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The Toxins of Cyanobacteria
... The microcystins and the nodularins are protein phosphatase ihibitors, as well as being potent tumor promoters in animals. It has been recorded that microcystins cause liver necrosis leading to death of animal within hours to days (Carmichael, 1994;Chorus, et al,1999;Humpage and Falcomer, 1999; NHMRC, , 1992;Repavich et aI., 1990;Yu 1995) and there have been frequent reports of thirsty domestic animals and wildlife consuming freshwater contaminated with toxic blue green algal blooms, and dying within minutes to days from acute neurotoxicity and I or hepatotoxicity (Carmichael, 1994;Carbis et aI., 1995;Codd et aI., 1997;Jochimsen et aI., 1998;Mahmood et aI., 1988;Negri et aI., 1995;Repavich et aI., 1990). Mammals and birds appear to be more susceptible to the blue green algal toxins than aquatic invertebrates and fish, with some species variability. ...
... The microcystins and the nodularins are protein phosphatase ihibitors, as well as being potent tumor promoters in animals. It has been recorded that microcystins cause liver necrosis leading to death of animal within hours to days (Carmichael, 1994;Chorus, et al,1999;Humpage and Falcomer, 1999; NHMRC, , 1992;Repavich et aI., 1990;Yu 1995) and there have been frequent reports of thirsty domestic animals and wildlife consuming freshwater contaminated with toxic blue green algal blooms, and dying within minutes to days from acute neurotoxicity and I or hepatotoxicity (Carmichael, 1994;Carbis et aI., 1995;Codd et aI., 1997;Jochimsen et aI., 1998;Mahmood et aI., 1988;Negri et aI., 1995;Repavich et aI., 1990). Mammals and birds appear to be more susceptible to the blue green algal toxins than aquatic invertebrates and fish, with some species variability. ...
... Studies in cultured cells have also shown tumor promotion, and microcystins are preferentially taken up by hepatic cells, so that hepatic tumor promotion is likely (Carmichael and Falconer, 1993). Carmichael, 1994;Humpage, 1999;Ito, 1997;Sugirnara, 1986). There are relatively few case reports and even fewer epidemiologic studies ofthe human health effects of the blue green algal toxins (Carmichael, 1993;Chorus and Bartram, 1999;Jalaludin and Smith, 1992). ...
The potential toxic effect of Microcystis aeruginosa through oral contamination is becoming important. The present study was carried out to find the possible hepatotoxic effects of toxic M. aeruginosa (PCC 7820) on male Wistar rats as animal model. Hepatotoxicity assessment 1vas done by estimation of serum hepatic enzyme levels of r-Glutamyl transferase (GGT). Alkaline phosphatase (ALP). Alanine aminotransferase (ALT/GPT), Aspartate aminotransferese (GOT/AST). Rat treated with non toxic (CYA -/3) and toxic non homogenized M. aeruginosa (PCC 7820) were normal in appearance where as rats receiving homogenized toxic M aeruginosa (PCC 7820) were lethargic and gained less weight which indicates a possible toxic effect on the test animals. The absolute and relative (% body weight) mean weight of liver and kidneys ofthe homogenous toxic M aeruginosa (PCC 7820) treated animal lj'ere lower than those who received non homogenized toxic M aeruginosa (PCC 7820) and the difference is statistically significant (p<0. 00J). Liver sections of rats receiving fresh toxic M aeruginosa and the homogenized toxic M aeruginosa did not show lymphatic infiltration or signs of necrosis. Rats treated 'with homogenized M aeruginosa showed lowering of absolute liver weight compared to the fresh M aeruginosa treated rats. Statisticcally significant (p<0.005) increase levels of serum y-Glutamyl transferase (GGT) was detected in rats 14 days after oral administration with homogenized toxic M aeruginosa (PCC 7820). There was no significant differentfound in serum Alanine aminotransferase (ALT/GPT) concentration between treated and control groups. The results indicate that prolonged oral administration of homogenized M. aeruginosa lead to functional hepatotoxicity in male Wister rats without evident histopathological liver necrosis.
