wijk, consisted of loose-lying calcareous red algae (rhodoliths and had species not recorded elsewhere. The sublittoral at the other sites was dominated by kelp. Molecular analysis confirmed the presence of the red alga Ceramium virgatum and a dwarf form of the brown alga Fucus vesiculosus. This study provides a baseline for future studies investigating changes in the vegetation due to environmental changes.

  4. Sixty years in algal physiology and photosynthesis.

    Science.gov (United States)

    Pirson, A

    1994-06-01

    This personal perspective records research experiences in chemistry and biology at four German universities, two before and two after World War II. The research themes came from cytophysiology of green unicellular algae, in particular their photosynthesis. The function of inorganic ions in photosynthesis and dark respiration was investigated at different degrees of specific mineral stress (deficiencies), and the kinetics of recovery followed after the addition of the missing element. Two types of recovery of photosynthesis were observed: indirect restitution via growth processes and immediate normalisation. From the latter case (K(+), phosphate, Mn(++)) the effect of manganese was emphasized as its role in photosynthetic O2 evolution became established during our research. Other themes of our group, with some bearing on photosynthesis were: synchronization of cell growth by light-dark change and effects of blue (vs. red) light on the composition of green cells. Some experiences in connection with algal mass cultures are included. Discussion of several editorial projects shows how photosynthesis, as an orginally separated field of plant biochemistry and biophysics, became included into general cell physiology and even ecophysiology of green plants. The paper contains an appreciation of the authors' main mentor Kurt Noack (1888-1963) and of Ernst Georg Pringsheim (1881-1970), founder of experimental phycology.

  5. Risk Assessment of Shellfish Toxins

    Directory of Open Access Journals (Sweden)

    Rex Munday

    2013-11-01

    Full Text Available Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved.

  6. Shigella Sonnei and Shiga Toxin

    Centers for Disease Control (CDC) Podcasts

    2016-07-28

    Katherine Lamba, an infectious disease epidemiologist with the California Department of Public Health, discusses Shiga Toxin producing Shigella sonnei.  Created: 7/28/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/28/2016.

  7. Harmful algal bloom smart device application: using image analysis and machine learning techniques for early classification of harmful algal blooms

    Science.gov (United States)

    The Ecological Stewardship Institute at Northern Kentucky University and the U.S. Environmental Protection Agency are collaborating to optimize a harmful algal bloom detection algorithm that estimates the presence and count of cyanobacteria in freshwater systems by image analysis...

  8. Novel receptors for bacterial protein toxins.

    Science.gov (United States)

    Schmidt, Gudula; Papatheodorou, Panagiotis; Aktories, Klaus

    2015-02-01

    While bacterial effectors are often directly introduced into eukaryotic target cells by various types of injection machines, toxins enter the cytosol of host cells from endosomal compartments or after retrograde transport via Golgi from the ER. A first crucial step of toxin-host interaction is receptor binding. Using optimized protocols and new methods novel toxin receptors have been identified, including metalloprotease ADAM 10 for Staphylococcus aureus α-toxin, laminin receptor Lu/BCAM for Escherichia coli cytotoxic necrotizing factor CNF1, lipolysis stimulated lipoprotein receptor (LSR) for Clostridium difficile transferase CDT and low-density lipoprotein receptor-related protein (LRP) 1 for Clostridium perfringens TpeL toxin.

  9. Ceramic Ultrafiltration of Marine Algal Solutions: A Comprehensive Study

    KAUST Repository

    Dramas, Laure

    2014-09-01

    Algal bloom can significantly impact reverse osmosis desalination process and reduce the drinking water production. In 2008, a major bloom event forced several UAE reverse osmosis plants to stop their production, and in this context, a better understanding of UF membrane fouling caused by algal organic matter (AOM) is needed, in order to adjust the filtration conditions during algal bloom events. Polymeric MF/UF membranes are already widely used for RO pretreatment, but ceramic UF membranes can also be an alternative for the filtration of marine algal solutions. The fouling potential of the Red Sea and the Arabian Sea, sampled at different seasons, along with four algal monocultures grown in laboratory, and one mesocosm experiment in the Red Sea was investigated. Algal solutions induce a stronger and more irreversible fouling than terrestrial humic solution, toward ceramic membrane. During algal bloom events, this fouling is enhanced and becomes even more problematic at the decline phase of the bloom, for a similar initial DOC. Three main mechanisms are involved: the formation of a cake layer at the membrane surface; the penetration of the algal organic matter (AOM) in the pore network of the membrane; the strong adhesion of AOM with the membrane surface. The last mechanism is species-specific and metal-oxide specific. In order to understand the stronger ceramic UF fouling at the decline phase, AOM quality was analyzed every two days. During growth, AOM is getting enriched in High Molecular Weight (HMW) structures (> 200 kDa), which are mainly composed by proteins and polysaccharides, and these compounds seem to be responsible for the stronger fouling at decline phase. In order to prevent the fouling of ceramic membrane, coagulation-flocculation (CF) using ferric chloride was implemented prior to filtration. It permits a high removal of HMW compounds and greatly reduces the fouling potential of the algal solution. During brief algal bloom events, CF should be

  10. Paralytic shellfish toxins in the freshwater cyanobacterium Aphanizomenon flos-aquae, isolated from Montargil reservoir, Portugal.

    Science.gov (United States)

    Pereira, P; Onodera, H; Andrinolo, D; Franca, S; Araújo, F; Lagos, N; Oshima, Y

    2000-12-01

    Montargil reservoir, located in a dry flat area in the centre of Portugal, was filled in 1958 to fulfil agricultural, electric and industrial requirements. In May 1996, an intensive bloom of phytoplankton was detected. The algal community was strongly dominated by cyanobacteria with predominance of Aphanizomenon flos-aquae from May to June and Microcystis aeruginosa from July to August. Extracts of samples collected during the bloom period showed high toxicity by mouse bioassay. During the M. aeruginosa predominance period, the toxicity was ascribed to the presence of hepatotoxins, but clear symptoms of paralytic shellfish poison were observed when A. flos-aquae was the dominant species. In order to confirm the production of neurotoxins a strain of A. flos-aquae was isolated and established in culture. In this manuscript, we show the morphological characteristics and confirm paralytic shellfish toxins production by the strain isolated and maintained in culture. Identification of the saxitoxin analogs was achieved using high performance liquid chromatography with postcolumn fluorescence derivatization (HPLC-FLD) and liquid chromatographic mass spectrometry technique (LC-MS). The toxins found in the culture extract were GTX5 (64.5 mol%), neoSTX (23.0 mol%), dcSTX (6.1 mol%), STX (5.4 mol%) and GTX6 (1.1 mol%). This is, to our knowledge, the first report of unambiguous evidence of paralytic shellfish toxins produced by freshwater cyanobacteria in Portugal. The toxin profile is rather different from the previously reported PSP producing A. flos-aquae and demonstrates its diversity in terms of toxin production. PMID:10858510

  11. Broadening the neutralizing capacity of a family of antibody fragments against different toxins from Mexican scorpions.

    Science.gov (United States)

    Rodríguez-Rodríguez, Everardo Remi; Olamendi-Portugal, Timoteo; Serrano-Posada, Hugo; Arredondo-López, Jonathan Noé; Gómez-Ramírez, Ilse; Fernández-Taboada, Guillermo; Possani, Lourival D; Anguiano-Vega, Gerardo Alfonso; Riaño-Umbarila, Lidia; Becerril, Baltazar

    2016-09-01

    New approaches aimed at neutralizing the primary toxic components present in scorpion venoms, represent a promising alternative to the use of antivenoms of equine origin in humans. New potential therapeutics developed by these approaches correspond to neutralizing antibody fragments obtained by selection and maturation processes from libraries of human origin. The high sequence identity shared among scorpion toxins is associated with an important level of cross reactivity exhibited by these antibody fragments. We have exploited the cross reactivity showed by single chain variable antibody fragments (scFvs) of human origin to re-direct the neutralizing capacity toward various other scorpion toxins. As expected, during these evolving processes several variants derived from a parental scFv exhibited the capacity to simultaneously recognize and neutralize different toxins from Centruroides scorpion venoms. A sequence analyses of the cross reacting scFvs revealed that specific mutations are responsible for broadening their neutralizing capacity. In this work, we generated a set of new scFvs that resulted from the combinatorial insertion of these point mutations. These scFvs are potential candidates to be part of a novel recombinant antivenom of human origin that could confer protection against scorpion stings. A remarkable property of one of these new scFvs (ER-5) is its capacity to neutralize at least three different toxins and its complementary capacity to neutralize the whole venom from Centruroides suffusus in combination with a second scFv (LR), which binds to a different epitope shared by Centruroides scorpion toxins.

  12. Potential developmental toxicity of anatoxin-a, a cyanobacterial toxin.

    Science.gov (United States)

    Rogers, E H; Hunter, E S; Moser, V C; Phillips, P M; Herkovits, J; Muñoz, L; Hall, L L; Chernoff, N

    2005-01-01

    Some 2000 species of cyanobacteria (blue-green algae) occur globally in aquatic habitats. They are able to survive under a wide range of environmental conditions and some produce potent toxins. Toxin production is correlated with periods of rapid growth (blooms) and 25%-70% of blooms may be toxic. Anatoxin-a is an alkaloid neurotoxin that acts as a potent neuro-muscular blocking agent at the nicotinic receptor. Acute toxicity, following consumption of contaminated water, is characterized by rapid onset of paralysis, tremors, convulsions and death. Human exposures may occur from recreational water activities and dietary supplements, but are primarily through drinking water. The current studies were conducted to examine the effect of in utero exposure on postnatal viability, growth and neurodevelopment, to evaluate the potential of in vitro embryotoxicity, and to explore the synergistic relationship between anatoxin-a and the algal toxin microcystin-LR by the oral route. The results of preliminary studies on amphibian toxicity are also reported. Time-pregnant mice received 125 or 200 microg kg(-1) anatoxin-a by intraperitoneal injection on gestation days (GD) 8-12 or 13-17. Pup viability and weight were monitored over a 6-day period. Maternal toxicity (decreased motor activity) was observed at 200 microg kg(-1) in both treatment periods. There were no significant treatment-related effects on pup viability or weight on postnatal day (PND) 1 or 6. The GD 13-17 pups were evaluated on PND 6, 12 and 20 for standard markers of neurodevelopmental maturation (righting reflex, negative geotaxis and hanging grip time). No significant postnatal neurotoxicity was observed. In vitro developmental toxicity was evaluated in GD 8 mouse embryos exposed to 0.1-25 microm anatoxin-a for 26-28 h. Perturbations in mouse yolk sac vasculature were noted from the 1.0 microm concentration in the absence of significant embryonic dysmorphology. Potential algal toxin synergism was tested in mice

  13. Harmful Algal Bloom Monitoring Data for Puget Sound - SoundToxins: Partnership for Enhanced Monitoring and Emergency Response to Harmful Algal Blooms in Puget Sound

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Toxic outbreaks of species of the dinoflagellate Alexandrium have become pervasive in the Puget Sound region over the last two decades, escalating the threats to...

  14. Anthrax toxin receptor 2-dependent lethal toxin killing in vivo.

    Directory of Open Access Journals (Sweden)

    Heather M Scobie

    2006-10-01

    Full Text Available Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2 have a related integrin-like inserted (I domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in the absence of metal ions, we reasoned that D683 mutant forms of PA might specifically interact with ANTXR2. We show here that this is the case. The differential ability of ANTXR1 and ANTXR2 to bind D683 mutant PA proteins was mapped to nonconserved receptor residues at the binding interface with PA domain 2. Moreover, a D683K mutant form of PA that bound specifically to human and rat ANTXR2 mediated killing of rats by anthrax lethal toxin, providing strong evidence for the physiological importance of ANTXR2 in anthrax disease pathogenesis.

  15. The zebrafish (Danio rerio) embryo as a model system for identification and characterization of developmental toxins from marine and freshwater microalgae.

    Science.gov (United States)

    Berry, John P; Gantar, Miroslav; Gibbs, Patrick D L; Schmale, Michael C

    2007-02-01

    The zebrafish (Danio rerio) embryo has emerged as an important model of vertebrate development. As such, this model system is finding utility in the investigation of toxic agents that inhibit, or otherwise interfere with, developmental processes (i.e. developmental toxins), including compounds that have potential relevance to both human and environmental health, as well as biomedicine. Recently, this system has been applied increasingly to the study of microbial toxins, and more specifically, as an aquatic animal model, has been employed to investigate toxins from marine and freshwater microalgae, including those classified among the so-called "harmful algal blooms" (HABs). We have developed this system for identification and characterization of toxins from cyanobacteria (i.e. "blue-green algae") isolated from the Florida Everglades and other freshwater sources in South and Central Florida. Here we review the use of this system as it has been applied generally to the investigation of toxins from marine and freshwater microalgae, and illustrate this utility as we have applied it to the detection, bioassay-guided fractionation and subsequent characterization of developmental toxins from freshwater cyanobacteria. PMID:17020820

  16. Accumulation, biotransformation, histopathology and paralysis in the Pacific calico scallop Argopecten ventricosus by the paralyzing toxins of the dinoflagellate Gymnodinium catenatum.

    Science.gov (United States)

    Escobedo-Lozano, Amada Y; Estrada, Norma; Ascencio, Felipe; Contreras, Gerardo; Alonso-Rodriguez, Rosalba

    2012-05-01

    The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2); after hydrolysis, the carbamate toxins (epimers GTX2/3) were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment.

  17. Accumulation, Biotransformation, Histopathology and Paralysis in the Pacific Calico Scallop Argopecten ventricosus by the Paralyzing Toxins of the Dinoflagellate Gymnodinium catenatum

    Science.gov (United States)

    Escobedo-Lozano, Amada Y.; Estrada, Norma; Ascencio, Felipe; Contreras, Gerardo; Alonso-Rodriguez, Rosalba

    2012-01-01

    The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2); after hydrolysis, the carbamate toxins (epimers GTX2/3) were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment. PMID:22822356

  18. Immunological cross-reactivity in the absence of DNA homology between Pseudomonas toxin A and diphtheria toxin.

    OpenAIRE

    Sadoff, J C; Buck, G A; Iglewski, B H; Bjorn, M J; Groman, N B

    1982-01-01

    The immunodominant determinant of Pseudomonas toxin A was shown to cross-react with a normally inaccessible determinant in fragment A of diphtheria toxin. Trypsin-treated diphtheria toxin and fragment A of diphtheria toxin inhibited binding of toxin A antibody to whole toxin A, whereas whole diphtheria toxin did not inhibit this reaction. However, even at the lowest stringency no hybridization was detected between diphtheria tox probe and Pseudomonas aeruginosa DNA.

  19. Development of a toxicity model for paralytic shellfish toxins in mussel: uptake and release of toxins in Green Bay mussel

    International Nuclear Information System (INIS)

    In view of the expressed need to study shellfish toxicity and elucidate the kinetics of saxitoxin in green mussels Perna viridis), uptake/depuration rates of saxitoxin were studied in Juag Lagoon, Sorsogon and Sorsogon Bay. Both areas experience recurring blooms of Pyrodinium bahamanse var compressum (PbC) making them excellent study sites. Two sampling stations were selected, to which, mussels were introduced. Algal cell density and mussel toxicity were measured by receptor binding assay (RBA) and high performance liquid chromatography (HPLC) from May to December 2007. During this period, two bloom events occurred, wherein, a decrease in cell density by two orders of magnitude (30,000 to 600 cells·1+1) caused an order of magnitude decrease in toxicity (600 to 30 μg STX eq./100 g shellfish meat). A time lag between peaks of cell density and the corresponding toxicity was revealed. Vegetative cells were present throughout the sampling period, and a uniform horizontal and vertical distribution of cells was observed between the stations. Cell densities were significantly correlated with both RBA and HPLC estimates of STX content in mussels (Pearson r values of 0.7486 and 0.4325 for RBA and HPLC, respectively). In Sorsogon Bay, six sampling stations were also chosen, from which, water and mussels were being collected. Preliminary data showed that the cellular toxin content was primarily STX, making up to 90-100% of total toxin quantified. The average toxicity was estimated at 52.81fmol/cell. The effect of physiological factors to overall shellfish toxicity, though not directly characterized, may be deduced from these studies. (author)

  20. Exfoliative Toxins of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michal Bukowski

    2010-05-01

    Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  1. Evaluation of attached periphytical algal communities for biofuel feedstock generation

    Energy Technology Data Exchange (ETDEWEB)

    Sandefur, H.N.; Matlock, M.D.; Costello, T.A. [Arkansas Univ., Division of Agriculture, Fayetteville, AR (United States). Dept. of Biological and Agricultural Engineering, Center for Agricultural and Rural Sustainability

    2010-07-01

    This paper reported on a study that investigated the feasibility of using algal biomass as a feedstock for biofuel production. Algae has a high lipid content, and with its high rate of production, it can produce more oil on less land than traditional bioenergy crops. In addition, algal communities can remove nutrients from wastewater. Enclosed photobioreactors and open pond systems are among the many different algal growth systems that can be highly productive. However, they can also be difficult to maintain. The objective of this study was to demonstrate the ability of a pilot scale algal turf scrubber (ATS) to facilitate the growth of attached periphytic algal communities for the production of biomass feedstock and the removal of nutrients from a local stream in Springdale, Arizona. The ATS operated for a 9 month sampling period, during which time the system productivity averaged 26 g per m{sup 2} per day. The removal of total phosphorus and total nitrogen averaged 48 and 13 per cent, respectively.

  2. Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

    Directory of Open Access Journals (Sweden)

    Colin M. Beal

    2012-06-01

    Full Text Available Worldwide, algal biofuel research and development efforts have focused on increasing the competitiveness of algal biofuels by increasing the energy and financial return on investments, reducing water intensity and resource requirements, and increasing algal productivity. In this study, analyses are presented in each of these areas—costs, resource needs, and productivity—for two cases: (1 an Experimental Case, using mostly measured data for a lab-scale system, and (2 a theorized Highly Productive Case that represents an optimized commercial-scale production system, albeit one that relies on full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein concludes that the energy and financial return on investments are less than 1, the water intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption (e.g., nitrogen. The analysis and presentation of results highlight critical areas for advancement and innovation that must occur for sustainable and profitable algal biofuel production can occur at a scale that yields significant petroleum displacement. To this end, targets for energy consumption, production cost, water consumption, and nutrient consumption are presented that would promote sustainable algal biofuel production. Furthermore, this work demonstrates a procedure and method by which subsequent advances in technology and biotechnology can be framed to track progress.

  3. Botulinum Toxin in Pediatric Neurology

    OpenAIRE

    Moawad, Eman M. I.; Abdallah, Enas Abdallah Ali

    2015-01-01

    Botulinum neurotoxins are natural molecules produced by anaerobic spore-forming bacteria called Clostradium boltulinum. The toxin has a peculiar mechanism of action by preventing the release of acetylcholine from the presynaptic membrane. Consequently, it has been used in the treatment of various neurological conditions related to muscle hyperactivity and/or spasticity. Also, it has an impact on the autonomic nervous system by acting on smooth muscle, leading to its use in the management of p...

  4. Common European harmful algal blooms affect the viability and innate immune responses of Mytilus edulis larvae.

    Science.gov (United States)

    De Rijcke, M; Vandegehuchte, M B; Vanden Bussche, J; Nevejan, N; Vanhaecke, L; De Schamphelaere, K A C; Janssen, C R

    2015-11-01

    Like marine diseases, harmful algal blooms (HABs) are globally increasing in frequency, severity and geographical scale. As a result, bivalves will have to face the combined threat of toxic algae and marine pathogens more frequently in the (near) future. These stressors combined may further affect the recruitment of ecologically and economically important bivalve species as HABs can affect the growth, viability and development of their larvae. To date, little is known on the specific effects of HABs on the innate immune system of bivalve larvae. This study therefore investigates whether two common harmful algae can influence the larval viability, development and immunological resilience of the blue mussel Mytilus edulis. Embryos of this model organism were exposed (48 h) to five densities of Pseudo-nitzschia multiseries or Prorocentrum lima cells. In addition, the effect of six concentrations of their respective toxins: domoic acid (DA) and okadaic acid (OA) were assessed. OA was found to significantly reduce larval protein phosphatase activity (p < 0.001) and larval viability (p < 0.01) at concentrations as low as 37.8 μg l(-1). P. multiseries (1400 cells ml(-1)), P. lima (150 cells ml(-1)) and DA (dosed five times higher than typical environmental conditions i.e. 623.2 μg l(-1)) increased the phenoloxidase (PO) innate immune activity of the mussel larvae. These results suggest that the innate immune response of even the earliest life stages of bivalves is susceptible to the presence of HABs. PMID:26348409

  5. Future increase in harmful algal blooms in the North Sea due to climate change.

    Science.gov (United States)

    Peperzak, L

    2005-01-01

    In temperate seas such as the North Sea harmful (toxic) algal blooms will probably increase as a result of climate change. This conclusion was reached after investigating the projected effect of climate change for the year 2100 in Dutch coastal waters (4 degrees C temperature rise and increased water column stratification) on the growth rates of six harmful and two non-harmful phytoplankton species. Micro algae form the basis of the marine food chain. However, toxin-producing species may seriously disrupt the food web and lead to fish kills and human intoxication. Two species with estimated doubled growth rates in 2100, F. japonica and C. antiqua, entered Europe via ship's ballast water or shellfish imports. This stresses the need to legally regulate such invasion routes in order to prevent the import of novel species. Future toxic phytoplankton blooms may further devaluate ecosystem deliverables such as fish production or recreational use. This devaluation can be estimated by monetary value assessments that are needed in cost-benefit analyses for policy guidance. The lack of understanding of future climate, ecosystem functioning and its response to climate change calls for a scientific effort to improve our knowledge on present day coastal ecosystem functioning and its resilience. PMID:15918356

  6. Common European harmful algal blooms affect the viability and innate immune responses of Mytilus edulis larvae.

    Science.gov (United States)

    De Rijcke, M; Vandegehuchte, M B; Vanden Bussche, J; Nevejan, N; Vanhaecke, L; De Schamphelaere, K A C; Janssen, C R

    2015-11-01

    Like marine diseases, harmful algal blooms (HABs) are globally increasing in frequency, severity and geographical scale. As a result, bivalves will have to face the combined threat of toxic algae and marine pathogens more frequently in the (near) future. These stressors combined may further affect the recruitment of ecologically and economically important bivalve species as HABs can affect the growth, viability and development of their larvae. To date, little is known on the specific effects of HABs on the innate immune system of bivalve larvae. This study therefore investigates whether two common harmful algae can influence the larval viability, development and immunological resilience of the blue mussel Mytilus edulis. Embryos of this model organism were exposed (48 h) to five densities of Pseudo-nitzschia multiseries or Prorocentrum lima cells. In addition, the effect of six concentrations of their respective toxins: domoic acid (DA) and okadaic acid (OA) were assessed. OA was found to significantly reduce larval protein phosphatase activity (p larval viability (p < 0.01) at concentrations as low as 37.8 μg l(-1). P. multiseries (1400 cells ml(-1)), P. lima (150 cells ml(-1)) and DA (dosed five times higher than typical environmental conditions i.e. 623.2 μg l(-1)) increased the phenoloxidase (PO) innate immune activity of the mussel larvae. These results suggest that the innate immune response of even the earliest life stages of bivalves is susceptible to the presence of HABs.

  7. Approaches to monitoring, control and management of harmful algal blooms (HABs).

    Science.gov (United States)

    Anderson, Donald M

    2009-07-01

    Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called "red tides"). These phenomena are caused by blooms of microscopic algae. Some of these algae are toxic, and can lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life, typically as a result of the transfer of toxins through the food web. Sometimes the direct release of toxic compounds can be lethal to marine animals. Non-toxic HABs cause damage to ecosystems, fisheries resources, and recreational facilities, often due to the sheer biomass of the accumulated algae. The term "HAB" also applies to non-toxic blooms of macroalgae (seaweeds), which can cause major ecological impacts such as the displacement of indigenous species, habitat alteration and oxygen depletion in bottom waters.Globally, the nature of the HAB problem has changed considerably over the last several decades. The number of toxic blooms, the resulting economic losses, the types of resources affected, and the number of toxins and toxic species have all increased dramatically. Some of this expansion has been attributed to storms, currents and other natural phenomena, but human activities are also frequently implicated. Humans have contributed by transporting toxic species in ballast water, and by adding massive and increasing quantities of industrial, agricultural and sewage effluents to coastal waters. In many urbanized coastal regions, these inputs have altered the size and composition of the nutrient pool which has, in turn, created a more favorable nutrient environment for certain HAB species. The steady expansion in the use of fertilizers for agricultural production represents a large and worrisome source of nutrients in coastal waters that promote some HABs.The diversity in HAB species and their impacts presents a significant challenge to those responsible for the management of coastal resources. Furthermore, HABs are complex oceanographic phenomena that

  8. Nutritional and environmental properties of algal products used in healthy diet by INAA and ICP-AES

    International Nuclear Information System (INIS)

    Spirulina platensis alga sampled in the Caribbean Sea and seven other commercial algal products available on the Italian market of different origin and aspect, have been analyzed by instrumental neutron activation analysis (INAA) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). By neutron irradiation and γ-ray spectrometry (INAA), as many as 20 elements could be measured instrumentally without any chemical treatment. Cu, Mg, Mn and Pb were determined after dissolution of the sample by ICP-AES. The cross-checking of the data, specifically by comparing those of Ca, Cr, Fe and Zn, obtained by the two techniques was found to be in good agreement. Special attention from analytical and nutritional point of view has been devoted to the toxic metals. The measurements have been carried out employing the reference algal material prepared by International Atomic Energy Agency (IAEA). (author)

  9. Formation of a Volunteer Harmful Algal Bloom Network in British Columbia, Canada, Following an Outbreak of Diarrhetic Shellfish Poisoning

    Directory of Open Access Journals (Sweden)

    Nicola Haigh

    2013-10-01

    Full Text Available Evidence for shellfish toxin illness in British Columbia (BC on the west coast of Canada can be traced back to 1793. For over two hundred years, domestically acquired bivalve shellfish toxin illnesses in BC were solely ascribed to paralytic shellfish poisonings caused by algal blooms of Alexandrium. This changed in 2011, when BC experienced its first outbreak of diarrhetic shellfish poisoning (DSP. As a result of this outbreak, Canada’s first DSP symposium was held in November, 2012, in North Vancouver, BC. Three of the objectives of the symposium were to provide a forum to educate key stakeholders on this emerging issue, to identify research and surveillance priorities and to create a DSP network. The purpose of this paper is to review what is known about shellfish poisoning in BC and to describe a novel volunteer network that arose following the symposium. The newly formed network was designed for industry shellfish growers to identify harmful algae bloom events, so that they may take actions to mitigate the effects of harmful blooms on shellfish morbidity. The network will also inform public health and regulatory stakeholders of potentially emerging issues in shellfish growing areas.

  10. Algal blooms: an emerging threat to seawater reverse osmosis desalination

    KAUST Repository

    Villacorte, Loreen O.

    2014-08-04

    Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  11. Consortium for Algal Biofuel Commercialization (CAB-COMM) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mayfield, Stephen P. [Univ. of California, San Diego, CA (United States)

    2015-12-04

    The Consortium for Algal Biofuel Commercialization (CAB-Comm) was established in 2010 to conduct research to enable commercial viability of alternative liquid fuels produced from algal biomass. The main objective of CAB-Comm was to dramatically improve the viability of algae as a source of liquid fuels to meet US energy needs, by addressing several significant barriers to economic viability. To achieve this goal, CAB-Comm took a diverse set of approaches on three key aspects of the algal biofuels value chain: crop protection; nutrient utilization and recycling; and the development of genetic tools. These projects have been undertaken as collaboration between six academic institutions and two industrial partners: University of California, San Diego; Scripps Institution of Oceanography; University of Nebraska, Lincoln; Rutgers University; University of California, Davis; Johns Hopkins University; Sapphire Energy; and Life Technologies.

  12. Bacterial protein toxins in human cancers.

    Science.gov (United States)

    Rosadi, Francesca; Fiorentini, Carla; Fabbri, Alessia

    2016-02-01

    Many bacteria causing persistent infections produce toxins whose mechanisms of action indicate that they could have a role in carcinogenesis. Some toxins, like CDT and colibactin, directly attack the genome by damaging DNA whereas others, as for example CNF1, CagA and BFT, impinge on key eukaryotic processes, such as cellular signalling and cell death. These bacterial toxins, together with other less known toxins, mimic carcinogens and tumour promoters. The aim of this review is to fulfil an up-to-date analysis of toxins with carcinogenic potential that have been already correlated to human cancers. Bacterial toxins-induced carcinogenesis represents an emerging aspect in bacteriology, and its significance is increasingly recognized.

  13. Bt Toxin Modification for Enhanced Efficacy

    Directory of Open Access Journals (Sweden)

    Benjamin R. Deist

    2014-10-01

    Full Text Available Insect-specific toxins derived from Bacillus thuringiensis (Bt provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry and cytolytic (Cyt toxins. These strategies include toxin truncation, modification of protease cleavage sites, domain swapping, site-directed mutagenesis, peptide addition, and phage display screens for mutated toxins with enhanced activity. Toxin optimization provides a useful approach to extend the utility of these proteins for suppression of pests that exhibit low susceptibility to native Bt toxins, and to overcome field resistance.

  14. Numerical Mesocosm Experimental Study on Harmful Algal Blooms of Two Algal Species in the East China Sea

    Directory of Open Access Journals (Sweden)

    Liangsheng Zhu

    2015-01-01

    Full Text Available From the results of algal culture and mesocosm experiments, a numerical mesocosm experiment is designed that accounts for the effect of the marine environment (sea currents, nutrient levels, and temperature on the harmful algal bloom (HAB processes of Skeletonema costatum and Prorocentrum donghaiense, two of the most frequent HAB-associated species in the East China Sea. Physical and ecological environment of the waters is simulated numerically by applying a hydrodynamic-ecological-one-way-coupled marine culture box model, which is semienclosed. The algal growth rate is digitalized by a temperature-factor-optimization Droop equation. A 90-mode-day numerical mesocosm experiment for the above two species is conducted. The species were found to alternately trigger algal blooms in the experimental waters, replicating the population succession phenomenon observed in the field and confirming that the two HAB species compete for nutrients. Deductively, the numerical result shows that both the Taiwan Warm Current and the eutrophication in the adjacent water of the Yangtze River Estuary contribute to the northward movement of algal concentration centers during HAB and also suggests that the lack of nutritious supplements in the open sea limits HAB occurrences in coastal waters.

  15. Toxin production in Dinophysis and the fate of these toxins in marine mussels

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor

    Diarrhetic shellfish poisoning (DSP) poses a considerable threat to food safety and to the economy of shellfish fishers and farmers in many parts of the world. Thousands of DSP intoxications have been reported, and bivalve harvesting can sometimes be closed down several months in a row. The toxins....... acuta. I grew the two species in laboratory cultures at different irradiances (7-130 μmol photons m-2 s-1) and with different food availability. The results showed that irradiance had no effects on toxin profiles, and only limited effects of the cellular toxin contents. Rather, toxin production rates...... followed growth rates, thus giving stable toxin contents. Food availability also did not change the toxin profiles of either species, but starvation did increase the cellular contents of each of the toxins present. The observation that toxin production continued for several weeks after the ciliate food...

  16. Small herbivores suppress algal accumulation on Agatti atoll, Indian Ocean

    Science.gov (United States)

    Cernohorsky, Nicole H.; McClanahan, Timothy R.; Babu, Idrees; Horsák, Michal

    2015-12-01

    Despite large herbivorous fish being generally accepted as the main group responsible for preventing algal accumulation on coral reefs, few studies have experimentally examined the relative importance of herbivore size on algal communities. This study used exclusion cages with two different mesh sizes (1 × 1 cm and 6 × 6 cm) to investigate the impact of different-sized herbivores on algal accumulation rates on the shallow (herbivores, which had rapid and lasting effects on the benthic communities, and, after 127 d of deployment, there was a visible and significant increase in algae (mainly macroalgae) with algal volume being 13 times greater than in adjacent open areas. The coarse-mesh cages excluded larger fishes (>8 cm body depth) while allowing smaller fishes to access the plots. In contrast to the conclusions of most previous studies, the exclusion of large herbivores had no significant effect on the accumulation of benthic algae and the amount of algae present within the coarse-mesh cages was relatively consistent throughout the experimental period (around 50 % coverage and 1-2 mm height). The difference in algal accumulation between the fine-mesh and coarse-mesh cages appears to be related to the actions of small individuals from 12 herbivorous fish species (0.17 ind. m-2 and 7.7 g m-2) that were able to enter through the coarse mesh. Although restricted to a single habitat, these results suggest that when present in sufficient densities and diversity, small herbivorous fishes can prevent the accumulation of algal biomass on coral reefs.

  17. Cementing mechanism of algal crusts from desert area

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    34-, 17-, 4-, 1.5-year old natural algal crusts were collected from Shapotou Scientific Station of the Chinese Academy of Sciences, 40-day old field and greenhouse artificial algal crusts were in situ developed in the same sandy soil and the same place (37°27′N, 104°57′E). Their different cohesions both against wind force and pressure were measured respectively by a sandy wind-tunnel experiment and a penetrometer. On the basis of these algal crusts, the cementing mechanism was revealed from many subjects and different levels. The results showed that in the indoor artificial crusts with the weakest cohesion bunchy algal filaments were distributed in the surface of the crusts, produced few extracellular polymers (EPS), the binding capacity of the crusts just accomplished by mechanical bundle of algal filaments. For field crusts, most filaments grew toward the deeper layers of algal crusts, secreted much more EPS, and when organic matter content was more than 2.4 times of chlorophyll a, overmuch organic matter (primarily is EPS) began to gather onto the surface of the crusts and formed an organic layer in the relatively lower micro-area, and this made the crust cohesion increase 2.5 times. When the organic layer adsorbed and intercepted amounts of dusts, soil particles and sand grains scattered down from wind, it changed gradually into an inorganic layer in which inorganic matter dominated, and this made the crusts cohesion further enhanced 2-6 times. For crust-building species Microcoleus vaginatus, 88.5% of EPS were the acidic components, 78% were the acidic proteglycan of 380 kD. The uronic acid content accounted for 8% of proteglycan, and their free carboxyls were important sites of binding with metal cations from surrounding matrix.

