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Ankita Srivastava, Seong-Jun Chun, So-Ra Ko, Junhwan Kim, Chi-Yong Ahn, Hee-Mock Oh
The increased inputs of nutrients have been demonstrated to be a major contributing factor to the eutrophication of lakes and reservoirs which can lead to the production of harmful algal/cyanobacterial blooms and deleteriously affect the aesthetics of water-bodies. Floating plant-culture systems have been widely used for the ecological remediation of eutrophic water in a cost-effective manner. We investigated the applicability of Korean japonica rice variety 'Nampyeong' in a floating-culture system in a eutrophic lake for nutrient uptake and biomass production...
August 11, 2017: Journal of Environmental Management
Daljit Vudathala, Stephen Smith, Lester Khoo, David D Kuhn, Mary E Mainous, James Steadman, Lisa Murphy
Microcystins (MCs) are hepatotoxic cyanobacterial metabolites produced sporadically in aquatic environments under favorable environmental conditions. Affinity of these toxins to covalently bind with protein phosphatases poses a challenge in their detection. Lemieux oxidation to release 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB), a common moiety to all MCs congeners, has been used in detection of these compounds, however a lack of sensitivity has limited the usefulness of the method. In this study, modifications of the oxidation and solid phase extraction procedures, combined with a sensitive LC/MS/MS (liquid chromatography/mass spectrometry) detection, have resulted in 25 ng/g method detection limits in both liver and plasma samples...
August 10, 2017: Toxicon: Official Journal of the International Society on Toxinology
Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, Tyler D Geer, John H Rodgers
Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release...
August 9, 2017: Ecotoxicology and Environmental Safety
Xiangdong Bi, Wei Dai, Shulin Zhang, Shaojie Dong, Dajuan Zhang
The cyanobacterium Microcystis occurs as colonies of different sizes with varying abundance of toxic genotypes versus non-toxic genotypes under natural conditions. To investigate the effects of toxic Microcystis genotypes on natural colony formation, samples collected from the mainstream of Haihe River from July to October 2015 were sieved into four colony classes with sizes of <8 μm, 8-20 μm, 20-90 μm and >90 μm. Each colony size class was analyzed for the proportion of toxic Microcystis genotypes, and microcystins (MCs) cellular production of toxic genotypes...
August 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Qing Cao, Alan D Steinman, Xiaomei Su, Liqiang Xie
A 30-day indoor incubation experiment was conducted to investigate the effects of different concentrations of microcystin (1, 10, 100 and 1000 μg eq. MC-LR L(-1)) on soil enzyme activity, soil respiration, physiological profiles, potential nitrification, and microbial abundance (total bacteria, total fungi, ammonia-oxidizing bacteria and archaea) in two lakeside soils in China (Soil A from the lakeside of Lake Poyanghu at Jiujiang; Soil B from the lakeside of Lake Taihu at Suzhou). Of the enzymes tested, only phenol oxidase activity was negatively affected by microcystin application...
August 7, 2017: Environmental Pollution
Qing Cao, Alan D Steinman, Lei Yao, Liqiang Xie
We conducted an indoor culture experiment to evaluate the phytotoxic effect of microcystins (MCs) on rice. After a 30day exposure, MCs induced a clear inhibition in rice growth, as well as a disruption of its antioxidant system and lipid peroxidation. We observed an increase in root membrane permeability; the conductivity of the leakage solution of the roots at 50 and 500μgL(-1) was significantly increased by 77% and 136%, respectively, compared to the control. Uptake of microelements (Fe, Mn, Cu and Zn) was generally not affected after the 30day exposure to MCs...
August 1, 2017: Ecotoxicology and Environmental Safety
Haifeng Qian, Tao Lu, Hao Song, Michel Lavoie, Jiahui Xu, Xiaoji Fan, Xiangliang Pan
Cyanobacterial blooms frequently occur in Lake Taihu (China), but the intertwined relationships between biotic and abiotic factors modulating the frequency and duration of the blooms remain enigmatic. To better understand the relationships between the key abiotic and biotic factors and cyanobacterial blooms, we measured the abundance and diversity of prokaryotic organisms by high-throughput sequencing, the abundance of key genes involved in microcystin production and nitrogen fixation or loss as well as several physicochemical parameters at several stations in Lake Taihu during a cyanobacterial bloom of Microcystis sp...
August 3, 2017: Bulletin of Environmental Contamination and Toxicology
Dariusz Dziga, Anna Maksylewicz, Magdalena Maroszek, Agnieszka Budzyńska, Agnieszka Napiorkowska-Krzebietke, Magdalena Toporowska, Magdalena Grabowska, Anna Kozak, Joanna Rosińska, Jussi Meriluoto
Cyanobacterial blooms and cyanotoxins occur in freshwater lakes and reservoirs all over the world. Bacterial degradation of microcystins (MC), hepatotoxins produced by several cyanobacterial species, has also been broadly documented. However, information regarding MC biodegradation in European water bodies is very limited. In this paper, the occurrence and identification of MC biodegradation products was documented for 21 European lakes and reservoirs, many of which have well-documented cyanobacterial bloom histories...