... When nutrients eluted by internal flow are delivered to a field with suitable water temperature and illuminance conditions, the bloom of phytoplankton occurs in a field that is spatiotemporally different from the direct supply of nutrients ( [2][3][4]). The predominance of certain species of phytoplankton can cause taste and odor problems that contribute to the degradation of drinking water supplies, inhibit recreational uses of surface waters [5], the reduction of suitable fish habitats, and some assemblages of cyanobacteria produce toxins that are harmful to humans and animals [6,7]. In eutrophic lakes, the species of the Microcystis, which have gas vesicles, often dominate and spread on the whole water surface. ...
... (www.preprints.org) | NOT PEER-REVIEWED | Posted: 5 April 2024 doi:10.20944/preprints202404.0428.v16 ...
The causes of algal blooms in reservoirs are often complexly intertwined with chemical, physical, and biological factors such as the supply of nutrients. Observation of phytoplankton distribution with high spatiotemporal resolution is necessary to track the nutrient sources that cause algal blooms and to understand their behavior in response to wind and water temperature stratification. Observation from a UAV, which has excellent temporal and spatial resolution, is considered to be an effective method to obtain water quality information comprehensively. On the other hand, it is not only the growth of plankton that affects the color of the water surface but also turbidity. Furthermore, since the brightness value of passive sensors such as optical cameras changes depending on the amount of insolation, it is necessary to perform analysis after making corrections for this. In this study, we attempted to develop a method for estimating chlorophyll concentration from aerial images taken from UAVs using machine learning that takes into account brightness correction based on insolation and the spatial distribution of turbidity evaluated by satellite image analysis.
... Eutrophication is often associated with the occurrence of cyanobacterial blooms. Cyanobacteria are nutritionally inadequate for most aquatic consumers due to poor ingestibility, the production of harmful secondary metabolites, and the lack of essential lipids (Carmichael 1994;DeMott et al. 2001;von Elert et al. 2003;Wilson and Hay 2007;Sanchez et al. 2024). Conditions of sufficient carbon but limited lipid supply (i.e., food quality) may occur regularly in nature, especially in eutrophic waters (Müller-Navarra et al. 2004;Taipale et al. 2019). ...
Zooplankton displays different inducible defenses against invertebrate and vertebrate predators. The response pattern to gape‐limited invertebrate predators involves increased somatic growth and offspring body size but delayed maturity and reduced offspring numbers. In contrast to this general pattern, the freshwater model organism Daphnia magna has been reported to exhibit a different response when encountering the gape‐limited tadpole shrimp Triops cancriformis. Under laboratory conditions, D. magna showed increased somatic growth, earlier maturation, and an increase in both offspring number and size. We propose here that the discrepancy between the previously observed and the theory‐based response patterns against invertebrate predators is due to differences in food availability in the applied laboratory settings and assessed whether the defensive response of D. magna against T. cancriformis is modulated differently by food quantity and quality. We found a strong impact of food quantity and quality on the defense response of D. magna to T. cancriformis kairomones. The prey seem to be able to overcome trade‐offs between morphological defense traits and reproductive traits, but distinctly between high food quantity and high food quality. Thereby, reproductive traits were preferred over morphological defenses. Furthermore, the removal of particles from the T. cancriformis‐conditioned water caused a defense pattern in D. magna that was consistent with the general response pattern known from other invertebrate predators, thus explaining the described discrepancy to previous studies with T. cancriformis. Our study highlights the importance of assessing food‐related effects on predator–prey interactions to understand trophic relationships and food web processes.
... Furthermore, recent studies have suggested that FPVs could help mitigate the occurrence of algal blooms 30,31 , which have increased in many 32 , but not all [33][34][35][36] , inland water bodies in recent decades. This has implications for water availability and ecosystem function, as algal blooms are among some of the main causes of poor water quality and can lead to serious health issues [37][38][39][40][41][42] . FPVs present a promising approach to water quality management, particularly in addressing algal bloom dynamics. ...
As climate change progresses, there is increasing emphasis on net zero and energy system decarbonization. Several technologies are contributing to this agenda, but among these, the growth of solar photovoltaics has consistently exceeded all projections. With increasing land-use pressures, and the expense of building-mounted photovoltaics, water surfaces are increasingly being exploited to host these technologies. However, to date, we lack an understanding of the global potential of floating solar photovoltaics and, as such, we do not yet have sufficient insight to inform decisions on (in)appropriate areas for future deployment. Here we quantify the energy generation potential of floating solar photovoltaics on over 1 million water bodies worldwide (14,906 TWh). Our analysis suggests that with a conservative 10% surface area coverage, floating solar photovoltaics could produce sufficient energy to contribute a considerable fraction (16%, on average) of the electricity demand of some countries, thus playing an important role in decarbonizing national economies.