  18. Physical Hydrography and Algal Bloom Transport in Hong Kong Waters

    Institute of Scientific and Technical Information of China (English)

    KUANG Cui-ping; LEE Joseph H.W.

    2005-01-01

    In sub-tropical coastal waters around Hong Kong, algal blooms and red tides are usually first sighted in the Mirs Bay, in the eastern waters of Hong Kong. A calibrated three-dimensional hydrodynamic model for the Pearl River Estuary (Delft3D) has been applied to the study of the physical hydrography of Hong Kong waters and its relationship with algal bloom transport patterns in the dry and wet seasons. The general 3D hydrodynamic circulation and salinity structure in the partially-mixed estuary are presented. Extensive numerical surface drogue tracking experiments are performed for algal blooms that are initiated in the Mirs Bay under different seasonal, wind and tidal conditions. The probability of bloom impact on the Victoria Harbour and nearby urban coastal waters is estimated. The computations show that: I) In the wet season (May~August), algal blooms initiated in the Mirs Bay will move in a clockwise direction out of the bay, and be transported away from Hong Kong due to SW monsoon winds which drive the SW to NE coastal current; ii) In the dry season (November~April), algal blooms initiated in the northeast Mirs Bay will move in an anti-clockwise direction and be carried away into southern waters due to the NE to SW coastal current driven by the NE monsoon winds; the bloom typically flows past the east edge of the Victoria Harbour and nearby waters. Finally, the role of hydrodynamic transport in an important episodic event - the spring 1998 massive red tide - is quantitatively examined. It is shown that the strong NE to E wind during late March to early April, coupled with the diurnal tide at the beginning of April, significantly increased the probability of bloom transport into the Port Shelter and East Lamma Channel, resulting in the massive fish kill. The results provide a basis for risk assessment of harmful algal bloom (HAB) impact on urban coastal waters around the Victoria Habour.

  19. Rho-modifying bacterial protein toxins.

    Science.gov (United States)

    Aktories, Klaus

    2015-12-01

    Rho proteins are targets of numerous bacterial protein toxins, which manipulate the GTP-binding proteins by covalent modifications, including ADP ribosylation, glycosylation, adenylylation, proteolytic cleavage and deamidation. Bacterial toxins are important virulence factors but are also potent and efficient pharmacological tools to study the physiological functions of their eukaryotic targets. Recent studies indicate that amazing variations exist in the molecular mechanisms by which toxins attack Rho proteins, which are discussed here.

  20. [Use of botulinum toxin in strabismus].

    Science.gov (United States)

    Wabbels, B

    2016-07-01

    Botulinum toxin can be a useful tool for treating acute sixth nerve palsy and excessive eye deviations due to unstable Graves' disease, when surgery is not yet possible. The diagnostic injection for estimation of possible postoperative double vision also makes sense. In convergence spasms, periocular botulinum toxin injections can be a therapeutic option. Botulinum toxin is not a first line option in infantile esotropia without binocularity or in adult horizontal strabismus. Side effects include ptosis and vertical deviations. PMID:27369733

  1. Application of Botulinum Toxin in Pain Management

    OpenAIRE

    Sim, Woo Seog

    2011-01-01

    Botulinum toxin has been used for the treatment of many clinical disorders by producing temporary skeletal muscle relaxation. In pain management, botulinum toxin has demonstrated an analgesic effect by reducing muscular hyperactivity, but recent studies suggest this neurotoxin could have direct analgesic mechanisms different from its neuromuscular actions. At the moment, botulinum toxin is widely investigated and used in many painful diseases such as myofascial syndrome, headaches, arthritis,...

  2. Anthrax lethal toxin suppresses murine cardiomyocyte contractile function and intracellular Ca2+ handling via a NADPH oxidase-dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Machender R Kandadi

    Full Text Available OBJECTIVES: Anthrax infection is associated with devastating cardiovascular sequelae, suggesting unfavorable cardiovascular effects of toxins originated from Bacillus anthracis namely lethal and edema toxins. This study was designed to examine the direct effect of lethal toxins on cardiomyocyte contractile and intracellular Ca(2+ properties. METHODS: Murine cardiomyocyte contractile function and intracellular Ca(2+ handling were evaluated including peak shortening (PS, maximal velocity of shortening/ relengthening (± dL/dt, time-to-PS (TPS, time-to-90% relengthening (TR(90, intracellular Ca(2+ rise measured as fura-2 fluorescent intensity (ΔFFI, and intracellular Ca(2+ decay rate. Stress signaling and Ca(2+ regulatory proteins were assessed using Western blot analysis. RESULTS: In vitro exposure to a lethal toxin (0.05-50 nM elicited a concentration-dependent depression on cardiomyocyte contractile and intracellular Ca(2+ properties (PS, ± dL/dt, ΔFFI, along with prolonged duration of contraction and intracellular Ca(2+ decay, the effects of which were nullified by the NADPH oxidase inhibitor apocynin. The lethal toxin significantly enhanced superoxide production and cell death, which were reversed by apocynin. In vivo lethal toxin exposure exerted similar time-dependent cardiomyocyte mechanical and intracellular Ca(2+ responses. Stress signaling cascades including MEK1/2, p38, ERK and JNK were unaffected by in vitro lethal toxins whereas they were significantly altered by in vivo lethal toxins. Ca(2+ regulatory proteins SERCA2a and phospholamban were also differentially regulated by in vitro and in vivo lethal toxins. Autophagy was drastically triggered although ER stress was minimally affected following lethal toxin exposure. CONCLUSIONS: Our findings indicate that lethal toxins directly compromised murine cardiomyocyte contractile function and intracellular Ca(2+ through a NADPH oxidase-dependent mechanism.

  3. Synthesis and Biology of Cyclic Imine Toxins, An Emerging Class of Potent, Globally Distributed Marine Toxins

    OpenAIRE

    Stivala, Craig E.; Benoit, Evelyne; Araoz, Romulo; Servent, Denis; Novikov, Alexei; Molgó, Jordi; Zakarian, Armen

    2015-01-01

    From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulat...

  4. Protein Translocation by Bacterial Toxin Channels: A Comparison of Diphtheria Toxin and Colicin Ia

    OpenAIRE

    Wu, Zhengyan; Jakes, Karen S.; Samelson-Jones, Ben S.; Lai, Bing; Zhao, Gang; London, Erwin; Finkelstein, Alan

    2006-01-01

    Regions of both colicin Ia and diphtheria toxin N-terminal to the channel-forming domains can be translocated across planar phospholipid bilayer membranes. In this article we show that the translocation pathway of diphtheria toxin allows much larger molecules to be translocated than does the translocation pathway of colicin Ia. In particular, the folded A chain of diphtheria toxin is readily translocated by that toxin but is not translocated by colicin Ia. This difference cannot be attributed...

  5. Cholera toxin-like toxin released by Salmonella species in the presence of mitomycin C.

    OpenAIRE

    Molina, N C; Peterson, J. W.

    1980-01-01

    Several serotypes of Salmonella were shown to release increased amounts of a cholera toxin-like toxin during culture in vitro with mitomycin C (MTC). Filter-sterilized culture supernatants containing the toxin caused elongation of Chinese hamster ovary cells, which could be blocked by heating the supernatants at 100 degrees C for 15 min or by adding mixed gangliosides or monospecific cholera antitoxin. When MTC was not added to the Salmonella cultures, little or no toxin was detected in crude...

  6. Application of botulinum toxin in pain management.

    Science.gov (United States)

    Sim, Woo Seog

    2011-03-01

    Botulinum toxin has been used for the treatment of many clinical disorders by producing temporary skeletal muscle relaxation. In pain management, botulinum toxin has demonstrated an analgesic effect by reducing muscular hyperactivity, but recent studies suggest this neurotoxin could have direct analgesic mechanisms different from its neuromuscular actions. At the moment, botulinum toxin is widely investigated and used in many painful diseases such as myofascial syndrome, headaches, arthritis, and neuropathic pain. Further studies are needed to understand the exact analgesic mechanisms, efficacy and complications of botulinum toxin in chronic pain disorders.

  7. Characterization and Performance of Algal Biofilms for Wastewater Treatment and Industrial Applications

    OpenAIRE

    Kesaano, Maureen

    2015-01-01

    This study was carried out on algal biofilms grown using rotating algal biofilm reactors (RABRs) with the aim of: i) characterizing their growth in terms of photosynthetic activity and morphology ii) evaluating their performance as a wastewater treatment option and a feedstock for biofuels production, and iii) examining the algal-bacteria interactions. A review of algal biofilm technologies currently employed in wastewater treatment processes was made to compare nutrient removal efficienci...

  8. Microorganisms living on algae : An interesting reservoir of enzymes hydrolyzing algal biomass

    OpenAIRE

    Martin, Marjolaine; Biver, Sophie; Barbeyron, Tristan; Michel, Gurvan; Portetelle, Daniel; Vandenbol, Micheline

    2013-01-01

    Algal polysaccharides are increasingly used in food industry for their gelling properties and in pharmacology for their therapeutic properties. Furthermore, increasingly interest is taken on algae for their use in the production of biofuels and bioenergies. To purify algal polysaccharides and degrade algal biomass, specific microbial enzymes are needed. Microorganisms living on algae are an interesting source of those enzymes, as they are in constant interaction with algal biomass. The aim...

  9. Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism

    OpenAIRE

    Song, Xiaozhao; Kain, Wendy; Cassidy, Douglas; Wang, Ping

    2015-01-01

    The resistance to the Bacillus thuringiensis (Bt) toxin Cry2Ab in a greenhouse-originated Trichoplusia ni strain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in the T. ni strain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab in T. ni. From the dual-toxin-resistant T. ni strain, a strain resistant to Cry2Ab only was isolated,...

  10. Effects of algal hydrolysate as reaction medium on enzymatic hydrolysis of lignocelluloses

    Science.gov (United States)

    Algal biomass has been proposed as a source of lipids and sugars for biofuel productions. However, a substantial portion of potentially valuable algal material remains as a liquid hydrolysate after sugar and lipid extractions. This study examined the effects of an algal hydrolysate on the enzymatic...

  11. Summative Mass Analysis of Algal Biomass - Integration of Analytical Procedures: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, L. M. L.

    2013-12-01

    This procedure guides the integration of laboratory analytical procedures to measure algal biomass constituents in an unambiguous manner and ultimately achieve mass balance closure for algal biomass samples. Many of these methods build on years of research in algal biomass analysis.

  12. Designing Inhibitors of Anthrax Toxin

    Science.gov (United States)

    Nestorovich, Ekaterina M.; Bezrukov, Sergey M.

    2014-01-01

    Introduction Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates, and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded “for the development of multiscale models for complex chemical systems” once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial and error approach to a minimum. The “rational drug design” term is rather comprehensive as it includes all contemporary methods of drug discovery where serendipity and screening are substituted by the information-guided search for new and existing compounds. Successful implementation of these innovative drug discovery approaches is inevitably preceded by learning the physics, chemistry, and physiology of functioning of biological structures under normal and pathological conditions. Areas covered This article provides an overview of the recent rational drug design approaches to discover inhibitors of anthrax toxin. Some of the examples include small-molecule and peptide-based post-exposure therapeutic agents as well as several polyvalent compounds. The review also directs the reader to the vast literature on the recognized advances and future possibilities in the field. Expert opinion Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (PA-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, in our view, the situation is still insecure. The FDA’s animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Besides, unlike PA, which is known to be unstable, LF remains active in cells and in animal tissues for days. Therefore, the effectiveness of the post-exposure treatment of the individuals

  13. Surveillance guidelines for toxic algal species of Italian sea and lake waters; Indicazioni per il controllo delle specie algali tossiche delle acque marine e lacustri italiane: Studio delle coste e di un lago del Lazio: 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Milena; Congestri, Roberta; Buzzelli, Elena [Istituot Superiore di Sanita`, Rome (Italy). Lab. di Igiene Ambientale

    1997-09-01

    The health conditions of the coasts of the Rome district and of a large lake in the northern area of the Latium Region were examined to evaluate the toxic algal species, during a 14-month study carried on in cooperation with the Region and the local prevention units of the Region. The study shows the existence of a mesotrophic state in the coastal waters of the lake Bolsena, and a trophic level increased in last years, along the sea coasts of the Rome district. alga populations of genus Dinophysis, harmless to bathing activities, but able to contaminate the edible molluscs with toxins of the okadaic acid group, have been found. The technical occurrences of this study points out the operators`need of a taxonomic atlas, collecting all the toxic algal species known in the Mediterranean basin. This report includes a number of drawings of all the signaled species, each one followed by a fried schedule with the main taxonomic characteristics.

  14. Beneficial Effects of Marine Algal Compounds in Cosmeceuticals

    OpenAIRE

    Noel Vinay Thomas; Se-Kwon Kim

    2013-01-01

    The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors) have been discussed toward cosmeceutical application. In addition, atopic dermatitis an...

  15. Flagellar waveform dynamics of freely swimming algal cells

    NARCIS (Netherlands)

    Kurtuldu, H.; Tam, D.; Hosoi, A.E.; Johnson, K.A.; Gollub, J.P.

    2013-01-01

    We present quantitative measurements of time-dependent flagellar waveforms for freely swimming biflagellated algal cells, for both synchronous and asynchronous beating. We use the waveforms in conjunction with resistive force theory as well as a singularity method to predict a cell's time-dependent

  16. Export of algal biomass from the melting Arctic Sea ice

    NARCIS (Netherlands)

    Boetius, A.; Albrecht, S.; Bakker, K.; Bienhold, C.; Felden, J.; Fernández-Méndez, M.; Hendricks, S.; Katlein, C.; Lalande, C.; Krumpen, T.; Nicolaus, M.; Peeken, I.; Rabe, B.; Rogacheva, A.; Rybakova, E.; Somavilla, R.; Wenzhöfer, F.; Shipboard Science Party

    2013-01-01

    In the Arctic, under-ice primary production is limited to summer months and is restricted not only by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. Research Vessel Polarstern visited the ice-covered eastern-central

  17. Automatic identification of algal community from microscopic images.

    Science.gov (United States)

    Santhi, Natchimuthu; Pradeepa, Chinnaraj; Subashini, Parthasarathy; Kalaiselvi, Senthil

    2013-01-01

    A good understanding of the population dynamics of algal communities is crucial in several ecological and pollution studies of freshwater and oceanic systems. This paper reviews the subsequent introduction to the automatic identification of the algal communities using image processing techniques from microscope images. The diverse techniques of image preprocessing, segmentation, feature extraction and recognition are considered one by one and their parameters are summarized. Automatic identification and classification of algal community are very difficult due to various factors such as change in size and shape with climatic changes, various growth periods, and the presence of other microbes. Therefore, the significance, uniqueness, and various approaches are discussed and the analyses in image processing methods are evaluated. Algal identification and associated problems in water organisms have been projected as challenges in image processing application. Various image processing approaches based on textures, shapes, and an object boundary, as well as some segmentation methods like, edge detection and color segmentations, are highlighted. Finally, artificial neural networks and some machine learning algorithms were used to classify and identifying the algae. Further, some of the benefits and drawbacks of schemes are examined. PMID:24151424

  18. Autonomous benthic algal cultivator under feedback control of ecosystem metabolism

    Science.gov (United States)

    An autonomous and internally-controlled techno-ecological hybrid was developed that controls primary production of algae in a laboratory-scale cultivator. The technoecosystem is based on an algal turf scrubber (ATS) system that combines engineered feedback control programming with internal feedback...

  19. Algal response to nutrient enrichment in a forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romani, A.M.; Tornes, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  20. MARTX toxins as effector delivery platforms.

    Science.gov (United States)

    Gavin, Hannah E; Satchell, Karla J F

    2015-12-01

    Bacteria frequently manipulate their host environment via delivery of microbial 'effector' proteins to the cytosol of eukaryotic cells. In the case of the multifunctional autoprocessing repeats-in-toxins (MARTX) toxin, this phenomenon is accomplished by a single, >3500 amino acid polypeptide that carries information for secretion, translocation, autoprocessing and effector activity. MARTX toxins are secreted from bacteria by dedicated Type I secretion systems. The released MARTX toxins form pores in target eukaryotic cell membranes for the delivery of up to five cytopathic effectors, each of which disrupts a key cellular process. Targeted cellular processes include modulation or modification of small GTPases, manipulation of host cell signaling and disruption of cytoskeletal integrity. More recently, MARTX toxins have been shown to be capable of heterologous protein translocation. Found across multiple bacterial species and genera--frequently in pathogens lacking Type 3 or Type 4 secretion systems--MARTX toxins in multiple cases function as virulence factors. Innovative research at the intersection of toxin biology and bacterial genetics continues to elucidate the intricacies of the toxin as well as the cytotoxic mechanisms of its diverse effector collection.

  1. Target-Driven Evolution of Scorpion Toxins.

    Science.gov (United States)

    Zhang, Shangfei; Gao, Bin; Zhu, Shunyi

    2015-01-01

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact with two adjacent loops in the voltage-sensor domain (DIV) of sodium channels, as validated by our newly constructed computational model of toxin-channel complex. Despite the lack of positive selection signals in these two loops, they accumulated extensive sequence variations by relaxed purifying selection in prey and predators of scorpions. The evolutionary variability in the toxin-bound regions of sodium channels indicates that accelerated substitutions in the multigene family of scorpion toxins is a consequence of dealing with the target diversity. This work presents an example of atypical co-evolution between animal toxins and their molecular targets, in which toxins suffered from more prominent selective pressure from the channels of their competitors. Our discovery helps explain the evolutionary rationality of gene duplication of toxins in a specific venomous species. PMID:26444071

  2. Plant insecticidal toxins in ecological networks.

    Science.gov (United States)

    Ibanez, Sébastien; Gallet, Christiane; Després, Laurence

    2012-04-01

    Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects' vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  3. [Axillary hyperhidrosis, botulinium A toxin treatment: Review].

    Science.gov (United States)

    Clerico, C; Fernandez, J; Camuzard, O; Chignon-Sicard, B; Ihrai, T

    2016-02-01

    Injection of type A botulinum toxin in the armpits is a temporary treatment for axillary hyperhidrosis. This technique described in 1996 by Bushara et al., is known to be efficient and safe. The purpose of this article was to review the data concerning the treatment of axillary hyperhidrosis with botulinum toxin type A, and discuss the other treatment modalities for this socially disabling entity.

  4. The Ins and Outs of Anthrax Toxin.

    Science.gov (United States)

    Friebe, Sarah; van der Goot, F Gisou; Bürgi, Jérôme

    2016-03-01

    Anthrax is a severe, although rather rare, infectious disease that is caused by the Gram-positive, spore-forming bacterium Bacillus anthracis. The infectious form is the spore and the major virulence factors of the bacterium are its poly-γ-D-glutamic acid capsule and the tripartite anthrax toxin. The discovery of the anthrax toxin receptors in the early 2000s has allowed in-depth studies on the mechanisms of anthrax toxin cellular entry and translocation from the endocytic compartment to the cytoplasm. The toxin generally hijacks the endocytic pathway of CMG2 and TEM8, the two anthrax toxin receptors, in order to reach the endosomes. From there, the pore-forming subunit of the toxin inserts into endosomal membranes and enables translocation of the two catalytic subunits. Insertion of the pore-forming unit preferentially occurs in intraluminal vesicles rather than the limiting membrane of the endosome, leading to the translocation of the enzymatic subunits in the lumen of these vesicles. This has important consequences that will be discussed. Ultimately, the toxins reach the cytosol where they act on their respective targets. Target modification has severe consequences on cell behavior, in particular on cells of the immune system, allowing the spread of the bacterium, in severe cases leading to host death. Here we will review the literature on anthrax disease with a focus on the structure of the toxin, how it enters cells and its immunological effects. PMID:26978402

  5. Plant Insecticidal Toxins in Ecological Networks

    Directory of Open Access Journals (Sweden)

    Sébastien Ibanez

    2012-04-01

    Full Text Available Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects’ vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  6. Interplay between toxin transport and flotillin localization

    DEFF Research Database (Denmark)

    Pust, Sascha; Dyve, Anne Berit; Torgersen, Maria L;

    2010-01-01

    The flotillin proteins are localized in lipid domains at the plasma membrane as well as in intracellular compartments. In the present study, we examined the importance of flotillin-1 and flotillin-2 for the uptake and transport of the bacterial Shiga toxin (Stx) and the plant toxin ricin and we...... investigated whether toxin binding and uptake were associated with flotillin relocalization. We observed a toxin-induced redistribution of the flotillins, which seemed to be regulated in a p38-dependent manner. Our experiments provide no evidence for a changed endocytic uptake of Stx or ricin in cells silenced...... for flotillin-1 or -2. However, the Golgi-dependent sulfation of both toxins was significantly reduced in flotillin knockdown cells. Interestingly, when the transport of ricin to the ER was investigated, we obtained an increased mannosylation of ricin in flotillin-1 and flotillin-2 knockdown cells. The toxicity...

  7. Stealth and mimicry by deadly bacterial toxins

    DEFF Research Database (Denmark)

    Yates, S.P.; Jørgensen, Rene; Andersen, Gregers Rom;

    2006-01-01

    Diphtheria toxin and exotoxin A are well-characterized members of the ADP-ribosyltransferase toxin family that serve as virulence factors in the pathogenic bacteria, Corynebacterium diphtheriae and Pseudomonas aeruginosa.  New high-resolution structural data of the Michaelis complex...... of the Pseudomonas toxin with an NAD+ analogue and eukaryotic elongation factor 2 have provided new insights into the mechanism of inactivation of protein synthesis caused by these protein factors.  Concomitantly, rigorous steady-state and stopped flow kinetic analyses of the toxin-catalyzed reaction, in combination...... with inhibitor studies, has resulted in a quantum leap in our understanding of the mechanistic details of this deadly enzyme mechanism.  Furthermore, it is now apparent that these toxins use stealth and molecular mimicry in unleashing their toxic strategy within the infected host eukaryotic cell....

  8. Toxins and Secretion Systems of Photorhabdus luminescens

    Directory of Open Access Journals (Sweden)

    Athina Rodou

    2010-06-01

    Full Text Available Photorhabdus luminescens is a nematode-symbiotic, gram negative, bioluminescent bacterium, belonging to the family of Enterobacteriaceae.Recent studies show the importance of this bacterium as an alternative source of insecticides, as well as an emerging human pathogen. Various toxins have been identified and characterized in this bacterium. These toxins are classified into four major groups: the toxin complexes (Tcs, the Photorhabdus insect related (Pir proteins, the “makes caterpillars floppy” (Mcf toxins and the Photorhabdus virulence cassettes (PVC; the mechanisms however of toxin secretion are not fully elucidated. Using bioinformatics analysis and comparison against the components of known secretion systems, multiple copies of components of all known secretion systems, except the ones composing a type IV secretion system, were identified throughout the entire genome of the bacterium. This indicates that Photorhabdus luminescens has all the necessary means for the secretion of virulence factors, thus it is capable of establishing a microbial infection.

  9. Effectiveness of an anti-algal compound in eliminating an aquatic unicellular harmful algal Phaeocystis globosa

    Directory of Open Access Journals (Sweden)

    Huajun eZhang

    2016-04-01

    Full Text Available Phaeocystis globosa blooms can have negative effects on higher trophic levels in the marine ecosystem and consequently influence human activities. Strain KA22, identified as the bacterium Hahella, was isolated from coastal surface water and used to control P. globosa growth. A methanol extract from the bacteral cells showed strong algicidal activity. After purification, the compound showed a similar structure to prodigiosin when identified with Q-Exactive Orbitrap MS and nuclear magnetic resonance spectra. The compound showed algicidal activity against P. globosa with a 50% Lethal Dose (LD50 of 2.24 μg/mL. The prodigiosin was stable under heat and acid environment, and it could be degraded under alkaline environment and natural light condition. The growth rates of strain KA22 was fast in 2216E medium and the content of prodigiosin in this medium was more than 70 μg/mL after 16 h incubation. The compound showed particularly strong algicidal activity against Prorocentrum donghaiense, P. globosa and Heterosigma akashiwo, but having little effect on three other phytoplankton species tested. The results of our research could increase our knowledge on harmful algal bloom control compound and lead to further study on the mechanisms of the lysis effect on harmful algae.

  10. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems

    OpenAIRE

    Pierce, R. H.; Henry, M S

    2008-01-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent ...

  11. Botulinum toxin: yesterday, today, tomorrow

    Directory of Open Access Journals (Sweden)

    A. R. Artemenko

    2013-01-01

    Full Text Available Botulinum toxin (BoNT is a bacterial neurotoxin presented with seven serotypes that inhibit neurotransmitter release from nerve endings. The serotypes of BoNT are antigenically dissimilar, act via different, but interconnected mechanisms, and are not interchangeable. The activity of BoNT is associated with impaired neuroexocytosis occurring in several steps: from the binding of BoNT to its specific receptor on the axon terminal membrane to the proteolytic enzymatic cleavage of SNARE substrate. The effect of BoNT is considered to be restricted to the peripheral nervous system, but when given in particularly high doses, it has been recently shown to affect individual brain structures. In addition, by modulating peripheral afferentation, BoNT may influence the excitability of central neuronal structures at both spinal and cortical levels. Only BoNT serotypes A and B are used in clinical practice and aesthetic medicine. The type A has gained the widest acceptance as a therapeutic agent for more than 100 abnormalities manifesting themselves as muscular hyperactivity, hyperfunction of endocrine gland, and chronic pain. The effect of BoNT preparations shows itself 2-5 days after injection, lasts 3 months or more, and gradually decreases with as a result of pharmacokinetic and intracellular reparative processes. Biotechnology advances and potentialities allow purposefully modification of the protein molecular structure of BoNT, which expands the use and efficiency of performed therapy with neurotoxins. Recombinant technologies provide a combination of major therapeutic properties of each used BoNT serotype and expand indications for recombinant chimeric toxins.

  12. The Enterotoxicity of Clostridium difficile Toxins

    OpenAIRE

    Hanping Feng; Tor Savidge; Xingmin Sun

    2010-01-01

    The major virulence factors of Clostridium difficile infection (CDI) are two large exotoxins A (TcdA) and B (TcdB). However, our understanding of the specific roles of these toxins in CDI is still evolving. It is now accepted that both toxins are enterotoxic and proinflammatory in the human intestine. Both purified TcdA and TcdB are capable of inducing the pathophysiology of CDI, although most studies have focused on TcdA. C. difficile toxins exert a wide array of biological activities by act...

  13. Phenolic Content and Antioxidant Capacity in Algal Food Products

    Directory of Open Access Journals (Sweden)

    Ludmila Machu

    2015-01-01

    Full Text Available The study objective was to investigate total phenolic content using Folin-Ciocalteu’s method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida and red (Porphyra tenera, Palmaria palmata seaweed, green freshwater algae (Chlorella pyrenoidosa, and cyanobacteria (Spirulina platensis. HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g−1 GAE; 7.53 µmol AA·g−1, respectively. A linear relationship existed between ACW and phenolic contents (r = 0.99. Some algal products seem to be promising functional foods rich in polyphenols.

  14. Unraveling algal lipid metabolism: Recent advances in gene identification.

    Science.gov (United States)

    Khozin-Goldberg, Inna; Cohen, Zvi

    2011-01-01

    Microalgae are now the focus of intensive research due to their potential as a renewable feedstock for biodiesel. This research requires a thorough understanding of the biochemistry and genetics of these organisms' lipid-biosynthesis pathways. Genes encoding lipid-biosynthesis enzymes can now be identified in the genomes of various eukaryotic microalgae. However, an examination of the predicted proteins at the biochemical and molecular levels is mandatory to verify their function. The essential molecular and genetic tools are now available for a comprehensive characterization of genes coding for enzymes of the lipid-biosynthesis pathways in some algal species. This review mainly summarizes the novel information emerging from recently obtained algal gene identification. PMID:20709142

  15. A Taste of Algal Genomes from the Joint Genome Institute

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2012-06-17

    Algae play profound roles in aquatic food chains and the carbon cycle, can impose health and economic costs through toxic blooms, provide models for the study of symbiosis, photosynthesis, and eukaryotic evolution, and are candidate sources for bio-fuels; all of these research areas are part of the mission of DOE's Joint Genome Institute (JGI). To date JGI has sequenced, assembled, annotated, and released to the public the genomes of 18 species and strains of algae, sampling almost all of the major clades of photosynthetic eukaryotes. With more algal genomes currently undergoing analysis, JGI continues its commitment to driving forward basic and applied algal science. Among these ongoing projects are the pan-genome of the dominant coccolithophore Emiliania huxleyi, the interrelationships between the 4 genomes in the nucleomorph-containing Bigelowiella natans and Guillardia theta, and the search for symbiosis genes of lichens.

  16. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan; Biddy, Mary J.; Jones, Susanne B.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

  17. Retrograde transport of protein toxins through the Golgi apparatus

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; Skotland, Tore; van Deurs, Bo;

    2013-01-01

    A number of protein toxins from plants and bacteria take advantage of transport through the Golgi apparatus to gain entry into the cytosol where they exert their action. These toxins include the plant toxin ricin, the bacterial Shiga toxins, and cholera toxin. Such toxins bind to lipids or proteins...... at the cell surface, and they are endocytosed both by clathrin-dependent and clathrin-independent mechanisms. Sorting to the Golgi and retrograde transport to the endoplasmic reticulum (ER) are common to these toxins, but the exact mechanisms turn out to be toxin and cell-type dependent. In the ER......, the enzymatically active part is released and then transported into the cytosol, exploiting components of the ER-associated degradation system. In this review, we will discuss transport of different protein toxins, but we will focus on factors involved in entry and sorting of ricin and Shiga toxin into and through...

  18. Selective algicidal action of peptides against harmful algal bloom species.

    Directory of Open Access Journals (Sweden)

    Seong-Cheol Park

    Full Text Available Recently, harmful algal bloom (HAB, also termed "red tide", has been recognized as a serious problem in marine environments according to climate changes worldwide. Many novel materials or methods to prevent HAB have not yet been employed except for clay dispersion, in which can the resulting sedimentation on the seafloor can also cause alteration in marine ecology or secondary environmental pollution. In the current study, we investigated that antimicrobial peptide have a potential in controlling HAB without cytotoxicity to harmless marine organisms. Here, antimicrobial peptides are proposed as new algicidal compounds in combating HAB cells. HPA3 and HPA3NT3 peptides which exert potent antimicrobial activity via pore forming action in plasma membrane showed that HPA3NT3 reduced the motility of algal cells, disrupted their plasma membrane, and induced the efflux of intracellular components. Against raphidoflagellate such as Heterosigma akashiwo, Chattonella sp., and C. marina, it displayed a rapid lysing action in cell membranes at 1~4 µM within 2 min. Comparatively, its lysing effects occurred at 8 µM within 1 h in dinoflagellate such as Cochlodium polykrikoides, Prorocentrum micans, and P. minimum. Moreover, its lysing action induced the lysis of chloroplasts and loss of chlorophyll a. In the contrary, this peptide was not effective against Skeletonema costatum, harmless algal cell, even at 256 µM, moreover, it killed only H. akashiwo or C. marina in co-cultivation with S. costatum, indicating to its selective algicidal activity between harmful and harmless algal cells. The peptide was non-hemolytic against red blood cells of Sebastes schlegeli, the black rockfish, at 120 µM. HAB cells were quickly and selectively lysed following treatment of antimicrobial peptides without cytotoxicity to harmless marine organisms. Thus, the antibiotic peptides examined in our study appear to have much potential in effectively controlling HAB with minimal

  19. Four novel algal virus genomes discovered from Yellowstone Lake metagenomes

    OpenAIRE

    Weijia Zhang; Jinglie Zhou; Taigang Liu; Yongxin Yu; Yingjie Pan; Shuling Yan; Yongjie Wang

    2015-01-01

    Phycodnaviruses are algae-infecting large dsDNA viruses that are widely distributed in aquatic environments. Here, partial genomic sequences of four novel algal viruses were assembled from a Yellowstone Lake metagenomic data set. Genomic analyses revealed that three Yellowstone Lake phycodnaviruses (YSLPVs) had genome lengths of 178,262 bp, 171,045 bp, and 171,454 bp, respectively, and were phylogenetically closely related to prasinoviruses (Phycodnaviridae). The fourth (YSLGV), with a genome...

  20. Assessment of the sustainability of bioenergy production from algal feedstock

    OpenAIRE

    Aitken, Douglas

    2014-01-01

    Growing concerns regarding the impact of fossil fuel use upon the environment and the cost of production have led to a growth in the interest of obtaining energy from biomass. 1st and 2nd generation biomass types, however, are often criticised for their high energy requirements and environmental impacts. Algal biomass is considered a 3rd generation biomass which does not require arable land for cultivation, typically has a high productivity and can be converted to a wide variet...

