Vertical and horizontal composition of fecal pollution indicator bacteria in lotic and lentic ecosystems at Turkish Thrace

Background and Purpose:Although freshwater ecosystems have natural bacterial populations, their distributions are negatively affected by agricultural activities, domestic and industrial discharges. Bacterial composition at different depths can limit the usage of the water column for drinking, irrigation or other intentions. This study was designed to give similar indications concerning the nature of distribution of indicator bacteria in two different freshwater ecosystem types (lotic and lentic biotopes), and also to identify the factors that might be responsible in shaping them.Materials and Methods:For this aim, stagnant and running water resources located in Meric-Ergene River Basin at Turkish Thrace were sampled at three water depths (surface, middle, bottom) and two sediment depths (shore and bottom) between the dates October 2014 and September 2015 at seasonal intervals. While the heterotrophic bacteria, total and fecal coliform bacteria, and Escherichia coli were recorded by the CFU and MPN techniques, some features (temperature, dissolved oxygen, pH, conductivity, salinity, nutrients, ions, and elements) were also measured by classical chemical, chromatographic or spectrometric methods.Results and Conslusions:According to the data, the bacterial distribution in each ecosystem was found as similar for the bottom and the surface water columns. Results were also supported statistically by Bray-Curtis similarity index and correspondence analyse. The relationships between the bacterial distribution and environmental features were evaluated by Spearman correlation index. Consequently, it was observed that the bacterial distribution can differ in both water column/sediment depths and lotic/lentic ecosystems. And, it was suggested that the middle water column in each ecosystem is the most proper column for human usage.</p

Análisis comparativo de la distribución química y bacteriana de lagunas costeras y lagos de agua dulce en la Tracia Turca

Background. Microbial contamination of water bodies is causing major environmental and public health concerns in developing countries. Bacterial inclusion of inland waters can be of allochthonous and/or autochthonous origins. Goals. The aim of this study was to determine and compare the microbial contamination with environmental factors controlling colonization of bacteria in lagoon-lakes and freshwater lakes. Methods. Two lagoon-lakes and two freshwater lakes in Turkish Thrace were chosen and sampling was undertaken from October 2014 to August 2015 at seasonal intervals. While total heterotrophic bacteria, E. coli, coliform, and fecal coliform bacteria distributions from allochthonous and autochthonous origins were determined, environmental conditions of the ecosystems were also measured. While the Bray-Curtis Similarity Index and the Correspondence Analysis with Abundance Plot Analyses were used to determine the similarities of the sampling habitats, the Spearman’s Correlation Index was applied to clarify relationships between the environmental variables and the bacterial distribution. Results. The bacterial distribution was positively related to dissolved oxygen in one of the sampled lagoon-lakes (r = 1.0, p &lt; 0.01) and negatively correlated with total dissolved solids and salinity in one of the sampled freshwater lakes (r = -0.95, p &lt; 0.01; r = -0.80, p &lt; 0.05, respectively). Conclusions. This research indicated that the saline water of the lagoon-lakes has limited the number of bacteria when compared with freshwater lakes.Antecedentes. La contaminación microbiana de los cuerpos de agua está causando importantes problemas ambientales y de salud pública en los países en desarrollo. La incorporación de bacterias en aguas continentales puede tener origen alóctono y/o autóctono. Objetivos. Determinar y comparar la contaminación microbiana con los factores ambientales que controlan la colonización de bacterias en lagunas y lagos de agua dulce. Métodos. Se eligieron dos lagunas y dos lagos de agua dulce en la Tracia turca. El muestreo se realizó entre octubre de 2014 y agosto de 2015 en diferentes estaciones del año. Se determinó la distribución de las bacterias heterótrofas, E. coli, coliformes y coliformes fecales de origen alóctono y autóctono, y también se midieron las condiciones ambientales de los ecosistemas. El Índice de similitud de Bray-Curtis y el Análisis de correspondencias con Abundance Plot Analyze se utilizaron para determinar las similitudes de los hábitats de muestreo; mientras que el índice de correlación de Spearman se aplicó para conocer las relaciones entre las variables ambientales y la distribución bacteriana. Resultados. La distribución bacteriana se relacionó positivamente con el oxígeno disuelto en una de las lagunas-lago muestreadas (r = 1.0, p &lt; 0.01) y se correlacionó negativamente con el total de sólidos disueltos y la salinidad en otro de los lagos de agua dulce muestreados (r = -0.95, p &lt; 0.01; r = -0.80, p &lt; 0.05, respectivamente). Conclusiones. Esta investigación indicó que el agua salina de las lagunas-lagos limita el número de bacterias en comparación con los lagos de agua dulce