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Combining coagulants with ballast (natural soil or modified clay) to remove cyanobacteria from the water column is a promising tool to mitigate nuisance blooms. Nevertheless, the possible effects of this technique on different toxin-producing cyanobacteria species have not been thoroughly investigated. This laboratory study evaluated the potential effects of the “Floc and Sink” technique on releasing microcystins (MC) from the precipitated biomass. A combined treatment of polyaluminium chloride (PAC) with lanthanum modified bentonite (LMB) and/or local red soil (LRS) was applied to the bloom material (mainly Dolichospermum circinalis and Microcystis aeruginosa) of a tropical reservoir. Intra and extracellular MC and biomass removal were evaluated. PAC alone was not efficient to remove the biomass, while PAC + LMB + LRS was the most efficient and removed 4.3–7.5 times more biomass than other treatments. Intracellular MC concentrations ranged between 12 and 2.180 µg L−1 independent from the biomass. PAC treatment increased extracellular MC concentrations from 3.5 to 6 times. However, when combined with ballast, extracellular MC was up to 4.2 times lower in the top of the test tubes. Nevertheless, PAC + LRS and PAC + LMB + LRS treatments showed extracellular MC concentration eight times higher than controls in the bottom. Our results showed that Floc and Sink appears to be more promising in removing cyanobacteria and extracellular MC from the water column than a sole coagulant (PAC).
Renan Arruda; Natália Noyma; Leonardo de Magalhães; Marcella Mesquita; Éryka de Almeida; Ernani Pinto; Miquel Lürling; Marcelo Marinho. ‘Floc and Sink’ Technique Removes Cyanobacteria and Microcystins from Tropical Reservoir Water. Toxins 2021, 13, 405 .
AMA StyleRenan Arruda, Natália Noyma, Leonardo de Magalhães, Marcella Mesquita, Éryka de Almeida, Ernani Pinto, Miquel Lürling, Marcelo Marinho. ‘Floc and Sink’ Technique Removes Cyanobacteria and Microcystins from Tropical Reservoir Water. Toxins. 2021; 13 (6):405.
Chicago/Turabian StyleRenan Arruda; Natália Noyma; Leonardo de Magalhães; Marcella Mesquita; Éryka de Almeida; Ernani Pinto; Miquel Lürling; Marcelo Marinho. 2021. "‘Floc and Sink’ Technique Removes Cyanobacteria and Microcystins from Tropical Reservoir Water." Toxins 13, no. 6: 405.
High temperature can promote cyanobacterial blooms, whereas ultraviolet radiation (UVR) can potentially depress cyanobacterial growth by damaging their photosynthetic apparatus. Although the damaging effect of UVR has been well documented, reports on the interactive effects of UV radiation exposure and warming on cyanobacteria remain scarce. To better understand the combined effects of temperature and UVR on cyanobacteria, two strains of nuisance species, Microcystis aeruginosa (MIRF) and Raphidiopsis raciborskii (formerly Cylindrospermopsis raciborskii, CYRF), were grown at 24°C and 28°C and were daily exposed to UVA + UVB (PAR + UVA+UVB) or only UVA (PAR + UVA) radiation. MIRF and CYRF growth rates were most affected by PAR + UVA+UVB treatment and to a lesser extent by the PAR + UVA treatment. Negative UVR effects on growth, Photosystem II (PSII) efficiency and photosynthesis were pronounced at 24°C when compared to that at 28°C. Our results showed a cumulative negative effect on PSII efficiency in MIRF, but not in CYRF. Hence, although higher temperature ameliorates UVR damage, interspecific differences may lead to deviating impacts on different species, and combined elevated temperature and UVR stress could influence species competition.
Natália Pessoa Noyma; Marcella C.B. Mesquita; Fábio Roland; Marcelo Manzi Marinho; Vera L.M. Huszar; Miquel Lürling. Increasing Temperature Counteracts the Negative Effect of UV Radiation on Growth and Photosynthetic Efficiency of Microcystis aeruginosa and Raphidiopsis raciborskii. Photochemistry and Photobiology 2021, 1 .
