Toxic cyanobacteria from the territory of the Republic of Serbia

Ispitano je prisustvo toksičnih cijanobakterija u različitim ekosistemima sa teritorije Republike Srbije i analizirane su negativne posledice koje mogu da prouzrokuju ovi mikroorganizmi. Formirana je Baza podataka cijanobakterija u Srbiji koja prilaže veliki broj bitnih  i korisnih informacija iz preko 70 literaturnih izvora o prostiranju i učestalosti pojave cijanobakterija i njihovih toksina u periodu od 130 godina, kao i njihovih efekata na živi svet u vodenim ekosistemima, ali i šire. Istraživana su 64 vodena ekosistema, uključujući reke, jezera, bare, kanale, ribnjake, akumulacije za navodnjavanje, akumulacije za snabdevanje vodom za piće i akumulacije sa drugom namenom, gde je najčešće cvetalo pet vrsta cijanobakterija i to:  Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flos-aquae  i  Planktothrix rubescens  koje ujedno i šire svoj areal rasprostranjenja na teritoriji Republike Srbije. U brojnim vodenim telima detektovani su mikrocistini i to u visokim koncentracijama. Istraživanje vodenog ekosistema Ludoš sa teritorije Republike Srbije vršeno je da bi se ustanovilo prisustvo i uticaj cijanobakterija i cijanotoksina na druge biljne i životinjske organizme u prirodnim uslovima. Trofički status jezera Ludoš najčešće je eutrofan, a cvetanje cijanobakterija kontinuirano još od 1970. godine. Tokom 2011. i 2012. godine  vrste Limnothrix  redekei  i  Pseudanabaena  limnetica  nađene  u  cvetanju. Detektovano je i prisustvo mikrocistina/nodularina i saksitoksina u biomasi i vodi, a mikrocistini su detektovani i u tkivu vodenih biljaka (trske  Phragmites communis, rogoza  Typha latifolia  i ljubičastog lokvanja Nymphaea elegans) i ribi (Carassius gibelio) iz jezera Ludoš. Histološkim pregledom tkiva ribe  pronađene su naizraženije promene u jetri, bubrezima i škrgama, a primećene su i na crevima. Testiranjem bioloških lesnih pokorica sa teritorije Vojvodine nisu detektovani mikrocistini/nodularini, a nije detektovana ni toksičnost uzoraka. Pretpostavlja se da su koncentracije cijanotoksina ispod granica detekcije ili ih nema u testiranim biološkim lesnim pokoricama. Razvojem novih metoda i optimizacijom postojećih za detekciju cijanotoksina u biološkim lesnim pokoricama i drugim terestričnim ekosistemima potrebno je proveriti dobijene rezultate. Proučavanjem svojstva 84 soja cijanobakterija iz NSCCC, koji potiču iz terestričnih i vodenih ekosistema sa teritorije Republike Srbije, dobijena je intracelularna toksičnost u eksponencijalnoj i stacionarnoj fazi rasta, kao i ekstracelularna toksičnost  kod jednog soja koji potiče sa terestričnog ekosistema. Dobijeni su i pozitivni rezultati  na prisustvo mikrocistina, nodularina ili/i saksitoksina kod 34,1% terestričnih i 55,5% vodenih sojeva koji potiču sa teritorije Republike Srbije. Rezultati ukazuju na  potencijalnu opasnost pojave ovih  mikroorganizama i njihovih toksičnih metabolita u različitim ekosistemima sa teritorije Republike Srbije. Eksperimentalno je potvrđena akumulacija mikrocistina u račiću  Daphnia pulex  usled ishrane toksičnim sojem iz NSCCC, zbog čega upotreba ove vrste račića u izvođenju bioloških testova za testiranje prisustva cijanotoksina treba da se preispita.  Štaviše, veliki broj jedinki dafnija (92,2%) koristio je istraživane sojeve iz NSCCC za ishranu, odnosno ishrana je bila moguća sa svim vodenim i sa gotovo 90% terestričnih sojeva, što može poslužiti kao osnov za dalja istraživanja prevencije cvetanja. S obzirom na mogućnost ishrane račića  Daphnia  sp. cijanobakterijama, kompleks  ribnjaka sa teritorije Republike Srbije korišćen je za istraživanje potencijalnog načina  prevencije pojave i cvetanja cijanobakterija u zavisnosti od pravovremenog unošenja  pomenutog račića. Na osnovu koncentracije hlorofila  a  i trofičkog statusa,  kvalitativne i kvantitativne analize cijanobakterija, toksičnosti vode  i prisustva cijanotoksina mikrocistina/nodularina i saksitoksina, potvrđeno je smanjenje cvetanja cijanobakterija i drugih negativnih efekata u eksperimentalnim jezerima u odnosu na kontrolna. Ukoliko pak dođe do cvetanja i proizvodnje toksina  ijanobakterija u vodenim ekosistemima, zbog ozbiljnost pojave i mogućih negativnih posledica po zdravlje ljudi, neohodno je uvesti postupke eliminacije ćelija  cijanobakterija