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Qing Zhong, Feng Sun, Weiguang Wang, Wenqing Xiao, Xiaoni Zhao, Kangding Gu
Microcystins (MCs) are a group of monocyclic heptapeptide toxins that have been shown to act as potent hepatotoxins. However, the observed symptoms of water metabolism disruption induced by microcystin-RR (MC-RR) or MCs have rarely been reported, and a relatively clear mechanism has not been identified. In the present study, male mice were divided into 4 groups (A: 140μg/kg, B: 70μg/kg,C: 35μg/kg, and D: 0μg/kg) and administered MC-RR daily for a month. On day 8 of treatment, an increase in water intake and urine output was observed in the high-dose group compared with the control, and the symptoms worsened with the repeated administration of the toxin until day 30...
March 19, 2017: Toxicology Letters
Xiu-Mei Chen, Gui-Liang Guo, Li Sun, Qiu-Shi Yang, Gui-Qin Wang, Dong-Ming Zhang
Microcystin-LR (MCLR), one of the most popular microcystins (MCs) found in many field water bodies around the world, poses great health risks to animals and humans. In the present study, healthy common carp (initial weight 24.8 ± 2.3 g) were randomly assigned to five groups. Group I was fed on normal diet as control. Group II was maintained on normal diet and received MCLR intraperitoneal injection (150 μg kg(-1) BW). Common carp in groups III, IV, and V were daily pretreated with L-carnitine (LC) at doses of 0...
March 17, 2017: Fish Physiology and Biochemistry
Ivan Zemskov, Stefan Altaner, Daniel R Dietrich, Valentin Wittmann
Microcystins (MCs) are highly toxic natural products which are produced by cyanobacteria. They can be released to the water during harmful algal blooms and are a serious threat to animals and humans. Described is the total synthesis of the cyanotoxin microcystin-LF (MC-LF, 1a) and two derivatives thereof. Deuterated derivative 1b is of interest as an internal standard during MC quantification in biological samples by mass spectrometry and alkyne-labeled 1c can be employed for toxin derivatization by click chemistry with an azide-containing reporter molecule or as an activity-based probe to identify interaction partners...
March 15, 2017: Journal of Organic Chemistry
Benoît Sotton, Alain Paris, Séverine Le Manach, Alain Blond, Gérard Lacroix, Alexis Millot, Charlotte Duval, Qin Qiao, Arnaud Catherine, Benjamin Marie
Cyanobacterial blooms induce important ecological constraints for aquatic organisms and strongly impact the functioning of aquatic ecosystems. In the past decades, the effects of the cyanobacterial secondary metabolites, so called cyanotoxins, have been extensively studied in fish. However, many of these studies have used targeted approaches on specific molecules, which are thought to react to the presence of these specific cyanobacterial compounds. Since a few years, untargeted metabolomic approaches provide a unique opportunity to evaluate the global response of hundreds of metabolites at a glance...
March 7, 2017: Science of the Total Environment
Avery O Tatters, Meredith D A Howard, Carey Nagoda, Lilian Busse, Alyssa G Gellene, David A Caron
Blooms of toxic cyanobacteria in freshwater ecosystems have received considerable attention in recent years, but their occurrence and potential importance at the land-sea interface has not been widely recognized. Here we present the results of a survey of discrete samples conducted in more than fifty brackish water sites along the coastline of southern California. Our objectives were to characterize cyanobacterial community composition and determine if specific groups of cyanotoxins (anatoxins, cylindrospermopsins, microcystins, nodularins, and saxitoxins) were present...
March 9, 2017: Toxins
Ye Liang, Yuqi Su, Kai Ouyang, Xinglan Chen, Jiaxin Yang
Toxic cyanobacterial blooms disrupt freshwater recreation and adversely affect zooplankton. The freshwater cyanobacterium Microcystis aeruginosa produces microcystins, which are compounds toxic to rotifers. This study evaluated the effects of M. aeruginosa on enzyme activity and nutrient content in the rotifer Brachionus calyciflorus Pallas. The rotifers were fed on Chlorella pyrenoidosa, Scenedesmus obliquus, microcystin-producing and microcystin-free M. aeruginosa alone, and mixtures of green algae combined with toxic and nontoxic cyanobacteria, respectively...
March 9, 2017: Environmental Science and Pollution Research International
Jeong-Ann Park, Sung-Mok Jung, In-Geol Yi, Jae-Woo Choi, Song-Bae Kim, Sang-Hyup Lee
Microcystin-LR (MC-LR) is a common toxin derived from cyanobacterial blooms an effective, rapid and non-toxic method needs to be developed for its removal from drinking water treatment plants (DWTP). For an adsorption-based method, mesoporous carbon can be a promising supplemental adsorbent. The effect of mesoporous carbon (MC1, MC2, and MC3) properties and water quality parameters on the adsorption of MC-LR were investigated and the results were analyzed by kinetic, isotherm, thermodynamic, Derjaguin-Landau-Verwey-Overbeek (DLVO), and intraparticle diffusion models...