July 31, 2017: Ecotoxicology and Environmental Safety
Yabing Chen, Jing Wang, Qin Zhang, Zou Xiang, Dongmei Li, Xiaodong Han
Microcystin-leucine arginine (MC-LR) causes testicular inflammation and hinders spermatogenesis. However, the molecular mechanisms underlying the immune responses to MC-LR in the testis have not been elucidated in detail. In this study, we show that MC-LR induced immune responses in Sertoli cells (SC), germ cells (GC), and Leydig cells (LC) via activating phosphatidylinositol 3-kinase (PI3K)/AKT/nuclear factor kappa B (NF-κB), resulting in the production of pro-inflammatory cytokines and chemokines including tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and chemokine (C-X-C motif) ligand 10 (CXCL10)...
July 29, 2017: Environmental Pollution
Bo-Ram Moon, Tae-Kyoung Kim, Moon-Kyung Kim, Jaewon Choi, Kyung-Duk Zoh
The removal and degradation pathways of microcystin-LR (MC-LR, [M+H](+) = 995.6) in UV-B photolysis and UV-B/H2O2 processes were examined using liquid chromatography-tandem mass spectrometry. The UV/H2O2 process was more efficient than UV-B photolysis for MC-LR removal. Eight by-products were newly identified in the UV-B photolysis ([M+H](+) = 414.3, 417.3, 709.6, 428.9, 608.6, 847.5, 807.4, and 823.6), and eleven by-products were identified in the UV-B/H2O2 process ([M+H](+) = 707.4, 414.7, 429.3, 445...
October 2017: Chemosphere
Houcheng Cheng, Wei Yan, Qin Wu, Chunsheng Liu, Xiuying Gong, Tien-Chieh Hung, Guangyu Li
Microcystin-LR is the most poisonous and commonly encountered hepatotoxin produced by cyanobacteria in an aquatic ecosystem, and it may cause thyroid dysfunction in fish. The present study aimed to reveal the effects of transgenerational toxicity of MCLR on the thyroid endocrine system under sub-chronic exposure conditions. Adult zebrafish (F0) were exposed to environmentally relevant concentrations (1, 5 and 25 μg/L) of MCLR for 45 days. The produced F1 embryos were then tested without further MCLR treatment...
July 25, 2017: Environmental Pollution
Man Xiao, Anusuya Willis, Michele A Burford, Ming Li
The freshwater cyanobacterium Microcystis is a nuisance species. It forms large blooms on the water surface and overwhelmingly dominates the ecosystem through the formation of colonies from single cells surrounded by mucilage; however, the mechanism of colony formation is poorly understood. Two mechanisms of Microcystis colony formation have been proposed: cell-division, where cells remain attached after binary fission; and cell-adhesion, where single cells stick together. This paper examined the published literature on Microcystis colony formation to clarify the mechanism of colony formation and its relationship to environmental drivers...
July 2017: Harmful Algae
Crettaz Minaglia Melina Celeste, Rosso Lorena, Aranda Jorge Oswaldo, Goñi Sandro, Sedan Daniela, Andrinolo Dario, Giannuzzi Leda
The effect of temperature (26°C, 28°C, 30°C and 35°C) on the growth of native CAAT-3-2005 Microcystis aeruginosa and the production of Chlorophyll-a (Chl-a) and Microcystin-LR (MC-LR) were examined through laboratory studies. Kinetic parameters such as specific growth rate (μ), lag phase duration (LPD) and maximum population density (MPD) were determined by fitting the modified Gompertz equation to the M. aeruginosa strain cell count (cellsmL(-1)). A 4.8-fold increase in μ values and a 10.8-fold decrease in the LPD values were found for M...
July 2017: Harmful Algae
Camilla Capelli, Andreas Ballot, Leonardo Cerasino, Alessio Papini, Nico Salmaso
In the last decades, the cyanobacterium Dolichospermum lemmermannii showed an increasing spread to Southern Europe, raising serious concerns due to its ability to produce cyanotoxins. The widening of its geographic distribution and the observation of strains showing high optimum temperature underline its ecological heterogeneity, suggesting the existence of different ecotypes. To investigate its biogeography, new isolates from different European water bodies, together with strains maintained by the Norwegian Institute for Water Research Culture Collection of Algae, were genetically characterised for the 16S rRNA gene and compared with strains obtained from public repositories...