i njihovih  toksina u praksu pri obradi  otpadnih voda i prečišćavanja vode iz površinskih akumulacija u Republici Srbiji.The presence of toxic  cyanobacteria in different ecosystems from the territory of the Republic of Serbia was analyzed as well as the negative consequences that may be causeed by these microorganisms. Serbian Cyanobacterial Data Base was formed where great number of important and useful information from over 70 literary sources regarding the distribution and frequency of cyanobacteria and their toxins over a period of 130 years, as well as their effects on wildlife in aquatic ecosystems, and beyond was presented. The study consisted of 64 aquatic ecosystems, including rivers, lakes, ponds, canals, irrigation reservoirs, reservoirs for drinking water supply and reservoirs with other purpose, where five species of cyanobacteria Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flosaquae  and  Planktothrix rubescens  frequently bloomed, and also expanded their area of distribution on the territory of the Republic of Serbia. In many water bodies microcystins were detected in high concentrations. Research into aquatic ecosystem Ludoš, located on the territory of the Republic of Serbia, was performed in order to determine the presence and effect of cyanobacteria and cyanotoxins on other plant and animal organisms in natural conditions. Trophic status of  the lake Ludoš was usually eutrophic, and cyanobacteria bloom is constant since 1970. During 2011 and 2012, the species Limnothrix  redekei  and  Pseudanabaena  limnetica  were found in blooming. Presence of microcystins/nodularin and saxitoxin was detected in  biomass and water, and microcystins were detected in tissues of aquatic plants (reed Phragmites communis, cattail Typha latifolia and royalblue waterlily  Nymphaea elegans) and fish (Carassius gibelio) from the lake Ludoš. Histological examination of tissue showed most prominent changes in liver, kidney and gills, and alterations were also observed in the intestine. Testing of the biological loess crust from Vojvodina showed no presence of microcystins/nodularin and toxicity of samples was not detected as well. It is assumed that cyanotoxin concentrations were below detection limit or are absent from the tested biological loess crusts. The development of new methods and optimization of existing ones for detection of cyanotoxins in biological loess crustsand  other terrestrial ecosystems is necessary in order to revise obtained results. Research of the properties from 84 strains of cyanobacteria from NSCCC originating from terrestrial and aquatic ecosystems from the territory of the Republic of  Serbia, resulte d inintracellular toxicity in exponential and stationary growth phase, as  well as extracellular toxicity of a strain originating from terrestrial ecosystems. The obtained results were positive for the presence of microcystins, nodularin and/or saxitoxin  for 34.1% terrestrial and 55.5% aquatic strains originating from the territory of the Republic of Serbia. These results demonstrate the potential risk of occurrence of these microorganisms and their metabolites in different ecosystems from the territory of the Republic of Serbia. Accumulation of microcystins in shrimp Daphnia pulex after feeding with toxic strain from NSCCC was experimentally confirmed, indicating that the use of this species of shrimp in biological tests which determine the presence of cyanotoxins needs to be revisited. Moreover, a large number of Daphnia  individuals (92.2%) used the investigated strains of NSCCC for food, and the feeding was possible with all  the water strains and nearly 90% of terrestrial strains, which can serve as a basis for further research of bloom prevention. With regard to the possibility shrimp Daphnia sp. feeding with cyanobacteria, a complex of ponds from the territory of the Republic of Serbia was used to explore  potential ways of prevention the occurrence and blooming of cyanobacteria, depending on the timely introduction of the aforementioned shrimp. Based on the concentrations of chlorophyll  a  and trophic status, qualitative and quantitative analysis of cyanobacteria, the toxicity of water and the presence of  cyanotoxins microcystins/nodularin and saxitoxin, reduction in blooming cyanobacteria and other negative effects in the experimental lakes when compared to the control lakes was confirmed. If the blooming regardless occurres as well as production of cyanobacterial  toxins in aquatic ecosystems, due to the seriousness of the phenomenon and the possible negative consequences for human health, it would be necessary to introduce  procedures for the elimination of cells of cyanobacteria and their toxins into practice in waste water treatment and purification of water from surface reservoirs in the Republic of Serbia