  1. Selective algicidal action of peptides against harmful algal bloom species.

    Science.gov (United States)

    Park, Seong-Cheol; Lee, Jong-Kook; Kim, Si Wouk; Park, Yoonkyung

    2011-01-01

    Recently, harmful algal bloom (HAB), also termed "red tide", has been recognized as a serious problem in marine environments according to climate changes worldwide. Many novel materials or methods to prevent HAB have not yet been employed except for clay dispersion, in which can the resulting sedimentation on the seafloor can also cause alteration in marine ecology or secondary environmental pollution. In the current study, we investigated that antimicrobial peptide have a potential in controlling HAB without cytotoxicity to harmless marine organisms. Here, antimicrobial peptides are proposed as new algicidal compounds in combating HAB cells. HPA3 and HPA3NT3 peptides which exert potent antimicrobial activity via pore forming action in plasma membrane showed that HPA3NT3 reduced the motility of algal cells, disrupted their plasma membrane, and induced the efflux of intracellular components. Against raphidoflagellate such as Heterosigma akashiwo, Chattonella sp., and C. marina, it displayed a rapid lysing action in cell membranes at 1~4 µM within 2 min. Comparatively, its lysing effects occurred at 8 µM within 1 h in dinoflagellate such as Cochlodium polykrikoides, Prorocentrum micans, and P. minimum. Moreover, its lysing action induced the lysis of chloroplasts and loss of chlorophyll a. In the contrary, this peptide was not effective against Skeletonema costatum, harmless algal cell, even at 256 µM, moreover, it killed only H. akashiwo or C. marina in co-cultivation with S. costatum, indicating to its selective algicidal activity between harmful and harmless algal cells. The peptide was non-hemolytic against red blood cells of Sebastes schlegeli, the black rockfish, at 120 µM. HAB cells were quickly and selectively lysed following treatment of antimicrobial peptides without cytotoxicity to harmless marine organisms. Thus, the antibiotic peptides examined in our study appear to have much potential in effectively controlling HAB with minimal impact on marine

  2. Coastal engineering and Harmful Algal Blooms along Alexandria coast, Egypt

    Directory of Open Access Journals (Sweden)

    Amany A. Ismael

    2014-01-01

    The phytoplankton composition and its standing crop became totally different during the two periods. The most important bloom was caused by Micromonas pusilla forming a heavy green tide accompanied by a bloom of Peridinium quinquecorne. Although there were no fish or invertebrate mortality, this bloom caused economic losses to internal tourism. In the absence of any Environmental Assessment, the coastal engineering works increased the harmful algal blooms in Alexandria coastal waters, even after corrective steps were taken to mitigate the harmful effects.

  3. Functional screening of a metagenomic library from algal biofilms

    OpenAIRE

    Martin, Marjolaine,

    2013-01-01

    Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To extract, hydrolyze and purify this biomass, algae hydrolyzing enzymes are needed. Our work aims to identify and characterize algal biomass hydrolyzing enzymes expressed by microorganisms living on the surface of algae, by functional metagenomics. Therefore, a microbial DNA extraction me...

  4. Efficient algal bioassay based on short-term photosynthetic response

    International Nuclear Information System (INIS)

    A procedure is described for measuring the effects of toxicants on algal photosynthesis (carbon-14 bicarbonate (H14CO3)uptake) in 4-h experiments. The results for individual aromatic compounds and the water-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and the responses of some species were pH-dependent. With Selenastrum capricornutum as the test organism, the bioassay results were unaffected by variations in pH from 7.0 to 9.0, light intensity from 40 to 200 μeinsteins m-2 s-1, culture density up to 0.5 mg chlorophyll a per litre, and agitation up to 100 rpm. The photosynthesis bioassay is simpler and faster (4 h versus 4 to 14 days), uses smaller culture volumes, and requires less space than static culture-growth tests. One person can conveniently test four materials per day, and the entire procedure, including preparation, exposure, and analysis, takes less than two days. The short incubation time reduces bottle effects such as pH changes, accumulation of metabolic products, nutrient depletion, and bacterial growth. Processes that remove or alter the test materials are also minimized. The data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (seven-day) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects. 25 references, 6 figures, 1 table

  5. Algal biofuels: key issues, sustainability and life cycle assessment

    OpenAIRE

    Singh, Anoop; Olsen, Stig Irving

    2011-01-01

    In recent years research activities are intensively focused on renewable fuels in order to fulfill the increasing energy demand and to reduce the fossil fuels consumption and external oil dependency either in order to provide local energetic resources and or as a means for reducing greenhouse gases (GHG) emissions to reduce the climate change effects. Among the various renewable energy sources algal biofuels is a very promising source of biomass as algae sequester huge quantities of carbon fr...

  6. Binding and uptake of diphtheria toxin by toxin-resistant Chinese hamster ovary and mouse cells.

    OpenAIRE

    Didsbury, J R; Moehring, J M; Moehring, T. J.

    1983-01-01

    We investigated two phenotypically distinct types of diphtheria toxin-resistant mutants of Chinese hamster cells and compared their resistance with that of naturally resistant mouse cells. All are resistant due to a defect in the process of internalization and delivery of toxin to its target in the cytosol, elongation factor 2. By cell hybridization studies, analysis of cross-resistance, and determination of specific binding sites for 125I-labeled diphtheria toxin, we showed that these cell s...

  7. Identification of the Helicobacter pylori VacA Toxin Domain Active in the Cell Cytosol

    Science.gov (United States)

    de Bernard, Marina; Burroni, Daniela; Papini, Emanuele; Rappuoli, Rino; Telford, John; Montecucco, Cesare

    1998-01-01

    Cells exposed to Helicobacter pylori toxin VacA develop large vacuoles which originate from massive swelling of membranous compartments at late stages of the endocytic pathway. When expressed in the cytosol, VacA induces vacuolization as it does when added from outside. This and other evidence indicate that VacA is a toxin capable of entering the cell cytosol, where it displays its activity. In this study, we have used cytosolic expression to identify the portion of the toxin molecule responsible for the vacuolating activity. VacA mutants with deletions at the C and N termini were generated, and their activity was analyzed upon expression in HeLa cells. We found that the vacuolating activity of VacA resides in the amino-terminal region, the whole of which is required for its intracellular activity. PMID:9826387

  8. Monthly Ensembles in Algal Bloom Predictions on the Baltic Sea

    Science.gov (United States)

    Roiha, Petra; Westerlund, Antti; Stipa, Tapani

    2010-05-01

    In this work we explore the statistical features of monthly ensembles and their capability to predict biogeochemical conditions in the Baltic Sea. Operational marine environmental modelling has been considered hard, and consequently there are very few operational ecological models. Operational modelling of harmful algal blooms is harder still, since it is difficult to separate the algal species in models, and in general, very little is known of HAB properties. We present results of an ensemble approach to HAB forecasting in the Baltic, and discuss the applicability of the forecasting method to biochemical modelling. It turns out that HABs are indeed possible to forecast with useful accuracy. For modelling the algal blooms in Baltic Sea we used FMI operational 3-dimensional biogeochemical model to produce seasonal ensemble forecasts for different physical, chemical and biological variables. The modelled variables were temperature, salinity, velocity, silicate, phosphate, nitrate, diatoms, flagellates and two species of potentially toxic filamentous cyanobacteria nodularia spumigena and aphanizomenon flos-aquae. In this work we concentrate to the latter two. Ensembles were produced by running the biogeochemical model several times and forcing it on every run with different set of seasonal weather parameters from ECMWF's mathematically perturbed ensemble prediction forecasts. The ensembles were then analysed by statistical methods and the median, quartiles, minimum and maximum values were calculated for estimating the probable amounts of algae. Validation for the forecast method was made by comparing the final results against available and valid in-situ HAB data.

  9. Variations of algal communities cause darkening of a Greenland glacier.

    Science.gov (United States)

    Lutz, Stefanie; Anesio, Alexandre M; Jorge Villar, Susana E; Benning, Liane G

    2014-08-01

    We have assessed the microbial ecology on the surface of Mittivakkat glacier in SE-Greenland during the exceptional high melting season in July 2012 when the so far most extreme melting rate for the Greenland Ice Sheet has been recorded. By employing a complementary and multi-disciplinary field sampling and analytical approach, we quantified the dramatic changes in the different microbial surface habitats (green snow, red snow, biofilms, grey ice, cryoconite holes). The observed clear change in dominant algal community and their rapidly changing cryo-organic adaptation inventory was linked to the high melting rate. The changes in carbon and nutrient fluxes between different microbial pools (from snow to ice, cryoconite holes and glacial forefronts) revealed that snow and ice algae dominate the net primary production at the onset of melting, and that they have the potential to support the cryoconite hole communities as carbon and nutrient sources. A large proportion of algal cells is retained on the glacial surface and temporal and spatial changes in pigmentation contribute to the darkening of the snow and ice surfaces. This implies that the fast, melt-induced algal growth has a high albedo reduction potential, and this may lead to a positive feedback speeding up melting processes. PMID:24920320

  10. Micro-structured surfaces for algal biofilm growth

    Science.gov (United States)

    Sathananthan, Suthamathy; Genin, Scott N.; Aitchison, J. Stewart; Allen, D. Grant

    2013-12-01

    It is well known that cells respond to structured surface cues that are on the micro/nanometer scale. Tissue engineering and bio-fouling fields have utilized the semiconductor device fabrication processes to make micro- and nanometer patterned surfaces to study animal cell tissue formation and to prevent algae attachment on marine surfaces respectively. In this paper we describe the use of micro-structured surfaces to study the attachment and growth of algal films. This paper gives an overview of how micro-structured surfaces are made for this purpose, how they are incorporated into a photo bioreactor and how this patterning influences the growth of an algal biofilm. Our results suggest that surface patterning with deeper V-groove patterns that are of the same size scale as the algal species has resulted in higher biomass productivity giving them a chance to embed and attach on the slope and flat surfaces whereas shallower size grooves and completely flat surfaces did not show this trend.

  11. Variations of algal communities cause darkening of a Greenland glacier.

    Science.gov (United States)

    Lutz, Stefanie; Anesio, Alexandre M; Jorge Villar, Susana E; Benning, Liane G

    2014-08-01

    We have assessed the microbial ecology on the surface of Mittivakkat glacier in SE-Greenland during the exceptional high melting season in July 2012 when the so far most extreme melting rate for the Greenland Ice Sheet has been recorded. By employing a complementary and multi-disciplinary field sampling and analytical approach, we quantified the dramatic changes in the different microbial surface habitats (green snow, red snow, biofilms, grey ice, cryoconite holes). The observed clear change in dominant algal community and their rapidly changing cryo-organic adaptation inventory was linked to the high melting rate. The changes in carbon and nutrient fluxes between different microbial pools (from snow to ice, cryoconite holes and glacial forefronts) revealed that snow and ice algae dominate the net primary production at the onset of melting, and that they have the potential to support the cryoconite hole communities as carbon and nutrient sources. A large proportion of algal cells is retained on the glacial surface and temporal and spatial changes in pigmentation contribute to the darkening of the snow and ice surfaces. This implies that the fast, melt-induced algal growth has a high albedo reduction potential, and this may lead to a positive feedback speeding up melting processes.

  12. Analysis of the Bacillus cereus SpoIIS antitoxin-toxin system reveals its three-component nature.

    Science.gov (United States)

    Melničáková, Jana; Bečárová, Zuzana; Makroczyová, Jana; Barák, Imrich

    2015-01-01

    Programmed cell death in bacteria is generally associated with two-component toxin-antitoxin systems. The SpoIIS toxin-antitoxin system, consisting of a membrane-bound SpoIISA toxin and a small, cytosolic antitoxin SpoIISB, was originally identified in Bacillus subtilis. In this work we describe the Bacillus cereus SpoIIS system which is a three-component system, harboring an additional gene spoIISC. Its protein product serves as an antitoxin, and similarly as SpoIISB, is able to bind SpoIISA and abolish its toxic effect. Our results indicate that SpoIISC seems to be present not only in B. cereus but also in other Bacilli containing a SpoIIS toxin-antitoxin system. In addition, we show that B. cereus SpoIISA can form higher oligomers and we discuss the possible role of this multimerization for the protein's toxic function.

  13. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  14. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2015. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  15. Bacterial Toxins as Pathogen Weapons Against Phagocytes.

    Science.gov (United States)

    do Vale, Ana; Cabanes, Didier; Sousa, Sandra

    2016-01-01

    Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favor microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signaling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.

  16. Toxin Detection by Surface Plasmon Resonance

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available Significant efforts have been invested in the past years for the development of analytical methods for fast toxin detection in food and water. Immunochemical methods like ELISA, spectroscopy and chromatography are the most used in toxin detection. Different methods have been linked, e.g. liquid chromatography and mass spectrometry (LC-MS, in order to detect as low concentrations as possible. Surface plasmon resonance (SPR is one of the new biophysical methods which enables rapid toxin detection. Moreover, this method was already included in portable sensors for on-site determinations. In this paper we describe some of the most common methods for toxin detection, with an emphasis on SPR.

  17. Bacterial toxins as pathogen weapons against phagocytes

    Directory of Open Access Journals (Sweden)

    Ana edo Vale

    2016-02-01

    Full Text Available Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favour microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signalling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.

  18. [Botulinum toxin in disabling dermatological diseases].

    Science.gov (United States)

    Messikh, R; Atallah, L; Aubin, F; Humbert, P

    2009-05-01

    Botulinum toxin could represent nowadays a new treatment modality especially for cutaneous conditions in course of which conventional treatments remain unsuccessful. Besides palmar and plantar hyperhidrosis, botulinum toxin has demonstrated efficacy in different conditions associated with hyperhidrosis, such as dyshidrosis, multiple eccrine hidrocystomas, hidradenitis suppurativa, Frey syndrome, but also in different conditions worsened by hyperhidrosis such as Hailey-Hailey disease, Darier disease, inversed psoriasis, aquagenic palmoplantar keratoderma, pachyonychia congenital. Moreover, different cutaneous conditions associated with sensitive disorders and/or neurological involvements could benefit from botulinum toxin, for example anal fissures, leg ulcers, lichen simplex, notalgia paresthetica, vestibulitis. Endly, a case of cutis laxa was described where the patient was improved by cutaneous injections of botulinum toxin. PMID:19576479

  19. Marine Toxin Okadaic Acid Affects the Immune Function of Bay Scallop (Argopecten irradians).

    Science.gov (United States)

    Chi, Cheng; Giri, Sib Sankar; Jun, Jin Woo; Kim, Hyoun Joong; Yun, Saekil; Kim, Sang Guen; Park, Se Chang

    2016-01-01

    Okadaic acid (OA) is produced by dinoflagellates during harmful algal blooms and is a diarrhetic shellfish poisoning toxin. This toxin is particularly problematic for bivalves that are cultured for human consumption. This study aimed to reveal the effects of exposure to OA on the immune responses of bay scallop, Argopecten irradians. Various immunological parameters were assessed (total hemocyte counts (THC), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), and nitric oxide (NO) in the hemolymph of scallops at 3, 6, 12, 24, and 48 h post-exposure (hpe) to different concentrations of OA (50, 100, and 500 nM). Moreover, the expression of immune-system-related genes (CLT-6, FREP, HSP90, MT, and Cu/ZnSOD) was also measured. Results showed that ROS, MDA, and NO levels and LDH activity were enhanced after exposure to different concentrations of OA; however, both THC and GSH decreased between 24-48 hpe. The expression of immune-system-related genes was also assessed at different time points during the exposure period. Overall, our results suggest that exposure to OA had negative effects on immune system function, increased oxygenic stress, and disrupted metabolism of bay scallops. PMID:27563864

  20. Accumulation, Biotransformation, Histopathology and Paralysis in the Pacific Calico Scallop Argopecten ventricosus by the Paralyzing Toxins of the Dinoflagellate Gymnodinium catenatum

    Directory of Open Access Journals (Sweden)

    Rosalba Alonso-Rodriguez

    2012-05-01

    Full Text Available The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2; after hydrolysis, the carbamate toxins (epimers GTX2/3 were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment.

  1. Augmenting the Efficacy of Immunotoxins and Other Targeted Protein Toxins by Endosomal Escape Enhancers

    Directory of Open Access Journals (Sweden)

    Hendrik Fuchs

    2016-07-01

    Full Text Available The toxic moiety of almost all protein-based targeted toxins must enter the cytosol of the target cell to mediate its fatal effect. Although more than 500 targeted toxins have been investigated in the past decades, no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date. Missing efficacy can be attributed in many cases to insufficient endosomal escape and therefore subsequent lysosomal degradation of the endocytosed toxins. To overcome this drawback, many strategies have been described to weaken the membrane integrity of endosomes. This comprises the use of lysosomotropic amines, carboxylic ionophores, calcium channel antagonists, various cell-penetrating peptides of viral, bacterial, plant, animal, human and synthetic origin, other organic molecules and light-induced techniques. Although the efficacy of the targeted toxins was typically augmented in cell culture hundred or thousand fold, in exceptional cases more than million fold, the combination of several substances harbors new problems including additional side effects, loss of target specificity, difficulties to determine the therapeutic window and cell type-dependent variations. This review critically scrutinizes the chances and challenges of endosomal escape enhancers and their potential role in future developments.

  2. Augmenting the Efficacy of Immunotoxins and Other Targeted Protein Toxins by Endosomal Escape Enhancers.

    Science.gov (United States)

    Fuchs, Hendrik; Weng, Alexander; Gilabert-Oriol, Roger

    2016-01-01

    The toxic moiety of almost all protein-based targeted toxins must enter the cytosol of the target cell to mediate its fatal effect. Although more than 500 targeted toxins have been investigated in the past decades, no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date. Missing efficacy can be attributed in many cases to insufficient endosomal escape and therefore subsequent lysosomal degradation of the endocytosed toxins. To overcome this drawback, many strategies have been described to weaken the membrane integrity of endosomes. This comprises the use of lysosomotropic amines, carboxylic ionophores, calcium channel antagonists, various cell-penetrating peptides of viral, bacterial, plant, animal, human and synthetic origin, other organic molecules and light-induced techniques. Although the efficacy of the targeted toxins was typically augmented in cell culture hundred or thousand fold, in exceptional cases more than million fold, the combination of several substances harbors new problems including additional side effects, loss of target specificity, difficulties to determine the therapeutic window and cell type-dependent variations. This review critically scrutinizes the chances and challenges of endosomal escape enhancers and their potential role in future developments. PMID:27376327

  3. Updates on tetanus toxin: a fundamental approach

    Directory of Open Access Journals (Sweden)

    Md. Ahaduzzaman

    2015-03-01

    Full Text Available Clostridium tetani is an anaerobic bacterium that produces second most poisonous protein toxins than any other bacteria. Tetanus in animals is sporadic in nature but difficult to combat even by using antibiotics and antiserum. It is crucial to understand the fundamental mechanisms and signals that control toxin production for advance research and medicinal uses. This review was intended for better understanding the basic patho-physiology of tetanus and neurotoxins (TeNT among the audience of related field.

  4. Nanoanalysis of the arthropod neuro-toxins

    OpenAIRE

    Nakajima, Terumi

    2006-01-01

    Many kinds of venomous principles modulate physiological responses of mammalian signal transduction systems, on which they act selectively as enhancers, inhibitors or some other kind of effectors. These toxins become useful tools for physiological research. We have employed and characterized paralyzing toxins from the venom of spiders, insects and scorpions with a limited supply. We have developed rapid and sensitive mass spectrometric technology and applied for the identification of these to...

  5. Target-Driven Evolution of Scorpion Toxins

    OpenAIRE

    Shangfei Zhang; Bin Gao; Shunyi Zhu

    2015-01-01

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact wi...

  6. Botulinum toxin treatment of hemifacial spasm.

    OpenAIRE

    Elston, J S

    1986-01-01

    Six patients with hemifacial spasm were treated with injections of botulinum toxin A into the orbicularis oculi; the abnormal movements around the eye were relieved for an average of 15 weeks. There were no systemic or significant local side effects, and in view of the risks involved in neurosurgical treatment, a trial of botulinum toxin injections is recommended in the first instance in this condition.

  7. Toxicological Perspective on Climate Change: Aquatic Toxins.

    Science.gov (United States)

    Botana, Luis M

    2016-04-18

    In recent years, our group and several others have been describing the presence of new, not previously reported, toxins of high toxicity in vectors that may reach the human food chain. These include tetrodotoxin in gastropods in the South of Europe, ciguatoxin in fish in the South of Spain, palytoxin in mussels in the Mediterranean Sea, pinnatoxin all over Europe, and okadaic acid in the south of the U.S. There seem to be new marine toxins appearing in areas that are heavy producers of seafood, and this is a cause of concern as most of these new toxins are not included in current legislation and monitoring programs. Along with the new toxins, new chemical analogues are being reported. The same phenomenom is being recorded in freshwater toxins, such as the wide appearance of cylindrospermopsin and the large worldwide increase of microcystin. The problem that this phenomenon, which may be linked to climate warming, poses for toxicologists is very important not only because there is a lack of chronic studies and an incomplete comprehension of the mechanism driving the production of these toxins but also because the lack of a legal framework for them allows many of these toxins to reach the market. In some cases, it is very difficult to control these toxins because there are not enough standards available, they are not always certified, and there is an insufficient understanding of the toxic equivalency factors of the different analogues in each group. All of these factors have been revealed and grouped through the massive increase in the use of LC-MS as a monitoring tool, legally demanded, creating more toxicological problems. PMID:26958981

  8. Life-cycle analysis of energy use, greenhouse gas emissions, and water consumption in the 2016 MYPP algal biofuel scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Edward [Argonne National Lab. (ANL), Argonne, IL (United States); Pegallapati, Ambica K. [Argonne National Lab. (ANL), Argonne, IL (United States); Davis, Ryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Markham, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Coleman, Andre [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Sue [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wigmosta, Mark S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhu, Yunhua [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-16

    The Department of Energy (DOE) Bioenergy Technologies Office (BETO) Multi-year Program Plan (MYPP) describes the bioenergy objectives pursued by BETO, the strategies for achieving those objectives, the current state of technology (SOT), and a number of design cases that explore cost and operational performance required to advance the SOT towards middle and long term goals (MYPP, 2016). Two options for converting algae to biofuel intermediates were considered in the MYPP, namely algal biofuel production via lipid extraction and algal biofuel production by thermal processing. The first option, lipid extraction, is represented by the Combined Algae Processing (CAP) pathway in which algae are hydrolyzed in a weak acid pretreatment step. The treated slurry is fermented for ethanol production from sugars. The fermentation stillage contains most of the lipids from the original biomass, which are recovered through wet solvent extraction. The process residuals after lipid extraction, which contain much of the original mass of amino acids and proteins, are directed to anaerobic digestion (AD) for biogas production and recycle of N and P nutrients. The second option, thermal processing, comprises direct hydrothermal liquefaction (HTL) of the wet biomass, separation of aqueous, gas, and oil phases, and treatment of the aqueous phase with catalytic hydrothermal gasification (CHG) to produce biogas and to recover N and P nutrients. The present report describes a life cycle analysis of energy use and greenhouse gas (GHG) emissions of the CAP and HTL options for the three scenarios just described. Water use is also reported. Water use during algal biofuel production comes from evaporation during cultivation, discharge to bleed streams to control pond salinity (“blowdown”), and from use during preprocessing and upgrading. For scenarios considered to date, most water use was from evaporation and, secondarily, from bleed streams. Other use was relatively small at the level of

  9. Evaluating algal growth performance and water use efficiency of pilot-scale revolving algal biofilm (RAB) culture systems.

    Science.gov (United States)

    Gross, Martin; Mascarenhas, Vernon; Wen, Zhiyou

    2015-10-01

    A Revolving Algal Biofilm (RAB) growth system in which algal cells are attached to a flexible material rotating between liquid and gas phases has been developed. In this work, different configurations of RAB systems were developed at pilot-scale by retrofitting the attachment materials to a raceway pond (2000-L with 8.5 m(2) footprint area) and a trough reservoir (150 L with 3.5 m(2) footprint area). The algal growth performance and chemical composition, as well as the water evaporative loss and specific water consumption were evaluated over a period of nine months in a greenhouse environment near Boone, Iowa USA. Additionally a raceway pond was run in parallel, which served as a control. On average the raceway-based RAB and the trough-based RAB outperformed the control pond by 309% and 697%, respectively. A maximum productivity of 46.8 g m(-2) day(-1) was achieved on the trough-based RAB system. The evaporative water loss of the RAB system was modeled based on an energy balance analysis and was experimentally validated. While the RAB system, particularly the trough-based RAB, had higher water evaporative loss, the specific water consumption per unit of biomass produced was only 26% (raceway-based RAB) and 7% (trough-based RAB) of that of the control pond. Collectively, this research shows that the RAB system is an efficient algal culture system and has great potential to commercially produce microalgae with high productivity and efficient water use. PMID:25899246

  10. Algal remediation of CO₂ and nutrient discharges: A review.

    Science.gov (United States)

    Judd, Simon; van den Broeke, Leo J P; Shurair, Mohamed; Kuti, Yussuf; Znad, Hussein

    2015-12-15

    The recent literature pertaining to the application of algal photobioreactors (PBRs) to both carbon dioxide mitigation and nutrient abatement is reviewed and the reported data analysed. The review appraises the influence of key system parameters on performance with reference to (a) the absorption and biological fixation of CO2 from gaseous effluent streams, and (b) the removal of nutrients from wastewaters. Key parameters appraised individually with reference to CO2 removal comprise algal speciation, light intensity, mass transfer, gas and hydraulic residence time, pollutant (CO2 and nutrient) loading, biochemical and chemical stoichiometry (including pH), and temperature. Nutrient removal has been assessed with reference to hydraulic residence time and reactor configuration, along with C:nutrient ratios and other factors affecting carbon fixation, and outcomes compared with those reported for classical biological nutrient removal (BNR). Outcomes of the review indicate there has been a disproportionate increase in algal PBR research outputs over the past 5-8 years, with a significant number of studies based on small, bench-scale systems. The quantitative impacts of light intensity and loading on CO2 uptake are highly dependent on the algal species, and also affected by solution chemical conditions such as temperature and pH. Calculations based on available data for biomass growth rates indicate that a reactor CO2 residence time of around 4 h is required for significant CO2 removal. Nutrient removal data indicate residence times of 2-5 days are required for significant nutrient removal, compared with high rate algal pond, HRAP) means that its footprint is at least two orders of magnitude greater than a classical BNR plant. It is concluded that the combined carbon capture/nutrient removal process relies on optimisation of a number of process parameters acting synergistically, principally microalgal strain, C:N:P load and balance, CO2 and liquid residence time, light

  11. Toxin-Antitoxin Systems of Staphylococcus aureus.

    Science.gov (United States)

    Schuster, Christopher F; Bertram, Ralph

    2016-05-05

    Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.

  12. Dynamics of cyanobacteria and cyanobacterial toxins and their correlation with environmental parameters in Tri An Reservoir, Vietnam.

    Science.gov (United States)

    Dao, Thanh-Son; Nimptsch, Jorge; Wiegand, Claudia

    2016-08-01

    This study evaluates the water quality from Tri An Reservoir, a drinking water supply for several million people in southern Vietnam, in terms of cyanobacterial biomass and their potent toxins, microcystins (MCs). Cyanobacteria, their toxins and environmental parameters were monitored monthly for 1 year (April 2008-March 2009) at six stations covering a transect through the reservoir. Dynamics of cyanobacterial abundance in relation to cyanobacterial biomass, toxins and environmental factors were investigated. Environmental variables from Tri An Reservoir favored algal and cyanobacterial development. However, cyanobacterial biomass and proportion varied widely, influenced by physical conditions, available nutrients and nutrient competition among the phytoplankton groups. Cyanobacterial biomass correlated slightly positively to temperature, pH and biochemical oxygen demand (BOD5), but negatively to total inorganic nitrogen concentrations. During most of the sampling times, MC concentrations in the reservoir were quite low (≤0.07 μg L(-1) MC-LR equivalent), and presented a slight positive correlation to BOD5, total nitrogen:total phosphorus ratio and cyanobacterial biomass. However, in cyanobacterial scum samples, which now and then occurred in the reservoir, MC concentrations reached up to 640 μg g(-1) DW(-1). The occurrence of MC in the reservoir poses a risk to local residents who use the water daily for domestic purposes. PMID:27441865

  13. Wind-driven interannual variability of sea ice algal production over the western Arctic Chukchi Borderland

    Directory of Open Access Journals (Sweden)

    E. Watanabe

    2015-05-01

    Full Text Available Seasonal and interannual variability in sinking flux of biogenic particles was reported by the multi-year bottom-tethered sediment trap measurements in the Northwind Abyssal Plain (Station NAP: 75° N, 162° W, 1975 m water depth of the western Arctic Chukchi Borderland. Whereas the trapped particle flux had an obvious peak with the dominance of sea ice-related diatom valve in August 2011, the observed particle flux was considerably suppressed throughout the summer season in 2012. In the present study, response of ice algal production and biomass to wind-driven changes in physical environments was addressed using a pan-Arctic sea ice–ocean modeling approach. Sea ice ecosystem with ice algae was newly incorporated into the lower-trophic marine ecosystem model, which was previously coupled with a high-resolution (i.e., horizontal grid size of 5 km ocean general circulation model. Seasonal experiments covering two year-long mooring periods indicated that primary productivity of ice algae around the Chukchi Borderland depended on basin-scale wind pattern through various processes. Easterly wind in the southern part of distinct Beaufort High supplied high abundance of nutrient for euphotic zones of the NAP region via both surface Ekman transport of Chukchi shelf water and vertical turbulent mixing with underlying nutricline water as in 2011. In contrast, northwesterly wind flowing in the northern part of extended Siberian High transported oligotrophic water within the Beaufort Gyre circulation toward the NAP region as in 2012. The modeled ice algal biomass during the summer season certainly reflected the differences in nutrient distribution. The sinking flux of Particulate Organic Nitrogen (PON was comparable with the time series obtained from the sediment trap data in summer 2011. On the other hand, lateral advection of shelf-origin ice algal patch during a great cyclone event might have caused a model bias on the PON flux in 2012. The extension

  14. Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

    DEFF Research Database (Denmark)

    Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.;

    2000-01-01

    Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well...... as to the test container. A simple filled closed bottle test with low algal densities and bicarbonate enrichment is described here as an approach to minimize the loss of test material from solution. The algal medium was enriched with 300 mg NaHCO3/L, the pH was adjusted to 7.0 by addition of HCl...

  15. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

  16. 糖尿病与火毒%Diabetes and Fire Toxin

    Institute of Scientific and Technical Information of China (English)

    黄世敬; 王永炎

    2015-01-01

    The objective of the paper is to explore the etiology,prevention and treatment of diabetes and fire toxin. Through literature analysis and clinical practice,it had been summarized that the formation and development of fire toxin presented in the entire progression of diabetes. Fire is classified as the physiological fire and pathological fire and the toxin is as the exogenous toxin and the endogenous toxin. Fire toxin in diabe-tes is related with improper diet(overeating greasy,sweet and strong flavor food,over - indulgence of food in fire toxin property,irregular food intake and unclean food),over - emotional changes(such as depression,an-ger,liver stagnation transforming into fire,grief,worry,hyperactivity of heart fire)and improper living condi-tion. Fire toxin is yang heat in nature and consumes qi. Flaring - up of fire toxin produces wind and stirs blood,disturbs heart mind and results in carbuncles. The upper jiao injury by fire toxin causes the upper xi-ao,the retention of fire toxin in the middle jiao causes the middle xiao and in the lower jiao causes diabetes of the lower xiao. Additionally,the transformations of fire toxin lead to the complications of diabetes. The proper diet is the origin of the disease prevention and the regular living habit protects the genuine qi. Clearing heat, eliminating toxin combined with nourishing yin,and reducing fire and removing toxin to consolidate the root are the treatment principles. All of these provide the reference for the study on the prevention and treatment of diabetes.%文章旨在探讨糖尿病火毒的成因与防治。通过文献分析,结合临床实践,总结出火毒的形成与演变贯穿于糖尿病始终。火有生理之火和病理之火之分,毒有外来之毒与内生之毒之别。糖尿病火毒形成与饮食不节(如过食肥甘厚味、偏食火毒性食物、饥饱无度、饮食不洁),情志过极(如郁闷恼怒、肝郁化火,忧愁思虑、心火亢盛)以及生

  17. Environmental influence on cyanobacteria abundance and microcystin toxin production in a shallow temperate lake.

    Science.gov (United States)

    Lee, Tammy A; Rollwagen-Bollens, Gretchen; Bollens, Stephen M; Faber-Hammond, Joshua J

    2015-04-01

    The increasing frequency of harmful cyanobacterial blooms in freshwater systems is a commonly recognized problem due to detrimental effects on water quality. Vancouver Lake, a shallow, tidally influenced lake in the flood plain of the Columbia River within the city of Vancouver, WA, USA, has experienced numerous summertime cyanobacterial blooms, dominated by Aphanizomenon sp. and Anabaena sp. Cyanobacteria abundance and toxin (microcystin) levels have been monitored in this popular urban lake for several years; however, no previous studies have identified which cyanobacteria species produce toxins, nor analyzed how changes in environmental variables contribute to the fluctuations in toxic cyanobacteria populations. We used a suite of molecular techniques to analyze water samples from Vancouver Lake over two summer bloom cycles (2009 and 2010). Both intracellular and extracellular microcystin concentrations were measured using an ELISA kit. Intracellular microcystin concentrations exceeded WHO guidelines for recreational waters several times throughout the sampling period. PCR results demonstrated that Microcystis sp. was the sole microcystin-producing cyanobacteria species present in Vancouver Lake, although Microcystis sp. was rarely detected in microscopical counts. qPCR results indicated that the majority of the Microcystis sp. population contained the toxin-producing gene (mcyE), although Microcystis sp. abundance rarely exceeded 1 percent of overall cyanobacteria abundance. Non-metric multidimensional scaling (NMDS) revealed that PO4-P was the main environmental variable influencing the abundance of toxic and non-toxic cyanobacteria, as well as intracellular microcystin concentrations. Our study underscores the importance of using molecular genetic techniques, in addition to traditional microscopy, to assess the importance of less conspicuous species in the dynamics of harmful algal blooms.