July 2017: Harmful Algae
Samuel Cirés, María Cristina Casero, Antonio Quesada
Cyanotoxins are secondary metabolites produced by cyanobacteria, of varied chemical nature and toxic effects. Although cyanobacteria thrive in all kinds of ecosystems on Earth even under very harsh conditions, current knowledge on cyanotoxin distribution is almost restricted to freshwaters from temperate latitudes. In this review, we bring to the forefront the presence of cyanotoxins in extreme environments. Cyanotoxins have been reported especially in polar deserts (both from the Arctic and Antarctica) and alkaline lakes, but also in hot deserts, hypersaline environments, and hot springs...
July 24, 2017: Marine Drugs
Meredith D A Howard, Carey Nagoda, Raphael M Kudela, Kendra Hayashi, Avery Tatters, David A Caron, Lilian Busse, Jeff Brown, Martha Sutula, Eric D Stein
Toxin producing cyanobacterial blooms have increased globally in recent decades in both frequency and intensity. Despite the recognition of this growing risk, the extent and magnitude of cyanobacterial blooms and cyanotoxin prevalence is poorly characterized in the heavily populated region of southern California. Recent assessments of lentic waterbodies (depressional wetlands, lakes, reservoirs and coastal lagoons) determined the prevalence of microcystins and, in some cases, additional cyanotoxins. Microcystins were present in all waterbody types surveyed although toxin concentrations were generally low across most habitats, as only a small number of sites exceeded California's recreational health thresholds for acute toxicity...
July 22, 2017: Toxins
Timothy G Otten, Hans W Paerl, Theo W Dreher, Wim J Kimmerer, Alex E Parker
Harmful blooms of the cyanobacterium Microcystis sp. have become increasingly pervasive in the San Francisco Estuary Delta (USA) since the early 2000's and their rise has coincided with substantial decreases in several important fish species. We sought to investigate direct and indirect effects Microcystis blooms may have on the Delta food web. The Microcystis population was tracked for two years at six sites throughout the Delta using quantitative PCR. High-throughput amplicon sequencing and colony PCR sequencing revealed the presence of 10 different strains of Microcystis, including six different microcystin-producing strains...
July 20, 2017: Environmental Microbiology
Bum Soo Park, Zhun Li, Yoon-Ho Kang, Hyeon Ho Shin, Jae-Hyoung Joo, Myung-Soo Han
Despite the importance of understanding the bloom mechanisms that influence cyanobacterial toxin production, the dynamics of toxic Microcystis subpopulations are largely unknown. Here, we quantified both toxic and entire (i.e., toxic and non-toxic) Microcystis populations based on the microcystin synthetase E (mcyE) and 16S ribosomal RNA genes. Samples were collected from pelagic water and sediments twice per week from October to December 2011, and we investigated the effects of physicochemical factors (pH, water temperature, dissolved oxygen, nutrients, etc...
July 19, 2017: Microbial Ecology
Hui Zeng, Hui Lin, Wenyi Liu, Jia Wang, Lingqiao Wang, Chuanfen Zheng, Yao Tan, Yujing Huang, Lixiong He, Jiaohua Luo, Chaowen Pu, Renping Zhang, Xiaohong Yang, Yingqiao Tian, Zhiqun Qiu, Ji-An Chen, Yang Luo, Xiaobin Feng, Guosheng Xiao, Liping Wu, Weiqun Shu
Abnormal liver function (ALF) plays a key role in metabolic syndrome (MetS), but only few data on the relationship between MetS and the risk factors for ALF (e.g., biotoxins) are available. We aimed to provide the prevalence of MetS and its association with the risk factors for ALF in rural area of Southwest China. A cross-sectional study within the hepatocellular carcinoma cohort was conducted, and included 5493 people with age from 30 to 85 years old. MetS was defined according to the Joint Scientific Statement...
July 17, 2017: Scientific Reports
Min-Seob Kim, Yeon-Jung Lee, Sun-Yong Ha, Baik-Ho Kim, Soon-Jin Hwang, Jung-Taek Kwon, Jong-Woo Choi, Kyung-Hoon Shin
Abstract: Stable isotope tracers were first applied to evaluate the Microcystis cell assimilation efficiency of Sinanodonta bivalves, since the past identification method has been limited to tracking the changes of each chl-a, clearity, and nutrient. The toxicity profile and accumulation of MC-LR, -RR and -YR in different organs (foot and digestive organs) from the three filter-feeders (Sinanodonta woodina, Sinanodonta arcaeformis, and Unio douglasiae) were assessed under the condition of toxigenic cyanobacteria (Microcystis aeruginosa) blooms through an in situ pond experiment using (13)C and (15)N dual isotope tracers...
July 17, 2017: Marine Drugs
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