Toxic cyanobacteria from the territory of the Republic of Serbia

Ispitano je prisustvo toksičnih cijanobakterija u različitim ekosistemima sa teritorije Republike Srbije i analizirane su negativne posledice koje mogu da prouzrokuju ovi mikroorganizmi. Formirana je Baza podataka cijanobakterija u Srbiji koja prilaže veliki broj bitnih  i korisnih informacija iz preko 70 literaturnih izvora o prostiranju i učestalosti pojave cijanobakterija i njihovih toksina u periodu od 130 godina, kao i njihovih efekata na živi svet u vodenim ekosistemima, ali i šire. Istraživana su 64 vodena ekosistema, uključujući reke, jezera, bare, kanale, ribnjake, akumulacije za navodnjavanje, akumulacije za snabdevanje vodom za piće i akumulacije sa drugom namenom, gde je najčešće cvetalo pet vrsta cijanobakterija i to:  Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flos-aquae  i  Planktothrix rubescens  koje ujedno i šire svoj areal rasprostranjenja na teritoriji Republike Srbije. U brojnim vodenim telima detektovani su mikrocistini i to u visokim koncentracijama. Istraživanje vodenog ekosistema Ludoš sa teritorije Republike Srbije vršeno je da bi se ustanovilo prisustvo i uticaj cijanobakterija i cijanotoksina na druge biljne i životinjske organizme u prirodnim uslovima. Trofički status jezera Ludoš najčešće je eutrofan, a cvetanje cijanobakterija kontinuirano još od 1970. godine. Tokom 2011. i 2012. godine  vrste Limnothrix  redekei  i  Pseudanabaena  limnetica  nađene  u  cvetanju. Detektovano je i prisustvo mikrocistina/nodularina i saksitoksina u biomasi i vodi, a mikrocistini su detektovani i u tkivu vodenih biljaka (trske  Phragmites communis, rogoza  Typha latifolia  i ljubičastog lokvanja Nymphaea elegans) i ribi (Carassius gibelio) iz jezera Ludoš. Histološkim pregledom tkiva ribe  pronađene su naizraženije promene u jetri, bubrezima i škrgama, a primećene su i na crevima. Testiranjem bioloških lesnih pokorica sa teritorije Vojvodine nisu detektovani mikrocistini/nodularini, a nije detektovana ni toksičnost uzoraka. Pretpostavlja se da su koncentracije cijanotoksina ispod granica detekcije ili ih nema u testiranim biološkim lesnim pokoricama. Razvojem novih metoda i optimizacijom postojećih za detekciju cijanotoksina u biološkim lesnim pokoricama i drugim terestričnim ekosistemima potrebno je proveriti dobijene rezultate. Proučavanjem svojstva 84 soja cijanobakterija iz NSCCC, koji potiču iz terestričnih i vodenih ekosistema sa teritorije Republike Srbije, dobijena je intracelularna toksičnost u eksponencijalnoj i stacionarnoj fazi rasta, kao i ekstracelularna toksičnost  kod jednog soja koji potiče sa terestričnog ekosistema. Dobijeni su i pozitivni rezultati  na prisustvo mikrocistina, nodularina ili/i saksitoksina kod 34,1% terestričnih i 55,5% vodenih sojeva koji potiču sa teritorije Republike Srbije. Rezultati ukazuju na  potencijalnu opasnost pojave ovih  mikroorganizama i njihovih toksičnih metabolita u različitim ekosistemima sa teritorije Republike Srbije. Eksperimentalno je potvrđena akumulacija mikrocistina u račiću  Daphnia pulex  usled ishrane toksičnim sojem iz NSCCC, zbog čega upotreba ove vrste račića u izvođenju bioloških testova za testiranje prisustva cijanotoksina treba da se preispita.  