  18. Algal endosymbionts as vectors of horizontal gene transfer in photosynthetic eukaryotes

    Directory of Open Access Journals (Sweden)

    Huan eQiu

    2013-09-01

    Full Text Available Photosynthesis in eukaryotes occurs in the plastid, an organelle that is derived from a single cyanobacterial primary endosymbiosis in the common ancestor of the supergroup Plantae (or Archaeplastida that includes green, red, and glaucophyte algae and plants. However a variety of other phytoplankton such as the chlorophyll c-containing diatoms, dinoflagellates, and haptophytes contain a red alga-derived plastid that traces its origin to secondary or tertiary (eukaryote engulfs eukaryote endosymbiosis. The hypothesis of Plantae monophyly has only recently been substantiated, however the extent and role of endosymbiotic and horizontal gene transfer (EGT and HGT in algal genome evolution still remain to be fully understood. What is becoming clear from analysis of complete genome data is that algal gene complements can no longer be considered essentially eukaryotic in provenance; i.e., with the expected addition of several hundred cyanobacterial genes derived from EGT and a similar number derived from the mitochondrial ancestor. For example, we now know that foreign cells such as Chlamydiae and other prokaryotes have made significant contributions to plastid functions in Plantae. Perhaps more surprising is the recent finding of extensive bacterium-derived HGT in the nuclear genome of the unicellular red alga Porphyridium purpureum that does not relate to plastid functions. These non-endosymbiont gene transfers not only shaped the evolutionary history of Plantae but also were propagated via secondary endosymbiosis to a multitude of other phytoplankton. Here we discuss the idea that Plantae (in particular red algae are one of the major players in eukaryote genome evolution by virtue of their ability to act as sinks and sources of foreign genes through HGT and endosymbiosis, respectively. This hypothesis recognizes the often under-appreciated Rhodophyta as major sources of genetic novelty among photosynthetic eukaryotes.

  19. Clostridium perfringens Delta-Toxin Induces Rapid Cell Necrosis.

    Directory of Open Access Journals (Sweden)

    Soshi Seike

    Full Text Available Clostridium perfringens delta-toxin is a β-pore-forming toxin and a putative pathogenic agent of C. perfringens types B and C. However, the mechanism of cytotoxicity of delta-toxin remains unclear. Here, we investigated the mechanisms of cell death induced by delta-toxin in five cell lines (A549, A431, MDCK, Vero, and Caco-2. All cell lines were susceptible to delta-toxin. The toxin caused rapid ATP depletion and swelling of the cells. Delta-toxin bound and formed oligomers predominantly in plasma membrane lipid rafts. Destruction of the lipid rafts with methyl β-cyclodextrin inhibited delta-toxin-induced cytotoxicity and ATP depletion. Delta-toxin caused the release of carboxyfluorescein from sphingomyelin-cholesterol liposomes and formed oligomers; toxin binding to the liposomes declined with decreasing cholesterol content in the liposomes. Flow cytometric assays with annexin V and propidium iodide revealed that delta-toxin treatment induced an elevation in the population of annexin V-negative and propidium iodide-positive cells. Delta-toxin did not cause the fragmentation of DNA or caspase-3 activation. Furthermore, delta-toxin caused damage to mitochondrial membrane permeability and cytochrome c release. In the present study, we demonstrate that delta-toxin produces cytotoxic activity through necrosis.

  20. Clostridium perfringens Delta-Toxin Induces Rapid Cell Necrosis

    Science.gov (United States)

    Seike, Soshi; Miyamoto, Kazuaki; Kobayashi, Keiko; Takehara, Masaya; Nagahama, Masahiro

    2016-01-01

    Clostridium perfringens delta-toxin is a β-pore-forming toxin and a putative pathogenic agent of C. perfringens types B and C. However, the mechanism of cytotoxicity of delta-toxin remains unclear. Here, we investigated the mechanisms of cell death induced by delta-toxin in five cell lines (A549, A431, MDCK, Vero, and Caco-2). All cell lines were susceptible to delta-toxin. The toxin caused rapid ATP depletion and swelling of the cells. Delta-toxin bound and formed oligomers predominantly in plasma membrane lipid rafts. Destruction of the lipid rafts with methyl β-cyclodextrin inhibited delta-toxin-induced cytotoxicity and ATP depletion. Delta-toxin caused the release of carboxyfluorescein from sphingomyelin-cholesterol liposomes and formed oligomers; toxin binding to the liposomes declined with decreasing cholesterol content in the liposomes. Flow cytometric assays with annexin V and propidium iodide revealed that delta-toxin treatment induced an elevation in the population of annexin V-negative and propidium iodide-positive cells. Delta-toxin did not cause the fragmentation of DNA or caspase-3 activation. Furthermore, delta-toxin caused damage to mitochondrial membrane permeability and cytochrome c release. In the present study, we demonstrate that delta-toxin produces cytotoxic activity through necrosis. PMID:26807591

  1. Toxin from skin of frogs of the genus Atelopus: differentiation from Dendrobatid toxins.

    Science.gov (United States)

    Fuhrman, F A; Fuhrman, G J; Mosher, H S

    1969-09-26

    A potent, dialyzable toxin (atelopidtoxin) occurs in the skin of frogs of the genus Atelopus. A concentrate of atelopidtoxin from Atelopus zeteki has an LD(50) in mice of 16 micrograms per kilogram. It differs from batrachotoxin, tetrodotoxin, and saxitoxin, the only known nonprotein substances of greater toxicity, as well as from all toxins previously isolated from amphibia. PMID:5807965

  2. Fatty acids and algal lipids as precursors of chlorination by-products

    Institute of Scientific and Technical Information of China (English)

    Yan Liang; Yuen Shan Lui; Huachang Hong

    2012-01-01

    Six common algal fatty acids (FAs) with different numbers of double bonds,lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal cells were chlorinated to evaluate their potential in generating disinfection by-products (DBPs).The result showed that the more double bonds in the FAs,the higher the amounts of chloroform and dichloroacetic acid (DCAA) produced,but such a pattern was not observed for trichloroacetic acid (TCAA).Based on the previously reported composition of fatty acids in algal lipids,the DBP generation potentials of algal lipids were calculated.These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction,suggesting unknown lipophilic fraction(s) served as potent DBPs precursors.Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition,given quantified measured DBP production per unit algal lipid and proteins.The analysis showed that the observed DBP production was similar to that predicted (< 35% difference),suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform,DCAA and TCAA formation upon chlorinating algae.

  3. Assessment of Algal Farm Designs using a Dynamic Modular Approach

    Energy Technology Data Exchange (ETDEWEB)

    Abodeely, Jared M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology

    2014-07-01

    The notion of renewable energy provides an importantmechanism for diversifying an energy portfolio,which ultimately would have numerous benefits including increased energy resilience, reduced reliance on foreign energysupplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth,and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associatedwith algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the development and application of the Algae Logistics Model (ALM) which is tailored to help address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments ofmultiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tierwere sub-selected and assessed using daily site-specific algaebiomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary

  4. Copper removal by algal biomass: Biosorbents characterization and equilibrium modelling

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Pinheiro, Jose P.S.; Domingos, Rute F. [Centro de Biomedicina Molecular e Estrutural, Department of Chemistry and Biochemistry, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2009-04-30

    The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better the experimental ion binding data for different pH values and copper concentrations, considering only the acid functional groups, than the discrete model. Values of pK{sup '}{sub M} (3.2; 3.6 and 3.3), n{sub M} (0.98, 0.91, 1.0) and p (0.67, 0.53 and 0.43) were obtained, respectively for algae Gelidium, algal waste and composite material. NICCA model reflects the complex macromolecular systems that take part in biosorption considering the heterogeneity of the biosorbent, the competition between protons and metals ions to the binding sites and the stoichiometry for different ions.

  5. Assessment of Algal Farm Designs Using a Dynamic Modular Approach

    Energy Technology Data Exchange (ETDEWEB)

    Abodeely, Jared [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology

    2014-07-01

    The notion of renewable energy provides an important mechanism for diversifying an energy portfolio, which ultimately would have numerous benefits including increased energy resilience, reduction of foreign energy supplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth, and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associated with algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the Algae Logistics Model (ALM) which helps to address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments of multiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tier were sub-selected and assessed using daily site-specific algae biomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass

  6. Dynamics of ellipsoidal tracers in swimming algal suspensions

    Science.gov (United States)

    Yang, Ou; Peng, Yi; Liu, Zhengyang; Tang, Chao; Xu, Xinliang; Cheng, Xiang

    2016-10-01

    Enhanced diffusion of passive tracers immersed in active fluids is a universal feature of active fluids and has been extensively studied in recent years. Similar to microrheology for equilibrium complex fluids, the unusual enhanced particle dynamics reveal intrinsic properties of active fluids. Nevertheless, previous studies have shown that the translational dynamics of spherical tracers are qualitatively similar, independent of whether active particles are pushers or pullers—the two fundamental classes of active fluids. Is it possible to distinguish pushers from pullers by simply imaging the dynamics of passive tracers? Here, we investigated the diffusion of isolated ellipsoids in algal C. reinhardtii suspensions—a model for puller-type active fluids. In combination with our previous results on pusher-type E. coli suspensions [Peng et al., Phys. Rev. Lett. 116, 068303 (2016), 10.1103/PhysRevLett.116.068303], we showed that the dynamics of asymmetric tracers show a profound difference in pushers and pullers due to their rotational degree of freedom. Although the laboratory-frame translation and rotation of ellipsoids are enhanced in both pushers and pullers, similar to spherical tracers, the anisotropic diffusion in the body frame of ellipsoids shows opposite trends in the two classes of active fluids. An ellipsoid diffuses fastest along its major axis when immersed in pullers, whereas it diffuses slowest along the major axis in pushers. This striking difference can be qualitatively explained using a simple hydrodynamic model. In addition, our study on algal suspensions reveals that the influence of the near-field advection of algal swimming flows on the translation and rotation of ellipsoids shows different ranges and strengths. Our work provides not only new insights into universal organizing principles of active fluids, but also a convenient tool for detecting the class of active particles.

  7. Beneficial Effects of Marine Algal Compounds in Cosmeceuticals

    Directory of Open Access Journals (Sweden)

    Noel Vinay Thomas

    2013-01-01

    Full Text Available The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors have been discussed toward cosmeceutical application. In addition, atopic dermatitis and the possible role of matrix metalloproteinase (MMP in skin-related diseases have been explored extensively for cosmeceutical products. The proper development of marine algae compounds will be helpful in cosmeceutical product development and in the development of the cosmeceutical industry.

  8. Copper Removal by Algal Biomass: Biosorbents Characterization and Equilibrium Modelling

    OpenAIRE

    V. J. P. Vilar; Botelho, C.M.S.; Boaventura, R.A.R.

    2009-01-01

    The purpose of this work was to evaluate the potential of algal waste from the agar extraction industry, immobilized in a polymer, and the algae Gelidium itself, the raw material of agar extraction, to remove Cu(II) and Cr(III) from industrial effluents. The study involved a Cu(II) bearing effluent and the mixture of this effluent with an effluent containing Cr(VI), previously reduced to Cr(III). The two effluents were collected from metal plating plants, and then filtered and diluted before ...

  9. A Collection of Algal Genomes from the JGI

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2012-03-19

    Algae, defined as photosynthetic eukaryotes other than plants, constitute a major component of fundamental eukaryotic diversity. Acquisition of the ability to conduct oxygenic photosynthesis through endosymbiotic events has been a principal driver of eukaryotic evolution, and today algae continue to underpin aquatic food chains as primary producers. Algae play profound roles in the carbon cycle, can impose health and economic costs through toxic blooms, and are candidate sources for bio-fuels; all of these research areas are part of the mission of DOE?s Joint Genome Institute (JGI). A collection of algal projects ongoing at JGI contributes to each of these areas and illustrates analyses employed in their genome exploration.

  10. A study of algal biomass potential in selected Canadian regions.

    Energy Technology Data Exchange (ETDEWEB)

    Passell, Howard David; Roach, Jesse Dillon; Klise, Geoffrey T.

    2011-11-01

    A dynamic assessment model has been developed for evaluating the potential algal biomass and extracted biocrude productivity and costs, using nutrient and water resources available from waste streams in four regions of Canada (western British Columbia, Alberta oil fields, southern Ontario, and Nova Scotia). The purpose of this model is to help identify optimal locations in Canada for algae cultivation and biofuel production. The model uses spatially referenced data across the four regions for nitrogen and phosphorous loads in municipal wastewaters, and CO{sub 2} in exhaust streams from a variety of large industrial sources. Other data inputs include land cover, and solar insolation. Model users can develop estimates of resource potential by manipulating model assumptions in a graphic user interface, and updated results are viewed in real time. Resource potential by location can be viewed in terms of biomass production potential, potential CO{sub 2} fixed, biocrude production potential, and area required. The cost of producing algal biomass can be estimated using an approximation of the distance to move CO{sub 2} and water to the desired land parcel and an estimation of capital and operating costs for a theoretical open pond facility. Preliminary results suggest that in most cases, the CO{sub 2} resource is plentiful compared to other necessary nutrients (especially nitrogen), and that siting and prospects for successful large-scale algae cultivation efforts in Canada will be driven by availability of those other nutrients and the efficiency with which they can be used and re-used. Cost curves based on optimal possible siting of an open pond system are shown. The cost of energy for maintaining optimal growth temperatures is not considered in this effort, and additional research in this area, which has not been well studied at these latitudes, will be important in refining the costs of algal biomass production. The model will be used by NRC-IMB Canada to identify

  11. Harmful Algal Bloom Characterization at Ultra-High Spatial and Temporal Resolution Using Small Unmanned Aircraft Systems

    Directory of Open Access Journals (Sweden)

    Deon Van der Merwe

    2015-03-01

    Full Text Available Harmful algal blooms (HABs degrade water quality and produce toxins. The spatial distribution of HAbs may change rapidly due to variations wind, water currents, and population dynamics. Risk assessments, based on traditional sampling methods, are hampered by the sparseness of water sample data points, and delays between sampling and the availability of results. There is a need for local risk assessment and risk management at the spatial and temporal resolution relevant to local human and animal interactions at specific sites and times. Small, unmanned aircraft systems can gather color-infrared reflectance data at appropriate spatial and temporal resolutions, with full control over data collection timing, and short intervals between data gathering and result availability. Data can be interpreted qualitatively, or by generating a blue normalized difference vegetation index (BNDVI that is correlated with cyanobacterial biomass densities at the water surface, as estimated using a buoyant packed cell volume (BPCV. Correlations between BNDVI and BPCV follow a logarithmic model, with r2-values under field conditions from 0.77 to 0.87. These methods provide valuable information that is complimentary to risk assessment data derived from traditional risk assessment methods, and could help to improve risk management at the local level.

  12. Genetic and Genomic Dissection of the Cochliobolus heterostrophus Tox1 Locus Controlling Biosynthesis of the Polyketide Virulence Factor T-toxin

    Energy Technology Data Exchange (ETDEWEB)

    Turgeon, Barbara G.; Baker, Scott E.

    2007-04-27

    Fungal pathogenesis to plants is an intricate developmental process requiring biological components found in most fungi, as well as factors that are unique to fungal taxa that participate in particular fungus–plant interactions. The host-selective polyketide toxin known as T-toxin produced by Cochliobolus heterostrophus race T, a highly virulent pathogen of maize, is an intriguing example of the latter type of virulence determinant. The Tox1 locus, which controls biosynthesis of T-toxin, originally defined as a single genetic locus, it is, in fact, two exceedingly complex loci on two chromosomes that are reciprocally translocated with respect to their counterparts in weakly pathogenic race O. Race O lacks the Tox1 locus and does not produce T-toxin. Highly virulent race T was first recognized when it caused an epidemic of Southern Corn Leaf Blight, which devastated the US corn crop in 1970. The evolutionary origin of the Tox1 locus remains unknown.

  13. Use of Clostridium botulinum toxin in gastrointestinalmotility disorders in children

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    More than a century has elapsed since the identificationof Clostridia neurotoxins as the cause of paralyticdiseases. Clostridium botulinum is a heterogeneousgroup of Gram-positive, rod-shaped, spore-forming,obligate anaerobic bacteria that produce a potentneurotoxin. Eight different Clostridium botulinumneurotoxins have been described (A-H) and 5 of thosecause disease in humans. These toxins cause paralysisby blocking the presynaptic release of acetylcholine atthe neuromuscular junction. Advantage can be taken ofthis blockade to alleviate muscle spams due to excessiveneural activity of central origin or to weaken a musclefor treatment purposes. In therapeutic applications,minute quantities of botulinum neurotoxin type A areinjected directly into selected muscles. The Food andDrug Administration first approved botulinum toxin (BT)type A in 1989 for the treatment of strabismus andblepharospasm associated with dystonia in patients 12years of age or older. Ever since, therapeutic applicationsof BT have expanded to other systems, including thegastrointestinal tract. Although only a single fatalityhas been reported to our knowledge with use of BTfor gastroenterological conditions, there are significantcomplications ranging from minor pain, rash and allergicreactions to pneumothorax, bowel perforation andsignificant paralysis of tissues surrounding the injection(including vocal cord paralysis and dysphagia). Thiseditorial describes the clinical experience and evidencefor the use BT in gastrointestinal motility disorders inchildren.

  14. Atypical Enteropathogenic Escherichia coli Secretes Plasmid Encoded Toxin

    Directory of Open Access Journals (Sweden)

    Rita C. Ruiz

    2014-01-01

    Full Text Available Plasmid encoded toxin (Pet is a serine protease originally described in enteroaggregative Escherichia coli (EAEC prototype strain 042 whose entire characterization was essentially obtained from studies performed with the purified toxin. Here we show that Pet is not exclusive to EAEC. Atypical enteropathogenic Escherichia coli (aEPEC strains, isolated from diarrhea cases, express Pet and its detection in supernatants of infected HEp-2 cells coincides with the appearance of cell damage, which, in turn, were similar to those described with purified Pet. Pet secretion and the cytotoxic effects are time and culture medium dependent. In presence of DMEM supplemented with tryptone cell rounding and detachment were observed after just 5 h of incubation with the bacteria. In the absence of tryptone, the cytotoxic effects were detected only after 24 h of infection. We also show that, in addition to the prototype EAEC, other pet+ EAEC strains, also isolated from diarrhea cases, induce cellular damage in the same degree as the aEPEC. The cytotoxic effects of EAEC and aEPEC strains were significantly reduced in the presence of a serine protease inhibitor or anti-Pet IgG serum. Our results show a common aspect between the aEPEC and EAEC and provide the first evidence pointing to a role of Pet in aEPEC pathogenesis.

  15. A truncated diphtheria toxin based recombinant porcine CTLA-4 fusion toxin.

    Science.gov (United States)

    Peraino, Jaclyn Stromp; Schenk, Marian; Zhang, Huiping; Li, Guoying; Hermanrud, Christina E; Neville, David M; Sachs, David H; Huang, Christene A; Duran-Struuck, Raimon; Wang, Zhirui

    2013-05-31

    Targeted cell therapies are possible through the generation of recombinant fusion proteins that combine a toxin, such as diphtheria toxin (DT), with an antibody or other molecule that confers specificity. Upon binding of the fusion protein to the cell of interest, the diphtheria toxin is internalized which results in protein synthesis inhibition and subsequent cell death. We have recently expressed and purified the recombinant soluble porcine CTLA-4 both with and without N-glycosylation in yeast Pichia pastoris for in vivo use in our preclinical swine model. The glycosylated and non-N-glycosylated versions of this recombinant protein each bind to a porcine CD80 expressing B-cell lymphoma line (LCL13271) with equal affinity (K(D)=13 nM). In this study we have linked each of the glycosylated and non-N-glycosylated soluble porcine CTLA-4 proteins to the truncated diphtheria toxin DT390 through genetic engineering yielding three versions of the porcine CTLA-4 fusion toxins: 1) monovalent glycosylated soluble porcine CTLA-4 fusion toxin; 2) monovalent non-N-glycosylated soluble porcine CTLA-4 fusion toxin and 3) bivalent non-N-glycosylated soluble porcine CTLA-4 fusion toxin. Protein synthesis inhibition analysis demonstrated that while all three fusion toxins are capable of inhibiting protein synthesis in vitro, the non-N-glycosylated porcine CTLA-4 isoforms function most efficiently. Binding analysis using flow cytometry of the porcine CTLA-4 fusion toxins to LCL13271 cells also demonstrated that the non-N-glycosylated porcine CTLA-4 isoforms bind to these cells with higher affinity compared to the glycosylated fusion toxin. The monovalent non-N-glycosylated porcine CTLA-4 fusion toxin was tested in vivo. NSG (NOD/SCID IL-2 receptor γ(-)/(-)) mice were injected with porcine CD80(+) LCL13271 tumor cells. All animals succumbed to tumors and those treated with the monovalent non-N-glycosylated porcine CTLA-4 fusion toxin survived longer based on a symptomatic scoring

  16. Yeast β-1,6-glucan is a primary target for the Saccharomyces cerevisiae K2 toxin.

    Science.gov (United States)

    Lukša, Juliana; Podoliankaitė, Monika; Vepštaitė, Iglė; Strazdaitė-Žielienė, Živilė; Urbonavičius, Jaunius; Servienė, Elena

    2015-04-01

    Certain Saccharomyces cerevisiae strains secrete different killer proteins of double-stranded-RNA origin. These proteins confer a growth advantage to their host by increasing its survival. K2 toxin affects the target cell by binding to the cell surface, disrupting the plasma membrane integrity, and inducing ion leakage. In this study, we determined that K2 toxin saturates the yeast cell surface receptors in 10 min. The apparent amount of K2 toxin, bound to a single cell of wild type yeast under saturating conditions, was estimated to be 435 to 460 molecules. It was found that an increased level of β-1,6-glucan directly correlates with the number of toxin molecules bound, thereby impacting the morphology and determining the fate of the yeast cell. We observed that the binding of K2 toxin to the yeast surface receptors proceeds in a similar manner as in case of the related K1 killer protein. It was demonstrated that the externally supplied pustulan, a poly-β-1,6-glucan, but not the glucans bearing other linkage types (such as laminarin, chitin, and pullulan) efficiently inhibits the K2 toxin killing activity. In addition, the analysis of toxin binding to the intact cells and spheroplasts confirmed that majority of K2 protein molecules attach to the β-1,6-glucan, rather than the plasma membrane-localized receptors. Taken together, our results reveal that β-1,6-glucan is a primary target of K2 toxin and is important for the execution of its killing property.

  17. Clostridium perfringens delta toxin is sequence related to beta toxin, NetB, and Staphylococcus pore-forming toxins, but shows functional differences.

    Directory of Open Access Journals (Sweden)

    Maria Manich

    Full Text Available Clostridium perfringens produces numerous toxins, which are responsible for severe diseases in man and animals. Delta toxin is one of the three hemolysins released by a number of C. perfringens type C and possibly type B strains. Delta toxin was characterized to be cytotoxic for cells expressing the ganglioside G(M2 in their membrane. Here we report the genetic characterization of Delta toxin and its pore forming activity in lipid bilayers. Delta toxin consists of 318 amino acids, its 28 N-terminal amino acids corresponding to a signal peptide. The secreted Delta toxin (290 amino acids; 32619 Da is a basic protein (pI 9.1 which shows a significant homology with C. perfringens Beta toxin (43% identity, with C. perfringens NetB (40% identity and, to a lesser extent, with Staphylococcus aureus alpha toxin and leukotoxins. Recombinant Delta toxin showed a preference for binding to G(M2, in contrast to Beta toxin, which did not bind to gangliosides. It is hemolytic for sheep red blood cells and cytotoxic for HeLa cells. In artificial diphytanoyl phosphatidylcholine membranes, Delta and Beta toxin formed channels. Conductance of the channels formed by Delta toxin, with a value of about 100 pS to more than 1 nS in 1 M KCl and a membrane potential of 20 mV, was higher than those formed by Beta toxin and their distribution was broader. The results of zero-current membrane potential measurements and single channel experiments suggest that Delta toxin forms slightly anion-selective channels, whereas the Beta toxin channels showed a preference for cations under the same conditions. C. perfringens Delta toxin shows a significant sequence homolgy with C. perfringens Beta and NetB toxins, as well as with S. aureus alpha hemolysin and leukotoxins, but exhibits different channel properties in lipid bilayers. In contrast to Beta toxin, Delta toxin recognizes G(M2 as receptor and forms anion-selective channels.

  18. Marine toxins and their toxicological significance: An overview

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    This article presents an overview of various types of marine toxins and their toxicological significance in the context of biotechnological research and development. The characteristics and toxic potentials of different marine toxins highlighted...

  19. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E.; Laurens, L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-01

    Beginning in 2013, NREL began transitioning from the singular focus on ethanol to a broad slate of products and conversion pathways, ultimately to establish similar benchmarking and targeting efforts. One of these pathways is the conversion of algal biomass to fuels via extraction of lipids (and potentially other components), termed the 'algal lipid upgrading' or ALU pathway. This report describes in detail one potential ALU approach based on a biochemical processing strategy to selectively recover and convert select algal biomass components to fuels, namely carbohydrates to ethanol and lipids to a renewable diesel blendstock (RDB) product. The overarching process design converts algal biomass delivered from upstream cultivation and dewatering (outside the present scope) to ethanol, RDB, and minor coproducts, using dilute-acid pretreatment, fermentation, lipid extraction, and hydrotreating.

  20. Recycling produced water for algal cultivation for biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Neal, Justin N. [Los Alamos National Laboratory; Sullivan, Enid J. [Los Alamos National Laboratory; Dean, Cynthia A. [Los Alamos National Laboratory; Steichen, Seth A. [Los Alamos National Laboratory

    2012-08-09

    Algal growth demands a continuous source of water of appropriate salinity and nutritional content. Fresh water sources are scarce in the deserts of the Southwestern United States, hence, salt water algae species are being investigated as a renewable biofuel source. The use of produced water from oil wells (PW) could offset the demand for fresh water in cultivation. Produced water can contain various concentrations of dissolved solids, metals and organic contaminants and often requires treatment beyond oil/water separation to make it suitable for algae cultivation. The produced water used in this study was taken from an oil well in Jal, New Mexico. An F/2-Si (minus silica) growth media commonly used to cultivate Nannochloropsis salina 1776 (NS 1776) was prepared using the produced water (F/2-Si PW) taking into account the metals and salts already present in the water. NS 1776 was seeded into a bioreactor containing 5L of the (F/2-Si PW) media. After eleven days the optical density at 750 nm (an indicator of algal growth) increased from 0 to 2.52. These results indicate algae are able to grow, though inhibited when compared with non-PW media, in the complex chemical conditions found in produced water. Savings from using nutrients present in the PW, such as P, K, and HCO{sub 3}{sup -}, results in a 44.38% cost savings over fresh water to mix the F/2-Si media.

  1. Raman spectroscopy for the characterization of algal cells

    Science.gov (United States)

    Samek, Ota; Jonáš, Alexandr; Pilát, Zdeněk; Zemánek, Pavel; Nedbal, Ladislav; Tříska, Jan; Kotas, Petr; Trtílek, Martin

    2010-12-01

    Raman spectroscopy can elucidate fundamental questions about intercellular variability and what governs it. Moreover, knowing the metabolic response on single cell level this can significantly contribute to the study and use of microalgae in systems biology and biofuel technology. Raman spectroscopy is capable to measure nutrient dynamics and metabolism in vivo, in real-time, label free making it possible to monitor/evaluate population variability. Also, degree of unsaturation of the algae oil (iodine value) can be measured using Raman spectra obtained from single microalgae. The iodine value is the determination of the amount of unsaturation contained in fatty acids (in the form of double bonds). Here we demonstrate the capacity of the spatially resolved Raman microspectroscopy to determine the effective iodine value in lipid storage bodies of individual living algal cells. We employed the characteristic peaks in the Raman scattering spectra at 1,656 cm-1 (cis C=C stretching mode) and 1,445 cm-1 (CH2 scissoring mode) as the markers defining the ratio of unsaturated-to-saturated carbon-carbon bonds of the fatty acids in the algal lipids.

  2. Four novel algal virus genomes discovered from Yellowstone Lake metagenomes

    Science.gov (United States)

    Zhang, Weijia; Zhou, Jinglie; Liu, Taigang; Yu, Yongxin; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2015-01-01

    Phycodnaviruses are algae-infecting large dsDNA viruses that are widely distributed in aquatic environments. Here, partial genomic sequences of four novel algal viruses were assembled from a Yellowstone Lake metagenomic data set. Genomic analyses revealed that three Yellowstone Lake phycodnaviruses (YSLPVs) had genome lengths of 178,262 bp, 171,045 bp, and 171,454 bp, respectively, and were phylogenetically closely related to prasinoviruses (Phycodnaviridae). The fourth (YSLGV), with a genome length of 73,689 bp, was related to group III in the extended family Mimiviridae comprising Organic Lake phycodnaviruses and Phaeocystis globosa virus 16 T (OLPG). A pair of inverted terminal repeats was detected in YSLPV1, suggesting that its genome is nearly complete. Interestingly, these four putative YSL giant viruses also bear some genetic similarities to Yellowstone Lake virophages (YSLVs). For example, they share nine non-redundant homologous genes, including ribonucleotide reductase small subunit (a gene conserved in nucleo-cytoplasmic large DNA viruses) and Organic Lake virophage OLV2 (conserved in the majority of YSLVs). Additionally, putative multidrug resistance genes (emrE) were found in YSLPV1 and YSLPV2 but not in other viruses. Phylogenetic trees of emrE grouped YSLPVs with algae, suggesting that horizontal gene transfer occurred between giant viruses and their potential algal hosts. PMID:26459929

  3. Algal and microbial exopolysaccharides: new insights as biosurfactants and bioemulsifiers.

    Science.gov (United States)

    Paniagua-Michel, José de Jesús; Olmos-Soto, Jorge; Morales-Guerrero, Eduardo Roberto

    2014-01-01

    Currently, efforts are being made to utilize more natural biological systems as alternatives as a way to replace fossil forms of carbon. There is a growing concern at global level to have nontoxic, nonhazardous surface-active agents; contrary to synthetic surfactants, their biological counterparts or biosurfactants play a primary function, facilitating microbial presence in environments dominated by hydrophilic-hydrophobic interfaces. Algal and microbial biosurfactants/bioemulsifiers from marine and deep-sea environments are attracting major interest due to their structural and functional diversity as molecules actives of surface and an alternative biomass to replace fossil forms of carbon. Algal and microbial surfactants are lipid in nature and classified as glycolipids, phospholipids, lipopeptides, natural lipids, fatty acids, and lipopolysaccharides. These metabolic bioactive products are applicable in a number of industries and processes, viz., food processing, pharmacology, and bioremediation of oil-polluted environments. This chapter presents an update of the progress and potentialities of the principal producers of exopolysaccharide (EPS)-type biosurfactants and bioemulsifiers, viz., macro- and microalgae (cyanobacteria and diatoms) and bacteria from marine and extreme environments. Particular interest is centered into new sources and applications, viz., marine and deep-sea environments and promissory uses of these EPSs as biosurfactants/emulsifiers and other polymeric roles. The enormous benefits of these molecules encourage their discovery, exploitation, and development of new microbial EPSs that could possess novel industrial importance and corresponding innovations.

  4. Marine Toxins Targeting Ion Channels

    Directory of Open Access Journals (Sweden)

    Hugo R. Arias

    2006-04-01

    Full Text Available Abstract: This introductory minireview points out the importance of ion channels for cell communication. The basic concepts on the structure and function of ion channels triggered by membrane voltage changes, the so-called voltage-gated ion channels (VGICs, as well as those activated by neurotransmitters, the so-called ligand-gated ion channel (LGICs, are introduced. Among the most important VGIC superfamiles, we can name the voltage-gated Na+ (NaV, Ca2+ (CaV, and K+ (KV channels. Among the most important LGIC super families, we can include the Cys-loop or nicotinicoid, the glutamate-activated (GluR, and the ATP-activated (P2XnR receptor superfamilies. Ion channels are transmembrane proteins that allow the passage of different ions in a specific or unspecific manner. For instance, the activation of NaV, CaV, or KV channels opens a pore that is specific for Na+, Ca2+, or K+, respectively. On the other hand, the activation of certain LGICs such as nicotinic acetylcholine receptors, GluRs, and P2XnRs allows the passage of cations (e.g., Na+, K+, and/or Ca2+, whereas the activation of other LGICs such as type A γ-butyric acid and glycine receptors allows the passage of anions (e.g., Cl− and/or HCO3−. In this regard, the activation of NaV and CaV as well as ligand-gated cation channels produce membrane depolarization, which finally leads to stimulatory effects in the cell, whereas the activation of KV as well as ligand-gated anion channels induce membrane hyperpolarization that finally leads to inhibitory effects in the cell. The importance of these ion channel superfamilies is emphasized by considering their physiological functions throughout the body as well as their pathophysiological implicance in several neuronal diseases. In this regard, natural molecules, and especially marine toxins, can be potentially used as modulators (e.g., inhibitors or prolongers of ion channel functions to treat or to alleviate a specific

  5. Algicidal bacteria in the sea and their impact on algal blooms.

    Science.gov (United States)

    Mayali, Xavier; Azam, Farooq

    2004-01-01

    Over the past two decades, many reports have revealed the existence of bacteria capable of killing phytoplankton. These algicidal bacteria sometimes increase in abundance concurrently with the decline of algal blooms, suggesting that they may affect algal bloom dynamics. Here, we synthesize the existing knowledge on algicidal bacteria interactions with marine eukaryotic microalgae. We discuss the effectiveness of the current methods to characterize the algicidal phenotype in an ecosystem context. We briefly consider the literature on the phylogenetic identification of algicidal bacteria, their interaction with their algal prey, the characterization of algicidal molecules, and the enumeration of algicidal bacteria during algal blooms. We conclude that, due to limitations of current methods, the evidence for algicidal bacteria causing algal bloom decline is circumstantial. New methods and an ecosystem approach are needed to test hypotheses on the impact of algicidal bacteria in algal bloom dynamics. This will require enlarging the scope of inquiry from its current focus on the potential utility of algicidal bacteria in the control of harmful algal blooms. We suggest conceptualizing bacterial algicidy within the general problem of bacterial regulation of algal community structure in the ocean. PMID:15134248

  6. Releasing Stored Solar Energy within Pond Scum: Biodiesel from Algal Lipids

    Science.gov (United States)

    Blatti, Jillian L.; Burkart, Michael D.

