Cyanobacteria In Water Samples Research Articles

Accumulation of Microcystin from Oscillatoria limnetica Lemmermann and Microcystis aeruginosa (Kützing) in Two Leafy Green Vegetable Crop Plants Lactuca sativa L. and Eruca sativa.

The use of contaminated water to irrigate crop plants poses a risk to human health from the bioaccumulation potential of microcystins (MCs) in the edible tissues of vegetable plants. The main objective of this study is to determine the concentration of total microcystins (MC-LR and MC-RR) in leafy green plants (Lactuca sativa L. var. longifolia and Eruca sativa) that have previously been irrigated with polluted water. Integrated water samples were collected by cleaned plastic bottles at a depth of about 30 cm from one of the sources of water used to irrigate agricultural lands for crop plants. At the same time, samples from plants were also collected because this water from the lake farm is used for the irrigation of surrounding vegetable plants such as Lactuca sativa L. var. longifolia and Eruca sativa. The dominant species of cyanobacteria in water samples are Microcystis aeruginosa (Kützing) and Oscillatoria limnetica Lemmermann, which were detected with an average cell count 2,300,000 and 450,000 cells/mL, respectively. These two dominant species in water produced two MCs variants (MC-LR, -RR) that were quantified by high-performance liquid chromatography (HPLC). Dissolve and particulate MCs were detected in the irrigation waters by HPLC with concentrations of 45.04–600 μg/L. MCs in the water samples exceeded the WHO safety limit (1 μg/L) of MC in drinking water. In addition, the total concentration of Microcystin in Lactuca sativa L. var. longifolia and Eruca sativa were 1044 and 1089 ng/g tissues, respectively. The estimated daily intake (EDI) of microcystins by a person (60 kg) consuming 300 g of fresh plants exceeded the total daily intake guidelines (0.04 μg kg−1 body weight) for human food consumption. According to the findings of this study, irrigation water and plants used for human consumption should be tested for the presence of MCs regularly through critical and regularly monitored programs to prevent the accumulation and transfer of such toxins through the food web.

Rapid detection of mcyG gene of microcystins producing cyanobacteria in water samples by recombinase polymerase amplification combined with lateral flow strips.

Nowadays, cyanobacteria blooms and microcystins (MCs) pollution are threatening water safety and public health. In this study, a rapid detection method was established for detecting MCs producing cyanobacteria. The MC synthesis gene mcyG was measured through recombinase polymerase amplification combined with lateral flow strips (LF-RPA) technology. The target gene mcyG was amplified at a temperature range of 37-45 °C, and the amplification time to detect mcyG was only 15 min at 37 °C. The optimal reaction conditions were confirmed using single dependent variable experiments, suggesting that the best probe dosage for 50 μL of the reaction mixture was 0.2 μL, the best dilution ratio of products was 1/100, and the best loading volume was 10 μL. The specificity test proved that the LF-RPA assay could distinguish MCs producing cyanobacteria from nontoxic algae well. Within 35 min of amplification time, the detection limit of the LF-RPA assay was 103 copies/mL mcyG and 104 cells/mL Microcystis aeruginosa FACHB-905. Overall, the LF-RPA assay could detect MCs producing cyanobacteria in water samples quickly and accurately, and it has a great promise to be applied for monitoring the MCs producing cyanobacteria blooms in natural waters.

Evaluation of Water Quality on TNF- α and IL- 1 Immune Genes in Oreochromis Niloticus Fish at El Manzala Lake in Egypt