Štaviše, veliki broj jedinki dafnija (92,2%) koristio je istraživane sojeve iz NSCCC za ishranu, odnosno ishrana je bila moguća sa svim vodenim i sa gotovo 90% terestričnih sojeva, što može poslužiti kao osnov za dalja istraživanja prevencije cvetanja. S obzirom na mogućnost ishrane račića  Daphnia  sp. cijanobakterijama, kompleks  ribnjaka sa teritorije Republike Srbije korišćen je za istraživanje potencijalnog načina  prevencije pojave i cvetanja cijanobakterija u zavisnosti od pravovremenog unošenja  pomenutog račića. Na osnovu koncentracije hlorofila  a  i trofičkog statusa,  kvalitativne i kvantitativne analize cijanobakterija, toksičnosti vode  i prisustva cijanotoksina mikrocistina/nodularina i saksitoksina, potvrđeno je smanjenje cvetanja cijanobakterija i drugih negativnih efekata u eksperimentalnim jezerima u odnosu na kontrolna. Ukoliko pak dođe do cvetanja i proizvodnje toksina  ijanobakterija u vodenim ekosistemima, zbog ozbiljnost pojave i mogućih negativnih posledica po zdravlje ljudi, neohodno je uvesti postupke eliminacije ćelija  cijanobakterija i njihovih  toksina u praksu pri obradi  otpadnih voda i prečišćavanja vode iz površinskih akumulacija u Republici Srbiji.The presence of toxic  cyanobacteria in different ecosystems from the territory of the Republic of Serbia was analyzed as well as the negative consequences that may be causeed by these microorganisms. Serbian Cyanobacterial Data Base was formed where great number of important and useful information from over 70 literary sources regarding the distribution and frequency of cyanobacteria and their toxins over a period of 130 years, as well as their effects on wildlife in aquatic ecosystems, and beyond was presented. The study consisted of 64 aquatic ecosystems, including rivers, lakes, ponds, canals, irrigation reservoirs, reservoirs for drinking water supply and reservoirs with other purpose, where five species of cyanobacteria Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flosaquae  and  Planktothrix rubescens  frequently bloomed, and also expanded their area of distribution on the territory of the Republic of Serbia. In many water bodies microcystins were detected in high concentrations. Research into aquatic ecosystem Ludoš, located on the territory of the Republic of Serbia, was performed in order to determine the presence and effect of cyanobacteria and cyanotoxins on other plant and animal organisms in natural conditions. Trophic status of  the lake Ludoš was usually eutrophic, and cyanobacteria bloom is constant since 1970. During 2011 and 2012, the species Limnothrix  redekei  and  Pseudanabaena  limnetica  were found in blooming. Presence of microcystins/nodularin and saxitoxin was detected in  biomass and water, and microcystins were detected in tissues of aquatic plants (reed Phragmites communis, cattail Typha latifolia and royalblue waterlily  Nymphaea elegans) and fish (Carassius gibelio) from the lake Ludoš. Histological examination of tissue showed most prominent changes in liver, kidney and gills, and alterations were also observed in the intestine. Testing of the biological loess crust from Vojvodina showed no presence of microcystins/nodularin and toxicity of samples was not detected as well. It is assumed that cyanotoxin concentrations were below detection limit or are absent from the tested biological loess crusts. The development of new methods and optimization of existing ones for detection of cyanotoxins in biological loess crustsand  other terrestrial ecosystems is necessary in order to revise obtained results. Research of the properties from 84 strains of cyanobacteria from NSCCC originating from terrestrial and aquatic ecosystems from the territory of the Republic of  Serbia, resulte d inintracellular toxicity in exponential and stationary growth phase, as  well as extracellular toxicity of a strain originating from terrestrial ecosystems. The obtained results were positive for the presence of microcystins, nodularin and/or saxitoxin  for 34.1% terrestrial and 55.5% aquatic strains originating from the territory of the Republic of Serbia. These results demonstrate the potential risk of occurrence of these microorganisms and their metabolites in different ecosystems from the territory of the Republic of Serbia. Accumulation of microcystins in shrimp Daphnia pulex after feeding with toxic strain from NSCCC was experimentally confirmed, indicating that the use of this species of shrimp in biological tests which determine the presence of cyanotoxins needs to be revisited. Moreover, a large number of Daphnia  individuals (92.2%) used the investigated strains of NSCCC for food, and the feeding was possible with all  the water strains and nearly 90% of terrestrial strains, which can serve as a basis for further research of bloom prevention. With regard to the possibility shrimp Daphnia sp. feeding with cyanobacteria, a complex