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Hagström, Johannes
Publications (10 of 10) Show all publications
McNamee, S. E., Medlin, L. K., Kegel, J., McCoy, G. R., Raine, R., Barra, L., . . . Campbell, K. (2016). Distribution, occurrence and biotoxin composition of the main shellfish toxin producing microalgae within European waters: A comparison of methods of analysis. Harmful Algae, 55, 112-120
Open this publication in new window or tab >>Distribution, occurrence and biotoxin composition of the main shellfish toxin producing microalgae within European waters: A comparison of methods of analysis
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2016 (English)In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 55, p. 112-120Article in journal (Refereed) Published
Abstract [en]

Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009-2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (VDU /DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 x 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray. (C) 2016 Elsevier B.V. All rights reserved.

Keywords
Harmful algal bloom, Microarray, Biosensor, Saxitoxin, Okadaic acid, Domoic acid
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-54690 (URN)10.1016/j.hal.2016.02.008 (DOI)000377323300011 ()2-s2.0-84960497178 (Scopus ID)
External cooperation:
Available from: 2016-07-22 Created: 2016-07-21 Last updated: 2017-11-28Bibliographically approved
Wen, S., Hagström, J., Yuhong, J., Yaping, L. & Fanxiang, K. (2014). Effects of rice straw on the cell viability, photosynthesis, and growth of Microcystis aeruginosa. Chinese Journal of Oceanology and Limnology, 32(1), 120-129
Open this publication in new window or tab >>Effects of rice straw on the cell viability, photosynthesis, and growth of Microcystis aeruginosa
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2014 (English)In: Chinese Journal of Oceanology and Limnology, ISSN 0254-4059, E-ISSN 1993-5005, Vol. 32, no 1, p. 120-129Article in journal (Refereed) Published
Abstract [en]

Rice straw is supposed to be an environment-friendly biomaterial for inhibiting the growth of harmful blooms of the cyanobacterium Microcystis aeruginosa. However, its potential mechanism is not well known. To explore this mechanism, the growth, cell viability (esterase activity, membrane potential, and membrane integrity), photosynthesis, and cell size of M. aeruginosa were determined using flow cytometry and Phyto-PAM after exposure to rice straw extracts (RSE). The results show that doses from 2.0 to 10.0 g/L of RSE efficiently inhibited the alga for 15 days, while the physiologic and morphologic responses of the cyanobacteria were time-dependent. RSE interfered with the cell membrane potential, cell size, and in vivo chlorophyll-a fluorescence on the first day. After 7 days of exposure, RSE was transported into the cytosol, which disrupted enzyme activity and photosynthesis. The cyanobacteria then started to repair its physiology (enzyme activity, photosynthesis) and remained viable, suggesting that rice straw act as an algistatic agent.

Keywords
esterase activity, membrane potential, Phyto-PAM, rice straw, Microcystis, flow cytometry
National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-33936 (URN)10.1007/s00343-014-3063-0 (DOI)000332003500014 ()2-s2.0-84894296715 (Scopus ID)
Available from: 2014-04-22 Created: 2014-04-22 Last updated: 2017-12-05Bibliographically approved
Pérez Blanco, E., Hagström, J., Salomon, P. & Granéli, E. (2013). Detection of Heterosigma akashiwo (Hada) using specific RNA probes: Variability of RNA content with environmental conditions. Harmful Algae, 24, 80-88
Open this publication in new window or tab >>Detection of Heterosigma akashiwo (Hada) using specific RNA probes: Variability of RNA content with environmental conditions
2013 (English)In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 24, p. 80-88Article in journal (Refereed) Published
Abstract [en]

The raphidophyte Heterosigma akashiwo, which forms toxic blooms, causes major economical losses to the fish industry because of the fish kills involved. It is therefore important to be able to detect not only H. akashiwo but other toxic phytoplankton species as well, rapidly and accurately to reduce losses by fish kills. With this purpose, DNA sequences from H. akashiwo 18S and 28S rRNA gene regions were studied in silico to design species-specific probes to be used in a microarray format. Three strains of H. akashiwo (AC 265, AC 266 and GUMACC 120) were grown at optimal conditions and transferred into new environmental conditions changing either the light intensity, salinity, temperature or nutrient concentrations, to check if any of these environmental conditions induced changes in the cellular RNA concentration. The aim of this experiment was the calibration of several species-specific probes for the quantification of H. akashiwo. Differences on RNA content were not significant (p < 0.05) in any of the treatments, therefore the calibration curves were validated. The designed probes are reliable for the detection and quantification of H. akashiwo cells in natural waters. (C) 2013 Elsevier B.V. All rights reserved.

