The First Report of Geosmin and 2-Methylisoborneol Producer Cyanobacteria From Turkish Freshwaters

DergiPark: 884423trkjnatWater users consider the safety of water according to its aesthetic properties, primarily taste and odour. Geosmin (GEO) and 2-methylisoborneol (MIB) are the most common taste and odour compounds in freshwaters which cause an earthy and musty odour in water. Since human nose can detect these compounds in concentrations as low as 10 ng/L, it is essential to monitor drinking waters before consumer complaints and to produce a timely solution. Therefore, it is necessary to identify GEO and MIB producers to manage the problem at its source. Cyanobacteria are one of the main producers of these compounds in freshwater ecosystems. In this study, we analyzed 13 samples (9 cyanobacteria cultures from Bafa Lake, Elmalı Dam Lake, İznik Lake, Küçükçekmece Lake, Manyas Lake and Taşkısığı Lake, and 4 environmental water samples from Erfelek and Günpınar Waterfalls and Ömerli Dam Lake) for GEO and MIB production by HS-SPME (Head space-solid phase microextraction) coupled with GC-MS (gas chromatography-mass spectrometry). The presence of Cyanobacteria-specific GEO and MIB synthase genes were also analyzed by PCR (Polymerase Chain Reaction). Taste and odour production was confirmed in 2 samples by GC-MS while 4 samples yielded positive results by PCR. All positive samples were environmental samples (3 samples from waterfalls from Günpınar and Erfelek Waterfalls, 1 sample from Ömerli Dam Lake -a drinking water reservoir) which were dominated by Nostoc Vaucher ex Bornet amp; Flahault, Phormidium Kützing ex Gomont and Pseudanabaena Lauterborn. This is the first report of GEO and MIB producing cyanobacteria in Turkish freshwaters by combining microscopy, analytical and molecular techniques.Su kullanıcıları, suyun güvenli olup olmadıklarına öncelikle onun tat ve kokusu gibi estetik özelliklerine bakarak karar vermektedir. Geosmin (GEO) ve 2-methylisoborneol (MIB), tatlısularda en yaygın olarak görülen tat ve koku bileşikleridir ve suyun toprak ve küf kokmasına neden olurlar. İnsanlar lt;10 ng/L gibi düşük konsantrasyonlarda dahi bu kokulara hassas olmalarından dolayı bu bileşiklerin içme sularında tüketici şikayetleri oluşmadan önce izlenmesi ve sorunun çözülmesi oldukça önemlidir. Bu sebeple, problemin kaynağında çözümlenebilmesi için GEO ve MIB üreticilerinin tespit edilmesi gereklidir. Tatlısu ekosistemlerinde bu bileşiklerin başlıca üreticilerinden biri siyanobakterilerdir (Cyanobacteria). Bu çalışmada 13 örnek (9 siyanobakteri kültürü, Bafa Gölü, Elmalı Baraj Gölü, İznik Gölü, Küçükçekmece Gölü, Manyas Gölü, Taşkısığı Gölü’nden ve 4 çevresel su örneği, Günpınar, Erfelek şelaleleri ve Ömerli Baraj Gölü’nden) GEO ve MIB üretiminin tespiti için HS-SPME (Tepe Boşluğu-Katı Faz Mikro Ekstraksiyon) GC-MS (Gaz Kromatografi-Kütle Spektrometresi) yöntemi kullanılarak analiz edilmiştir. Ayrıca siyanobakterilere özgü GEO ve MIB sentaz genlerinin varlığının tespiti için PZR (Polimeraz Zincir Reaksiyonu) yöntemi kullanılmıştır. İki örnekte GC-MS ile tat ve koku üretimi tespit edilmiş ve 4 örnekte de PZR ile pozitif sonuç alınmıştır. Pozitif sonuç elde edilen örnekler Nostoc Vaucher ex Bornet amp; Flahault, Phormidium Kützing ex Gomont ve Pseudanabaena Lauterborn cinslerinin baskın olduğu çevresel örneklerdir (3 şelale, 1 içme suyu kaynağı örneği). Bu çalışma Türkiye tatlısularındaki tat ve koku üreticisi siyanobakterilerin mikroskobik, analitik ve moleküler yöntemler birlikte kullanılarak tespit edildiği ilk kayıttır