AMA StyleNatália Pessoa Noyma, Marcella C.B. Mesquita, Fábio Roland, Marcelo Manzi Marinho, Vera L.M. Huszar, Miquel Lürling. Increasing Temperature Counteracts the Negative Effect of UV Radiation on Growth and Photosynthetic Efficiency of Microcystis aeruginosa and Raphidiopsis raciborskii. Photochemistry and Photobiology. 2021; ():1.
Chicago/Turabian StyleNatália Pessoa Noyma; Marcella C.B. Mesquita; Fábio Roland; Marcelo Manzi Marinho; Vera L.M. Huszar; Miquel Lürling. 2021. "Increasing Temperature Counteracts the Negative Effect of UV Radiation on Growth and Photosynthetic Efficiency of Microcystis aeruginosa and Raphidiopsis raciborskii." Photochemistry and Photobiology , no. : 1.
Temperature increase may influence competition among phytoplankton species, potentially intensifying cyanobacteria blooms that can be favored by direct and indirect effects of temperature. In this study, we aimed to clarify how cyanobacteria can be favored by the direct effects of increased temperature compared to diatoms and chlorophytes. Strains of the most representative species of a eutrophic coastal lagoon (Microcystis aeruginosa, Planktothrix agardhii, Desmodesmus communis, and Cyclotella meneghiniana) were used to test the hypothesis that cyanobacteria would be favored by the direct effect of temperature increase. First, we evaluated the effect of temperature increase on growth in monocultures (batch and chemostats) at 25 and 30 °C and after in mixed cultures (chemostats). In batch monocultures, the cyanobacteria showed higher growth rates in 30 °C than in 25 °C. However, in continuous culture experiments (chemostats), growth rates of M. aeruginosa and P. agardhii were not affected by temperature, but the strains showed higher biovolume in steady-state with the temperature increase. In continuous mixed cultures, M. aeruginosa was always dominant and C. meneghiniana was excluded, regardless of temperature tested. D. communis was able to coexist with lower biomass. This study shows that rising temperatures can be detrimental to diatoms, even for a tropical strain. Although some studies indicate that the dominance of cyanobacteria in warmer climates may be due to the indirect effect of warming that will promote physical conditions in the environment more favorable to cyanobacteria, the outcomes of mixed cultures demonstrate that the direct effect of temperature can also favor the dominance of cyanobacteria.
Marcella C.B. Mesquita; Ana Carolina C. Prestes; Andreia Gomes; Marcelo Marinho. Direct Effects of Temperature on Growth of Different Tropical Phytoplankton Species. Microbial Ecology 2019, 79, 1 -11.
AMA StyleMarcella C.B. Mesquita, Ana Carolina C. Prestes, Andreia Gomes, Marcelo Marinho. Direct Effects of Temperature on Growth of Different Tropical Phytoplankton Species. Microbial Ecology. 2019; 79 (1):1-11.
Chicago/Turabian StyleMarcella C.B. Mesquita; Ana Carolina C. Prestes; Andreia Gomes; Marcelo Marinho. 2019. "Direct Effects of Temperature on Growth of Different Tropical Phytoplankton Species." Microbial Ecology 79, no. 1: 1-11.