March 1, 2017: Chemosphere
Haibing Cong, Feng Sun, Wenjing Chen, Yajun Xu, Wei Wang
In order to effectively remove the Microcystis from drinking water sources, pre-pressure treatment was first used to make the Microcystis lose buoyancy and easy to be removed by the following coagulation and sedimentation processes. The water containing Microcystis from Taihu Lake was taken for the pre-pressure coagulation and sedimentation treatments in this study. Both intermittent laboratory experiment and continuous-flow field experiment were studied to clarify the mechanism of pre-pressure enhanced coagulation and sedimentation for Microcystis removal, as well as investigate the treatment effect and optimize the treatment conditions...
March 1, 2017: Environmental Technology
Meichuan Liu, Xue Ding, Qiwei Yang, Yu Wang, Guohua Zhao, Nianjun Yang
A simple and highly sensitive photoelectrochemical (PEC) sensor towards Microcystin-LR (MC-LR), a kind of typical cyanobacterial toxin in water samples, was developed on a surface molecular imprinted TiO2 coated multiwalled carbon nanotubes (MI-TiO2@CNTs) hybrid nanostructure. It was synthesized using a feasible two-step sol-gel method combining with in situ surface molecular imprinting technique (MIT). With a controllable core-shell tube casing structure, the resultant MI-TiO2@CNTs are enhanced greatly in visible-light driven response capacity...
February 21, 2017: Journal of Hazardous Materials
Elisabeth Entfellner, Mark Frei, Guntram Christiansen, Li Deng, Jochen Blom, Rainer Kurmayer
Cyanobacteria are frequently involved in the formation of harmful algal blooms wherein, apart from the toxic microcystins, other groups of bioactive peptides are abundant as well, such as anabaenopeptins (APs). The APs are synthesized nonribosomally as cyclic hexapeptides with various amino acids at the exocyclic position. We investigated the presence and recombination of the AP synthesis gene cluster (apnA-E) through comparing 125 strains of the bloom-forming cyanobacterium Planktothrix spp., which were isolated from numerous shallow and deep water habitats in the temperate and tropical climatic zone...
2017: Frontiers in Microbiology
Dany Domínguez-Pérez, Armando Alexei Rodríguez, Hugo Osorio, Joana Azevedo, Olga Castañeda, Vítor Vasconcelos, Agostinho Antunes
Cnidarian constitutes a great source of bioactive compounds. However, research involving peptides from organisms belonging to the order Zoanthidea has received very little attention, contrasting to the numerous studies of the order Actiniaria, from which hundreds of toxic peptides and proteins have been reported. In this work, we performed a mass spectrometry analysis of a low molecular weight (LMW) fraction previously reported as lethal to mice. The low molecular weight (LMW) fraction was obtained by gel filtration of a Zoanthus sociatus (order Zoanthidea) crude extract with a Sephadex G-50, and then analyzed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS) in positive ion reflector mode from m/z 700 to m/z 4000...
March 1, 2017: Toxins
Min Sik Kim, Hak-Hyeon Kim, Ki-Myeong Lee, Hye-Jin Lee, Changha Lee
Ferrous-tetrapolyphosphate complexes (Fe(II)-TPP) activate oxygen and hydrogen peroxide to produce reactive oxidants capable of degrading organic compounds. In this study, the Fe(II)-TPP/O2 and Fe(II)-TPP/H2O2 systems were assessed for oxidative degradation of microcystin-LR (MC-LR), the most toxic and abundant cyanotoxin. The degradation of MC-LR was optimized for both the Fe(II)-TPP/O2 and Fe(II)-TPP/H2O2 systems when the molar ratio of TPP:Fe(II) was approximately 5.7-5.9. The optimal H2O2 dose for MC-LR degradation by Fe(II)-TPP/H2O2 was found to be 320 μM...
February 20, 2017: Water Research
Boyoung Jeong, Min-Seok Oh, Hyun-Mee Park, Chanhyuk Park, Eun-Ju Kim, Seok Won Hong
The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M(-1)s(-1) (r(2) > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect...
February 20, 2017: Water Research
Audrey Roy-Lachapelle, Morgan Solliec, Maryse F Bouchard, Sébastien Sauvé
Algae dietary supplements are marketed worldwide as natural health products. Although their proprieties have been claimed as beneficial to improve overall health, there have been several previous reports of contamination by cyanotoxins. These products generally contain non-toxic cyanobacteria, but the methods of cultivation in natural waters without appropriate quality controls allow contamination by toxin producer species present in the natural environment. In this study, we investigated the presence of total microcystins, seven individual microcystins (RR, YR, LR, LA, LY, LW, LF), anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine in 18 different commercially available products containing Spirulina or Aphanizomenon flos-aquae...