    2012-01-01

    Microalgae have emerged as an attractive feedstock for the mass production of renewable transportation fuels due to their fast growth rate, flexible habitat preferences, and substantial oil yields. As an educational tool, a laboratory was developed that mimics emerging algal biofuel technology, including the extraction of algal lipids and…

  7. Inhibiting bacterial toxins by channel blockage.

    Science.gov (United States)

    Bezrukov, Sergey M; Nestorovich, Ekaterina M

    2016-03-01

    Emergent rational drug design techniques explore individual properties of target biomolecules, small and macromolecule drug candidates, and the physical forces governing their interactions. In this minireview, we focus on the single-molecule biophysical studies of channel-forming bacterial toxins that suggest new approaches for their inhibition. We discuss several examples of blockage of bacterial pore-forming and AB-type toxins by the tailor-made compounds. In the concluding remarks, the most effective rationally designed pore-blocking antitoxins are compared with the small-molecule inhibitors of ion-selective channels of neurophysiology.

  8. Streptococcal toxins: role in pathogenesis and disease.

    Science.gov (United States)

    Barnett, Timothy C; Cole, Jason N; Rivera-Hernandez, Tania; Henningham, Anna; Paton, James C; Nizet, Victor; Walker, Mark J

    2015-12-01

    Group A Streptococcus (Streptococcus pyogenes), group B Streptococcus (Streptococcus agalactiae) and Streptococcus pneumoniae (pneumococcus) are host-adapted bacterial pathogens among the leading infectious causes of human morbidity and mortality. These microbes and related members of the genus Streptococcus produce an array of toxins that act against human cells or tissues, resulting in impaired immune responses and subversion of host physiological processes to benefit the invading microorganism. This toxin repertoire includes haemolysins, proteases, superantigens and other agents that ultimately enhance colonization and survival within the host and promote dissemination of the pathogen.

  9. Streptococcal toxins: role in pathogenesis and disease.

    Science.gov (United States)

    Barnett, Timothy C; Cole, Jason N; Rivera-Hernandez, Tania; Henningham, Anna; Paton, James C; Nizet, Victor; Walker, Mark J

    2015-12-01

    Group A Streptococcus (Streptococcus pyogenes), group B Streptococcus (Streptococcus agalactiae) and Streptococcus pneumoniae (pneumococcus) are host-adapted bacterial pathogens among the leading infectious causes of human morbidity and mortality. These microbes and related members of the genus Streptococcus produce an array of toxins that act against human cells or tissues, resulting in impaired immune responses and subversion of host physiological processes to benefit the invading microorganism. This toxin repertoire includes haemolysins, proteases, superantigens and other agents that ultimately enhance colonization and survival within the host and promote dissemination of the pathogen. PMID:26433203

  10. Natural Toxins for Use in Pest Management

    Directory of Open Access Journals (Sweden)

    Kevin K. Schrader

    2010-07-01

    Full Text Available Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are highly successful products based on natural compounds in the major pesticide classes. These include the herbicide glufosinate (synthetic phosphinothricin, the spinosad insecticides, and the strobilurin fungicides. These and other examples of currently marketed natural product-based pesticides, as well as natural toxins that show promise as pesticides from our own research are discussed.

  11. Positive regulation of Clostridium difficile toxins.

    OpenAIRE

    Moncrief, J S; Barroso, L A; Wilkins, T D

    1997-01-01

    The toxigenic element of Clostridium difficile VPI 10463 contains a small open reading frame (ORF) immediately upstream of the toxin B gene (G. A. Hammond and J. L. Johnson, Microb. Pathog. 19:203-213, 1995). The deduced amino acid sequence of the ORF, which we have designated txeR, encodes a 22-kDa protein which contains a helix-turn-helix motif with sequence identity to DNA binding regulatory proteins. We used a DNA fragment containing the C. difficile toxin A repeating units (ARU) as a rep...

  12. Structural interactions of a voltage sensor toxin with lipid membranes

    OpenAIRE

    Mihailescu, Mihaela; Krepkiy, Dmitriy; Milescu, Mirela; Gawrisch, Klaus; Swartz, Kenton J.; White, Stephen

    2014-01-01

    Tarantula venom contains protein toxins that interact with diverse families of ion channels and alter their activity. A number of tarantula toxins are known to interact with membranes and are thought to bind to ion channel proteins within the lipid bilayer. In the present study, we find that tarantula toxins influence the structure and dynamics of the lipid bilayer, and that the toxin orients itself within membranes to facilitate formation of the toxin–channel complexes. Our results have impl...

  13. Validation of algal viability treated with total residual oxidant and organic matter by flow cytometry.

    Science.gov (United States)

    Lee, Junghyun; Choi, Eun Joo; Rhie, Kitae

    2015-08-15

    Algal cell growth after starch and oxidant treatments in seawater species (Isochrysis galbana and Phaeodactylum tricornutum) and freshwater species (Selenastrum capricornutum and Scenedesmus obliquus) were evaluated by flow cytometry with fluorescein diacetate (FDA) staining to determine algal viability. Growth of algal cell was found to be significantly different among groups treated with NaOCl, starch and/or sodium thiosulfate, which are active substance (Total Residual Oxidant; TRO as Cl2), organic compound to meet efficacy testing standard and neutralizer of TRO by Ballast Water Management Convention of International Maritime Organization, respectively. The viability of algal cell treated with TRO in starch-add culture of 5days after treatment and neutralization was decreased significantly. ATP contents of the treated algal cells corresponded to the FL1 fluorescent signal of flow cytometry with FDA staining. I. galbana was the most sensitive to TRO-neutralized cultures during viability analysis.

  14. 77 FR 9888 - Shiga Toxin-Producing Escherichia coli

    Science.gov (United States)

    2012-02-21

    ... Food Safety and Inspection Service Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products... manufacturing trimmings for six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45..., non-intact product, that are contaminated with Shiga toxin-producing Escherichia coli (STEC) O26,...

  15. Characterisation of cholera toxin by liquid chromatography - Electrospray mass spectrometry

    NARCIS (Netherlands)

    Baar, B.L.M. van; Hulst, A.G.; Wils, E.R.J.

    1999-01-01

    Cholera toxin, one of the toxins that may be generated by various strains of the bacterium Vibrio cholerae, can be considered as a substance possibly used in biological warfare. The possibilities of characterising the toxin by liquid chromatography electrospray mass spectrometry (LC-ES-MS) were inve

  16. Anthrax toxin-induced rupture of artificial lipid bilayer membranes

    Science.gov (United States)

    Nablo, Brian J.; Panchal, Rekha G.; Bavari, Sina; Nguyen, Tam L.; Gussio, Rick; Ribot, Wil; Friedlander, Art; Chabot, Donald; Reiner, Joseph E.; Robertson, Joseph W. F.; Balijepalli, Arvind; Halverson, Kelly M.; Kasianowicz, John J.

    2013-08-01

    We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm.

  17. Effect of treatment with botulinum toxin on spasticity.

    OpenAIRE

    Das, T K; Park, D M

    1989-01-01

    Botulinum toxin, a product of Clostridium botulinum, produces presynaptic neuromuscular block by preventing release of acetylcholine from nerve endings. The toxin was injected directly into the skeletal muscles of six patients with severe spasticity due to stroke-related hemiplegia. It produced both subjective and objective improvement. The toxin injections were well tolerated and no significant side effect was reported.

  18. Bacterial protein toxins : tools to study mammalian molecular cell biology

    NARCIS (Netherlands)

    Wüthrich, I.W.

    2014-01-01

    Bacterial protein toxins are genetically encoded proteinaceous macromolecules that upon exposure causes perturbation of cellular metabolism in a susceptible host. A bacterial toxin can work at a distance from the site of infection, and has direct and quantifiable actions. Bacterial protein toxins ca

  19. Pichia acaciae Killer System: Genetic Analysis of Toxin Immunity▿

    OpenAIRE

    Paluszynski, John P.; Klassen, Roland; Meinhardt, Friedhelm

    2007-01-01

    The gene responsible for self-protection in the Pichia acaciae killer plasmid system was identified by heterologous expression in Saccharomyces cerevisiae. Resistance profiling and conditional toxin/immunity coexpression analysis revealed dose-independent protection by pPac1-2 ORF4 and intracellular interference with toxin function, suggesting toxin reinternalization in immune killer cells.

  20. Interactions and hybrid complex formation of anionic algal polysaccharides with a cationic glycine betaine-derived surfactant.

    Science.gov (United States)

    Covis, Rudy; Vives, Thomas; Gaillard, Cédric; Benoit, Maud; Benvegnu, Thierry

    2015-05-01

    The interaction between anionic algal polysaccharides ((κ)-, (ι)-, (λ)-carrageenans, alginate and ulvan) and a cationic glycine betaine (GB) amide surfactant possessing a C18:1 alkyl chain has been studied using isothermal titration calorimetry (ITC), zeta-potential measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and surface tension measurements. It was observed that this cationic surfactant derived from renewable raw materials induced cooperative binding with the anionic polymers at critical aggregation concentration (CAC) and the CAC values are significantly lower than the corresponding critical micelle concentration (CMC) for the surfactant. The CMC of cationic GB surfactant was obtained at higher surfactant concentration in polysaccharide solution than in pure water. More interestingly, the presence of original polysaccharide/surfactant hybrid complexes formed above the CMC value was evidenced from (κ)-carrageenan by microscopy (TEM and AFM). Preliminary investigations of the structure of these complexes revealed the existence of surfactant nanoparticles surrounded with polysaccharide matrix, probably resulting from electrostatic attraction. In addition, ITC measurements clearly showed that the interactions of the κ-carrageenan was stronger than for other polysaccharides ((ι)-, (λ)-carrageenans, alginate and ulvan). These results may have important impact on the use of the GB amide surfactant in formulations based on algal polysaccharides for several applications such as in food, cosmetics, and detergency fields.

  1. A Cell-Based Fluorescent Assay to Detect the Activity of Shiga Toxin and Other Toxins That Inhibit Protein Synthesis

    Science.gov (United States)

    Escherichia coli O157:H7, a major cause of food-borne illness, produces Shiga toxins that block protein synthesis by inactivating the ribosome. In this chapter we describe a simple cell-based fluorescent assay to detect Shiga toxins and inhibitors of toxin activity. The assay can also be used to d...

  2. Original pedagogues

    DEFF Research Database (Denmark)

    Schmidt, Christina Haandbæk

    Original pedagogues Distention between competences and originality By Christina Haandbæk Schmidt, ph. d. student Aarhus University, Denmark This presentation concerns a Ph.D. project (Sept. 2012 –Sept. 2015) about pedagogues in day care facilities and their struggles to develop and retain...... of pedagogues and in everyday life in daycare facilities. The competence term includes at least two discourses of interest; a pedagogical competence discourse and a political jurisdiction discourse which forms a distention between authenticity and competence. In order that pedagogues may regain their autonomy I...... shall argue that it is necessary for the pedagogues to know how they are constituted by the regimes of power on one side and on the other side are forced to create themselves. This knowledge could transform pedagogues into what I suggest calling ‘original pedagogues’, who have an authentic, ethic...

  3. How hydrodynamics control algal blooms in the Ythan estuary, Scotland

    Science.gov (United States)

    Champangern, Khruewan; Hoey, Trevor; Thomas, Rhian

    2016-04-01

    The Ythan estuary, northeast Scotland, was designated in 2000 as a Nitrate Vulnerable Zone (NVZ) under the European Commission (EC) Nitrates Directive. Much of the catchment is intensively farmed and water quality has been adversely affected by nutrients from agricultural fertilizers. As a result, algal mats develop annually on tidal flats where sediment from upstream and from the adjacent dune systems is deposited. Understanding the patterns of water (river and ocean) circulation in the estuary as well as understanding how nutrients and sediments are transported in the estuary is crucial for understanding the role of several factors (elevation; sediment characteristics; nutrient flux) control the locations and scale of annual algal blooms. In order to understand those controls, study of interactions between hydrodynamic factors and water quality, in particular chlorophyll levels, at different time scales has been carried out. The results from the study reveal complex seasonal and event-scale relationships of river flow with the amount of chlorophyll, which provide an initial comprehension of controls over the concentrations of chlorophyll in the estuary. The concentration of chlorophyll changes, whether increasing or decreasing, with regards to changes in river flow. During high flow events, high amounts of chlorophyll are found when the tide is low. During low flow events, high amounts of chlorophyll are found at high tides. These phenomena reveal that both river flow and tidal cycle affect the amount of chlorophyll in the estuary. In addition, the Delft3d flow model, which has been extensively applied to many coastal and estuarine studies is used to simulate hydrodynamic patterns in the estuary during high flow and low flow events. The model is composed of 36,450 fine resolution grids and the upstream/ downstream boundary that represents water level is based on time-series data from river flow and tidal measurements. The bathymetry used for the model domain is

  4. Immunogenicity of toxins during Staphylococcus aureus infection

    NARCIS (Netherlands)

    N.J. Verkaik (Nelianne); O. Dauwalder (Olivier); K. Antri (Kenza); I. Boubekri (Ilhem); C.P. de Vogel (Corné); C. Badiou (Cédric); M. Bes (Michèle); F. Vandenesch (François); M. Tazir (Mohammed); H. Hooijkaas (Herbert); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); J. Etienne (Jerome); G. Lina (Gérard); N. Ramdani-Bouguessa (Nadjia); W.J.B. van Wamel (Willem)

    2010-01-01

    textabstractAB - BACKGROUND: Toxins are important Staphylococcus aureus virulence factors, but little is known about their immunogenicity during infection. Here, additional insight is generated. METHODS: Serum samples from 206 S. aureus-infected patients and 201 hospital-admitted control subjects we

  5. Natural toxins for use in pest management

    Science.gov (United States)

    Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are highly ...

  6. Treatment of Frontal Hyperhidrosis With Botulinum Toxin

    Directory of Open Access Journals (Sweden)

    Ayşe Esra Koku Aksu

    Full Text Available Focal hyperhidrosis is usually localized to the axillae, palms and soles. Less frequently, hyperhidrosis may be confined to the forehead and may have negative impact on patient’s quality of life. A 34-year-old man presented to our clinic with the complaint of frontal hyperhidrosis. He was treated with botulinum toxin A. Thirty points were marked over the forehead and at each injection point, 0.15 ml (3U botulinum toxin A were injected intracutaneously. Hyperhidrosis was significantly reduced and the effect lasted for 12 months. Skindex-29, a quality-of-life measure for skin disease, was administered to the patient at the beginning and at the end of second week of botulinum toxin A injection. There was a significant improvement on the Skindex-29 scale at the end of the treatment. There was no any side effect detected during and after the treatment. Botulinum toxin A treatment is considered to be effective and safe for frontal hyperhidrosis.

  7. Noncosmetic periocular therapeutic applications of botulinum toxin

    Directory of Open Access Journals (Sweden)

    Kaynak-Hekimhan Pelin

    2010-01-01

    Full Text Available Botulinum toxin blocks acetylcholine release at the neuromuscular junction. The drug which was initially found to be useful in the treatment of strabismus has been extremely effective in the treatment of variety of conditions, both cosmetic and noncosmetic. Some of the noncosmetic uses of botulinum toxin applications include treatment of spastic facial dystonias, temporary treatment of idiopathic or thyroid dysfunction-induced upper eyelid retraction, suppression of undesired hyperlacrimation, induction of temporary ptosis by chemodenervation in facial paralysis, and correction of lower eyelid spastic entropion. Additional periocular uses include control of synchronic eyelid and extraocular muscle movements after aberrant regeneration of cranial nerve palsies. Cosmetic effects of botulinum toxin were discovered accidentally during treatments of facial dystonias. Some of the emerging nonperiocular application for the drug includes treatment of hyperhidrosis, migraine, tension-type headaches, and paralytic spasticity. Some of the undesired side effects of periocular applications of botulinum toxin inlcude ecchymosis, rash, hematoma, headache, flu-like symptoms, nausea, dizziness, loss of facial expression, lower eyelid laxity, dermatochalasis, ectropion, epiphora, eyebrow and eyelid ptosis, lagophthalmos, keratitis sicca, and diplopia.

  8. Okadaic Acid: More than a Diarrheic Toxin

    Directory of Open Access Journals (Sweden)

    Josefina Méndez

    2013-10-01

    Full Text Available Okadaic acid (OA is one of the most frequent and worldwide distributed marine toxins. It is easily accumulated by shellfish, mainly bivalve mollusks and fish, and, subsequently, can be consumed by humans causing alimentary intoxications. OA is the main representative diarrheic shellfish poisoning (DSP toxin and its ingestion induces gastrointestinal symptoms, although it is not considered lethal. At the molecular level, OA is a specific inhibitor of several types of serine/threonine protein phosphatases and a tumor promoter in animal carcinogenesis experiments. In the last few decades, the potential toxic effects of OA, beyond its role as a DSP toxin, have been investigated in a number of studies. Alterations in DNA and cellular components, as well as effects on immune and nervous system, and even on embryonic development, have been increasingly reported. In this manuscript, results from all these studies are compiled and reviewed to clarify the role of this toxin not only as a DSP inductor but also as cause of alterations at the cellular and molecular levels, and to highlight the relevance of biomonitoring its effects on human health. Despite further investigations are required to elucidate OA mechanisms of action, toxicokinetics, and harmful effects, there are enough evidences illustrating its toxicity, not related to DSP induction, and, consequently, supporting a revision of the current regulation on OA levels in food.

  9. Toxins and antimicrobial peptides: interactions with membranes

    Science.gov (United States)

    Schlamadinger, Diana E.; Gable, Jonathan E.; Kim, Judy E.

    2009-08-01

    The innate immunity to pathogenic invasion of organisms in the plant and animal kingdoms relies upon cationic antimicrobial peptides (AMPs) as the first line of defense. In addition to these natural peptide antibiotics, similar cationic peptides, such as the bee venom toxin melittin, act as nonspecific toxins. Molecular details of AMP and peptide toxin action are not known, but the universal function of these peptides to disrupt cell membranes of pathogenic bacteria (AMPs) or a diverse set of eukaryotes and prokaryotes (melittin) is widely accepted. Here, we have utilized spectroscopic techniques to elucidate peptide-membrane interactions of alpha-helical human and mouse AMPs of the cathelicidin family as well as the peptide toxin melittin. The activity of these natural peptides and their engineered analogs was studied on eukaryotic and prokaryotic membrane mimics consisting of peptide potency, was monitored with a sensitive fluorescence leakage assay. Detailed molecular information on peptidemembrane interactions and peptide structure was further gained through vibrational spectroscopy combined with circular dichroism. Finally, steady-state fluorescence experiments yielded insight into the local environment of native or engineered tryptophan residues in melittin and human cathelicidin embedded in bilayer vesicles. Collectively, our results provide clues to the functional structures of the engineered and toxic peptides and may impact the design of synthetic antibiotic peptides that can be used against the growing number of antibiotic-resistant pathogens.

  10. Mutant with diphtheria toxin receptor and acidification function but defective in entry of toxin

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, Kenji (National Institute for Basic Biology, Aichi (Japan)); Hayes, H.; Mekada, Eisuke (Osaka Univ. (Japan)); Uchida, Tsuyoshi (National Institute for Basic Biology, Aichi (Japan) Osaka Univ. (Japan))

    1987-09-01

    A mutant of Chinese hamster ovary cells, GE1, that is highly resistant to diphtheria toxin was isolated. The mutant contains 50% ADP-ribosylatable elongation factor 2, but its protein synthesis was not inhibited by the toxin even at concentrations above 100 {mu}g/ml. {sup 125}I-labeled diphtheria toxin was associated with GE1 cells as well as with the parent cells but did not block protein synthesis of GE1 cells even when the cells were exposed to low pH in the presence or absence of NH{sub 4}Cl. The infections of GE1 cells and the parent cells by vesicular stomatitis virus were similar. GE1 cells were cross-resistant to Pseudomonas aeruginosa exotoxin A and so were about 1,000 times more resistant to this toxin than the parent cells. Hybrids of GE1 cells and the parent cells or mutant cells lacking a functional receptor were more sensitive to diphtheria toxin than GE1 cells. These results suggest that entry of diphtheria toxin into cells requires a cellular factor(s) in addition to those involved in receptor function and acidification of endosomes and that GE1 cells do not express this cellular factor. This character is recessive in GE1 cells.

  11. Discussion about mechanism of harmful algal blooms breakout

    Institute of Scientific and Technical Information of China (English)

    BU Xianwei; XU Weiyi; ZHU Dedi; CHEN Gengxin

    2005-01-01

    HAB (harmful algal bloom) is a serious marine ecological disaster. Up to now there is no definite conclusion about its mechanism of occurrence.The observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence ca pacity,and the breakout process had no direct relation to eutrophication. As a new idea it is thought that the process of the HAB break out is mainly a physical convergence or accumulation process in some areas. A hypothesis about dynamic mechanism of the HAB ap pearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work, and a breakthrough is expected to be made for doing further research.

  12. Enzyme-like Activities of Algal Polysaccharide - Cerium Complexes

    Institute of Scientific and Technical Information of China (English)

    WANG Dongfeng; SUN Jipeng; DU Dehong; YE Shen; WANG Changhong; ZHOU Xiaoling; XUE Changhu

    2005-01-01

    Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS- Ce4+ complexes have some enzyme-like activities. Fucoidan and its complex with Cea+ have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS- Ce4+complexes show these measurable activities under the comparable condition when APS bind Ce4 + and form homogenous solutions. The laminaran- Ce4 + complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropyrifos under neutral conditions.

  13. Marine harmful algal blooms, human health and wellbeing

    DEFF Research Database (Denmark)

    Berdalet, Elisa; Fleming, Lora E.; Gowen, Richard;

    2016-01-01

    Microalgal blooms are a natural part of the seasonal cycle of photosynthetic organisms in marine ecosystems. They are key components of the structure and dynamics of the oceans and thus sustain the benefits that humans obtain from these aquatic environments. However, some microalgal blooms can...... cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments...... multidisciplinary research. At the beginning of the 21st century, with expanding human populations, particularly in coastal and developing countries, mitigating HABs impacts on human health and wellbeing is becoming a more pressing public health need. The available tools to address this global challenge include...

  14. Excitation Energy-Transfer Dynamics of Brown Algal Photosynthetic Antennas.

    Science.gov (United States)

    Kosumi, D; Kita, M; Fujii, R; Sugisaki, M; Oka, N; Takaesu, Y; Taira, T; Iha, M; Hashimoto, H

    2012-09-20

    Fucoxanthin-chlorophyll-a/c protein (FCP) complexes from brown algae Cladosiphon okamuranus TOKIDA (Okinawa Mozuku in Japanese) contain the only species of carbonyl carotenoid, fucoxanthin, which exhibits spectral characteristics attributed to an intramolecular charge-transfer (ICT) property that arises in polar environments due to the presence of the carbonyl group in its polyene backbone. Here, we investigated the role of the ICT property of fucoxanthin in ultrafast energy transfer to chlorophyll-a/c in brown algal photosynthesis using femtosecond pump-probe spectroscopic measurements. The observed excited-state dynamics show that the ICT character of fucoxanthin in FCP extends its absorption band to longer wavelengths and enhances its electronic interaction with chlorophyll-a molecules, leading to efficient energy transfer from fucoxanthin to chlorophyll-a. PMID:26295888

  15. Heterologous expression of an algal hydrogenase in a heterocystous cyanobacterium

    International Nuclear Information System (INIS)

    For the expression of an active algal [FeFe] hydrogenase in the heterocystous cyanobacterium Nostoc punctiforme A TCC 29133 the Chlamydomonas reinhardtii hydrogenase gene hydA1 and the accessory genes hydEF and hydG are to be introduced into the cyanobacteria cells. The genes were amplified by PCR from EST clones, cloned into the cloning vector pBluescript SK+ and sequenced. An expression vector for multi-cistronic cloning, based on pSCR202, was constructed and for a functional test GFP was inserted as a reporter gene. The GFP construct was transformed into Nostoc punctiforme A TCC 29133 by electroporation and expression of GFP was visualized by fluorescence microscopy. (authors)

  16. Distribution of heavy metals from flue gas in algal bioreactor

    Science.gov (United States)

    Napan, Katerine

    Flue gas from coal-fired power plants is a major source of CO2 to the atmosphere. Microalgae can use this enriched form of CO2 as carbon source and in turn the biomass can be used to produce food, feed, fertilizer and biofuels. However, along with CO2, coal-based flue gas will inevitably introduce heavy metals, which have a high affinity to bind algal cells, could be toxic to the organisms and if transferred to the products could limit their uses. This study seeks to address the distribution and impact of heavy metals present in flue gas on microalgae production systems. To comprehend its effects, algae Scenedesmus obliquus was grown in batch reactors in a multimetal system. Ten heavy metals (Cu, Co, Zn, Pb, As, Se, Cr, Hg, Ni and Cd) were selected and were evaluated at four concentrations (1X, 2X, 5X and 10X). Results show that most heavy metals accumulated mainly in biomass and were found in very low concentrations in media. Hg was shown to be lost from the culture, with low amounts present in the biomass. An upper limit for As uptake was observed, suggesting its likelihood to build-up in the system during medium recycle. The As limited bioaccumulation was overcome by addition of sulfur to the algal medium. Heavy metal at 2X, 5X and 10X inhibited both growth and lipid production, while at the reference concentration both biomass and lipids yields were increased. Heavy metal concentrations in the medium and biomass were time dependent, and at the end of the cultivation most heavy metals in the supernatant solution complied with the recommendations for irrigation water, while biomass was below limits for cattle and poultry feed, fertilizer, plastic and paper. This research shows that bioremediation of CO2 and heavy metals in combination with energy production can be integrated, which is an environmentally friendly form of biotechnology.

  17. Mode of action of mosquitocidal Bacillus thuringiensis toxins.

    Science.gov (United States)

    Soberón, Mario; Fernández, Luisa E; Pérez, Claudia; Gill, Sarjeet S; Bravo, Alejandra

    2007-04-01

    Cry toxins from Bacillus thuringiensis (Bt) are used for insect control. Their primary action is to lyse midgut epithelial cells. In lepidopteran insects, Cry1A monomeric toxins interact with a first receptor and this interaction triggers toxin oligomerization. The oligomeric structure interacts then with a second GPI-anchored receptor that induces insertion into membrane microdomains and larvae death. In the case of mosquitocidal Bt strains, two different toxins participate, Cry and Cyt. These toxins have a synergistic effect and Cyt1Aa overcomes Cry toxin-resistance. We will summarize recent findings on the identification of Cry receptors in mosquitoes and the mechanism of synergism: Cyt1Aa synergizes or suppresses resistance to Cry toxins by functioning as a Cry membrane-bound receptor. PMID:17145072

  18. Daphnia fed algal food grown at elevated temperature have reduced fitness

    Directory of Open Access Journals (Sweden)

    Anna B. Sikora

    2014-05-01

    Full Text Available Lake water temperature is negatively correlated with fatty acids content and P:C ratio in green algae. Hence, elevated temperature may indirectly reduce the fitness of Daphnia due to induced decrease in algal food quality. The aim of this study was to test the hypotheses that quality of algal food decreases with increasing temperature of its culture and that large-bodied Daphnia are more vulnerable to the temperature-related deterioration of algal food quality than small-bodied ones. Laboratory life-table experiments were performed at 20°C with large-bodied D. pulicaria and small-bodied D. cucullata fed with the green alga Scenedesmus obliquus, that had been grown at temperatures of 16, 24 or 32°C. The somatic growth rates of both species decreased significantly with increasing algal culture temperature and this effect was more pronounced in D. pulicaria than in D. cucullata. In the former species, age at first reproduction significantly increased and clutch size significantly decreased with increasing temperature of algae growth, while no significant changes in these two parameters were observed in the latter species. The proportion of egg-bearing females decreased with increasing algal culture temperature in both species. The results of this study support the notion that the quality of algal food decreases with increasing water temperature and also suggest that small-bodied Daphnia species might be less vulnerable to temperature-related decreases in algal food quality than large-bodied ones.

  19. Algal Pretreatment Improves Biofuels Yield and Value; Highlights in Science, NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-15

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. This research has been highlighted in the Green Chemistry journal article mentioned above and a milestone report, and is based on the work the researchers are doing for the AOP projects Algal Biomass Conversion and Algal Biofuels Techno-economic Analysis. That work has demonstrated an advanced process for algal biofuel production that captures the value of both the algal lipids and carbohydrates for conversion to biofuels.  With this process, as much as 150 GGE/ton of biomass can be produced, 2-3X more than can be produced by terrestrial feedstocks.  This can also reduce the cost of biofuel production by as much as 40%. This also represents the first ever design case for the algal lipid upgrading pathway.

  20. The native forms of the phycobilin chromophores of algal biliproteins. A clarification.

    Science.gov (United States)

    O'Carra, P; Murphy, R F; Killilea, S D

    1980-05-01

    Pigments released from phycoerythrins and phycocyanins by treatment with hot methanol are currently regarded as equivalent to the native chromophores phycoerythrobilin and phycocyanobilin. However, evidence presented here confirms the original view of O'Carra & O'hEocha [(1966 Phytochemistry 5, 993-997] that these methanol-released pigments are artefacts differing in their chromophoric conjugated systems from the native protein-bound prosthetic groups. By contrast, the native spectral properties are retained in pigments released by careful acid treatment of the biliproteins and these acid-released phycobilins, rather than the methanol-released pigments, are therefore regarded as the protein-free forms of the native chromophores. The conclusion reached by Chapman, Cole & Siegelman [(1968) J. Am. Chem. Soc. 89, 3643-3645], that all the algal biliproteins contain only phycoerythrobilin and phycocyanobilin, is shown to be incorrect. The identification of a urobilinoid chromophore, phycourobilin, accompanying phycoerythrobilin in B- and R- phycoerythrins is confirmed and supported by more extensive evidence. The cryptomonad phycocyanins are shown to contain a phycobilin chromophore accompanying phycocyanobilin. This further phycobilin has the spectral properties of the class of bilins known as violins and the provisional name "cryptoviolin" is proposed pending elucidation of its structure. PMID:7396851

  1. General synthesis of β-alanine-containing spider polyamine toxins and discovery of nephila polyamine toxins 1 and 8 as highly potent inhibitors of ionotropic glutamate receptors

    DEFF Research Database (Denmark)

    Lucas, Simon; Poulsen, Mette H; Nørager, Niels G;

    2012-01-01

    Certain spiders contain large pools of polyamine toxins, which are putative pharmacological tools awaiting further discovery. Here we present a general synthesis strategy for this class of toxins and prepare five structurally varied polyamine toxins. Electrophysiological testing at three ionotropic...

  2. Evolutionary Significance of an Algal Gene Encoding an [FeFe]-Hydrogenase with F-Domain Homology and Hydrogenase Activity in Chlorella Variabilis NC64A

    Energy Technology Data Exchange (ETDEWEB)

    Meuser, J. E.; Boyd, E. S.; Ananyev, G.; Karns, D.; Radakovits, R.; Murthy, U. M. N.; Ghirardi, M. L.; Dismukes, G. C.; Peters, J. W.; Posewitz, M. C.

    2011-10-01

    [FeFe]-hydrogenases (HYDA) link the production of molecular H{sub 2} to anaerobic metabolism in many green algae. Similar to Chlamydomonas reinhardtii, Chlorella variabilis NC64A (Trebouxiophyceae, Chlorophyta) exhibits [FeFe]-hydrogenase (HYDA) activity during anoxia. In contrast to C. reinhardtii and other chlorophycean algae, which contain hydrogenases with only the HYDA active site (H-cluster), C. variabilis NC64A is the only known green alga containing HYDA genes encoding accessory FeS cluster-binding domains (F-cluster). cDNA sequencing confirmed the presence of F-cluster HYDA1 mRNA transcripts, and identified deviations from the in silico splicing models. We show that HYDA activity in C. variabilis NC64A is coupled to anoxic photosynthetic electron transport (PSII linked, as well as PSII-independent) and dark fermentation. We also show that the in vivo H{sub 2}-photoproduction activity observed is as O2 sensitive as in C. reinhardtii. The two C. variabilis NC64A HYDA sequences are similar to homologs found in more deeply branching bacteria (Thermotogales), diatoms, and heterotrophic flagellates, suggesting that an F-cluster HYDA is the ancestral enzyme in algae. Phylogenetic analysis indicates that the algal HYDA H-cluster domains are monophyletic, suggesting that they share a common origin, and evolved from a single ancestral F-cluster HYDA. Furthermore, phylogenetic reconstruction indicates that the multiple algal HYDA paralogs are the result of gene duplication events that occurred independently within each algal lineage. Collectively, comparative genomic, physiological, and phylogenetic analyses of the C. variabilis NC64A hydrogenase has provided new insights into the molecular evolution and diversity of algal [FeFe]-hydrogenases.

