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Bacterial indicators, including total coliforms, fecal coliforms, total Streptococci , Enterococci and Clostridium perfringens , were evaluated in alpine lake water environments at elevated altitudes in the Pindos mountain region. Classical methods and techniques were used for the isolation and characterization of indicator microorganisms and a selective nutrient medium supplemented with lactose-sulphite (LS) for the rapid determination of C. perfringens . In most lake samples examined, low numbers of microorganisms were enumerated in the order 10 1 -10 3 , whereas no Enterococci were present. Vegetative forms of C. perfringens were not recovered in any of the lake samples, on the contrary spore forms where detected in all samples. Finally, determination of levels of various metal ions such as Cu, Ni, Mn, Zn, Fe and Pb in lake waters revealed very low concentrations for these metals. Our results demonstrated a range of indicator microorganisms present in low numbers and also certain metal ions at low concentrations, thus, presenting no immediate concern for pollution to the surrounding ecosystem of the Pindos mountain range. Keywords: bioindicators, Clostridium perfringens , extreme environments, heavy metals, microbial flora, pollution. |