of ponds from the territory of the Republic of Serbia was used to explore  potential ways of prevention the occurrence and blooming of cyanobacteria, depending on the timely introduction of the aforementioned shrimp. Based on the concentrations of chlorophyll  a  and trophic status, qualitative and quantitative analysis of cyanobacteria, the toxicity of water and the presence of  cyanotoxins microcystins/nodularin and saxitoxin, reduction in blooming cyanobacteria and other negative effects in the experimental lakes when compared to the control lakes was confirmed. If the blooming regardless occurres as well as production of cyanobacterial  toxins in aquatic ecosystems, due to the seriousness of the phenomenon and the possible negative consequences for human health, it would be necessary to introduce  procedures for the elimination of cells of cyanobacteria and their toxins into practice in waste water treatment and purification of water from surface reservoirs in the Republic of Serbia

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

Toxic cyanobacteria from the territory of the Republic of Serbia

Ispitano je prisustvo toksičnih cijanobakterija u različitim ekosistemima sa teritorije Republike Srbije i analizirane su negativne posledice koje mogu da prouzrokuju ovi mikroorganizmi. Formirana je Baza podataka cijanobakterija u Srbiji koja prilaže veliki broj bitnih  i korisnih informacija iz preko 70 literaturnih izvora o prostiranju i učestalosti pojave cijanobakterija i njihovih toksina u periodu od 130 godina, kao i njihovih efekata na živi svet u vodenim ekosistemima, ali i šire. Istraživana su 64 vodena ekosistema, uključujući reke, jezera, bare, kanale, ribnjake, akumulacije za navodnjavanje, akumulacije za snabdevanje vodom za piće i akumulacije sa drugom namenom, gde je najčešće cvetalo pet vrsta cijanobakterija i to:  Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flos-aquae  i  Planktothrix rubescens  koje ujedno i šire svoj areal rasprostranjenja na teritoriji Republike Srbije. U brojnim vodenim telima detektovani su mikrocistini i to u visokim koncentracijama. Istraživanje vodenog ekosistema Ludoš sa teritorije Republike Srbije vršeno je da bi se ustanovilo prisustvo i uticaj cijanobakterija i cijanotoksina na druge biljne i životinjske organizme u prirodnim uslovima. Trofički status jezera Ludoš najčešće je eutrofan, a cvetanje cijanobakterija kontinuirano još od 1970. godine. Tokom 2011. i 2012. godine  vrste Limnothrix  redekei  i  Pseudanabaena  limnetica  nađene  u  cvetanju. Detektovano je i prisustvo mikrocistina/nodularina i saksitoksina u biomasi i vodi, a mikrocistini su detektovani i u tkivu vodenih biljaka (trske  Phragmites communis, rogoza  Typha latifolia  i ljubičastog lokvanja Nymphaea elegans) i ribi (Carassius gibelio) iz jezera Ludoš. Histološkim pregledom tkiva ribe  pronađene su naizraženije promene u jetri, bubrezima i škrgama, a primećene su i na crevima. Testiranjem bioloških lesnih pokorica sa teritorije Vojvodine nisu detektovani mikrocistini/nodularini, a nije detektovana ni toksičnost uzoraka. Pretpostavlja se da su koncentracije cijanotoksina ispod granica detekcije ili ih nema u testiranim biološkim lesnim pokoricama. Razvojem novih metoda i optimizacijom postojećih za detekciju cijanotoksina u biološkim lesnim pokoricama i drugim terestričnim ekosistemima potrebno je proveriti dobijene rezultate. Proučavanjem svojstva 84 soja cijanobakterija iz NSCCC, koji potiču iz terestričnih i vodenih ekosistema sa teritorije Republike Srbije, dobijena je intracelularna toksičnost u eksponencijalnoj i stacionarnoj fazi rasta, kao i ekstracelularna toksičnost  kod jednog soja koji potiče sa terestričnog ekosistema. Dobijeni su i pozitivni rezultati  na prisustvo mikrocistina, nodularina ili/i saksitoksina kod 34,1% terestričnih i 55,5% vodenih sojeva koji potiču sa teritorije Republike Srbije. Rezultati ukazuju na  potencijalnu opasnost pojave ovih  mikroorganizama i njihovih toksičnih metabolita u različitim ekosistemima sa teritorije Republike Srbije. Eksperimentalno je potvrđena akumulacija mikrocistina u račiću  Daphnia pulex  usled ishrane toksičnim sojem iz NSCCC, zbog čega upotreba ove vrste račića u izvođenju bioloških testova za testiranje prisustva cijanotoksina treba da se preispita.  