  3. An integrated renewable energy park approach for algal biofuel production in United States

    International Nuclear Information System (INIS)

    Algal biomass provides viable third generation feedstock for liquid transportation fuel that does not compete with food crops for cropland. However, fossil energy inputs and intensive water usage diminishes the positive aspects of algal energy production. An integrated renewable energy park (IREP) approach is proposed for aligning renewable energy industries in resource-specific regions in United States for synergistic electricity and liquid biofuel production from algal biomass with net zero carbon emissions. The benefits, challenges and policy needs of this approach are discussed.

  4. Algal Biomass Analysis by Laser-Based Analytical Techniques—A Review

    Directory of Open Access Journals (Sweden)

    Pavel Pořízka

    2014-09-01

    Full Text Available Algal biomass that is represented mainly by commercially grown algal strains has recently found many potential applications in various fields of interest. Its utilization has been found advantageous in the fields of bioremediation, biofuel production and the food industry. This paper reviews recent developments in the analysis of algal biomass with the main focus on the Laser-Induced Breakdown Spectroscopy, Raman spectroscopy, and partly Laser-Ablation Inductively Coupled Plasma techniques. The advantages of the selected laser-based analytical techniques are revealed and their fields of use are discussed in detail.

  5. Mitochondrial origins.

    OpenAIRE

    Yang, D.; Oyaizu, Y; Oyaizu, H; Olsen, G J; Woese, C R

    1985-01-01

    The 16S ribosomal RNA sequences from Agrobacterium tumefaciens and Pseudomonas testosteroni have been determined to further delimit the origin of the endosymbiont that gave rise to the mitochondrion. These two prokaryotes represent the alpha and beta subdivisions, respectively, of the so-called purple bacteria. The endosymbiont that gave rise to the mitochondrion belonged to the alpha subdivision, a group that also contains the rhizobacteria, the agrobacteria, and the rickettsias--all prokary...

  6. Toxin(s), Other Than Cholera Toxin, Produced by Environmental Non O1 Non O139 Vibrio cholerae

    Institute of Scientific and Technical Information of China (English)

    Kohinur Begum; Chowdhury R. Ahsan; Mohammad Ansaruzzaman; Dilip K. Dutta; Qazi S.Ahmad; Kaisar A. Talukder

    2006-01-01

    A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analysis.Eighteen representative strains were tested for enterotoxin production using a rabbit ileal loop model, of which live cells of 8 strains and culture filtrates of 6 strains produced fluid accumulation in ileal loops. However, none of them produced heat stable toxin (ST), as detected by suckling mouse assay. On the other hand, 15% of isolates produced cytotoxin as detected by the Chinese Hamster Ovary (CHO) cell assay. Fifty times concentrated culture filtrates of the representative strains did not give any precipitin band against the anti-cholera toxin, suggesting the strains produced an enterotoxin, which is antigenically different from known cholera toxin (CT). Eighty percent of the total isolates were found to be positive for heat labile haemolysin detected by tube method, whereas, 39% were found positive by the Christie-Atkins-Munch-Petersen (CAMP) method. However, 87% of the isolates were positive for haemagglutinin/protease and all of the strains were positive for mannose-sensitive-haemagglutinin assay.

  7. Sea Anemone (Cnidaria, Anthozoa, Actiniaria Toxins: An Overview

    Directory of Open Access Journals (Sweden)

    Agostinho Antunes

    2012-08-01

    Full Text Available The Cnidaria phylum includes organisms that are among the most venomous animals. The Anthozoa class includes sea anemones, hard corals, soft corals and sea pens. The composition of cnidarian venoms is not known in detail, but they appear to contain a variety of compounds. Currently around 250 of those compounds have been identified (peptides, proteins, enzymes and proteinase inhibitors and non-proteinaceous substances (purines, quaternary ammonium compounds, biogenic amines and betaines, but very few genes encoding toxins were described and only a few related protein three-dimensional structures are available. Toxins are used for prey acquisition, but also to deter potential predators (with neurotoxicity and cardiotoxicity effects and even to fight territorial disputes. Cnidaria toxins have been identified on the nematocysts located on the tentacles, acrorhagi and acontia, and in the mucous coat that covers the animal body. Sea anemone toxins comprise mainly proteins and peptides that are cytolytic or neurotoxic with its potency varying with the structure and site of action and are efficient in targeting different animals, such as insects, crustaceans and vertebrates. Sea anemones toxins include voltage-gated Na+ and K+ channels toxins, acid-sensing ion channel toxins, Cytolysins, toxins with Kunitz-type protease inhibitors activity and toxins with Phospholipase A2 activity. In this review we assessed the phylogentic relationships of sea anemone toxins, characterized such toxins, the genes encoding them and the toxins three-dimensional structures, further providing a state-of-the-art description of the procedures involved in the isolation and purification of bioactive toxins.

  8. Toxins for Transgenic Resistance to Hemipteran Pests

    Directory of Open Access Journals (Sweden)

    Bryony C. Bonning

    2012-06-01

    Full Text Available The sap sucking insects (Hemiptera, which include aphids, whiteflies, plant bugs and stink bugs, have emerged as major agricultural pests. The Hemiptera cause direct damage by feeding on crops, and in some cases indirect damage by transmission of plant viruses. Current management relies almost exclusively on application of classical chemical insecticides. While the development of transgenic crops expressing toxins derived from the bacterium Bacillus thuringiensis (Bt has provided effective plant protection against some insect pests, Bt toxins exhibit little toxicity against sap sucking insects. Indeed, the pest status of some Hemiptera on Bt-transgenic plants has increased in the absence of pesticide application. The increased pest status of numerous hemipteran species, combined with increased prevalence of resistance to chemical insecticides, provides impetus for the development of biologically based, alternative management strategies. Here, we provide an overview of approaches toward transgenic resistance to hemipteran pests.

  9. Shiga Toxin Interaction with Human Intestinal Epithelium

    OpenAIRE

    Stephanie Schüller

    2011-01-01

    After ingestion via contaminated food or water, enterohaemorrhagic E. coli colonises the intestinal mucosa and produces Shiga toxins (Stx). No Stx-specific secretion system has been described so far, and it is assumed that Stx are released into the gut lumen after bacterial lysis. Human intestinal epithelium does not express the Stx receptor Gb3 or other Stx binding sites, and it remains unknown how Stx cross the intestinal epithelial barrier and gain access to the systemic circulation. This ...

  10. Abstract Action Potential Models for Toxin Recognition

    OpenAIRE

    Peterson, James; Khan, Taufiquar

    2005-01-01

    In this paper, we present a robust methodology using mathematical pattern recognition schemes to detect and classify events in action potentials for recognizing toxins in biological cells. We focus on event detection in action potential via abstraction of information content into a low dimensional feature vector within the constrained computational environment of a biosensor. We use generated families of action potentials from a classic Hodgkin–Huxley model to verify our methodology and build...

  11. Toxins for Transgenic Resistance to Hemipteran Pests

    OpenAIRE

    Bryony C. Bonning; Chougule, Nanasaheb P.

    2012-01-01

    The sap sucking insects (Hemiptera), which include aphids, whiteflies, plant bugs and stink bugs, have emerged as major agricultural pests. The Hemiptera cause direct damage by feeding on crops, and in some cases indirect damage by transmission of plant viruses. Current management relies almost exclusively on application of classical chemical insecticides. While the development of transgenic crops expressing toxins derived from the bacterium Bacillus thuringiensis (Bt) ha...

  12. Natural Toxins for Use in Pest Management

    OpenAIRE

    Schrader, Kevin K.; Nurhayat Tabanca; Wedge, David E; Meepagala, Kumudini M.; Cantrell, Charles L.; Duke, Stephen O.

    2010-01-01

    Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are highly successful products based on natural compounds in the major pesticide classes. These include the herbicide glufosinate (synthetic phosphinothricin), the spinosad insecticides, and the strobilurin f...

  13. Prokaryotic toxin-antitoxin systems--the role in bacterial physiology and application in molecular biology.

    Science.gov (United States)

    Bukowski, Michal; Rojowska, Anna; Wladyka, Benedykt

    2011-01-01

    Bacteria have developed multiple complex mechanisms ensuring an adequate response to environmental changes. In this context, bacterial cell division and growth are subject to strict control to ensure metabolic balance and cell survival. A plethora of studies cast light on toxin-antitoxin (TA) systems as metabolism regulators acting in response to environmental stress conditions. Many of those studies suggest direct relations between the TA systems and the pathogenic potential or antibiotic resistance of relevant bacteria. Other studies point out that TA systems play a significant role in ensuring stability of mobile genetic material. The evolutionary origin and relations between various TA systems are still a subject of a debate. The impact of toxin-antitoxin systems on bacteria physiology prompted their application in molecular biology as tools allowing cloning of some hard-to-maintain genes, plasmid maintenance and production of recombinant proteins.

  14. Original Copies

    DEFF Research Database (Denmark)

    Sørensen, Tim Flohr

    2013-01-01

    copied imported foreign artefacts, and that lithic producers tried to imitate bronze artefacts in flint. This article argues that these archaeological attitudes to resemblance in the material repertoire are a product of typological analyses, but that it is possible to reclaim the cultural reality...... of similarity by looking at artefactual similarity as the results of prototyping and as a production of simulacra. In this light, the concept of copying turns out to be more than simply a matter of trying to imitate an exotic or prestigious original, and it fundamentally raises the question how different a copy...

  15. The Biology of the Cytolethal Distending Toxins

    Directory of Open Access Journals (Sweden)

    Teresa Frisan

    2011-03-01

    Full Text Available The cytolethal distending toxins (CDTs, produced by a variety of Gram-negative pathogenic bacteria, are the first bacterial genotoxins described, since they cause DNA damage in the target cells. CDT is an A-B2 toxin, where the CdtA and CdtC subunits are required to mediate the binding on the surface of the target cells, allowing internalization of the active CdtB subunit, which is functionally homologous to the mammalian deoxyribonuclease I. The nature of the surface receptor is still poorly characterized, however binding of CDT requires intact lipid rafts, and its internalization occurs via dynamin-dependent endocytosis. The toxin is retrograde transported through the Golgi complex and the endoplasmic reticulum, and subsequently translocated into the nuclear compartment, where it exerts the toxic activity. Cellular intoxication induces DNA damage and activation of the DNA damage responses, which results in arrest of the target cells in the G1 and/or G2 phases of the cell cycle and activation of DNA repair mechanisms. Cells that fail to repair the damage will senesce or undergo apoptosis. This review will focus on the well-characterized aspects of the CDT biology and discuss the questions that still remain unanswered.

  16. Perfringolysin O: The Underrated Clostridium perfringens Toxin?

    Directory of Open Access Journals (Sweden)

    Stefanie Verherstraeten

    2015-05-01

    Full Text Available The anaerobic bacterium Clostridium perfringens expresses multiple toxins that promote disease development in both humans and animals. One such toxin is perfringolysin O (PFO, classically referred to as θ toxin, a pore-forming cholesterol-dependent cytolysin (CDC. PFO is secreted as a water-soluble monomer that recognizes and binds membranes via cholesterol. Membrane-bound monomers undergo structural changes that culminate in the formation of an oligomerized prepore complex on the membrane surface. The prepore then undergoes conversion into the bilayer-spanning pore measuring approximately 250–300 Å in diameter. PFO is expressed in nearly all identified C. perfringens strains and harbors interesting traits that suggest a potential undefined role for PFO in disease development. Research has demonstrated a role for PFO in gas gangrene progression and bovine necrohemorrhagic enteritis, but there is limited data available to determine if PFO also functions in additional disease presentations caused by C. perfringens. This review summarizes the known structural and functional characteristics of PFO, while highlighting recent insights into the potential contributions of PFO to disease pathogenesis.

  17. Review of Water Consumption and Water Conservation Technologies in the Algal Biofuel Process.

    Science.gov (United States)

    Tu, Qingshi; Lu, Mingming; Thiansathit, Worrarat; Keener, Tim C

    2016-01-01

    Although water is one of the most critical factors affecting the sustainable development of algal biofuels, it is much less studied as compared to the extensive research on algal biofuel production technologies. This paper provides a review of the recent studies on water consumption of the algae biofuel process and presents the water conservation technologies applicable at different stages of the algal biofuel process. Open ponds tend to have much higher water consumption (216 to 2000 gal/gal) than photobioreactors (25 to 72 gal/gal). Algae growth accounts for the highest water consumption (165 to 2000 gal/gal) in the open pond system. Water consumption during harvesting, oil extraction, and biofuel conversion are much less compared with the growth stage. Potential water conservation opportunities include technology innovations and better management practices at different stages of algal biofuel production.

  18. Effect of Tetracycline Antibiotics on Performance and Microbial Community of Algal Photo-Bioreactor.

    Science.gov (United States)

    Taşkan, Ergin

    2016-07-01

    Tetracycline antibiotics have been increasingly used in medical applications and have been found in wastewater treatment plants as a result of human and industrial activities. This study investigates the combined effects of tetracycline antibiotics on the performance of an algal photo-bioreactor operated under different antibiotic concentrations in the ranges of 0.25 to 30 mg/L and considers the inhibition of algal growth, carbon and nutrient removal rates, and eukaryotic and cyanobacterial algal community changes. The results indicated that increases in the concentration of tetracycline mixtures have adverse effects on the algal community and the performance of a photo-bioreactor, and the eukaryotic algae species were more sensitive to tetracycline antibiotics than were the cyanobacterial species. Cultivation tests showed that approximately 94 % growth inhibition of mixed algae occurred at 30 mg/L. PMID:26961083

  19. Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa.

    Science.gov (United States)

    Shukla, Rishikesh; Kumar, Manoj; Chakraborty, Subhojit; Gupta, Rishi; Kumar, Savindra; Sahoo, Dinabandhu; Kuhad, Ramesh Chander

    2016-11-01

    The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale.

  20. Carbohydrate-degrading bacteria closely associated with Tetraselmis indica: Influence on algal growth

    Digital Repository Service at National Institute of Oceanography (India)

    Arora, M.; Anil, A.C.; Delany, J.; Rajarajan, N.; Emami, K.; Mesbahi, E.

    The interactions between the algal species Tetraselmis indica and strains of bacteria are examined. Three bacterial strains were isolated and sequence analysis of the 16S rDNA indicated that the organisms belong to the genera Pseudomonas...

  1. Non-conventional approaches to food processing in CELSS. I - Algal proteins: Characterization and process optimization

    Science.gov (United States)

    Nakhost, Z.; Karel, M.; Krukonis, V. J.

    1987-01-01

    Protein isolate obtained from green algae (Scenedesmus obliquus) cultivated under controlled conditions was characterized. Molecular weight determination of fractionated algal proteins using SDS-polyacrylamide gel electrophoresis revealed a wide spectrum of molecular weights ranging from 15,000 to 220,000. Isoelectric points of dissociated proteins were in the range of 3.95 to 6.20. Amino acid composition of protein isolate compared favorably with FAO standards. High content of essential amino acids leucine, valine, phenylalanine and lysine makes algal protein isolate a high quality component of CELSS diets. To optimize the removal of algal lipids and pigments supercritical carbon dioxide extraction (with and without ethanol as a co-solvent) was used. Addition of ethanol to supercritical CO2 resulted in more efficient removal of algal lipids and produced protein isolate with a good yield and protein recovery. The protein isolate extracted by the above mixture had an improved water solubility.

  2. Harmful algal blooms discovered during the Mote Monthly transect cruises, 1998 and 1999 (NODC Accession 0000532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, have caused massive fish kills in the Gulf of Mexico since the 1500's, with most occurrences on...

  3. Non-conventional approaches to food processing in CELSS, 1. Algal proteins: Characterization and process optimization

    Science.gov (United States)

    Nakhost, Z.; Karel, M.; Krukonis, V. J.

    1987-01-01

    Protein isolate obtained from green algae cultivated under controlled conditions was characterized. Molecular weight determination of fractionated algal proteins using SDS-polyacrylamide gel electrophoresis revealed a wide spectrum of molecular weights ranging from 15,000 to 220,000. Isoelectric points of dissociated proteins were in the range of 3.95 to 6.20. Amino acid composition of protein isolate compared favorably with FAO standards. High content of essential amino acids leucine, valine, phenylalanine and lysine make algal protein isolate a high quality component of closed ecological life support system diets. To optimize the removal of algal lipids and pigments supercritical carbon dioxide extraction (with and without ethanol as a co-solvent) was used. Addition of ethanol to supercritical carbon dioxide resulted in more efficient removal of algal lipids and produced protein isolate with a good yield and protein recovery. The protein isolate extracted by the above mixture had an improved water solubility.

  4. Algal-bloom control by allelopathy of aquatic macrophytes——A review

    Institute of Scientific and Technical Information of China (English)

    Hongying HU; Yu HONG

    2008-01-01

    Algal-bloom control is an important issue for water environment protection as it induces several nega-tive impacts on the lives of aquatic organisms, aquacul-ture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the develop-ment and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macro-phytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.

  5. Cyanobacterial-algal cenoses in ordinary chernozems under the impact of different phytoameliorants

    Science.gov (United States)

    Dubovik, I. E.; Suyundukov, Ya. T.; Khasanova, R. F.; Shalygina, R. R.

    2016-04-01

    General ecological and taxonomic characteristics of cyanobacterial-algal cenoses in ordinary chernozems under different ameliorative plants (phytoameliorants) were studied in the Trans-Ural region of the Republic of Bashkortostan. A comparative analysis of the taxa of studied cenoses in the soils under leguminous herbs and grasses was performed. The phytoameliorative effect of different herbs and their relationships with cyanobacterial-algal cenoses were examined. Overall, 134 cyanoprokaryotic and algal species belonging to 70 genera, 36 families, 15 orders, and 9 classes were identified. Cyanobacterial-algal cenoses included the divisions of Chlorophyta, Cyanoprokaryota, Xanthophyta, Bacillariophyta, and Euglenophyta. Representatives of Ch-, X-, CF-, and P-forms were the leading ecobiomorphs in the studied cenoses.

  6. COMBUSTION ANALYSIS OF ALGAL OIL METHYL ESTER IN A DIRECT INJECTION COMPRESSION IGNITION ENGINE

    Directory of Open Access Journals (Sweden)

    HARIRAM V.

    2013-02-01

    Full Text Available Algal oil methyl ester was derived from microalgae (Spirulina sp. The microalga was cultivated in BG 11 media composition in a photobioreactor. Upon harvesting, the biomass was filtered and dried. The algal oil was obtained by a two step solvent extraction method using hexane and ether solvent. Cyclohexane was added to biomass to expel the remaining algal oil. By this method 92% of algal oil is obtained. Transesterification process was carried out to produce AOME by adding sodium hydroxide and methanol. The AOME was blended with straight diesel in 5%, 10% and 15% blend ratio. Combustion parameters were analyzed on a Kirloskar single cylinder direct injection compression ignition engine. The cylinder pressure characteristics, the rate of pressure rise, heat release analysis, performance and emissions were studied for straight diesel and the blends of AOME’s. AOME 15% blend exhibits significant variation in cylinder pressure and rate of heat release.

  7. Enhancement of Chlorophyll Concentration and Growing Harmful Algal Bloom Along the California Coast

    Science.gov (United States)

    Aceves, Joselyn; Singh, Ramesh

    2016-07-01

    We have carried out detailed analysis of satellite and ground data at different locations, Cal Poly, Goleta, Newport, Santa Monica, and Scripps piers and Monterey, Stearns and Santa Cruz wharfs along the California coast for the period 2008-2015. The sea surface temperature and chlorophyll concentrations derived from satellite data are analyzed together with ground observations of nitrogen, phosphorus, domoic acids and harmful algal blooms. The frequency of harmful algal blooms are found to increase in recent years depending upon the enhancement of chlorophyll concentrations and the discharges along the coast and dynamics of the sea surface temperature. The frequency of harmful algal blooms is higher in the northern California compared to southern California. The anthropogenic activities along the coast have increased which are associated with the forest fires and long range transport of dusts from Asia. The aerosol optical depth derived from satellite data during summer months seems to play an important role in the frequency of harmful algal blooms.

  8. The efficacy and mechanisms of fungal suppression of freshwater harmful algal bloom species

    Energy Technology Data Exchange (ETDEWEB)

    Jia Yong; Han Guomin; Wang Congyan; Guo Peng; Jiang Wenxin; Li Xiaona [School of Life Science, Nanjing University, Nanjing, 210093 (China); Tian Xingjun, E-mail: tianxj@nju.edu.cn [School of Life Science, Nanjing University, Nanjing, 210093 (China)

    2010-11-15

    Microorganisms have attracted worldwide attention as possible agents for inhibiting water blooms. Algae are usually indirectly inhibited and degraded by secretion from microorganisms. In this study, algal cultures Microcystis aeruginosa (Ma) FACH-918, Microcystis flos-aquae (Mf) FACH-1028, Oocystis borgei (Ob) FACH-1108, and M. aeruginosa PCC 7806 were co-cultured with the fungus strain Trichaptum abietinum 1302BG. All algal cells were destroyed within 48 hours (h) of co-incubation. Scanning electron microscope and transmission electron microscope observation revealed that the fungal strain had preying ability on the algal cells. The mechanism may be that the algal cells were encased with a mucous membrane secreted by the fungal mycelia, and finally degraded by the fungus directly.

  9. Effect of macrophyte community composition and nutrient enrichment on plant biomass and algal blooms.

    NARCIS (Netherlands)

    Bakker, E.S.; Van Donk, E.; Declerck, S.A.J.; Helmsing, N.R.; Hidding, B.; Nolet, B.A.

    2010-01-01

    Submerged freshwater macrophytes decline with increasing eutrophication. This has consequences for ecosystem processes in shallow lakes and ponds as macrophytes can reduce algal blooms under eutrophic conditions. We hypothesize that the productivity of submerged vegetation, biomass change under eutr

  10. Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa.

    Science.gov (United States)

    Shukla, Rishikesh; Kumar, Manoj; Chakraborty, Subhojit; Gupta, Rishi; Kumar, Savindra; Sahoo, Dinabandhu; Kuhad, Ramesh Chander

    2016-11-01

    The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale. PMID:27619709

  11. Effect of Algal Inoculation on COD and Nitrogen Removal, and Indigenous Bacterial Dynamics in Municipal Wastewater.

    Science.gov (United States)

    Lee, Jangho; Lee, Jaejin; Shukla, Sudheer Kumar; Park, Joonhong; Lee, Tae Kwon

    2016-05-28

    The effects of algal inoculation on chemical oxygen demand (COD) and total nitrogen (TN) removal, and indigenous bacterial dynamics were investigated in municipal wastewater. Experiments were conducted with municipal wastewater inoculated with either Chlorella vulgaris AG10032, Selenastrum gracile UTEX 325, or Scenedesmus quadricauda AG 10308. C. vulgaris and S. gracile as fast growing algae in municipal wastewater, performed high COD and TN removal in contrast to Sc. quadricauda. The indigenous bacterial dynamics revealed by 16S rRNA gene amplification showed different bacterial shifts in response to different algal inoculations. The dominant bacterial genera of either algal case were characterized as heterotrophic nitrifying bacteria. Our results suggest that selection of indigenous bacteria that symbiotically interact with algal species is important for better performance of wastewater treatment. PMID:26930350

  12. Algal-based immobilization process to treat the effluent from a secondary wastewater treatment plant (WWTP)

    Energy Technology Data Exchange (ETDEWEB)

    He Shengbing, E-mail: heshengbing@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiaotong University, 800 DongChuan Road, Shanghai 200240 (China); Xue Gang [School of Environmental Science and Engineering, Donghua University, Shanghai 200051 (China)

    2010-06-15

    Algal-based immobilization process was applied to treat the effluent from a secondary wastewater treatment plant. Batch test proved that algae could attach onto fiber-bundle carrier in 7 days, and then the algal-based immobilization reactor could reduce TN (total nitrogen) and TP (total phosphorus) significantly within 48 h. Based on the above investigations, the hydraulic retention time (HRT) of the algal-based immobilization reactor in continuous operation mode was determined to be 2 days. During the 91 days of experiment on the treating secondary effluent of Guang-Rao wastewater treatment plant, it was found that the fiber-bundle carrier could collect the heterobacteria and nitrifying bacteria gradually, and thus improved the COD removal efficiency and nitrification performance step by step. Results of the continuous operation indicated that the final effluent could meet the Chinese National First A-level Sewage Discharge Standard when the algal-based immobilization reactor reached steady state.

  13. Determination of Total Carbohydrates in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, S.; Laurens, L. M. L.

    2013-12-01

    This procedure uses two-step sulfuric acid hydrolysis to hydrolyze the polymeric forms of carbohydrates in algal biomass into monomeric subunits. The monomers are then quantified by either HPLC or a suitable spectrophotometric method.

  14. Comparison of Algal Biodiesel Production Pathways Using Life Cycle Assessment Tool

    DEFF Research Database (Denmark)

    Singh, Anoop; Olsen, Stig Irving

    2013-01-01

    The consideration of algal biomass in biodiesel production increased very rapidly in the last decade. A life cycle assessment (LCA) study is presented to compare six different biodiesel production pathways (three different harvesting techniques, i.e., aluminum as flocculent, lime flocculent......, and centrifugation, and two different oil extraction methods, i.e., supercritical CO2 (sCO2) and press and co-solvent extraction). The cultivation of Nannochloropsis sp. considered in a flat-panel photobioreactor (FPPBR). These algal biodiesel production systems were compared with the conventional diesel in a EURO 5...... passenger car used for transport purpose (functional unit 1 person km (pkm). The algal biodiesel production systems provide lesser impact (22–105 %) in comparison with conventional diesel. Impacts of algal biodiesel on climate change were far better than conventional diesel, but impacts on human health...

  15. Original Thinking

    Directory of Open Access Journals (Sweden)

    Ashok Natarajan

    2012-04-01

    Full Text Available History that comes to us as a chronology of events is really a collective existence that is evolving through several stages to develop Individuality in all members of the society. The human community, nation states, linguistic groups, local castes and classes, and families are the intermediate stages in development of the Individual. The social process moves through phases of survival, growth, development and evolution. In the process it organizes the consciousness of its members at successive levels from social external manners, formed behavior, value-based character and personality to culminate in the development of Individuality. Through this process, society evolves from physicality to Mentality. The power of accomplishment in society and its members develops progressively through stages of skill, capacity, talent, and ability. Original thinking is made possible by the prior development of thinking that organizes facts into information. The immediate result of the last world war was a shift in reliance from physical force and action to mental conception and mental activity on a global scale. At such times no problem need defy solution, if only humanity recognizes the occasion for thinking and Original Thinking. The apparently insoluble problems we confront are an opportunity to formulate a comprehensive theory of social evolution. The immediate possibility is to devise complete solutions to all existing problems, if only we use the right method of thought development.

  16. EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin

    Science.gov (United States)

    Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R.; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-01-01

    The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins. PMID:27043629

  17. EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin.

    Science.gov (United States)

    Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-04-01

    The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins. PMID:27043629

  18. EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin

    Directory of Open Access Journals (Sweden)

    Leonie Schnell

    2016-04-01

    Full Text Available The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B and a separate enzyme component (A. When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenylsemicarbazone (EGA, a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins.

  19. Supported liquid membrane-liquid chromatography-mass spectrometry analysis of cyanobacterial toxins in fresh water systems

    Science.gov (United States)

    Mbukwa, Elbert A.; Msagati, Titus A. M.; Mamba, Bhekie B.

    Harmful algal blooms (HABs) are increasingly becoming of great concern to water resources worldwide due to indiscriminate waste disposal habits resulting in water pollution and eutrophication. When cyanobacterial cells lyse (burst) they release toxins called microcystins (MCs) that are well known for their hepatotoxicity (causing liver damage) and have been found in eutrophic lakes, rivers, wastewater ponds and other water reservoirs. Prolonged exposure to low concentrated MCs are equally of health importance as they are known to be bioaccumulative and even at such low concentration do exhibit toxic effects to aquatic animals, wildlife and human liver cells. The application of common treatment processes for drinking water sourced from HABs infested reservoirs have the potential to cause algal cell lyses releasing low to higher amounts of MCs in finished water. Trace microcystins in water/tissue can be analyzed and quantified using Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) following solid-phase extraction (SPE) sample clean-up procedures. However, extracting MCs from algal samples which are rich in chlorophyll pigments and other organic matrices the SPE method suffers a number of drawbacks, including cartridge clogging, long procedural steps and use of larger volumes of extraction solvents. We applied a supported liquid membrane (SLM) based technique as an alternative sample clean-up method for LC-ESI-MS analysis of MCs from both water and algal cells. Four (4) MC variants (MC-RR, -YR, -LR and -WR) from lyophilized cells of Microcystis aeruginosa and water collected from a wastewater pond were identified) and quantified using LC-ESI-MS following a SLM extraction and liquid partitioning step, however, MC-WR was not detected from water extracts. Within 45 min of SLM extraction all studied MCs were extracted and pre-concentrated in approximately 15 μL of an acceptor phase at an optimal pH 2.02 of the donor phase (sample). The highest

  20. Spatiotemporal Distribution of Harmful Algal Flora in the Tropical Estuarine Complex of Goa, India

    OpenAIRE

    Pednekar, Suraksha M.; Prabhu Matondkar, S. G.; Vijaya Kerkar

    2012-01-01

    Mandovi and Zuari estuarine complex is monsoon-influenced estuaries located along the central west coast of India. During the past few years, there has been an increase in nutrient loading specially during monsoonal runoff which is responsible for the growth of harmful algal flora. To understand occurrence and distribution of harmful algal blooms species, daily/alternate day samplings were carried out in Mandovi and Zuari estuaries during 2007-2008 and 2008-2009 periods, respectively, compris...

  1. Photoproduction of molecular hydrogen by a plant-algal symbiotic system

    Energy Technology Data Exchange (ETDEWEB)

    Newton, J.W.

    1976-02-13

    The rapidly growing water fern Azolla, which contains a nitrogen-fixing blue-green algal symbiont, has been studied as a possible system for photoproduction of molecular hydrogen. When this plant is grown on a combined nitrogen supply, photochemically generated hydrogen can be diverted through the algal nitrogenase system, which serves as a source of molecular hydrogen generated from water. This symbiosis has several advantages as a possible biological energy conversion system. (auth)

  2. Algal Biofuels Strategy. Proceedings from the March 26-27, 2014, Workshop, Charleston, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-06-01

    This report is based on the proceedings of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy’s Bioenergy Technologies Office’s Algal Biofuel Strategy Workshop on March 26-27, 2014, in Charleston, South Carolina. The workshop objective was to convene stakeholders to engage in discussion on strategies over the next 5 to 10 years to achieve affordable, scalable, and sustainable algal biofuels.

  3. Raman Microspectroscopy of Individual Algal Cells: Sensing Unsaturation of Storage Lipids in vivo

    Directory of Open Access Journals (Sweden)

    Ladislav Nedbal

    2010-09-01

    Full Text Available Algae are becoming a strategic source of fuels, food, feedstocks, and biologically active compounds. This potential has stimulated the development of innovative analytical methods focused on these microorganisms. Algal lipids are among the most promising potential products for fuels as well as for nutrition. The crucial parameter characterizing the algal lipids is the degree of unsaturation of the constituent fatty acids quantified by the iodine value. Here we demonstrate the capacity of the spatially resolved Raman microspectroscopy to determine the effective iodine value in lipid storage bodies of individual living algal cells. The Raman spectra were collected from three selected algal species immobilized in an agarose gel. Prior to immobilization, the algae were cultivated in the stationary phase inducing an overproduction of lipids. We employed the characteristic peaks in the Raman scattering spectra at 1,656 cm−1 (cis C=C stretching mode and 1,445 cm−1 (CH2 scissoring mode as the markers defining the ratio of unsaturated-to-saturated carbon-carbon bonds of the fatty acids in the algal lipids. These spectral features were first quantified for pure fatty acids of known iodine value. The resultant calibration curve was then used to calculate the effective iodine value of storage lipids in the living algal cells from their Raman spectra. We demonstrated that the iodine value differs significantly for the three studied algal species. Our spectroscopic estimations of the iodine value were validated using GC-MS measurements and an excellent agreement was found for the Trachydiscus minutus species. A good agreement was also found with the earlier published data on Botryococcus braunii. Thus, we propose that Raman microspectroscopy can become technique of choice in the rapidly expanding field of algal biotechnology.

  4. Fold modulating function: Bacterial toxins to functional amyloids

    Directory of Open Access Journals (Sweden)

    Adnan Khawaja Syed

    2014-08-01

    Full Text Available Many bacteria produce cytolytic toxins that target host cells or other competing microbes. It is well known that environmental factors control toxin expression, however recent work suggests that some bacteria manipulate the fold of these protein toxins to control their function. The β-sheet rich amyloid fold is a highly stable ordered aggregate that many toxins form in response to specific environmental conditions. When in the amyloid state, toxins become inert, losing the cytolytic activity they display in the soluble form. Emerging evidence suggest that some amyloids function as toxin storage systems until they are again needed, while other bacteria utilize amyloids as a structural matrix component of biofilms. This amyloid matrix component facilitates resistance to biofilm disruptive challenges. The bacterial amyloids discussed in this review reveal an elegant system where changes in protein fold and solubility dictate the function of proteins in response to the environment.