Keywords
Calibration, Environmental conditions, Heterosigma, Microarray, RNA probes
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-26299 (URN)10.1016/j.hal.2013.02.001 (DOI)000317327100008 ()2-s2.0-84874970188 (Scopus ID)
Available from: 2013-06-11 Created: 2013-06-11 Last updated: 2017-12-06Bibliographically approved
Granéli, E., Edvardsen, B., Roelke, D. L. & Hagström, J. (2012). The ecophysiology and bloom dynamics of Prymnesium spp.. Harmful Algae, 14(SI), 260-270
Open this publication in new window or tab >>The ecophysiology and bloom dynamics of Prymnesium spp.
2012 (English)In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 14, no SI, p. 260-270Article in journal (Refereed) Published
Abstract [en]

Members of Prymnesium belong to the division Haptophyta, class Prymnesiophyceae, order Prymnesialesand family Prymnesiaceae. As most haptophytes, members of the genus Prymnesium are unicellular andplanktonic. The most known of these species is the ichthyotoxic P. parvum, which may form nearlymonospecific dense blooms in coastal and inland waters. This species possesses extraordinary plasticityconcerning life survival strategies, and is specifically addressed in this review.Toxins produced by P. parvum have hemolytic properties, that not only kill fish but also co-existingplankton. These substances are allelopathic (when other algae are killed) and grazer deterrent (whengrazers are killed). Allelopathy enables P. parvum to utilize inorganic nutrients present in the surroundingwater without competition from other algal species; and by eliminating its grazers P. parvum reduces celllosses. The paralized microalgae and/or zooplankton, are therefter ingested by the P. parvum cells, aprocess called phagotrophy. P. parvum is also able of osmotrophy, i.e. utilization of dissolved organicmatter. In this review, the cellular characteristics, life cycles, bloom formation, and factors affectingtoxicity, allelopathy, phagotrophy, and osmotrophy of P. parvum are discussed.

Keywords
Allelochemicals, Allelopathy, Mixotrophy, Prymnesium, Toxins
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-16915 (URN)10.1016/j.hal.2011.10.024 (DOI)2-s2.0-84856116027 (Scopus ID)
Available from: 2012-01-19 Created: 2012-01-19 Last updated: 2017-12-08Bibliographically approved
Hagström, J., Granéli, E., Moreira, M. O. & Odebrecht, C. (2011). Domoic acid production and elemental composition of two Pseudo-nitzschia multiseries strains, from the NW and SW Atlantic Ocean, growing in phosphorus- or nitrogen-limited chemostat cultures.. Journal of Plankton Research, 33(2), 297-308
Open this publication in new window or tab >>Domoic acid production and elemental composition of two Pseudo-nitzschia multiseries strains, from the NW and SW Atlantic Ocean, growing in phosphorus- or nitrogen-limited chemostat cultures.
2011 (English)In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 33, no 2, p. 297-308Article in journal (Refereed) Published
Abstract [en]

Here we compare cell physiology and domoic acid (DA) production for two strains of the diatom Pseudo-nitzschia multiseries originating from two opposite latitudes: Canada (CA) and Brazil (BR). The algae were grown as chemostat cultures at 0.2, 0.3 and 0.4 day−1 under nitrogen (N)- and phosphorus (P)-deficient conditions. The level of deficiency significantly affected the atomic C:N, C:P, C:Si and N:P ratios in both strains. In both strains, P per cell was 2–4× higher in the N- than in the P-deficient cultures. The opposite was not found for N in the P-deficient cultures, as shown by the N:P ratios and C:N ratios. The C:N and C:P ratios were significantly lower in the CA strain, and this did not change due to the level of deficiency. The concentration and production of DA per cell per day were significantly higher for both strains under P deficiency as expected since the toxin is rich in N. However, DA was also produced by both strains during continuous cell division under N deficiency. High or low bacterial densities associated with P. multiseries did not increase or decrease DA production. Our data imply that more attention needs to be given to the N:P ratios and concentrations in the waters where these algae occur, as both N and P deficiencies affect DA production and cellular DA concentrations.