Štaviše, veliki broj jedinki dafnija (92,2%) koristio je istraživane sojeve iz NSCCC za ishranu, odnosno ishrana je bila moguća sa svim vodenim i sa gotovo 90% terestričnih sojeva, što može poslužiti kao osnov za dalja istraživanja prevencije cvetanja. S obzirom na mogućnost ishrane račića  Daphnia  sp. cijanobakterijama, kompleks  ribnjaka sa teritorije Republike Srbije korišćen je za istraživanje potencijalnog načina  prevencije pojave i cvetanja cijanobakterija u zavisnosti od pravovremenog unošenja  pomenutog račića. Na osnovu koncentracije hlorofila  a  i trofičkog statusa,  kvalitativne i kvantitativne analize cijanobakterija, toksičnosti vode  i prisustva cijanotoksina mikrocistina/nodularina i saksitoksina, potvrđeno je smanjenje cvetanja cijanobakterija i drugih negativnih efekata u eksperimentalnim jezerima u odnosu na kontrolna. Ukoliko pak dođe do cvetanja i proizvodnje toksina  ijanobakterija u vodenim ekosistemima, zbog ozbiljnost pojave i mogućih negativnih posledica po zdravlje ljudi, neohodno je uvesti postupke eliminacije ćelija  cijanobakterija i njihovih  toksina u praksu pri obradi  otpadnih voda i prečišćavanja vode iz površinskih akumulacija u Republici Srbiji.The presence of toxic  cyanobacteria in different ecosystems from the territory of the Republic of Serbia was analyzed as well as the negative consequences that may be causeed by these microorganisms. Serbian Cyanobacterial Data Base was formed where great number of important and useful information from over 70 literary sources regarding the distribution and frequency of cyanobacteria and their toxins over a period of 130 years, as well as their effects on wildlife in aquatic ecosystems, and beyond was presented. The study consisted of 64 aquatic ecosystems, including rivers, lakes, ponds, canals, irrigation reservoirs, reservoirs for drinking water supply and reservoirs with other purpose, where five species of cyanobacteria Microcystis aeruginosa,  Aphanizomenon flos-aquae,  Planktothrix agardhii,  Microcystis flosaquae  and  Planktothrix rubescens  frequently bloomed, and also expanded their area of distribution on the territory of the Republic of Serbia. In many water bodies microcystins were detected in high concentrations. Research into aquatic ecosystem Ludoš, located on the territory of the Republic of Serbia, was performed in order to determine the presence and effect of cyanobacteria and cyanotoxins on other plant and animal organisms in natural conditions. Trophic status of  the lake Ludoš was usually eutrophic, and cyanobacteria bloom is constant since 1970. During 2011 and 2012, the species Limnothrix  redekei  and  Pseudanabaena  limnetica  were found in blooming. Presence of microcystins/nodularin and saxitoxin was detected in  biomass and water, and microcystins were detected in tissues of aquatic plants (reed Phragmites communis, cattail Typha latifolia and royalblue waterlily  Nymphaea elegans) and fish (Carassius gibelio) from the lake Ludoš. Histological examination of tissue showed most prominent changes in liver, kidney and gills, and alterations were also observed in the intestine. Testing of the biological loess crust from Vojvodina showed no presence of microcystins/nodularin and toxicity of samples was not detected as well. It is assumed that cyanotoxin concentrations were below detection limit or are absent from the tested biological loess crusts. The development of new methods and optimization of existing ones for detection of cyanotoxins in biological loess crustsand  other terrestrial ecosystems is necessary in order to revise obtained results. Research of the properties from 84 strains of cyanobacteria from NSCCC originating from terrestrial and aquatic ecosystems from the territory of the Republic of  Serbia, resulte d inintracellular toxicity in exponential and stationary growth phase, as  well as extracellular toxicity of a strain originating from terrestrial ecosystems. The obtained results were positive for the presence of microcystins, nodularin and/or saxitoxin  for 34.1% terrestrial and 55.5% aquatic strains originating from the territory of the Republic of Serbia. These results demonstrate the potential risk of occurrence of these microorganisms and their metabolites in different ecosystems from the territory of the Republic of Serbia. Accumulation of microcystins in