The phylosophy and applicability of ecoremediations for the protection of water ecosystems

The problem of accelerated eutrophication of the water ecosystems has not been appreciated proportionally to the development of human society today. Accelerated or fast eutrophication is detected destiny in majority of ecosystems today, mainly due to adverse human impact. This paper aims to introduce ERM methods in treating the problems arising from increased total capacity and saprobity and also accelerated eutrophication. In this way the broadness and importance of ERM as an ecosystem service for the water protection should be emphasized. The basic characteristics of ERM are its high buffer and self-protective capacities, and preservation of natural habitats and biological diversity. ERM represents the ‘returning to nature’ approach aiming to preserve or re-establish the natural balance of the ecosystems, but also a human endeavor that enables new jobs and by-side activities important for economic and social development of the human society

Freshwater Cyanobacterial blooms and Cyanotoxin production in Serbia in the past 25 years

Since 1980 cyanobacterial blooms occurred in a large number of reservoirs lakes and water flows (rivers and channels) in Serbia. Among 83 water ecosystems examined, 58 were found in blooming condition almost every year during last 2 decades. All natural lakes, accumulations, rivers and canals in Vojvodina province (agricultural part) proved to be sites with frequent cyanobacterial proliferation. During the summer 2005-spring 2006 microcystin-LR survey in Vojvodina, the toxin was permanently present in all examined ecosystems and the highest value of 362.68 μgL-1 was detected in Ludoš Lake. The part of Central Serbia is very problematic for ground water supply. For that reason more than 20 reservoirs serve as drinking water suppliers. Significant and persistent cyanobacterial blooms have been recognized in 9 of them. Samples for cyanotoxin analyses were taken during and after blooms in Ćelije Reservoir and in drinking water in Kruševac town 2 days later. Concentration of microcystin-LR was 650 μgL-1 in the reservoir while the tap water contained 2.5μgL-1

Obtaining Polysaccharide-Based Fabrics with Improved Moisture Sorption and Dye Adsorption Properties

Featured Application: This work has a potential application in biocarpet engineering, which involves the use of cyanobacterial crusts either in the rehabilitation of damaged land surfaces or to combat desertification. Attempts to apply cyanobacterial crusts have not been completely successful so far because the growth of the initial inoculum requires more moisture than arid and semiarid environments can provide. To accelerate the development of the inoculum, it is necessary to provide additional moisture for the growth of cyanobacterial cells. Controlled water delivery could be achieved by using moisture-retentive material that is applied together with the inoculum in the treatment of damaged surfaces. Biocarpet engineering has the potential to solve not only some problems of damaged surfaces and desertification but also reduce and prevent air and water pollution caused by erosion. Raw jute fabric was treated with 0.5, 1.0, or 2.0% chitosan solution to improve its sorption properties (evaluated through the moisture sorption and adsorption of textile dye Reactive Orange 16 (RO 16)), which are essential for fabric utilization as geo-prebiotic polysaccharide support that should provide the necessary water for the growth of cyanobacterial communities in biocarpet engineering. Chitosan-treated fabrics possessed 39–78% higher moisture sorption values than the untreated ones. Concerning the dye adsorption, with the increase in its initial concentration, the adsorption potential of raw and fabrics treated with 0.5 or 1.0% chitosan solution was increased up to 1.9 times. The dye adsorption onto these fabrics was exothermic and enthalpy driven. By increasing the chitosan solution percentage up to 1.0%, fabric adsorption potential increased up to 2.2 times. An inverse relationship was observed in the case of the fabric treated with 2.0% chitosan solution, its adsorption potential decreased with increasing the initial dye concentration and temperature due to the different dominant binding interactions. Concerning the contact time, dye adsorption onto fabric treated with 1.0% chitosan solution was rapid in the first 2 h, while the equilibrium was attained after 4.5 h. The isotherm and kinetic data were represented by the Langmuir model and the pseudo-second-order kinetic model, respectively

Cyanobacteria and loess-an underestimated interaction

Background: Biocrusts are important functional units in dryland ecosystems. Regarded as ecosystem engineers, cyanobacteria in biocrusts contribute several major physico-chemical and biological processes. However, the role of cyanobacteria in the process of loess formation has been underestimated. Recently, their contribution to sediment development was presented in the BLOCDUST model of loess formation. Scope: This perspective paper features the environmental impact of cyanobacteria and biocrusts with a focus on processes involved in the formation of loess sediments. We propose that the formation of loess can be mediated by cyanobacteria, including initial trapping, and the accumulation and preservation of loess-forming particles. Moreover, the initial structure may be further altered by weak mineral weathering, dissolution and mineral re-precipitation due to cyanobacterial metabolic processes. Possible negative aspects of environmental impact related to the potential toxicity of cyanobacterial biocrusts are also discussed. We highlight specific biotic-abiotic interactions between biocrusts and loess (e.g. exudation of organic polymers, carbonate dissolution and re-precipitation, and dust-dependent metabolic activities of cyanobacteria) which are essential for the formation of stabilized loess and propose the term “synergosis” to comprise these interactions. Conclusion: The role of cyanobacteria in loess formation has only recently been recognized and the possible biogenic nature of loessification is underestimated as compared to their eolian nature. Mineral weathering and mineral precipitation processes as well as mineral dust flux between litho- and atmosphere mediated by cyanobacteria and biocrusts require more attention due to their significant contribution to ecosystem properties

Microcystins: Potential risk factors in carcinogenesis of primary liver cancer in Serbia

The Primary Liver Carcinoma (PLC) is one of the most common malignant diseases in the world. In Central Serbia during the period from 2000 to 2006 the average incidence was 16.9/100 000 that complies to the European epidemiology. The main risk factors for PLC are considered to be cirrhosis of liver and viral chronic Hepatitis B and C. The goal of this research was to analyze epidemiological data of these diseases and to state the correlation between PLC, liver cirrhosis and Hepatitis B and C in Serbia. During the research period of 6 years the correlations between PLC and the corresponding risk factors were negative. For this reason it was necessary to examine other risk factors. The high incidence of PLC in Nišavski, Toplički and Šumadijski region correlate with emerging blooms of Cyanobacteria in water reservoirs supplying these areas with drinking water. Since we examined only 7 years span and have no completed cyanotoxin analysis, it is necessary to complete more research in this field. The identification of cyanotoxins as risk factors that contribute to the development of liver cancer will help in the prevention of this disease

Putevi izloženosti ljudi cijanotoksinima i njihovi utjecaji na zdravlje

Cyanotoxins are secondary metabolites produced by cyanobacteria. They pose a threat to human health and the environment. This review summarises the existing data on human exposure to cyanotoxins through drinking water, recreational activities (e.g., swimming, canoeing or bathing), the aquatic food web, terrestrial plants, food supplements, and haemodialysis. Furthermore, it discusses the tolerable daily intake and guideline values for cyanotoxins (especially microcystins) as well as the need to implement risk management measures via national and international legislation.Cijanotoksini su sekundarni metaboliti potencijalno opasni za ljudsko zdravlje i okoliš, koje proizvodecijanobakterije. Ovaj pregledni rad donosi prikaz postojećih podataka o izloženosti ljudi cijanotoksinima putem vode za piće, rekreacije, vodenog hranidbenog lanca, kopnenih biljaka i nekih drugih specifičnih puteva (dodaci prehrani i intravenozni put). Nadalje, u njemu se raspravlja o dopuštenom dnevnom unosu (TDI) i preporučenim vrijednostima za cijanotoksine (naročito mikrocistine) i nužnost provedbe mjera upravljanja rizicima putem nacionalnih i međunarodnih zakona. To su mjere od najveće važnosti za očuvanje okoliša i ljudskog zdravlja

Limnological characteristics, water regime and water quality problems of Borkovac reservoir (Vojvodina, Serbia)

In this study we present interdisciplinary investigations of the Borkovac reservoir (Vojvodina, Serbia). The limnological characteristics of the reservoir were analysed in the scope of its sustainable use for irrigation, fishing and tourism. This multipurpose water accumulation has been established in 1975 as a part of regional hydrological system of the Fruška Gora mountain region.The main environmental problems recognized in this study were: water regime, intensive sedimentation in the reservoir, enhanced water eutrophycation and toxic cyanobacterial blooms. Observed environmental problems and proposed solutions in the case of the Borkovac accumulation including construction of the sediment precipitator at the Borkovac stream junction to lake, sediment removal, artificial water mixing and oxygenation, phosphorous inactivitation, different kinds of biomanipulations and biomass removal and introduction of ecoremedation methods could also be applied to other artificial water bodies of the Fruška Gora slopes

Assessment of Common Cyanotoxins in Cyanobacteria of Biological Loess Crusts

Cyanotoxins are a diverse group of bioactive compounds produced by cyanobacteria that have adverse effects on human and animal health. While the phenomenon of cyanotoxin production in aquatic environments is well studied, research on cyanotoxins in terrestrial environments, where cyanobacteria abundantly occur in biocrusts, is still in its infancy. Here, we investigated the potential cyanotoxin production in cyanobacteria-dominated biological loess crusts (BLCs) from three different regions (China, Iran, and Serbia) and in cyanobacterial cultures isolated from the BLCs. The presence of cyanotoxins microcystins, cylindrospermopsin, saxitoxins, and beta-N-methylamino-L-alanine was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, while the presence of cyanotoxin-encoding genes (mcyE, cyrJ, sxtA, sxtG, sxtS, and anaC) was investigated by polymerase chain reaction (PCR) method. We could not detect any of the targeted cyanotoxins in the biocrusts or the cyanobacterial cultures, nor could we amplify any cyanotoxin-encoding genes in the cyanobacterial strains. The results are discussed in terms of the biological role of cyanotoxins, the application of cyanobacteria in land restoration programs, and the use of cyanotoxins as biosignatures of cyanobacterial populations in loess research. The article highlights the need to extend the field of research on cyanobacteria and cyanotoxin production to terrestrial environments

Microcystins: Potent xenobiotics

Having in mind that exposure to low levels of microcystin in drinking water represents the health risk for people, microcystins can be observed as potent xenobiotics. The consequences of exposure to natural products of the blue-green algae, the microcystins, are numerous. Among other things, there is a possibility of development of malignant disease of colon and liver. The occurrence of the tumor is, on one side, enabled by the active transportation of microcystin for achievement of high concentration intracellularly and, on the other side, by high affinity of microcystins for serine/threonine phosphatase PP1 and PP2A after which follows their inactivation. The system, which is responsible for the active transportation of microcystin, is a family of polypeptides for transportation of organic anions (OATP). Isoforms of these carriers are distributed in one tissue, like OATP1B1 and OATP1B3, which are specific for liver or many tissues, OATP1A2 carrier, present in the liver, kidney, brain and the small intestine. The consequences of high concentration of microcystin intracellularly, binding and the inhibitions of protein phosphatase, are numerous. For the occurrence of a tumor, the changes in the nucleus are important, which are related to the gene expression changes, changes in the system for damaged DNA repair and the changes in mitosis. Mediators of these changes have their role in protein activity regulation, signal transmission in the cell, damaged DNA repair, performance of the cell cycle, apoptosis, tumor suppression, cell proliferation and differentiation. Phosphatase inhibition is observed as the strategy of development of a new group of anticancer agents. As phosphatase inhibitors, microcystins and analogs are applied, possibly having the potential to express the difference in toxicity mechanism and detoxification mechanism between the healthy and the tumor cell of liver. High expression of OATP1B1 and OATP1B3 microcystin transporters in hepatocellular carcinoma would confirm selective impact of phosphatase inhibitors to the tumor cell