Lake Manzala is known to be from the most significant sources of inexpensive different fish species for human consumption in Egypt. The Lake receives pollution from various sources; domestic wastewater, industrial wastewater, and agricultural drainage directly without any treatments, which lead to many environmental disorders. The following research was conducted for lake water quality evaluation and how it impacts the expression of Tumor necrosis factor- α (TNF- α) and Interleukin-1 (IL- 1) immune genes. Sampling was done seasonally from October 2015 to September 2016, where water and fish samples were collected from 4 locations in El Manzala Lake after mixing with Bahr El Baqr drain (sampling points were 4 km apart from each other). Average values of dissolved oxygen, chemical oxygen, and biological oxygen demand were 6.7 mg O2/l, 139.4 mg O2/l, 92.8 mg O2/l, respectively. For the Nitrogen group, the average concentration of ammonia, nitrite, and nitrate was 0.7 mg/l, 0.38 mg/l, and 0.38 mg/l, respectively. The average records of total bacterial count and total and fecal coliform suggesting high loads of contaminants, particularly in sampling sites close to Bahr El Baqr drain. The relative occurrence of cyanobacteria in water samples was influenced by increasing lake water temperature. The expression of the immune genes for TNF- α and IL- 1 in Nile Tilapia fish liver was confirmed by RT-PCR. The results showed up-regulation of these genes in the liver of Nile Tilapia fish, especially in warm seasons (summer, late summer). TNF-α and IL- 1 level in Nile Tilapia fish could be used as early diagnostic indicators to different environmental events and also are helpful and reliable bioindicators in estimating pollutants of the aquatic environment. High levels of pollution in El Manzala Lake were recorded in this study that may proceed with health risks to a human. Therefore, the Lake needs proper policies to protect and preserve its ecological integrity and biodiversity.

Detection of microcystin-producing cyanobacteria in water samples using loop-mediated isothermal amplification targeting mcyB gene.

Microcystin toxin-producing cyanobacteria are known to have harmful effects on humans and animals. We have developed a loop-mediated isothermal amplification (LAMP)-based detection method by targeting the microcystin synthetase B gene (mcyB), the gene responsible for the production of microcystin. The sensitivity of the method was found to be 1fg per reaction, and it was 1000-fold higher than the conventional PCR. The LAMP method was able to amplify the target gene with a minimum amount of dNTP (0.4mM), which further reduces the cost of reaction. The improved LAMP assay could detect the presence of the toxin-producing cyanobacteria in water samples within 2h of time, which demonstrates the rapidness of the method. Freshwater samples were screened using the developed LAMP, and seven water samples collected from lakes and a bird sanctuary tested positive for mcyB gene harboring cyanobacteria, and negative in all other drinking waters. Hence, the developed LAMP could be a possible alternative to the existing molecular methods for screening for microcystin in environmental samples with greater sensitivity.

Smartphone Calibration for Crowd-Sourced Determination of the Presence of Cyanobacteria in Water Samples

Smartphone Calibration for Crowd-Sourced Determination of the Presence of Cyanobacteria in Water Samples

Cianobactérias e microcistina em águas de rio destinadas ao abastecimento de centro industrial de Caruaru, PE, Brasil

Cyanotoxin producing Cyanobacteria can cause serious harm to human and animal health. Microcystins, the most common type of cyanotoxins, promote liver tumors in men. Thus, we aimed at verifying the occurrence of cyanobacteria in water samples from the Ipojuca’s river at the perimeter of Caruaru-PE, Brazil, and determining if the toxin was also present. Water samples were collected at five strategic points over thirteen consecutive months. High Performance Liquid Chromatography (HPLC) was used to obtain microcystins. The Utermohl sedimentation method was used to identify and quantify species. This approach found that the toxin was present in 100% of the samples, and pointed to three genera of microcystin producers. The river provides the one of the source for public water supply in the region, confirming the relevance of continuous monitoring of cyanobacteria and cyanotoxins. As observed in the Ipojuca river, several water sources at Pernambuco also present recurrent cyanobacterial blooms, which may contain toxin producers. The blooms occur mainly in the dry season, when water is an invaluable commodity for humans and life stock. Finally, this study showed the importance of monitoring microcystin to support preventive actions in environmental and public health surveillance.

Benchtop fluorometry of phycocyanin as a rapid approach for estimating cyanobacterial biovolume

Cyanobacteria are the primary taxa responsible for freshwater harmful algal blooms (HABs), with several genera capable of producing potent intracellular toxins and off-flavor compounds. There is considerable growing interest in methods to rapidly quantify cyanobacteria in water samples. Past studies have demonstrated poor correlations between phycocyanin in vivo fluorescence and cyanobacterial cell densities. We conducted a series of laboratory experiments aimed at refining a protocol that uses benchtop fluorometry to measure the cyanobacterial pigment, phycocyanin, to accurately estimate cyanobacterial biovolume. In our study, we found strong correlations between phycocyanin concentration and cyanobacterial biovolume (but not for cell densities) both within and across ponds, which varied widely in productivity and algal diversity. Thus, benchtop fluorometry of phycocyanin is a viable method for water resource managers to quickly estimate cyanobacterial biovolume.