February 25, 2017: Toxins
Marcelo Gustavo Paulino, Priscila Adriana Rossi, Francine Perri Venturini, Driele Tavares, Naiara Elisabete da Silva Souza, Marise Margareth Sakuragui, Gilberto Moraes, Ana Paula Terezan, João Batista Fernandes, Alessandra Giani, Marisa Narciso Fernandes
The toxicological effect of cellular extract of cyanobacterium Radiocystis fernandoi strain R28 containing RR and YR microcystins was analyzed in the fish Hoplias malabaricus with emphasis on the liver structure and energetic metabolism, after short-term exposure. Fish were intraperitoneally (i.p.) injected with 100 μg of equivalent MC-LR kg(-1) body mass containing in the cellular extract of R. fernandoi strain R28. Twelve and 96 h post-injection, the plasma, liver and white muscle were sampled for biochemical analyses and liver was also sampled for morphological analyses...
May 2017: Chemosphere
Shi Chen, Ying Liu, Jian Zhang, Baoyu Gao
Research on the combined effects of antibiotic contaminants and environmental factors in cyanobacteria is still limited. This study focused on the action and its mechanism of spiramycin combined with changes in nitrogen and phosphorus level in Microcystis aeruginosa at environmentally relevant concentrations. Though photosynthetic activity was stimulated by spiramycin at a high nutrient level, no significant correlation (p>0.05) was found between photosynthesis-related proteins and growth-related proteins, and the growth rate was inhibited by 200ngL(-1) of spiramycin...
April 2017: Aquatic Toxicology
Jiazhang Chen, Shunlong Meng, Hai Xu, Zhen Zhang, Xiangyang Wu
In the present study, Nile tilapia (Oreochromis niloticus) were used to assess the endocrine disruption potential of Microcytis aeruginosa. Male Nile tilapia were exposed to lyophilized M. aeruginosa or purified microcystin-LR (8.3 μg/L) for 28 days. The levels of serum hormones (17β-estradiol and testosterone) and transcripts of selected genes in the hypothalamus-pituitary-gonadal-liver axis were analyzed. The results showed that serum hormones were significantly up-regulated, and transcripts of 13 genes (GHRH, PACAP, GH, GHR1, GHR2, IGF1, IGF2, CYP19a, CYP19b, 3β-HSD1, 20β-HSD, 17β-HSD1 and 17β-HSD8) were significantly altered after Microcytis exposure...
April 2017: Bulletin of Environmental Contamination and Toxicology
Jing Ye, Yuping Du, Lumei Wang, Jingru Qian, Jiejing Chen, Qingwen Wu, Xiaojun Hu
The global usage of veterinary antibiotics is significant. Antibiotics can be released into aquatic environments and elicit toxic effects on non-target organisms. In this study, the growth characteristics and toxin release of the cyanobacterium Microcystis aeruginosa (M. aeruginosa) were examined to investigate the physiological effects of tetracycline antibiotics on aquatic life. Results showed that the degree of toxicities of the following target antibiotics was TC (tetracycline hydrochloride) > CTC (chlortetracycline hydrochloride) > OTC (oxytetracycline hydrochloride) in terms of growth parameters, EC10 (0...
February 21, 2017: Toxins
Ye Liang, Kai Ouyang, Xinglan Chen, Yuqi Su, Jiaxin Yang
The occurrence of Microcystis blooms is a worldwide concern due to the numerous adverse effects on zooplankton. We therefore hypothesized that the cyanobacterium Microcystis aeruginosa is harmful to rotifer growth. Population and individual experiments were conducted with the same proportional volumes of Chlorella and Microcystis for given food densities. Life-table parameters, life-history traits, and the grazing intensity of Brachionus calyciflorus were evaluated after they had fed on microcystin-producing and microcystin-free Microcystis, both alone and combined with an edible alga (Chlorella pyrenoidosa), at concentrations of 1 × 10(5), 1 × 10(6), and 1 × 10(7) cells mL(-1)...
February 23, 2017: Scientific Reports
Jana Naceradska, Martin Pivokonsky, Lenka Pivokonska, Magdalena Baresova, Rita K Henderson, Arash Zamyadi, Vaclav Janda
The study investigates the effect of permanganate pre-oxidation on the coagulation of peptides/proteins of Microcystis aeruginosa which comprise a major proportion of the organic matter during cyanobacterial bloom decay. Four different permanganate dosages (0.1, 0.2, 0.4 and 0.6 mg KMnO4 mg(-1) DOC) were applied prior to coagulation by ferric sulphate. Moreover, changes in sample characteristics, such as UV254, DOC content and molecular weight distribution, after pre-oxidation were monitored. The results showed that permanganate pre-oxidation led to a reduction in coagulant dose, increased organic matter removals by coagulation (by 5-12% depending on permanganate dose), microcystin removal (with reductions of 91-96%) and a shift of the optimum pH range from 4...
February 14, 2017: Water Research
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