Cylindrospermopsis raciborskii is a potentially toxic freshwater cyanobacterium that can tolerate a wide range of light and temperature. Due to climatic changes, the interaction between light and temperature is studied in aquatic systems, but no study has addressed the effect of both variables on the saxitoxins production. This study evaluated the combined effect of light and temperature on saxitoxins production and cellular quota in C. raciborskii. Experiments were performed with three C. raciborskii strains in batch cultures under six light intensities (10, 40, 60, 100, 150, and 500 μmol of photons m−2 s−1) and four temperatures (15, 20, 25, and 30 °C). The growth of C. raciborskii strains was limited at lower temperatures and the maximum growth rates were obtained under higher light combined with temperatures equal or above 20 °C, depending on the strain. In general, growth was highest at 30 °C at the lower light intensities and equally high at 25 °C and 30 °C under higher light. Highest saxitoxins concentration and cell-quota occurred at 25 °C under high light intensities, but were much lower at 30 °C. Hence, increased temperatures combined with sufficient light will lead to higher C. raciborskii biomass, but blooms could become less toxic in tropical regions.
Marcella Mesquita; Miquel Lürling; Fabiane Dorr; Ernani Pinto; Marcelo Marinho. Combined Effect of Light and Temperature on the Production of Saxitoxins in Cylindrospermopsis raciborskii Strains. Toxins 2019, 11, 38 .
AMA StyleMarcella Mesquita, Miquel Lürling, Fabiane Dorr, Ernani Pinto, Marcelo Marinho. Combined Effect of Light and Temperature on the Production of Saxitoxins in Cylindrospermopsis raciborskii Strains. Toxins. 2019; 11 (1):38.
Chicago/Turabian StyleMarcella Mesquita; Miquel Lürling; Fabiane Dorr; Ernani Pinto; Marcelo Marinho. 2019. "Combined Effect of Light and Temperature on the Production of Saxitoxins in Cylindrospermopsis raciborskii Strains." Toxins 11, no. 1: 38.
Aphanizomenonaceae is a recently proposed family of Cyanobacteria encompassing 12 planktic genera. The formation and distribution of heterocytes and akinetes along the trichome are the main morphological characteristics of this family. In this context, Sphaerospermopsis and Cylindrospermopsis are close related genera both molecularly and morphologically differing by 1) rounded akinetes adjacent to the heterocytes disposed along the trichome in Sphaerospermopsis; 2) apical heterocytes and akinetes separated by a few cells (2–3) in Cylindrospermopsis. Recently, during a survey on cyanobacteria from tropical Brazilian eutrophic lakes, strains with similarities to Sphaerospermopsis and Cylindrospermopsis were isolated. Aiming to elucidate the phylogenetic placement of these strains, we performed morphological, physiological and molecular studies. The Brazilian strains were confirmed to be closely related to Sphaerospermopsis and Cylindrospermopsis, but the phylogeny, based on 16S rRNA gene and 16S–23S rRNA intergenic region, clustered them in a well-defined clade separate from these genera. According to these results, we detailed the morphology, physiology, and phylogeny of the proposed new genus Amphiheterocytum, which showed potential to create blooms in tropical shallow lakes.
Célia L. Sant'anna; Watson A. Gama; Janaina Rigonato; Gilsinéia Correa; Marcella C.B. Mesquita; Marcelo Manzi Marinho. Phylogenetic connection among close genera of Aphanizomenonaceae (Cyanobacteria): Amphiheterocytum gen. nov., Cylindrospermopsis and Sphaerospermopsis. Algal Research 2018, 37, 205 -214.
AMA StyleCélia L. Sant'anna, Watson A. Gama, Janaina Rigonato, Gilsinéia Correa, Marcella C.B. Mesquita, Marcelo Manzi Marinho. Phylogenetic connection among close genera of Aphanizomenonaceae (Cyanobacteria): Amphiheterocytum gen. nov., Cylindrospermopsis and Sphaerospermopsis. Algal Research. 2018; 37 ():205-214.
Chicago/Turabian StyleCélia L. Sant'anna; Watson A. Gama; Janaina Rigonato; Gilsinéia Correa; Marcella C.B. Mesquita; Marcelo Manzi Marinho. 2018. "Phylogenetic connection among close genera of Aphanizomenonaceae (Cyanobacteria): Amphiheterocytum gen. nov., Cylindrospermopsis and Sphaerospermopsis." Algal Research 37, no. : 205-214.