  5. Cytoskeleton as an Emerging Target of Anthrax Toxins

    Directory of Open Access Journals (Sweden)

    Jean-Nicolas Tournier

    2012-02-01

    Full Text Available Bacillus anthracis, the agent of anthrax, has gained virulence through its exotoxins produced by vegetative bacilli and is composed of three components forming lethal toxin (LT and edema toxin (ET. So far, little is known about the effects of these toxins on the eukaryotic cytoskeleton. Here, we provide an overview on the general effects of toxin upon the cytoskeleton architecture. Thus, we shall discuss how anthrax toxins interact with their receptors and may disrupt the interface between extracellular matrix and the cytoskeleton. We then analyze what toxin molecular effects on cytoskeleton have been described, before discussing how the cytoskeleton may help the pathogen to corrupt general cell processes such as phagocytosis or vascular integrity.

  6. Recent Insights into Clostridium perfringens Beta-Toxin

    Directory of Open Access Journals (Sweden)

    Masahiro Nagahama

    2015-02-01

    Full Text Available Clostridium perfringens beta-toxin is a key mediator of necrotizing enterocolitis and enterotoxemia. It is a pore-forming toxin (PFT that exerts cytotoxic effect. Experimental investigation using piglet and rabbit intestinal loop models and a mouse infection model apparently showed that beta-toxin is the important pathogenic factor of the organisms. The toxin caused the swelling and disruption of HL-60 cells and formed a functional pore in the lipid raft microdomains of sensitive cells. These findings represent significant progress in the characterization of the toxin with knowledge on its biological features, mechanism of action and structure-function having been accumulated. Our aims here are to review the current progresses in our comprehension of the virulence of C. perfringens type C and the character, biological feature and structure-function of beta-toxin.

  7. Removing nitrogen and phosphorus from simulated wastewater using algal biofilm technique

    Institute of Scientific and Technical Information of China (English)

    Qun WEI; Zhiquan HU; Genbao LI; Bo XIAO; Hao SUN; Meiping TAO

    2008-01-01

    Algal biofilm technology is a new and advanced wastewater treatment method. Experimental study on removing nitrogen and phosphorus from simulated waste-water using algal biofilm under the continuous light of 3500 Lux in the batch and continuous systems was carried out in this paper to assess the performance of algal biofilm in removing nutrients. The results showed that the effect of removing nitrogen and phosphorus by algal biofilm was remarkable in the batch system. The removal efficiencies of total phosphorus (TP), total nitrogen (TN), ammonia-nitrogen (NH3-N), and chemical oxygen demand (COD) reached 98.17%, 86.58%, 91.88%, and 97.11%, respect-ively. In the continuous system, hydraulic retention time (HRT) of 4 days was adopted; the effects of removing TP, TN, NH3-N, and COD by algal biofilm were very stable. During a run of 24 days, the removal efficiencies of TP, TN, NH3-N, and COD reached 95.38%, 83.93%, 82.38%, and 92.31%, respectively. This study demonstrates the feasibility of removing nitrogen and phosphorus from simulated wastewater using algal biofilm.

  8. Emerging contaminant degradation and removal in algal wastewater treatment ponds: Identifying the research gaps.

    Science.gov (United States)

    Norvill, Zane N; Shilton, Andy; Guieysse, Benoit

    2016-08-01

    Whereas the fate of emerging contaminants (ECs) during 'conventional' and 'advanced' wastewater treatment (WWT) has been intensively studied, little research has been conducted on the algal WWT ponds commonly used in provincial areas. The long retention times and large surface areas exposed to light potentially allow more opportunities for EC removal to occur, but experimental evidence is lacking to enable definite predictions about EC fate across different algal WWT systems. This study reviews the mechanisms of EC hydrolysis, sorption, biodegradation, and photodegradation, applying available knowledge to the case of algal WWT. From this basis the review identifies three main areas that need more research due to the unique environmental and ecological conditions occurring in algal WWT ponds: i) the effect of diurnally fluctuating pH and dissolved oxygen upon removal mechanisms; ii) the influence of algae and algal biomass on biodegradation and sorption under relevant conditions; and iii) the significance of EC photodegradation in the presence of dissolved and suspended materials. Because of the high concentration of dissolved organics typically found in algal WWT ponds, most EC photodegradation likely occurs via indirect mechanisms rather than direct photolysis in these systems. PMID:27135171

  9. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture.

  10. Abundance, biomass and composition of spring ice algal and phytoplankton communities of the Laptev Sea (Arctic)

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Abundance, biomass and composition of the ice algal and phytoplankton communities were investigated in the southeastern Laptev Sea in spring 1999.Diatoms dominated the algal communities and pennate diatoms dominated the diatom population. 12 dominant algal species occurred within sea ice and underlying water column, including Fragilariopsis oceanica, F. cylindrus, Nitzschia frigida , N. promare, Achnanthes taeniata , Nitzschia neofrigida , Navicula pelagica , N. vanhoef fenii, N. septentrionalis, Melosira arctica , Clindrotheca closterium and Pyramimonas sp. The algal abundance of bottom 10 cm sea ice varied between 14.6 and 1562.2 × 104 cells l-1 with an average of 639.0 × 104cells l-1 , and the algal biomass ranged from 7.89 to 2093.5 μg C l-1 with an average of 886.9 μg C l-1 , which were generally one order of magnitude higher than those of sub-bottom ice and two orders of magnitude higher than those of underlying surface water. The integrated algal abundance and biomass of lowermost 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 m water column, respectively, suggesting that the ice algae might play an important role in maintaining the coastal marine ecosystem before the thawing of sea ice. Ice algae influenced the phytoplankton community of the underlying water column.However, the "seeding" of ice algae for phytoplankton bloom was negligible because of the low phytoplankton biomass within the underlying water column.

  11. Advancing Commercialization of Algal Biofuels Through Increased Biomass Productivity and Technology Integration

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xuemei [Cellana LLC; Sabarsky, Martin

    2013-09-30

    Cellana is a leading developer of algae-based bioproducts, and its pre-commercial production of marine microalgae takes place at Cellana?s Kona Demonstration Facility (KDF) in Hawaii. KDF is housing more than 70 high-performing algal strains for different bioproducts, of which over 30 have been grown outside at scale. So far, Cellana has produced more than 10 metric tons of algal biomass for the development of biofuels, animal feed, and high-value nutraceuticals. Cellana?s ALDUO algal cultivation technology allows Cellana to grow non-extremophile algal strains at large scale with no contamination disruptions. Cellana?s research and production at KDF have addressed three major areas that are crucial for the commercialization of algal biofuels: yield improvement, cost reduction, and the overall economics. Commercially acceptable solutions have been developed and tested for major factors limiting areal productivity of algal biomass and lipids based on years of R&D work conducted at KDF. Improved biomass and lipid productivity were achieved through strain improvement, culture management strategies (e.g., alleviation of self-shading, de-oxygenation, and efficient CO2 delivery), and technical advancement in downstream harvesting technology. Cost reduction was achieved through optimized CO2 delivery system, flue gas utilization technology, and energy-efficient harvesting technology. Improved overall economics was achieved through a holistic approach by integration of high-value co-products in the process, in addition to yield improvements and cost reductions.

  12. Textural variation within Great Salt Lake algal mounds: Chapter 8.5 in Stromatolites

    Science.gov (United States)

    1976-01-01

    This chapter discusses textural variation within the Great Salt Lake algal mounds. Great Salt Lake algal mounds contain: (1) a framework of non-skeletal, algally induced aragonite precipitates; (2) internal sediment; and (3) inorganic cement. These three elements create a variety of laminated, poorly laminated, and unlaminated internal textures. Interior framework precipitates bear little resemblance to the present living film of the mound surface. Internal texture of the mounds is believed to be largely relict and to have resulted from precipitation by algae different than those presently living at the surface. The most probable cause of local extinction of the algal flora is change in brine salinity. Precipitated blue-green algal structures in ancient rocks may indicate other than normal marine salinity and near shore sedimentation. Extreme variation of internal texture reflects extreme environmental variability typical of closed basin lakes. Recognition of mounds similar to those in the Great Salt Lake can be a first step toward recognition of ancient hyper-saline lake deposits, if such an interpretation is substantiated by consideration of the entire depositional milieu of precipitated algal mounds.

  13. Fusarial toxins: secondary metabolites of Fusarium fungi.

    Science.gov (United States)

    Nesic, Ksenija; Ivanovic, Snezana; Nesic, Vladimir

    2014-01-01

    Exposure to mycotoxins occurs worldwide, even though there are geographic and climatic differences in the amounts produced and occurrence of these substances.Mycotoxins are secondary chemical metabolites of different fungi. They are natural contaminants of cereals, so their presence is often inevitable. Among many genera that produce mycotoxins, Fusarium fungi are the most widespread in cereal-growing areas of the planet. Fusarium fungi produce a diversity of mycotoxin types, whose distributions are also diverse. What is produced and where it is produced is influenced primarily by environmental conditions, and crop production and storage methods. The amount of toxin produced depends on physical (viz., moisture, relative humidity, temperature, and mechanical damage), chemical (viz., carbon dioxide,oxygen, composition of substrate, insecticides and fungicides), and biological factors (viz., plant variety, stress, insects, spore load, etc.). Moisture and temperature have a major influence on mold growth rate and mycotoxin production.Among the most toxic and prevalent fusaria) toxins are the following: zearalenone,fumonisins, moniliformin and trichothecenes (T-2/HT-2 toxin, deoxynivalenol,diacetoxyscirpenol, nivalenol). Zearalenone (ZEA; ZON, F-2 toxin) isaphy to estrogenic compound, primarily a field contaminant, which exhibits estrogenic activity and has been implicated in numerous mycotoxicoses of farm animals,especially pigs. Recently, evidence suggests that ZEA has potential to stimulate the growth of human breast cancer cells. Fumonisins are also cancer-promoting metabolites,of which Fumonisin 8 I (FBI) is the most important. Moniliformin (MON) isalso highly toxic to both animals and humans. Trichothecenes are classified as gastrointestinal toxins, dermatotoxins, immunotoxins, hematotoxins, and gene toxins.T-2 and HT-2 toxin, and diacetoxyscirpenol (DAS, anguidine) are the most toxic mycotoxins among the trichothecene group. Deoxynivalenol (DON, vomitoxin) and

  14. Fusarial toxins: secondary metabolites of Fusarium fungi.

    Science.gov (United States)

    Nesic, Ksenija; Ivanovic, Snezana; Nesic, Vladimir

    2014-01-01

    Exposure to mycotoxins occurs worldwide, even though there are geographic and climatic differences in the amounts produced and occurrence of these substances.Mycotoxins are secondary chemical metabolites of different fungi. They are natural contaminants of cereals, so their presence is often inevitable. Among many genera that produce mycotoxins, Fusarium fungi are the most widespread in cereal-growing areas of the planet. Fusarium fungi produce a diversity of mycotoxin types, whose distributions are also diverse. What is produced and where it is produced is influenced primarily by environmental conditions, and crop production and storage methods. The amount of toxin produced depends on physical (viz., moisture, relative humidity, temperature, and mechanical damage), chemical (viz., carbon dioxide,oxygen, composition of substrate, insecticides and fungicides), and biological factors (viz., plant variety, stress, insects, spore load, etc.). Moisture and temperature have a major influence on mold growth rate and mycotoxin production.Among the most toxic and prevalent fusaria) toxins are the following: zearalenone,fumonisins, moniliformin and trichothecenes (T-2/HT-2 toxin, deoxynivalenol,diacetoxyscirpenol, nivalenol). Zearalenone (ZEA; ZON, F-2 toxin) isaphy to estrogenic compound, primarily a field contaminant, which exhibits estrogenic activity and has been implicated in numerous mycotoxicoses of farm animals,especially pigs. Recently, evidence suggests that ZEA has potential to stimulate the growth of human breast cancer cells. Fumonisins are also cancer-promoting metabolites,of which Fumonisin 8 I (FBI) is the most important. Moniliformin (MON) isalso highly toxic to both animals and humans. Trichothecenes are classified as gastrointestinal toxins, dermatotoxins, immunotoxins, hematotoxins, and gene toxins.T-2 and HT-2 toxin, and diacetoxyscirpenol (DAS, anguidine) are the most toxic mycotoxins among the trichothecene group. Deoxynivalenol (DON, vomitoxin) and

  15. Transcriptional Stimulation of Anthrax Toxin Receptors by Anthrax Edema Toxin and Bacillus anthracis Sterne Spore

    OpenAIRE

    Xu, Qingfu; Hesek, Eric D.; Zeng, Mingtao

    2007-01-01

    We used quantitative real-time RT-PCR to not only investigate the mRNA levels of anthrax toxin receptor 1 (ANTXR1) and 2 (ANTXR2) in the murine J774A.1 macrophage cells and different tissues of mice, but also evaluate the effect of anthrax edema toxin and Bacillus anthracis Sterne spores on the expression of mRNA of these receptors. The mRNA transcripts of both receptors was detected in J774A.1 cells and mouse tissues such as the lung, heart, kidney, spleen, stomach, jejunum, brain, skeleton ...

  16. Staphylococcus hyicus exfoliative toxin: Purification and demonstration of antigenic diversity among toxins from virulent strains

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Bille-Hansen, Vivi; Wegener, Henrik Caspar

    1997-01-01

    The exfoliative toxin produced by Staphylococcus hyicus strain 1289D-88 was purified as a single protein of approximately 30 kDa. Extracellular proteins of S. hyicus grown under small scale fermentation conditions were precipitated with ammonium sulfate. Separation of proteins was performed...... by hydrophobic interaction chromatography and successively anion exchange chromatography. The purified toxin was tested in a piglet skin assay. Weak epidermal lesions were macroscopically and microscopically similar to lesions caused by (NH4)(2)SO4-precipitated culture supernatant from the same strain. Addition...

  17. Staphylococcus aureus α-Toxin: Nearly a Century of Intrigue

    Directory of Open Access Journals (Sweden)

    Bryan J. Berube

    2013-06-01

    Full Text Available Staphylococcus aureus secretes a number of host-injurious toxins, among the most prominent of which is the small β-barrel pore-forming toxin α-hemolysin. Initially named based on its properties as a red blood cell lytic toxin, early studies suggested a far greater complexity of α-hemolysin action as nucleated cells also exhibited distinct responses to intoxication. The hemolysin, most aptly referred to as α-toxin based on its broad range of cellular specificity, has long been recognized as an important cause of injury in the context of both skin necrosis and lethal infection. The recent identification of ADAM10 as a cellular receptor for α-toxin has provided keen insight on the biology of toxin action during disease pathogenesis, demonstrating the molecular mechanisms by which the toxin causes tissue barrier disruption at host interfaces lined by epithelial or endothelial cells. This review highlights both the historical studies that laid the groundwork for nearly a century of research on α-toxin and key findings on the structural and functional biology of the toxin, in addition to discussing emerging observations that have significantly expanded our understanding of this toxin in S. aureus disease. The identification of ADAM10 as a proteinaceous receptor for the toxin not only provides a greater appreciation of truths uncovered by many historic studies, but now affords the opportunity to more extensively probe and understand the role of α-toxin in modulation of the complex interaction of S. aureus with its human host.

  18. Role of Toxin Functional Domains in Anthrax Pathogenesis

    OpenAIRE

    Brossier, Fabien; Weber-Levy, Martine; Mock, Michele; SIRARD, Jean-Claude

    2000-01-01

    We investigated the role of the functional domains of anthrax toxins during infection. Three proteins produced by Bacillus anthracis, the protective antigen (PA), the lethal factor (LF), and the edema factor (EF), combine in pairs to produce the lethal (PA+LF) and edema (PA+EF) toxins. A genetic strategy was developed to introduce by allelic exchange specific point mutations or in-frame deletions into B. anthracis toxin genes, thereby impairing either LF metalloprotease or EF adenylate cyclas...

  19. Military Importance of Natural Toxins and Their Analogs.

    Science.gov (United States)

    Pitschmann, Vladimír; Hon, Zdeněk

    2016-01-01

    Toxin weapon research, development, production and the ban on its uses is an integral part of international law, with particular attention paid to the protection against these weapons. In spite of this, hazards associated with toxins cannot be completely excluded. Some of these hazards are also pointed out in the present review. The article deals with the characteristics and properties of natural toxins and synthetic analogs potentially constituting the basis of toxin weapons. It briefly describes the history of military research and the use of toxins from distant history up to the present age. With respect to effective disarmament conventions, it mentions certain contemporary concepts of possible toxin applications for military purposes and the protection of public order (suppression of riots); it also briefly refers to the question of terrorism. In addition, it deals with certain traditional as well as modern technologies of the research, synthesis, and use of toxins, which can affect the continuing development of toxin weapons. These are, for example, cases of new toxins from natural sources, their chemical synthesis, production of synthetic analogs, the possibility of using methods of genetic engineering and modern biotechnologies or the possible applications of nanotechnology and certain pharmaceutical methods for the effective transfer of toxins into the organism. The authors evaluate the military importance of toxins based on their comparison with traditional chemical warfare agents. They appeal to the ethics of the scientific work as a principal condition for the prevention of toxin abuse in wars, military conflicts, as well as in non-military attacks. PMID:27136512

  20. ArachnoServer: a database of protein toxins from spiders

    OpenAIRE

    Kaas Quentin; Raven Robert J; Cai Shuzhi; Miljenović Tomas; Wood David LA; Escoubas Pierre; Herzig Volker; Wilson David; King Glenn F

    2009-01-01

    Abstract Background Venomous animals incapacitate their prey using complex venoms that can contain hundreds of unique protein toxins. The realisation that many of these toxins may have pharmaceutical and insecticidal potential due to their remarkable potency and selectivity against target receptors has led to an explosion in the number of new toxins being discovered and characterised. From an evolutionary perspective, spiders are the most successful venomous animals and they maintain by far t...

  1. ATDB: a uni-database platform for animal toxins

    OpenAIRE

    He, Quan-Yuan; He, Quan-Ze; Deng, Xing-Can; Yao, Lei; Meng, Er; Liu, Zhong-Hua; Liang, Song-Ping

    2007-01-01

    Venomous animals possess an arsenal of toxins for predation and defense. These toxins have great diversity in function and structure as well as evolution and therefore are of value in both basic and applied research. Recently, toxinomics researches using cDNA library sequencing and proteomics profiling have revealed a large number of new toxins. Although several previous groups have attempted to manage these data, most of them are restricted to certain taxonomic groups and/or lack effective s...

  2. ClanTox: a classifier of short animal toxins

    OpenAIRE

    Naamati, Guy; Askenazi, Manor; Linial, Michal

    2009-01-01

    Toxins are detected in sporadic species along the evolutionary tree of the animal kingdom. Venomous animals include scorpions, snakes, bees, wasps, frogs and numerous animals living in the sea such as the stonefish, snail, jellyfish, hydra and more. Interestingly, proteins that share a common scaffold with animal toxins also exist in non-venomous species. However, due to their short length and primary sequence diversity, these, toxin-like proteins remain undetected by classical search engines...

  3. Military Importance of Natural Toxins and Their Analogs

    Directory of Open Access Journals (Sweden)

    Vladimír Pitschmann

    2016-04-01

    Full Text Available Toxin weapon research, development, production and the ban on its uses is an integral part of international law, with particular attention paid to the protection against these weapons. In spite of this, hazards associated with toxins cannot be completely excluded. Some of these hazards are also pointed out in the present review. The article deals with the characteristics and properties of natural toxins and synthetic analogs potentially constituting the basis of toxin weapons. It briefly describes the history of military research and the use of toxins from distant history up to the present age. With respect to effective disarmament conventions, it mentions certain contemporary concepts of possible toxin applications for military purposes and the protection of public order (suppression of riots; it also briefly refers to the question of terrorism. In addition, it deals with certain traditional as well as modern technologies of the research, synthesis, and use of toxins, which can affect the continuing development of toxin weapons. These are, for example, cases of new toxins from natural sources, their chemical synthesis, production of synthetic analogs, the possibility of using methods of genetic engineering and modern biotechnologies or the possible applications of nanotechnology and certain pharmaceutical methods for the effective transfer of toxins into the organism. The authors evaluate the military importance of toxins based on their comparison with traditional chemical warfare agents. They appeal to the ethics of the scientific work as a principal condition for the prevention of toxin abuse in wars, military conflicts, as well as in non-military attacks.

  4. Impact of Iron Porphyrin Complexes when Hydroprocessing Algal HTL Biocrude

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Jacqueline M.; Sudasinghe, Nilusha; Albrecht, Karl O.; Schmidt, Andrew J.; Hallen, Richard T.; Anderson, Daniel B.; Billing, Justin M.; Schaub, Tanner

    2016-06-06

    We apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for direct characterization of iron-porphyrins in hydrothermal liquefaction (HTL) biocrude oils derived from two algae: Tetraselmis sp. and cyanobacteria. The ironporphyrin compounds are shown to cause catalyst bed plugging during hydroprocessing due to iron deposition. Inductively-coupled plasma optical emission spectrometry (ICPOES) was utilized for iron quantitation in the plugged catalyst beds formed through hydroprocessing of the two HTL biocrudes and identifies an enrichment of iron in the upper five centimeters of the catalyst bed for Tetraselmis sp. (Fe=100,728 ppm) and cyanobacteria (Fe=115,450 ppm). Direct infusion FT-ICR MS analysis of the two HTL biocrudes with optimized instrument conditions facilitates rapid screening and identification of iron-porphyrins without prior chromatographic separation. With FT-ICR MS we identify 138 unique iron-porphyrin compounds in the two HTL biocrudes that are structurally similar to metal-porphyrins (e.g. Ni and V) observed in petroleum. No ironporphyrins are observed in the cyanobacteria HTL biocrude after hydroprocessing, which indicates that iron-porphyrin structures in the HTL biocrude are degraded during hydroprocessing. Hydrodemetallization reactions that occur through hydroprocessing of HTL biocrudes could be responsible for the decomposition of iron-porphyrin structures leading to metal deposition in the catalyst bed that result in catalyst deactivation and bed plugging, and must be addressed for effective upgrading of algal HTL biocrudes.

  5. Epilithic Algal Diversity of Cimil Stream (Rize, Turkey

    Directory of Open Access Journals (Sweden)

    Beyhan Taş

    2015-10-01

    Full Text Available The Ikizdere Valley is one of priority ecologic region within 200 areas where is under protection in the world. It is natural conservation area. In this study, epilithic algal diversity of Cimil Stream in the Cimil (Tiron Valley where is one of the most important protection areas were investigated. The ecological structure of the stream is to determine by using indicator algae. According to sampling results obtained from four different stations after rainy and dry seasons (November 2010 and August 2011, total 113 taxa belongs to five different division were identified. Diatoms have the most species diversity in terms of other groups (74, 65%. This was followed by Cyanophyta (28, 25%, Charophyta (6, 5%, Chlorophyta (4, 4% and Euglenophyta (1, 1%. Achnanthidium minutissimum, Cocconeis pediculus, C. placentula, Cymbella affinis, Gomphonema parvulum, G. truncatum, Encyonema minutum, Hannaea arcus, Navicula menisculus, N. salinarum ve Nitzschia palea are common and dominant diatom species in the Cimil Stream. Indicator species showed that the ecological situation of the Cimil Stream is not yet under intense pressure pollution. However, it is seen that the stream showed a change towards β-α-mesosaprobic conditions from oligosaprobic top to bottom. For the area's tourism potential is very high, it is recommended that the necessary measures take as to maintaining ecological structure in future.

  6. Algal photosynthetic activity measurement by 14C uptake, (1)

    International Nuclear Information System (INIS)

    There are many sample preparation techniques for 14C-labeled phytoplankton for radioactivity measurement by liquid scintillation counting. A number of sample preparation procedures were tested to identify the ones most suitable for the intended experiments. The following results were obtained: 1. The calculated radioactivity of solubilized samples were about 10% lower than that of combusted samples. This was caused by settling out of algal cells. 2. The agreement between calculated radioactivity of solubilized samples and combusted samples was improved by the addition of Cab-O-Sil. 3. Virtually all of the residual inorganic 14C radioactivity was removed during drying. 4. The loss of 14C radioactivity caused by formaldehyde fixation differed from species to species. Based on these results, the following procedure was selected for use in our experiments: 1. After incubation with 14C, the 14C-labeled phytoplankton samples were immediately filtered and rinsed with filtered seawater under low illumination. 2. The filters were then dried in a vacuum desiccator with sodalime and silica gel. 3. The dried filters were solubilized with ethylene glycol monomethyl ether-toluene fluor which contains PPO, POPOP, and Cab-O-Sil. 4. The activity of solubilized samples was measured using liquid scintillation counting. (author)

  7. Hydrogen production from algal biomass via steam gasification.

    Science.gov (United States)

    Duman, Gozde; Uddin, Md Azhar; Yanik, Jale

    2014-08-01

    Algal biomasses were tested as feedstock for steam gasification in a dual-bed microreactor in a two-stage process. Gasification experiments were carried out in absence and presence of catalyst. The catalysts used were 10% Fe₂O₃-90% CeO₂ and red mud (activated and natural forms). Effects of catalysts on tar formation and gasification efficiencies were comparatively investigated. It was observed that the characteristic of algae gasification was dependent on its components and the catalysts used. The main role of the catalyst was reforming of the tar derived from algae pyrolysis, besides enhancing water gas shift reaction. The tar reduction levels were in the range of 80-100% for seaweeds and of 53-70% for microalgae. Fe₂O₃-CeO₂ was found to be the most effective catalyst. The maximum hydrogen yields obtained were 1036 cc/g algae for Fucus serratus, 937 cc/g algae for Laminaria digitata and 413 cc/g algae for Nannochloropsis oculata. PMID:24880809

  8. Anaerobic digestion of nitrophilic algal biomass from the Venice Lagoon

    Energy Technology Data Exchange (ETDEWEB)

    Rigoni-Stern, S.; Rismondo, R. (Technital S.p.A., Verona (IT)); Szpyrkowicz, L.; Zilio-Grandi, F. (Venice Univ. (Italy)); Vigato, P.A. (Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi)

    1990-01-01

    The feasibility of producing biogas by anaerobic digestion of a nitrophilic algae biomass obtained from the highly eutrophicated Venice Lagoon has been investigated. Methods for harvesting algal biomass have been examined in detail and different pretreatments used prior to analysis and digestion of the algae described. Results obtained from three pilot plant digesters over a period of 12 months using Ulva rigida and Gracilaria as feed material gave no indication of inhibition of the process by either high salinity or high metals content resulting from pollutants discharged into the lagoon. Sulphides were formed during digestion as a consequence of the high sulphate content of the interstitial water as well as the level of sulphur present in the algae. However, the sulphides did not appear to cause inhibition or result in a reduction in gas yield. A maximum biogas production rate of 0.347 m{sup 3} kg VS{sup -1} day{sup -1} was obtained during digestion at a retention time of 20 days with an organic loading rate of 1 kg VS m{sup -3} day{sup -1}. (author).

  9. EFFECT OF PRETREATMENT OF ALGAL BIOMASS ON BIOADSORPTION OF MANGANESE

    Directory of Open Access Journals (Sweden)

    Mane P. C

    2010-12-01

    Full Text Available The presence of heavy metals in aquatic environment is known to cause severe damage to aquatic life. Most of the heavy metals are soluble in water and form aqueous solutions and consequently cannot be separated by ordinary physical and chemical means of separation. Biological methods such as biosorption/ bioaccumulation for the removal of heavy metal ions may provide an attractive alternative to physico-chemical methods. The biomass is capable of absorbing and adsorbing metal ions from aqueous solution. In this study the effect of pretreatment of Algal biomasses like Spirogyra on the Mn biosorption capacity were investigated under laboratory conditions. For this purpose, the biomasses were subjected to physical treatments such as heat and autoclaving and chemical treatments such as sodium hydroxide and acetic acid. Under laboratory condition, all the pretreated biomass increased biosorption of Mn in comparison with live biomass (spirogyra - 37.75%; Nostoc – 41.73%. The maximum metal removal efficiency was observed under autoclaved biomass (spirogyra - 89.91%; Nostoc – 91.73% followed by acetic acid treatment (spirogyra - 82.90%; Nostoc – 87.83%. Among the pretreatments the oven driedbiomass (spirogyra - 57.23%; Nostoc – 61.81% and NaOH treated cells (spirogyra - 49.90%; Nostoc – 51.54% adsorbed least amount of metal.

  10. Characteristics of turbulent boundary layer flow over algal biofilm

    Science.gov (United States)

    Murphy, Elizabeth; Barros, Julio; Schultz, Michael; Steppe, Cecily; Flack, Karen; Reidenbach, Matthew

    2015-11-01

    Algal biofilms are an important fouling community on ship hulls, with severe economic consequences due to drag-induced increases in fuel use and cleaning costs. Here, we characterize the boundary layer flow structure in turbulent flow over diatomaceous slime, a type of biofilm. Diatomaceous slime composed of three species of diatoms commonly found on ship hulls was grown on acrylic test plates under shear stress. The slime averages 1.6 mm in thickness and has a high density of streamers, which are flexible elongated growths with a length on the order of 1- 2 mm located at the top of the biofilm that interact with the flow. Fouled acrylic plates were placed in a water tunnel facility specialized for detailed turbulent boundary layer measurements. High resolution Particle Image Velocimetry (PIV) data are analyzed for mean velocity profile as well as local turbulent stresses and turbulent kinetic energy (TKE) production, dissipation and transport. Quadrant analysis is used to characterize the impact of the instantaneous events of Reynolds shear stress (RSS) in the flow. To investigate the coherence of the large-scale motion in the flow two-point correlation analysis is employed. Funding provided by the Office of Naval Research and the National Science Foundation.

  11. In vivo reconstitution of algal triacylglycerol production in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Chun-Hsien eHung

    2016-02-01

    Full Text Available The current fascination with algal biofuel production stems from a high lipid biosynthetic capacity and little conflict with land plant cultivation. However, the mechanisms which enable algae to accumulate massive oil remain elusive. An enzyme for triacylglycerol (TAG biosynthesis in Chlamydomonas reinhardtii, CrDGTT2, can produce a large amount of TAG when expressed in yeast or higher plants, suggesting a unique ability of CrDGTT2 to enhance oil production in a heterologous system. Here, we performed metabolic engineering in Saccharomyces cerevisiae by taking advantage of CrDGTT2. We suppressed membrane phospholipid biosynthesis at the log phase by mutating OPI3, enhanced TAG biosynthetic pathway at the stationary phase by overexpressing PAH1 and CrDGTT2, and suppressed TAG hydrolysis on growth resumption from the stationary phase by knocking out DGK1. The resulting engineered yeast cells accumulated about 70-fold of TAG compared with wild type cells. Moreover, TAG production was sustainable. Our results demonstrated the enhanced and sustainable TAG production in the yeast synthetic platform.

  12. Enhancing Algal Growth by Stimulation with LED Lighting and Ultrasound

    Directory of Open Access Journals (Sweden)

    Shao-Yi Hsia

    2015-01-01

    Full Text Available Algae are not only rich in natural nutrients, but are also a high-priced health food. An important constituent called “growth factor” is extracted from algae and used as an ingredient in medical drugs, foods, cosmetics, and other products. Its enormous potential market should not be taken lightly. Algae are mostly found near coastal areas and their habitats are limited by a number of natural factors, leading to large labor and financial expenditures to harvest. This report describes our study of indoor algae production using LED lights and ultrasound and manipulating other growth factors at different temperatures. Ultrasound treatment at the alga’s natural resonant frequency was varied to determine optimal algal growth using the Taguchi method to plan and to analyze the experiments. The results were very satisfying, showing an 8.23% increase in the growth rate by the fifth day due to ultrasound treatment and an amazing 27.01% growth rate due to biomechanical stimulation.

  13. Expanding Fungal Diets Through Synthetic Algal-Fungal Mutualism

    Science.gov (United States)

    Sharma, Alaisha; Galazka, Jonathan (Editor)

    2015-01-01

    Fungi can synthesize numerous molecules with important properties, and could be valuable production platforms for space exploration and colonization. However, as heterotrophs, fungi require reduced carbon. This limits their efficiency in locations such as Mars, where reduced carbon is scarce. We propose a system to induce mutualistic symbiosis between the green algae Chlamydomonas reinhardtii and the filamentous fungi Neurospora crassa. This arrangement would mimic natural algal-fungal relationships found in lichens, but have added advantages including increased growth rate and genetic tractability. N. crassa would metabolize citrate (C6H5O7 (sup -3)) and release carbon dioxide (CO2) that C. reinhardtii would assimilate into organic sugars during photosynthesis. C. reinhardtii would metabolize nitrate (NO3-) and release ammonia (NH3) as a nitrogen source for N. crassa. A N. crassa mutant incapable of reducing nitrate will be used to force this interaction. This system eliminates the need to directly supply its participants with carbon dioxide and ammonia. Furthermore, the release of oxygen by C. reinhardtii via photosynthesis would enable N. crassa to respire. We hope to eventually create a system closer to lichen, in which the algae transfers not only nitrogen but reduced carbon, as organic sugars, to the fungus for growth and production of valuable compounds.

  14. Pyrolysis kinetics of algal consortia grown using swine manure wastewater.

    Science.gov (United States)

    Sharara, Mahmoud A; Holeman, Nathan; Sadaka, Sammy S; Costello, Thomas A

    2014-10-01

    In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 °C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data.

  15. Animal Toxins: How is Complexity Represented in Databases?

    OpenAIRE

    Jungo F.; Estreicher A.; Bairoch A.; Bougueleret L.; Xenarios I.