National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-10833 (URN)10.1093/plankt/fbq102 (DOI)2-s2.0-79951788943 (Scopus ID)
Available from: 2011-02-17 Created: 2011-02-17 Last updated: 2017-12-11Bibliographically approved
Hagström, J., Sengco, M. & Villareal, T. (2010). Potential methods for managing Prymnesium parvum blooms and toxicity, with emphasis on clay and barley straw: A review. Journal of the American Water Resources Association, 46(1), 187-198
Open this publication in new window or tab >>Potential methods for managing Prymnesium parvum blooms and toxicity, with emphasis on clay and barley straw: A review
2010 (English)In: Journal of the American Water Resources Association, ISSN 1093-474X, E-ISSN 1752-1688, Vol. 46, no 1, p. 187-198Article in journal (Refereed) Published
Abstract [en]

Harmful algal bloom (HAB) control and mitigation is a complex problem in ecosystem management. Phytoplankton play an important role in aquatic ecosystems as primary producers and food sources for many commercially important shellfish and there are limited options for targeting just a single species within the community. Chemical treatments (e.g., algaecides), rotting barley straw, nitrogen and phosphorus manipulation, and clay and/or flocculants are but a few techniques tested or used to reduce fish kills or shellfish contamination during a HAB event. Prymnesium parvum control has focused on the use of chemicals, nutrient manipulation, and clay flocculation. However, many HAB control methods have been rejected due to their effects on ecosystems, high costs, or limited effects on target organisms. For example, rotting barley straw (Hordeum vulgare) is considered to be an environmentally friendly alternative, but has been found to have very different results on the phytoplankton community depending on the dominating taxa and is ineffective against P. parvum and dinoflagellate blooms. Clay flocculation is a useful control/mitigation technique during fish kills in marine aquaculture sites in South Korea and can be effective in freshwater if the correct combination of clay and flocculent is used. Toxins produced by P. parvum and Karenia brevis also bind to phosphatic clay, thereby removing and/or neutralizing the toxins, but there is concern that the clay will have a negative effect on sessile organisms. Some shellfish suffer high mortalities and significant impacts on somatic and reproductive tissue growth at high clay loads; however, benthic communities appear to be unchanged after five years of clay treatment in South Korea. There are likely site-specific and ecosystem-specific characteristics that make generalizations about control options difficult and require careful assessment of options at each location.

National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-10832 (URN)10.1111/j.1752-1688.2009.00402.x (DOI)
Available from: 2011-02-17 Created: 2011-02-17 Last updated: 2017-12-11Bibliographically approved
Hagström, J., Granéli, E., Maneiro, I., Barreiro, A., Petermann, A. & Svensen, C. (2007). Release and degradation of amnesic shellfish poison from decaying Pseudo-nitzschia multiseries in presence of bacteria and organic matter. Harmful Algae, 6(2), 175-188
Open this publication in new window or tab >>Release and degradation of amnesic shellfish poison from decaying Pseudo-nitzschia multiseries in presence of bacteria and organic matter
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2007 (English)In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 6, no 2, p. 175-188Article in journal (Refereed) Published
National Category
Natural Sciences
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-1682 (URN)
External cooperation:
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
R. Sengco, M., Hagström, J., Granéli, E. & M. Anderson, D. (2005). Removal of Prymnesium parvum (Haptophyceae) and its toxins using clay minerals. Harmful Algae, 4, 261-274
Open this publication in new window or tab >>Removal of Prymnesium parvum (Haptophyceae) and its toxins using clay minerals
2005 (English)In: Harmful Algae, Vol. 4, p. 261-274Article in journal (Refereed) Published
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-434 (URN)
External cooperation:
Available from: 2010-03-31 Created: 2010-03-31 Last updated: 2016-09-09Bibliographically approved
Sengco, M., Hagström, J., Granéli, E., M. Anderson, D. & Kuuppo, P. (2005). Removal of Prymnesium parvum (Haptophyceae) and its toxins using clay minerals (vol 4, pg 261, 2005). Harmful Algae, 4 (4), 801-801
Open this publication in new window or tab >>Removal of Prymnesium parvum (Haptophyceae) and its toxins using clay minerals (vol 4, pg 261, 2005)
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2005 (English)In: Harmful Algae, Vol. 4 (4), p. 801-801Article in journal (Refereed) Published
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-651 (URN)
External cooperation:
Available from: 2010-04-01 Created: 2010-04-01 Last updated: 2016-09-09Bibliographically approved
Hagström, J. & Granéli, E. (2005). Removal of Prymnesium parvum (Haptophyceae) cells under different nutrient conditions by clay. Harmful Algae, 4: pp. 249-260
Open this publication in new window or tab >>Removal of Prymnesium parvum (Haptophyceae) cells under different nutrient conditions by clay
2005 (English)In: Harmful Algae, Vol. 4: pp. 249-260Article in journal (Refereed) Published
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-433 (URN)
External cooperation:
Available from: 2010-03-31 Created: 2010-03-31 Last updated: 2016-09-09Bibliographically approved
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