... When nutrients eluted by internal flow are delivered to a field with a suitable water temperature and illuminance conditions, the bloom of phytoplankton occurs in a field that is spatiotemporally different from the direct supply of nutrients [2][3][4]. The predominance of certain species of phytoplankton can cause taste and odor problems that contribute to the degradation of drinking water supplies, inhibit recreational uses of surface waters [5], and reduce suitable fish habitats, and some assemblages of cyanobacteria produce toxins that are harmful to humans and animals [6,7]. In eutrophic lakes, the species of the Microcystis genus, which have gas vesicles, often dominate and spread on the whole water surface. ...
The observation of the phytoplankton distribution with a high spatiotemporal resolution is necessary to track the nutrient sources that cause algal blooms and to understand their behavior in response to hydraulic phenomena. Photography from UAVs, which has an excellent temporal and spatial resolution, is an effective method to obtain water quality information comprehensively. In this study, we attempted to develop a method for estimating the chlorophyll concentration from aerial images using machine learning that considers brightness correction based on insolation and the spatial distribution of turbidity evaluated by satellite image analysis. The reflectance of harmful algae bloom (HAB) was different from that of phytoplankton seen under normal conditions; so, the images containing HAB were the causes of error in the estimation of the chlorophyll concentration. First, the images when the bloom occurred were extracted by the discrimination with machine learning. Then, the other images were used for the regression of the concentration. Finally, the coefficient of determination between the estimated chlorophyll concentration when no bloom occurred by the image analysis and the observed value reached 0.84. The proposed method enables the detailed depiction of the spatial distribution of the chlorophyll concentration, which contributes to the improvement in water quality management in reservoirs.
... For example, blooms of algae in freshwaters can produce potent toxins, potentially making water bodies unsafe for recreational activities and threatening the health of humans, pets, or livestock that use affected waters. These blooms are often produced by cyanobacteria which can cause a range of health problems, from minor skin irritations to severe stomach upsets, and can even lead to death 39 . However, even if algal blooms are non-toxic, they can negatively impact aquatic life by, for example, irritating or even clogging fish gills causing suffocation and blocking out sunlight from reaching deeper water. ...
Extreme within-lake conditions have the potential to exert detrimental effects on lakes. Here we use satellite observations to investigate how the occurrence of multiple types of extremes, notably algal blooms, lake heatwaves, and low lake levels, have varied in 2724 lakes since the 1980s. Our study, which focuses on bloom-affected lakes, suggests that 75% of studied lakes have experienced a concurrent increase in at least two of the extremes considered (27% defined as having a notable increase), with 25% experiencing an increase in frequency of all three extremes (5% had a notable increase). The greatest increases in the frequency of these extremes were found in regions that have experienced increases in agricultural fertilizer use, lake warming, and a decline in water availability. As extremes in lakes become more common, understanding their impacts must be a primary focus of future studies and they must be carefully considered in future risk assessments.
... They are always composed of the following five amino acid residues: (1) β-amino acid (ADDA); (2) alanine (Dala); (3) D-β-methyl-isoaspartate (D-β-Me-isoAsp); (4) N-methyl-dehydro-alanine (Mdha); and (5) glutamic acid (D-Glu), plus two additional variable amino acid residues. The variable portion of MCs is responsible for microcystin variability and the different degree of toxicity [4,5]. If the MC variable region is composed of arginine (R) and leucine (L), the microcystin is named microcystin-LR (MC-LR). ...