    2010-01-01

    Peptide toxins synthesized by venomous animals have been extensively studied in the last decades. To be useful to the scientific community, this knowledge has been stored, annotated and made easy to retrieve by several databases. The aim of this article is to present what type of information users can access from each database. ArachnoServer and ConoServer focus on spider toxins and cone snail toxins, respectively. UniProtKB, a generalist protein knowledgebase, has an animal toxin-dedicated a...

  16. Tumor Targeting and Drug Delivery by Anthrax Toxin.

    Science.gov (United States)

    Bachran, Christopher; Leppla, Stephen H

    2016-01-01

    Anthrax toxin is a potent tripartite protein toxin from Bacillus anthracis. It is one of the two virulence factors and causes the disease anthrax. The receptor-binding component of the toxin, protective antigen, needs to be cleaved by furin-like proteases to be activated and to deliver the enzymatic moieties lethal factor and edema factor to the cytosol of cells. Alteration of the protease cleavage site allows the activation of the toxin selectively in response to the presence of tumor-associated proteases. This initial idea of re-targeting anthrax toxin to tumor cells was further elaborated in recent years and resulted in the design of many modifications of anthrax toxin, which resulted in successful tumor therapy in animal models. These modifications include the combination of different toxin variants that require activation by two different tumor-associated proteases for increased specificity of toxin activation. The anthrax toxin system has proved to be a versatile system for drug delivery of several enzymatic moieties into cells. This highly efficient delivery system has recently been further modified by introducing ubiquitin as a cytosolic cleavage site into lethal factor fusion proteins. This review article describes the latest developments in this field of tumor targeting and drug delivery. PMID:27376328

  17. ArachnoServer: a database of protein toxins from spiders

    Directory of Open Access Journals (Sweden)

    Kaas Quentin

    2009-08-01

    Full Text Available Abstract Background Venomous animals incapacitate their prey using complex venoms that can contain hundreds of unique protein toxins. The realisation that many of these toxins may have pharmaceutical and insecticidal potential due to their remarkable potency and selectivity against target receptors has led to an explosion in the number of new toxins being discovered and characterised. From an evolutionary perspective, spiders are the most successful venomous animals and they maintain by far the largest pool of toxic peptides. However, at present, there are no databases dedicated to spider toxins and hence it is difficult to realise their full potential as drugs, insecticides, and pharmacological probes. Description We have developed ArachnoServer, a manually curated database that provides detailed information about proteinaceous toxins from spiders. Key features of ArachnoServer include a new molecular target ontology designed especially for venom toxins, the most up-to-date taxonomic information available, and a powerful advanced search interface. Toxin information can be browsed through dynamic trees, and each toxin has a dedicated page summarising all available information about its sequence, structure, and biological activity. ArachnoServer currently manages 567 protein sequences, 334 nucleic acid sequences, and 51 protein structures. Conclusion ArachnoServer provides a single source of high-quality information about proteinaceous spider toxins that will be an invaluable resource for pharmacologists, neuroscientists, toxinologists, medicinal chemists, ion channel scientists, clinicians, and structural biologists. ArachnoServer is available online at http://www.arachnoserver.org.

  18. Role of receptors in Bacillus thuringiensis crystal toxin activity.

    Science.gov (United States)

    Pigott, Craig R; Ellar, David J

    2007-06-01

    Bacillus thuringiensis produces crystalline protein inclusions with insecticidal or nematocidal properties. These crystal (Cry) proteins determine a particular strain's toxicity profile. Transgenic crops expressing one or more recombinant Cry toxins have become agriculturally important. Individual Cry toxins are usually toxic to only a few species within an order, and receptors on midgut epithelial cells have been shown to be critical determinants of Cry specificity. The best characterized of these receptors have been identified for lepidopterans, and two major receptor classes have emerged: the aminopeptidase N (APN) receptors and the cadherin-like receptors. Currently, 38 different APNs have been reported for 12 different lepidopterans. Each APN belongs to one of five groups that have unique structural features and Cry-binding properties. While 17 different APNs have been reported to bind to Cry toxins, only 2 have been shown to mediate toxin susceptibly in vivo. In contrast, several cadherin-like proteins bind to Cry toxins and confer toxin susceptibility in vitro, and disruption of the cadherin gene has been associated with toxin resistance. Nonetheless, only a small subset of the lepidopteran-specific Cry toxins has been shown to interact with cadherin-like proteins. This review analyzes the interactions between Cry toxins and their receptors, focusing on the identification and validation of receptors, the molecular basis for receptor recognition, the role of the receptor in resistant insects, and proposed models to explain the sequence of events at the cell surface by which receptor binding leads to cell death. PMID:17554045

  19. Botulinum toxin for treatment of glandular hypersecretory disorders.

    LENUS (Irish Health Repository)

    Laing, T A

    2012-02-03

    SUMMARY: The use of botulinum toxin to treat disorders of the salivary glands is increasing in popularity in recent years. Recent reports of the use of botulinum toxin in glandular hypersecretion suggest overall favourable results with minimal side-effects. However, few randomised clinical trials means that data are limited with respect to candidate suitability, treatment dosages, frequency and duration of treatment. We report a selection of such cases from our own department managed with botulinum toxin and review the current data on use of the toxin to treat salivary gland disorders such as Frey\\'s syndrome, excessive salivation (sialorrhoea), focal and general hyperhidrosis, excessive lacrimation and chronic rhinitis.

  20. Nanoparticle-detained toxins for safe and effective vaccination

    Science.gov (United States)

    Hu, Che-Ming J.; Fang, Ronnie H.; Luk, Brian T.; Zhang, Liangfang

    2013-12-01

    Toxoid vaccines--vaccines based on inactivated bacterial toxins--are routinely used to promote antitoxin immunity for the treatment and prevention of bacterial infections. Following chemical or heat denaturation, inactivated toxins can be administered to mount toxin-specific immune responses. However, retaining faithful antigenic presentation while removing toxin virulence remains a major challenge and presents a trade-off between efficacy and safety in toxoid development. Here, we show a nanoparticle-based toxin-detainment strategy that safely delivers non-disrupted pore-forming toxins for immune processing. Using erythrocyte membrane-coated nanoparticles and staphylococcal α-haemolysin, we demonstrate effective virulence neutralization via spontaneous particle entrapment. Compared with vaccination with heat-denatured toxin, mice vaccinated with the nanoparticle-detained toxin showed superior protective immunity against toxin-mediated adverse effects. We find that the non-disruptive detoxification approach benefited the immunogenicity and efficacy of toxoid vaccines. We anticipate that this study will open new possibilities in the preparation of antitoxin vaccines against the many virulence factors that threaten public health.

  1. Gene therapy for carcinoma of the breast: Genetic toxins

    International Nuclear Information System (INIS)

    Gene therapy was initially envisaged as a potential treatment for genetically inherited, monogenic disorders. The applications of gene therapy have now become wider, however, and include cardiovascular diseases, vaccination and cancers in which conventional therapies have failed. With regard to oncology, various gene therapy approaches have been developed. Among them, the use of genetic toxins to kill cancer cells selectively is emerging. Two different types of genetic toxins have been developed so far: the metabolic toxins and the dominant-negative class of toxins. This review describes these two different approaches, and discusses their potential applications in cancer gene therapy

  2. Entry of diphtheria toxin into cells: possible existence of cellular factor(s) for entry of diphtheria toxin into cells was studied in somatic cell hybrids and hybrid toxins

    OpenAIRE

    1984-01-01

    Ehrlich ascites tumor cells were found to be very insensitive to diphtheria toxin. We formed 37 hybrids from Ehrlich tumor cells and diphtheria toxin-sensitive human fibroblasts. The effects of diphtheria toxin on protein synthesis in those hybrids were examined. The hybrids were divided into three groups on the basis of toxin sensitivity. Group A hybrids were as sensitive to diphtheria toxin as human fibroblasts, Group C were as resistant as Ehrlich tumor cells, and Group B had intermediate ...

  3. SVM-Based Prediction of Propeptide Cleavage Sites in Spider Toxins Identifies Toxin Innovation in an Australian Tarantula

    OpenAIRE

    Wong, Emily S. W.; Hardy, Margaret C.; David Wood; Timothy Bailey; Glenn F. King

    2013-01-01

    Spider neurotoxins are commonly used as pharmacological tools and are a popular source of novel compounds with therapeutic and agrochemical potential. Since venom peptides are inherently toxic, the host spider must employ strategies to avoid adverse effects prior to venom use. It is partly for this reason that most spider toxins encode a protective proregion that upon enzymatic cleavage is excised from the mature peptide. In order to identify the mature toxin sequence directly from toxin tran...

  4. Data mining approach identifies research priorities and data requirements for resolving the red algal tree of life

    Directory of Open Access Journals (Sweden)

    Yoon Hwan

    2010-01-01

    Full Text Available Abstract Background The assembly of the tree of life has seen significant progress in recent years but algae and protists have been largely overlooked in this effort. Many groups of algae and protists have ancient roots and it is unclear how much data will be required to resolve their phylogenetic relationships for incorporation in the tree of life. The red algae, a group of primary photosynthetic eukaryotes of more than a billion years old, provide the earliest fossil evidence for eukaryotic multicellularity and sexual reproduction. Despite this evolutionary significance, their phylogenetic relationships are understudied. This study aims to infer a comprehensive red algal tree of life at the family level from a supermatrix containing data mined from GenBank. We aim to locate remaining regions of low support in the topology, evaluate their causes and estimate the amount of data required to resolve them. Results Phylogenetic analysis of a supermatrix of 14 loci and 98 red algal families yielded the most complete red algal tree of life to date. Visualization of statistical support showed the presence of five poorly supported regions. Causes for low support were identified with statistics about the age of the region, data availability and node density, showing that poor support has different origins in different parts of the tree. Parametric simulation experiments yielded optimistic estimates of how much data will be needed to resolve the poorly supported regions (ca. 103 to ca. 104 nucleotides for the different regions. Nonparametric simulations gave a markedly more pessimistic image, some regions requiring more than 2.8 105 nucleotides or not achieving the desired level of support at all. The discrepancies between parametric and nonparametric simulations are discussed in light of our dataset and known attributes of both approaches. Conclusions Our study takes the red algae one step closer to meaningful inclusion in the tree of life. In addition

  5. Determining algal-available phosphorus in pulp and paper mill effluents: Algal assays vs routine phosphorus analyses

    International Nuclear Information System (INIS)

    We determined the potentially algal-available P (Paa ) in pulp and paper mill effluents by two bioassay techniques (a dual-culture assay and a batch approach) and compared it with chemically analysed P (total P, total dissolved P, reactive P, dissolved reactive P and dissolved hydrolysable P). The mean Paa given by the dual-culture assay was within a 40% range of that given by the batch approach. The Paa obtained by both bioassays differed from total P. Dissolved reactive P appeared to be the most readily available chemical P fraction, but other P fractions also contributed to Paa . The analysis of reactive P, which involves direct staining of an unfiltered sample, best approximated the Paa given by the dual-culture assay (relative error 9%). The results suggest that assessment of eutrophying effluent P can be improved by analysing simple chemical P fractions in wastewater. The fractions to be analysed, however, may be site specific. - Eutrophying phosphorus load from forest industry can be approximated by simple chemical analyses

  6. First chemical synthesis of a scorpion alpha-toxin affecting sodium channels: the Aah I toxin of Androctonus australis hector.

    Science.gov (United States)

    M'Barek, Sarrah; Fajloun, Ziad; Cestèle, Sandrine; Devaux, Christiane; Mansuelle, Pascal; Mosbah, Amor; Jouirou, Besma; Mantegazza, Massimo; Van Rietschoten, Jurphaas; El Ayeb, Mohamed; Rochat, Hervé; Sabatier, Jean-Marc; Sampieri, François

    2004-11-01

    Aah I is a 63-residue alpha-toxin isolated from the venom of the Buthidae scorpion Androctonus australis hector, which is considered to be the most dangerous species. We report here the first chemical synthesis of Aah I by the solid-phase method, using a Fmoc strategy. The synthetic toxin I (sAah I) was renatured in DMSO-Tris buffer, purified and subjected to thorough analysis and comparison with the natural toxin. The sAah I showed physico-chemical (CD spectrum, molecular mass, HPLC elution), biochemical (amino-acid composition, sequence), immunochemical and pharmacological properties similar to those of the natural toxin. The synthetic toxin was recognized by a conformation-dependent monoclonal anti-Aah I antibody, with an IC50 value close to that for the natural toxin. Following intracerebroventricular injection, the synthetic and the natural toxins were similarly lethal to mice. In voltage-clamp experiments, Na(v) 1.2 sodium channel inactivation was inhibited by the application of sAah I or of the natural toxin in a similar way. This work describes a simple protocol for the chemical synthesis of a scorpion alpha-toxin, making it possible to produce structural analogues in time.

  7. Involvement of the processing step in the susceptibility/tolerance of two lepidopteran larvae to Bacillus thuringiensis Cry1Aa toxin.

    Science.gov (United States)

    Dammak, Mariam; Khedher, Saoussen Ben; Boukedi, Hanen; Chaib, Ikbel; Laarif, Asma; Tounsi, Slim

    2016-02-01

    Bacillus thuringiensis (Bt) Cry1A toxins are known for their effectiveness against lepidopteran insects. In this study, the entomopathogenic activity of Cry1Aa was investigated against two lepidopteran larvae causing serious threat to various crops, Spodoptera littoralis and Tuta absoluta. Contrarily to S. littoralis, which showed low susceptibility to Cry1Aa (40% mortality with 1μg/cm(2)), T. absoluta was very sensitive to this delta-endotoxin (LC50 of 95.8ng/cm(2)). The different steps in the mode of action of this toxin on the two larvae were studied with the aim to understand the origin of their difference of susceptibility. Activation of the 130kDa Cry1Aa protein by T. absoluta larvae juice generated a 65kDa active toxin, whereas S. littoralis gut juice led to a complete degradation of the protoxin. The study of the interaction of the brush border membrane vesicles (BBMV) with purified biotinylated Cry1Aa toxin revealed six and seven toxin binding proteins in T. absoluta and S. littoralis BBMV, respectively. Midgut histopathology of Cry1Aa fed larvae demonstrated approximately similar damage caused by the toxin in the two larvae midguts. These results suggest that the activation step was strongly involved in the difference of susceptibility of the two larvae to Cry1Aa.

  8. Tetanus toxin : primary structure, expression in E. coli, and homology with botulinum toxins

    NARCIS (Netherlands)

    Eisel, Ulrich; Jarausch, Wolfgang; Goretzki, Karin; Henschen, Agnes; Engels, Joachim; Weller, Ulrich; Hudel, Martina; Habermann, Ernst; Niemann, Heiner; Rott, R.

    1986-01-01

    A pool of synthetic oligonucleotides was used to identify the gene encoding tetanus toxin on a 75-kbp plasmid from a toxigenic non-sporulating strain of Clostridium tetani. The nucleotide sequence contained a single open reading frame coding for 1315 amino acids corresponding to a polypeptide with a

  9. Binding of Diphtheria Toxin to Phospholipids in Liposomes

    Science.gov (United States)

    Alving, Carl R.; Iglewski, Barbara H.; Urban, Katharine A.; Moss, Joel; Richards, Roberta L.; Sadoff, Jerald C.

    1980-04-01

    Diphtheria toxin bound to the phosphate portion of some, but not all, phospholipids in liposomes. Liposomes consisting of dimyristoyl phosphatidylcholine and cholesterol did not bind toxin. Addition of 20 mol% (compared to dimyristoyl phosphatidylcholine) of dipalmitoyl phosphatidic acid, dicetyl phosphate, phosphatidylinositol phosphate, cardiolipin, or phosphatidylserine in the liposomes resulted in substantial binding of toxin. Inclusion of phosphatidylinositol in dimyristol phosphatidylcholine / cholesterol liposomes did not result in toxin binding. The calcium salt of dipalmitoyl phosphatidic acid was more effective than the sodium salt, and the highest level of binding occurred with liposomes consisting only of dipalmitoyl phosphatidic acid (calcium salt) and cholesterol. Binding of toxin to liposomes was dependent on pH, and the pattern of pH dependence varied with liposomes having different compositions. Incubation of diphtheria toxin with liposomes containing dicetyl phosphate resulted in maximal binding at pH 3.6, whereas binding to liposomes containing phosphatidylinositol phosphate was maximal above pH 7. Toxin did not bind to liposomes containing 20 mol% of a free fatty acid (palmitic acid) or a sulfated lipid (3-sulfogalactosylceramide). Toxin binding to dicetyl phosphate or phosphatidylinositol phosphate was inhibited by UTP, ATP, phosphocholine, or p-nitrophenyl phosphate, but not by uracil. We conclude that (a) diphtheria toxin binds specifically to the phosphate portion of certain phospholipids, (b) binding to phospholipids in liposomes is dependent on pH, but is not due only to electrostatic interaction, and (c) binding may be strongly influenced by the composition of adjacent phospholipids that do not bind toxin. We propose that a minor membrane phospholipid (such as phosphatidylinositol phosphate or phosphatidic acid), or that some other phosphorylated membrane molecule (such as a phosphoprotein) may be important in the initial binding of

  10. Botulinum toxin in the treatment of sialorrhea

    Directory of Open Access Journals (Sweden)

    Svetel Marina

    2009-01-01

    Full Text Available Background/Aim. Botulinum toxin-A (BTX-A is known to block the release of acetylcholine from motor and autonomic nerve terminals and may significantly decrease saliva production when injected intraglandulary. The aim of this study was to evaluate effects of BTX-A injections in the treatment of disabling sialorrhea in various neurological disorders. Methods. This study included 19 consecutive patients with significant sialorrhea associated with various neurological disorders. Out of them 13 patients were with Parkinson's disease, two with pantothenate kinase-associated neurodegeneration, two with multiple system atrophy, one with Wilson's disease, and one patient with postoperative sialorrhea. Botulinum toxin-A (Dysport®, Ipsen Pharma was injected into the parotid glands with (n = 7 patients or without (n = 12 patients ultrasound guidance. All the patients were scored before and after the treatment and in weekly intervals thereafter using the salivation item of the part II (Activities of Daily Living of the Unified Parkinson's Disease Rating Scale (UPDRS. Results. Thirteen patients (68% reported beneficial effect of BTX-A injection, while 6 of them (32% had no response at all. The sialorrhea scores before and after the treatment were 3.1 ± 0.1 (range 2-4 and 1.8 ± 0.1 (range 0- 3, respectively (t = 5.636; p < 0.001. There was no difference in the magnitude of response between the groups with (t = 4.500; p = 0.004 and without (t = 3.674; p = 0.005 ultrasound control of injection sites. Adverse effects were registered in 5 patients (26%. Conclusions. Botulinum toxin-A injections to easily accessible parotid glands, without necessity for ultrasound guidance, are safe and efficaceous treatment for sialorrhea in different neurological disorders.

  11. Ultrasound-guided botulinum toxin injections

    Directory of Open Access Journals (Sweden)

    S. E. Khatkova

    2016-01-01

    Full Text Available One of the key conditions for achieving the desirable result during botulinum toxin therapy for muscular dystonia, spasticity, and other diseases accompanied by spasm, pain, and autonomic dysfunction (dystonias, spasticity, etc. is the proper administration of the agent into the muscles directly involved in the pathological process. The exact entry of botulinum toxin into the target muscles is essential for successful and safe treatment because its injection into a normal muscle may cause side effects. The most common errors are the incorrect depth and incorrect direction of a needle on insertion. Therefore, the exact injection of the agent particularly into the shallow and deep muscles is a difficult task even for an experienced specialist and requires the use of controlling methods.The European Consensus on Botulinum Toxin Therapy points out that various injection techniques are needed for the better identification of necessary muscles. However, there are currently no reports on the clear advantage of any technique. In our country, injections using palpation and anatomical landmarks have been widely used in routine practice so far; electromyographic monitoring and electrostimulation have been less frequently applied. In recent years, the new method ultrasound-guided injection has continued to grow more popular. This effective, accessible, and easy-to-use method makes it possible to manage a real-time injection process and to ensure the exact entry of the agent into the muscle. This paper is dedicated to a comparative analysis of different injection methods and to a description of the ultrasound-guided technique and its advantages over others. 

  12. Glycolipid binding preferences of Shiga toxin variants.

    Directory of Open Access Journals (Sweden)

    Sayali S Karve

    Full Text Available The major virulence factor of Shiga toxin producing E. coli, is Shiga toxin (Stx, an AB5 toxin that consists of a ribosomal RNA-cleaving A-subunit surrounded by a pentamer of receptor-binding B subunits. The two major isoforms, Stx1 and Stx2, and Stx2 variants (Stx2a-h significantly differ in toxicity. The exact reason for this toxicity difference is unknown, however different receptor binding preferences are speculated to play a role. Previous studies used enzyme linked immunosorbent assay (ELISA to study binding of Stx1 and Stx2a toxoids to glycolipid receptors. Here, we studied binding of holotoxin and B-subunits of Stx1, Stx2a, Stx2b, Stx2c and Stx2d to glycolipid receptors globotriaosylceramide (Gb3 and globotetraosylceramide (Gb4 in the presence of cell membrane components such as phosphatidylcholine (PC, cholesterol (Ch and other neutral glycolipids. In the absence of PC and Ch, holotoxins of Stx2 variants bound to mixtures of Gb3 with other glycolipids but not to Gb3 or Gb4 alone. Binding of all Stx holotoxins significantly increased in the presence of PC and Ch. Previously, Stx2a has been shown to form a less stable B-pentamer compared to Stx1. However, its effect on glycolipid receptor binding is unknown. In this study, we showed that even in the absence of the A-subunit, the B-subunits of both Stx1 and Stx2a were able to bind to the glycolipids and the more stable B-pentamer formed by Stx1 bound better than the less stable pentamer of Stx2a. B-subunit mutant of Stx1 L41Q, which shows similar stability as Stx2a B-subunits, lacked glycolipid binding, suggesting that pentamerization is more critical for binding of Stx1 than Stx2a.

  13. Prevention, control and detection of Fusarial toxins

    Directory of Open Access Journals (Sweden)

    Nešić Ksenija D.

    2013-01-01

    Full Text Available The past couple of decades have provided considerable details on fungi and the toxins that they produce, as well on the mechanism of toxin action, toxicity and effects on animal and human health. But, since they are natural contaminants, their presence is often inevitable. Fusaria are widespread in all cereal-growing territories of the world, but they are especially common in our geographic area. Therefore, special attention is paid to the prevention and control, and also to the improvement of methods for their detection. Although all collected data were critical for understanding this worldwide problem, managing the impact of these toxins on the feed and food safety is still great practical challenge. There are a number of approaches that can be taken to minimize mycotoxin contamination in this chain: prevention of fungal growth and thus mycotoxin formation, strategies to reduce or eliminate mycotoxins from contaminated feedstuffs or diverting the contaminated products to low risk uses. A control program for mycotoxins from field to table should in­volve the criteria of an HACCP (Hazard Analysis Critical Control Points approach. It requires an understanding of the important aspects of the interactions of the toxigenic fungi with crop plants, the on-farm production and harvest methods for crops, the production of livestock using grains and processed feeds, including diagnostic capabilities for mycotoxicoses, and all the way to the development of processed foods for human consumption, as well as understanding the marketing and trade channels including storage and delivery of foods to the consumer’s table. A good testing protocol for mycotoxins is necessary to manage all of the control points and in order to be able to ensure a food supply free of toxic levels of mycotoxins for the consumer. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

  14. Shared Binding Sites in Lepidoptera for Bacillus thuringiensis Cry1Ja and Cry1A Toxins

    OpenAIRE

    Herrero, Salvador; González-Cabrera, Joel; Tabashnik, Bruce E; Ferré, Juan

    2001-01-01

    Bacillus thuringiensis toxins act by binding to specific target sites in the insect midgut epithelial membrane. The best-known mechanism of resistance to B. thuringiensis toxins is reduced binding to target sites. Because alteration of a binding site shared by several toxins may cause resistance to all of them, knowledge of which toxins share binding sites is useful for predicting cross-resistance. Conversely, cross-resistance among toxins suggests that the toxins share a binding site. At lea...

  15. Modeling the effects of environmental conditions on HT2 and T2 toxin accumulation in field oat grains.

    Science.gov (United States)

    Xu, Xiangming; Madden, Laurence V; Edwards, Simon G

    2014-01-01

    Fusarium head blight (FHB) of wheat and barley has been extensively researched worldwide; in contrast, there is limited information on the effects of environmental conditions on Fusarium toxin accumulation in oat grains. More than 300 samples of oat grain from various regions of the United Kingdom from 2006 to 2008 were analyzed for mycotoxin contamination due to infection by Fusarium spp. HT2 and T2 toxins were the two most commonly detected, and their concentrations in individual samples were highly correlated. Hourly weather data were obtained from meteorological recording stations near most of the sampling sites. Statistical modeling was applied to both the original toxin (HT2 plus T2) data and the toxin data adjusted for oat cultivars and number of cereal crops in the previous four seasons. Accumulation of HT2 and T2 toxin was positively correlated with warm and wet conditions during early May and dry conditions thereafter. Using a collection of 51 environmental variables summarized over three lengths (10, 15, and 20 days) of time periods encompassing early May, late May, and early July, all-subsets regression showed that many models, consisting of three to six predictor variables, could be identified with similar explanatory strength for the effect of environmental conditions on toxin accumulation. Most important predictor variables were related to wet conditions during the early-May period, which was before anthesis. These results suggest that the predominant period for Fusarium langsethiae infection of oat is likely to be before rather than during anthesis, as for other head blight pathogens. These empirical models may be further improved by using quantified pathogen biomass within the grains and weather predictor variables summarized in relation to plant growth stages (instead of calendar times).

  16. Overview of Botulinum Toxins for Aesthetic Uses.

    Science.gov (United States)

    Gart, Michael S; Gutowski, Karol A

    2016-07-01

    Botulinum toxin type A (BTA) can be used for facial aesthetics. The 3 currently available BTA types include onabotulinumtoxinA (Botox; Botox Cosmetic, Allergan, Irvine, CA), abobotulinumtoxinA (Dysport; Ipsen, Ltd, Berkshire, UK), and incobotulinumtoxinA (Xeomin; Merz Pharmaceuticals, Frankfurt, Germany). The mechanism of action and clinical uses for treatment of dynamic lines of the forehead, brow, glabella, lateral orbit, nose, and lips are presented, as well as treatment of masseter hypertrophy, platysmal bands, and improvements of the perioral region. Specific BTA injection sites and suggested doses are presented. PMID:27363760

  17. Arctic spring awakening - Steering principles behind the phenology of vernal ice algal blooms

    Science.gov (United States)

    Leu, E.; Mundy, C. J.; Assmy, P.; Campbell, K.; Gabrielsen, T. M.; Gosselin, M.; Juul-Pedersen, T.; Gradinger, R.

    2015-12-01

    Marine ecosystems at high latitudes are characterized by extreme seasonal changes in light conditions, as well as a limited period of high primary production during spring and early summer. As light returns at the end of winter to Arctic ice-covered seas, a first algal bloom takes place in the bottom layer of the sea ice. This bottom ice algae community develops through three distinct phases in the transition from winter to spring, starting with phase I, a predominantly net heterotroph community that has limited interaction with the pelagic or benthic realms. Phase II begins in the spring once light for photosynthesis becomes available at the ice bottom, although interaction with the water column and benthos remains limited. The transition to the final phase III is then mainly driven by a balance of atmospheric and oceanographic forcing that induce structural changes in the sea ice and ultimately the removal of algal biomass from the ice. Due to limited data availability an incomplete understanding exists of all the processes determining ice algal bloom phenology and the considerable geographic differences in sympagic algal standing stocks and primary production. We present here the first pan-Arctic compilation of available time-series data on vernal sea ice algal bloom development and identify the most important factors controlling its development and termination. Using data from the area surrounding Resolute Bay (Nunavut, Canada) as an example, we support previous investigations that snow cover on top of the ice influences sea ice algal phenology, with highest biomass development, but also earliest termination of blooms, under low snow cover. We also provide a pan-Arctic overview of sea ice algae standing stocks and primary production, and discuss the pertinent processes behind the geographic differences we observed. Finally, we assess potential future changes in vernal algal bloom phenology as a consequence of climate change, including their importance to

  18. Algal Accessory Pigment Detection Using AVIRIS Image-Derived Spectral Radiance Data

    Science.gov (United States)

    Richardson, Laurie L.; Ambrosia, Vincent G.

    1996-01-01

    Visual and derivative analyses of AVIRIS spectral data can be used to detect algal accessory pigments in aquatic communities. This capability extends the use of remote sensing for the study of aquatic ecosystems by allowing detection of taxonomically significant pigment signatures which yield information about the type of algae present. Such information allows remote sensing-based assessment of aquatic ecosystem health, as in the detection of nuisance blooms of cyanobacteria or toxic blooms of dinoflagellates. Remote sensing of aquatic systems has traditionally focused on quantification of chlorophyll a, a photoreactive (and light-harvesting) pigment which is common to all algae as well as cyanobacteria (bluegreen algae). Due to the ubiquitousness of this pigment within algae, chl a is routinely measured to estimate algal biomass both during ground-truthing and using various airborne or satellite based sensors, including AVIRIS. Within the remote sensing and aquatic sciences communities, ongoing research has been performed to detect algal accessory pigments for assessment of algal population composition. This research is based on the fact that many algal accessory pigments are taxonomically significant, and all are spectrally unique. Aquatic scientists have been refining pigment analysis techniques, primarily high performance liquid chromatography, or HPLC, to detect specific pigments as a time-saving alternative to individual algal cell identifications and counts. Remote sensing scientists are investigating the use of pigment signatures to construct pigment libraries analogous to mineral spectral libraries used in geological remote sensing applications. The accessory pigment approach has been used successfully in remote sensing using data from the Thematic Mapper, low-altitude, multiple channel scanners, field spectroradiometers and the AVIRIS hyperspectral scanner. Due to spectral and spatial resolution capabilities, AVIRIS is the sensor of choice for such

  19. A Lagrangian Physical-Biological Model to Study Water Parcels Associated with Algal Blooms from Southern California Bight to Todos Santos Bay.

    Science.gov (United States)

    Vivas Téllez, I. E.; Rivas, D.

    2015-12-01

    Lagrangian ocean circulation and biological dynamics are numerically studied in Todos Santos Bay during the spring of 2007. This period is particularly interesting after an intense toxic algal bloom occurred in April 2007 in this area, which was associated with the wind-driven upwelling in the region. High resolution, numerical model simulations were carried out to study dynamical features along of the Southern California Bight (SCB), the coast of the northern Baja California (BC), and the interior of Todos Santos Bay (TSB). These simulations are used in a three-dimensional Lagrangian (particle tracking) analysis which provides information about the origin and distribution of the waters present in the Bay during the occurrence of the toxic bloom. After the selection of trajectories of particles showing coherent patterns, a Nitrate-Phytoplankton-Zooplankton-Detritus (NPZD) lower trophic model is implemented to study the influence of the environmental conditions that occur during the particle advection, solving the NPZD equations at every time-varying position of the advected particles. The model is also modified for phytoplankton growth as a function of the environmental temperature to somehow emulate the life cycle of Pseudo-nitzschia. The analysis of the trajectories shows that particles mainly come from two regions: from the north, in the southern portion of SCB and from regions west of the TSB. Knowing the regional circulation patterns and their phytoplankton dynamics can help to understand and even predict the origin and destination of the harmful algal blooms that occur in TSB and its surroundings.

  20. Route of metabolization and detoxication of paralytic shellfish toxins in humans.

    Science.gov (United States)

    García, Carlos; Barriga, Andrés; Díaz, Juan Carlos; Lagos, Marcelo; Lagos, Néstor

    2010-01-01

    Paralytic shellfish toxins (PST) are a collection of over 26 structurally related imidazoline guanidinium derivatives produced by marine dinoflagellates and freshwater cyanobacteria. Glucuronidation of drugs by UDP-glucuronosyltransferase (UGT) is the major phase II conjugation reaction in mammalian liver. In this study, using human liver microsomes, the in vitro paralytic shellfish toxins oxidation and sequential glucuronidation are achieved. Neosaxitoxin (neoSTX), Gonyautoxin 3/2 epimers (GTX3/GTX2) and Saxitoxin (STX) are used as starting enzymatic substrates. The enzymatic reaction final product metabolites are identified by using HPLC-FLD and HPLC/ESI-IT/MS. Four metabolites from GTX3/GTX2 epimers precursors, three of neoSTX and two of STX are clearly identified after incubating with UDPGA/NADPH and fresh liver microsomes. The glucuronic-Paralytic Shellfish Toxins were completely hydrolysed by treatment with beta-glucuronidase. All toxin analogs were identified comparing their HPLC retention time with those of analytical standard reference samples and further confirmed by HPLC/ESI-IT/MS. Paralytic Shellfish Toxins (PST) were widely metabolized by human microsomes and less than 15% of the original PST, incubated as substrate, stayed behind at the end of the incubation. The apparent V(max) and Km formation values for the respective glucuronides of neoSTX, GTX3/GTX2 epimers and STX were determined. The V(max) formation values for Glucuronic-GTX3 and Glucuronic-GTX2 were lower than Glucuronic-neoSTX and Glucuronic-STX (6.8+/-1.9x10(-3); 8.3+/-2.8x10(-3) and 9.7+/-2.8x10(-3)pmol/min/mg protein respectively). Km of the glucuronidation reaction for GTX3/GTX2 epimers was less than that of glucuronidation of neoSTX and STX (20.2+/-0.12; 27.06+/-0.23 and 32.02+/-0.64microM respectively). In conclusion, these data show for the first time, direct evidence for the sequential oxidation and glucuronidation of PST in vitro, both being the initial detoxication reactions for