Gala Gölü (Edirne/Türkiye) fitoplanktonunun mevsimsel dağılımı

This study was performed from March 2004 to February 2005 in 4 stations in Gala Lake, a shallow lake located inside Gala Lake National Park in Meriç Delta. Water samples were taken from the lake in order to determine the phytoplankton present in the lake and to perform physicochemical analysis. A total of 112 taxa from 5 divisio were identified during the study period. Chlorophyta was the most diversed group in the lake with 47 taxa and diatoms were found to have the highest cell counts with a mean value of 670011 cell L-1. The general pattern of seasonal succession in phytoplankton of the lake was represented with Chlorophyta in June and with Cyanophyta in September and Diatoms were the dominant group of the lake in all other months. A spatial heterogeneity was observed in the lake where a slight Microsystis spp. increase occurred in early autumn months. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of the phytoplankton community of Lake Gala, which indicates lake deterioration.Bu çalışma Meriç deltasında Gala Gölü Milli Parkı içerisinde bulunan ve sığ bir göl olan Gala Gölü’nde belirlenen 4 istayonda Mart 2004-Şubat 2005 tarihleri arasında yapılmıştır. Gölden alınan su örneklerinde fitoplanktonun belirlenmesinin yanı sıra bazı fizikokimyasal analizler de yapılmıştır. Çalışma süresince 5 divizyoya ait toplam 112 taxa gözlemlenmiştir. En fazla tür sayısının 47 tür ile Chlorophyta’ya ait olduğu gölde Diatomlar ortalama 670011 hücre L-1 ile en çok hücre sayısına sahip grup olmuştur. Göl fitoplanktonunun mevsimsel süksesyonunda genel yapı Haziran ayında Chlorophyta, Eylül ayında ise Cyanophyta hakimiyeti şeklindedir. Bu ayların dışında tüm örnekleme periyodu boyunca Diatomlar gölün hakim organizmaları konumundadır. Bunun yanısıra sonbahar aylarında hafif bir Microsystis spp. çoğalmasının meydana geldiği gölde fitoplanktonun yıl boyunca değiştiği gözlemlenmiştir. Daha önceki veriler ile karşılaştırıldığında Gala Gölü fitoplanktonunda nitel ve nicel olarak farklılıklar tespit edilmiştir

Cyanobacterial Diversity and the Presence of Microcystins in the Küçük Menderes River Basin, Turkiye

Although cyanobacteria are commonly associated with eutrophic lakes, they are the basic compo-nents of phytoplankton communities in lakes that have different trophic statuses. In inland waters, both nutrient loading from watersheds and warmer conditions promote phytoplankton growth and cause extensive cyanobacterial blooms. Certain bloom-forming cyanobacterial species can pose a healthrisktohumansandaquaticecosystemsthroughcyanotoxinproduction.Theaimofthisstudy was to evaluate the cyanobacterial composition and toxins in five reservoirs and two natural lakes in the Küçük Menderes River Basin, all with varying trophic statuses. Within this scope, sam-pleswerecollectedinautumn2017andspring2018.CyanobacterialspecieswereenumeratedaccordingtotheUtermöhlmethod.CyanotoxinsampleswereanalyzedusingHPLC.Tofindthetrophic status of the water bodies, the Trophic State Index (TSI) developed by Carlson (1977) was used and Total Phosphorus (TP), Secchi Depth (SD), and Chlorophyll-ɑ (chl-ɑ) measurements were performed. Cyanobacterial abundance, species composition, and cyanotoxin production differed significantly between the lakes and reservoirs. A total of 13 cyanobacteria species were identified including potential cyanotoxin producers such as Microcystis, Aphanizomenon, and Dolichospermum. According to the TSI, three reservoirs were mesotrophic and the other four waterbodies had eutro-phic-hypereutrophic conditions. Microcystis is the most common bloom-forming freshwater cyano-bacteria in the Küçük Menderes River Basin. However, microcystin concentrations were relatively low and the highest microcystin concentration was detected in the Tahtalı Reservoir at 9 μg/L. The Küçük Menderes River Basin is under water-stressed conditions and the cyanobacteria blooms in the region might pose another threat for wildlife and humans

Palynomorphs of brackish and marine species in cores from the freshwater Lake Sapanca, NW Turkey

Lake Sapanca, which is located on the Sakarya–Sapanca–İzmit corridor in NW Turkey, is a freshwater lake with numerous fish farms in its catchment. Palynological analyses including non-pollen palynomorphs of a short (38.5 cm) and a longer sediment core (586 cm), taken in the centre of the lake and dated in previous investigations, revealed the presence of brackish and marine palynomorphs. The longer sediment sequence shows the occurrence of Brigantedinium sp., Impagidinium caspienense and Spiniferites cruciformis from the base of the core at c. AD 580 years up to 300 cm depth at shortly after c. AD 910. A similar assemblage, but this time with the additional presence of dinoflagellate thecae and the acritarch, Radiosperma corbiferum, was found in the recent core, especially from AD 1986 until the present. Past connections between the Gulf of İzmit and the Black Sea, via the River Sakarya and Lake Sapanca, could be the origin of these two microfossil assemblages. Accidental re-introduction via fish translocation since the Roman times may have been a additional mechanism. The consequences of the survival of brackish and marine forms in a freshwater lake are discussed in terms of wider euryhalinity than has been suggested for those still poorly known organisms

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe