Tehnika (Jan 2019)
Microbiological diversity of thermomineral waters of Vrnjačka Banja and Metković (Mačva) -Serbia
Abstract
The microbiological and biochemical diversity of thermomineral waters of Vrnjačka Banja -the Jezero Spring (well VBJ-2/85) and Metković in Mačva District (well BMe-1) were analyzed for the first time in 2017. Six biological activity reaction tests (BART): IRB, SRB, HAB, DN, SLYM and FLOR were used simultaneously. The thermomineral waters are captured by the wells at a depth of 302 m and 627 m, respectively, from aquifers featuring different structural geological, petrographic-mineralogic, hydrogeological and other characteristics. The groundwater is stored and the aquifers renewed at pressure levels typical of the petrographic varieties of Paleozoic schists with marble lenses (Vrnjačka Banja) and Eocene sandstones (Metković). The magma activity and accompanying volcanic equivalents indicated elevated temperatures and CO2 concentrations of the thermomineral waters. Based on previously defined physico-chemical compositions, it was concluded that the studied occurrences are of the HCO3 --Na + basic ionic type, that they are hypothermal (Vrnjačka Banja -27.0°C) and hyperthermal (Metković -59.8°C), neutral (pH 7.0) and with a high mineral content (Vrnjačka Banja -2009 mg/L; Metković -1082 mg/L), as well as carbonated in Vrnjačka Banja (CO2 -1120.0 mg/L). Due to the specific features and importance of the selected occurrences of thermomineral waters, microbiological analyses were performed as well. Representatives of aerobic iron bacteria and anaerobic bacteria were detected at a low level of biochemical activity. Sulphate-reducing, heterotrophic, slime-forming, respiratory denitrifying and fluorescent Pseudomonas species were not detected. Daily observations of BART biodetector signatures and BART-Soft v-6 software indicated that the biocorrosion, biofouling and apparent health risks were low. However, periodic tests of the thermomineral waters for the target physiological group of bacteria and regular checks of sanitary and hygienic adequacy are recommended.