Técnicas moleculares para la detección de cianobacterias en los embalses Riogrande II y La Fe, Colombia

In lentic water bodies as reservoirs occur eutrophication processes, originated mainly from human activities (i.e. agriculture, animal exploitation). This influx of nutrients in aquatic ecosystems could promote blooms of potentially toxic cyanobacteria. The purpose of this work is to detect the presence of cyanobacteria strains in water samples, using molecular techniques to help in preventive management of reservoirs dedicated to water purification. We used two molecular techniques to detect genes implied with the synthesis of hepatotoxic microcystins from potentially toxic cyanobacteria strains, and to evaluate the molecular diversity of cyanobacteria in water samples from two high-mountain reservoirs used for purification of drinking water for the metropolitan area of Medellin, Colombia. Between 2010-2011 collections of 12 water samples were taken and DNA extraction together with PCR and DGGE analyses where carried out. We amplified 22 sequences between 250-300bp of the genes mcyA and mcyE, and these sequences were related with several strains and cyanobacteria genera accessions from NCBI-GenBank databases. Moreover, sequence amplifications of the 16S small ribosomal RNA subunit - 16S rRNA- between 400-800bp were also performed in order to use them for the DGGE technique. The amplification products of DGGE were set in polyacrilamide gel with posterior denaturing electrophoresis, and the scanned images of the gel bands were analysed with the software GelCompar II. For Riogrande II and La Fe reservoirs we found 35 and 30 different DGGE bands, respectively, as a measurement of molecular diversity in these artificial ecosystems. Here, we demonstrated the utility of two molecular techniques for the detection of genes associated with toxicity and molecular diversity of cyanobacteria in reservoirs destined for drinking water in urban centers. We recommend strongly following with periodically molecular biology studies in these ecosystems combined with limnological and ecological data, as new tools for management of plants of water purification and for the prevention of potentially public health concerns.

Cyanotoxin occurrence and potentially toxin producing cyanobacteria in freshwaters of Greece: A multi-disciplinary approach

Cyanobacteria harmful algal blooms (or CyanoHABs) represent one of the most conspicuous waterborne microbial hazards in aquatic environments mostly due to the production of harmful secondary metabolites, known as cyanotoxins. In freshwaters of Greece only the presence of microcystins (MCs) has been reported despite the increasing occurrence of species able to produce other cyanotoxins too. In this paper, we studied the occurrence of potentially toxic cyanobacteria in water samples collected from six lakes and reservoirs in Greece. A multi-technique approach was applied by the use of microscopy, molecular, and immunological methods. Cyanobacteria were found in all the sites ranging from 4.7 × 103 to 5.3 × 108 individuals L−1, representing >70% of the total phytoplankton abundance. Microcystins (MCs), cylindrospermopsins (CYNs), and saxitoxins (STXs) were detected using ELISA, in concentrations ranging from 3.9 to 108 μg L−1, from 0.3 to 2.8 μg L−1 and from 0.4 to 1.2 μg L−1, respectively. In half of the samples examined more than one cyanotoxins were detected. Our results document the first report on the occurrence of CYN and STX in freshwaters of Greece and show that potential STX producers are Cylindrospermopsis raciborskii and Aphanizomenon flos-aquae. Further studies are needed to assess potential CYN producers. This study provides further data on the distribution and toxicity of C. raciborskii and Aph. flos-aquae and documents a C. raciborskii dominated bloom producing STX in Europe.

A simple and rapid DNA extraction method for Cyanobacteria and Monocots

The isolation of DNA from biological samples is a crucial step in the process of DNA-based molecular biological assays. In this study, we present a simple method to extract and purify genomic DNA from different sample types (standard cyanobacteria, cyanobacteria in water samples and leaves of bamboo plants) which would be suitable for any molecular analyses. In this method, cyanobacteria are lysed by three sequential freezing and heating followed by enzymatic treatment with lysozyme and proteinase K. The extraction and purification of DNA was achieved with the lysing and nuclease inactivating properties of the chaotropic agent guanidium isothiocyanate and the nucleic acid binding properties of silica particles. The DNA extraction method yielded high quality reproducible DNA. The technique described here is a rapid, robust and cost effective method suitable for the extraction of DNA from any source for routine molecular biological assays. Key Words: Boom’s method, guanidine thiocyanate, silica, Polymerase Chain Reaction (PCR) DOI: http://dx.doi.org/10.4038/cjsbs.v40i1.3407 CJSBS 2011; 40(1): 59-63

