Investigation of Heavy Metal-Resistant Sediment Bacteria and Some Water Quality Parameters: A Case Study of Lake Bafa (Turkey)

Surface waters such as lakes and rivers which are multipurpose fields used for drinking water supply, agricultural irrigation, fisheries and energy production are being threatened by domestic, industrial and agricultural pollution caused by rapidly growing population. Due to the insufficient numbers of studies on Lake Bafa, the largest coastal lake of Turkey, this study was conducted to investigate some physico-chemical properties of the lake's water and levels of fecal indicator bacteria in it. Additionally, bacteria species isolated from sediments that could be cultured and their heavy metal (Cu, Zn, Ni, Cr, Hg) and antibiotic resistance were determined. Levels of fecal coliforms (FC) and fecal streptococci (FS) were determined through membrane-filtration techniques. While fecal coliform levels detected in the three sampling stations were above the limit value, fecal streptococci levels were below the limit value. Seventeen isolates identified through the 16S rDNA analysis were determined to be the members of the genus Bacillus and Arthrobacter. The resistance displayed by the isolates to heavy metals was in the following order: Cu> Zn> Ni> Cr> Hg. The isolates were also resistant to ampicillin and tetracycline. The results of this preliminary study suggest that the lake which serves agriculture, fishing and recreation purposes should be regularly monitored in terms of public health

Some microbial characteristics of mussels (Mytilus galloprovincialis) in coastal city area

Purpose The aim of this work was to determine some microbial characteristics of Mytilus galloprovincialis harvested from four stations, located in Izmir coastal area (Eastern Aegean Sea, Turkey). The area along the Izmir coast is densely populated, and it includes extensive agricultural lands, industrial and domestic discharge. Shellfish contamination from sewage-polluted waters is very important for public health

Effects of anti-fouling paints on marine bacterial biofilm development

Biyofilm bakterileri sualtı yapılarda ciddi sorunlara neden olabilmektedir. Bu çalışmanın amacı, sabit plakalar yüzeyinde hücre dışı polimerik maddeler (EPS) üreten biyofilm bakterilerinin tanılanmaları ve çeşitli antifouling ajanların biyofilm bakterilerinin gelişimini engelleyen minimum inhibisyon konsantrasyonlarının (MICs) tespitidir. Boyalardaki antifouling ajanlar olarak, çinko oksit, bakır oksit, tribütiltin, florin, triazine diamin gibi katkılar kullanılmış boyalar ve bir de sadece antipas boya uygulanmıştır. Örnekleme sürecince, İzmir civarında yer alan iki yat limanında bulunan test plakalarının tümünde bakteriyal büyüme gözlenmiştir. Çalışma süresince plakaların yüzeyinden yüz yirmi ırk kültüre edilmiş, bunlardan yirmi tanesi ileri biyokimyasal ve moleküler analizlerle karakterizasyon için seçilmiştir. Ribozamal DNA dizileri kullanılarak yapılan filogenetik analizler sonucunda, yirmi ırkın ?-Proteobacteria ve Firmicutes (Pseudoalteromonas, Alteromonas, Klebsiella, Vibrio ve Exiguobacterium) alt sınıflarına dahil oldukları belirlenmiştir. Sekiz ırk, EPS üretme yetenekleri açısından ve EPS'lerindeki şeker ile protein içeriklerinin belirlenmesi açısından ileri testler için seçilmişlerdir. Çalışmada, hücre büyümesi ile EPS verimliliği açısından negatif bir ilişki olduğu belirlenmiştir. EPS'lerdeki şeker içerikleri ince tabaka kromatografisi (TLC) ile belirlenmiştir. EPS yapısında şekerler olarak glukoz, galaktoz, fruktoz ve ramnoz tespit edilmiştir. Minimum inhibisyon konsantrasyonu analizlerinde triazine diamin ve bakır oksit içeren boyanın bireysel ırklara karşı en güçlü antibakteriyal etkiyi gösterdiği tespit edilmiştir. Sonuç olarak, bireysel biyofilm bakterileri, antifouling boyalara karşı oldukça duyarlı iken biyofilmin gelişmesini takiben direnç kazanmaktadırlar. Ayrıca, çalışma süreci boyunca, toplam canlı bakteri yoğunluğu ile deniz suyunun fiziko-kimyasal değişkenleri arasında ilişki görülürken, toplam canlı bakteri yoğunluğu ile besin elementleri arasında güçlü bir korelasyon bulunamamıştır. Biofilm bacteria can cause several problems in marine infrastructures. The goal of the research was to isolate and identify biofilm bacteria that produce extracellular polymeric substance (EPS) on static panels and to determine minimum inhibitory concentrations (MICs) of the antifouling agents preventing the growth of biofilm bacteria. Zinc oxide, copper oxide, tributyltin, fluorine, triazine diamine based additives and one type rustproof paint were used as the antifouling agents in the paints. Bacterial growth was detected on all test panels coated by each of the antifouling paints during the sampling period in the two marinas located at the Izmir region. One hundered twenty strains isolated from the test panels were cultured, and a total of twenty unique strains were selected for further characterization using biochemical and molecular methods. Phylogenetic analysis using rDNA sequences indicated that the twenty strains belonged to the ?-Proteobacteria subclass and Firmicutes subclass (Pseudoalteromonas, Alteromonas, Klebsiella, Vibrio, and Exiguobacterium). Eight isolates were selected for further study based on their EPS-producing ability and sugar and protein contents of the EPS. Cell growth and EPS productivity were found to be negatively correlated. Sugar composition of EPS were determined by thin layer choromatography (TLC). It was observed that of these polysaccharides contained glucose, galactose, fructose and rhamnose. The paint, which contains triazine diamine and copper oxide, showed strong antibacterial activity against each individual strains in the MIC test. It was observed that while biofilm bacteria were very sensitive to antifouling paints, they were able to gain resistance following the development of biofilm. Additionally, physico-chemical parameters of seawater and viable bacteria counts displayed relations during the study period. However, it was not found any strong correlation between viable bacteria density and nutrient concentrations