shrimp Daphnia pulex after feeding with toxic strain from NSCCC was experimentally confirmed, indicating that the use of this species of shrimp in biological tests which determine the presence of cyanotoxins needs to be revisited. Moreover, a large number of Daphnia  individuals (92.2%) used the investigated strains of NSCCC for food, and the feeding was possible with all  the water strains and nearly 90% of terrestrial strains, which can serve as a basis for further research of bloom prevention. With regard to the possibility shrimp Daphnia sp. feeding with cyanobacteria, a complex of ponds from the territory of the Republic of Serbia was used to explore  potential ways of prevention the occurrence and blooming of cyanobacteria, depending on the timely introduction of the aforementioned shrimp. Based on the concentrations of chlorophyll  a  and trophic status, qualitative and quantitative analysis of cyanobacteria, the toxicity of water and the presence of  cyanotoxins microcystins/nodularin and saxitoxin, reduction in blooming cyanobacteria and other negative effects in the experimental lakes when compared to the control lakes was confirmed. If the blooming regardless occurres as well as production of cyanobacterial  toxins in aquatic ecosystems, due to the seriousness of the phenomenon and the possible negative consequences for human health, it would be necessary to introduce  procedures for the elimination of cells of cyanobacteria and their toxins into practice in waste water treatment and purification of water from surface reservoirs in the Republic of Serbia

Special Issue on harmful cyanobacteria and their metabolites

Cyanobacteria, previously called blue-green algae, are photosynthetic microorganisms which thrive especially in aquatic ecosystems suffering from eutrophication [...

Cyanotoxins in Serbia and water treatment procedures for their elimination

Cyanotoxins are secondary metabolites produced by cyanobacteria, mainly as a result of eutrofication and water quality deterioration. The most common cyanotoxins are cyclic peptide hepatotoxins called microcystins. Cyanotoxins represent a potential health risk for humans when occurring in freshwaters used for drinking water supply, recreation and irrigation. In Serbia there is a problem with cyanobacterial blooms and production of cyanotoxins in most of the surface freshwaters. In order to restore water quality, various techniques and methods in water treatment procedures must be employed. These procedures include technologies like coagulation/floculation, flotation, filtration, activated carbon adsorption, UV photolysis, ozonization and oxidation processes. This review focuses on cyanotoxins, their occurrence in Serbia, as well as ways of their removal from the water

Cyanophage infections reduce photosynthetic activity and expression of CO2 fixation genes in the freshwater bloom-forming cyanobacterium Aphanizomenon flos-aquae

Cyanobacteria play a significant role in ecosystem functioning as photosynthetic and CO2 fixing microorganisms. Whether and to what extent cyanophages alter these carbon and energy cycles in their cyanobacterial hosts is still poorly understood. In this study, we investigated changes in photosynthetic activity (PSII), expression of genes associated with the light phase of photosynthesis (psbA, petA, ndhK) and carbon metabolism (rbcL, zwf) as well as intracellular ATP and NADHP concentrations in freshwater bloom-forming filamentous cyanobacterium Aphanizomenon flos-aquae infected by cyanophage vB_AphaS-CL131. We found that PSII activity and expression level of rbcL genes, indicating potential for CO2 fixation, had decreased in response to cyanophage adsorption and DNA injection. During the period of viral DNA replication and assembly, PSII performance and gene expression remained at this decreased level and did not change significantly, indicating lack of transcriptional shutdown by the cyanophage. Combined, these observations suggest that although there is little to no interference between cyanophage DNA replication, host transcription and cellular metabolism, A. flos-aquae underwent a physiological state-shift toward lower efficiency of carbon and energy cycling. This further suggest potential cascading effect for co-occurring non-infected members of the microbial community