Amplified rDNA Restriction Analysis (ARDRA) for monitoring of potentially toxic cyanobacteria in water samples

Cyanobacterial blooms have become an increasing worldwide problem in aquatic habitats. Certain species of cyanobacteria produce toxins of several types that threaten the health of animals and humans and may affect tourism and recreation activities. Therefore, early identification and prediction of such toxic blooms are essential for proper management of the aquatic environment. Here we report on the development and application of a molecular diagnostic tool for rapid identification of potentially toxic cyanobacteria. Toxic cyanobacteria species, Aphanizomenon ovalisporum and two Microcystis strains, were isolated from Lake Kinneret (Sea of Galilee, Israel), and a large DNA fragment of the rDNA gene was cloned and sequenced for these species. Restriction enzymes were selected according to the sequences to yield species-specific fragment patterns. A set of primers was designed to amplify the 16S-ITS1-23S region, which was then digested by the selected restriction enzymes to yield known fragment patterns. Th...

Detection and monitoring toxigenicity of cyanobacteria by application of molecular methods

The aim of this study was early genetic identification of microcystin-producing cyanobacteria and monitoring their toxigenicity by determining toxin concentrations in three Polish lakes throughout the summer of 2004. The assessment of cyanobacterial blooms was carried out in shallow, eutrophic water bodies: Lake Jeziorak, Lake Bninskie, and Sulejow Reservoir. Samples for DNA, phycological, and toxin analyses were collected from July till October. Molecular analysis of the 16S rRNA region was used to detect cyanobacteria in water samples. The microscopic analysis was performed to investigate seasonal variation of phytoplankton. Cyanobacteria, with domination by Microcystis, Planktothrix, and Planktolyngbya were detected during the whole monitoring period in Sulejow Reservoir, Lake Bninskie, and Lake Jeziorak, respectively. The presence and identification of toxic strains in water bodies was studied by PCR amplification of mcy genes in the microcystis synthesis pathway. The presence of the mcyA, mcyB, mcyD, and mcyE genes in water samples indicated the genetic potential to produce microcystins. Toxicity of water samples and microcystin concentrations were established by PPIA and HPLC, respectively. The maximum concentration of microcystins was 11.13 microg/L and 4.67 microg/L in samples dominated by P. agardhii and M. aeruginosa, respectively. Molecular analysis showed that toxigenic strains of cyanobacteria occurred in the three lakes throughout the summer season.

Cyanobacteria associated with Anopheles albimanus (Diptera: Culicidae) larval habitats in southern Mexico.

Cyanobacteria associated with Anopheles albimanus Wiedemann larval habitats from southern Chiapas, Mexico, were isolated and identified from water samples and larval midguts using selective medium BG-11. Larval breeding sites were classified according to their hydrology and dominant vegetation. Cyanobacteria isolated in water samples were recorded and analyzed according to hydrological and vegetation habitat breeding types, and mosquito larval abundance. In total, 19 cyanobacteria species were isolated from water samples. Overall, the most frequently isolated cyanobacterial taxa were Phormidium sp., Oscillatoria sp., Aphanocapsa cf. littoralis, Lyngbya lutea, P. animalis, and Anabaena cf. spiroides. Cyanobacteria were especially abundant in estuaries, irrigation canals, river margins and mangrove lagoons, and more cyanobacteria were isolated from Brachiaria mutica, Ceratophyllum demersum, and Hymenachne amplexicaulis habitats. Cyanobacteria were found in habitats with low to high An. albimanus larval abundance, but Aphanocapsa cf. littoralis was associated with habitats of low larval abundance. No correlation was found between water chemistry parameters and the presence of cyanobacteria, however, water temperature (29.2-29.4 degrees C) and phosphate concentration (79.8-136.5 ppb) were associated with medium and high mosquito larvae abundance. In An. albimanus larval midguts, only six species of cyanobacteria were isolated, the majority being from the most abundant cyanobacteria in water samples.