Cyanobacteria bloom is the term used to describe an abnormal and rapid growth of cyanobacteria in aquatic ecosystems such as lakes, rivers, and oceans as a consequence of anthropic factors, ecosystem degradation, or climate change. Cyanobacteria belonging to the genera Microcystis, Anabaena, Planktothrix, and Nostoc produce and release toxins called microcystins (MCs) into the water. MCs can have severe effects on human and animal health following their ingestion and inhalation. The MC structure is composed of a constant region (composed of five amino acid residues) and a variable region (composed of two amino acid residues). When the MC variable region is composed of arginine and leucine, it is named MC-LR. The most-common methods used to detect the presence of MC-LR in water are chromatographic-based methods (HPLC, LC/MS, GC/MS) and immunological-based methods (ELISA). In this work, we developed a new competitive Förster resonance energy transfer (FRET) assay to detect the presence of traces of MC-LR in water. Monoclonal antibody anti-MC-LR and MC-LR conjugated with bovine serum albumin (BSA) were labeled with the near-infrared fluorophores CF568 and CF647, respectively. Steady-state fluorescence measurements were performed to investigate the energy transfer process between anti-MC-LR 568 and MC-LR BSA 647 upon their interaction. Since the presence of unlabeled MC-LR competes with the labeled one, a lower efficiency of FRET process can be observed in the presence of an increasing amount of unlabeled MC-LR. The limit of detection (LoD) of the FRET assay is found to be 0.245 nM (0.245 µg/L). This value is lower than the provisional limit established by the World Health Organization (WHO) for quantifying the presence of MC-LR in drinking water.
... Excessive algae growth can lead to negative consequences for ecosystem function (Huisman et al., 2018), economic opportunity (Dodds et al., 2009), and human and animal health (Carmichael & Boyer, 2016), due to the capability for toxin production in certain species. Cyanobacteria (blue-green algae) are a species of photosynthetic microorganisms of particular concern in freshwater systems (Paerl et al., 2001), that are capable of producing a range of toxins (Carmichael, 1994(Carmichael, , 2001. Rapid growth of cyanobacteria may result in large mats of algae known as cyanobacterial harmful algal blooms (cHABs). ...
Excessive algae growth can lead to negative consequences for ecosystem function, economic opportunity, and human and animal health. Due to the cost-effectiveness and temporal availability of satellite imagery, remote sensing has become a powerful tool for water quality monitoring. The use of remotely sensed products to monitor water quality related to algae and cyanobacteria productivity during a bloom event may help inform management strategies for inland waters. To evaluate the ability of satellite imagery to monitor algae pigments and dissolved oxygen conditions in a small inland lake, chlorophyll-a, phycocyanin, and dissolved oxygen concentrations are measured using a YSI EXO2 sonde during Sentinel-2 and Sentinel-3 overpasses from 2019 to 2022 on Lake Mendota, WI. Machine learning methods are implemented with existing algorithms to model chlorophyll-a, phycocyanin, and Pc:Chla. A novel machine learning-based dissolved oxygen modeling approach is developed using algae pigment concentrations as predictors. Best model results based on Sentinel-2 (Sentinel-3) imagery achieved R 2 scores of 0.47 (0.42) for chlorophyll-a, 0.69 (0.22) for phycocyanin, and 0.70 (0.41) for Pc:Chla. Dissolved oxygen models achieved an R 2 of 0.68 (0.36) when applied to Sentinel-2 (Sentinel-3) imagery, and Pc:Chla is found to be the most important predictive feature. Random forest models are better suited to water quality estimations in this system given built in methods for feature selection and a relatively small data set. Use of these approaches for estimation of Pc:Chla and dissolved oxygen can increase the water quality information extracted from satellite imagery and improve characterization of algae conditions among inland waters.
The unique properties of certain biomaterials, such as antibodies and aptamers, are attracting attention in electrochemical biosensors because of their ability to diagnose the occurrence of diseases, viruses, and toxic chemicals. However, biomaterials used in biosensors are unstable and have a low signal-to-noise ratio, making it difficult to develop innovative and sophisticated measurements using only biomaterials for electrochemical biosensor development. Recently, to overcome the inherent limitations of biomaterials, nanomaterials have been introduced into electrochemical biosensors to enhance the functionality of biomaterials, leading to the development of highly innovative functional electrochemical biosensors. This chapter provides the comprehensive knowledge of electrochemical biosensor and nanomaterials, and discussed by categorized section as various types of biomaterials such as antibody- and aptamer-based electrochemical biosensor.
Amplicon sequencing data of the 16S rRNA (V1-V3) gene from 56 effluent and sediment samples from an Australian wastewater treatment plant are reported. Proteobacteria (3.50%–90.09%), Actinobacteria (0.02%–45.71%), and Cyanobacteria (0.05%–63.73%) were dominant in the effluent. The sediment samples were dominated by Proteobacteria (13.14%–84.83%), Chloroflexi (0.84%–42.52%), and Firmicutes (1.54%–17.21%).
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