Eds analysis

Pure culture of Stenotrophomonas sp. and the Consortium growing at MTC of As-compounds were further examined by scanning electron microscopy / energy dispersive spectroscopy (SEM/EDS) analysis. Glutaraldehyde-fixed bacterial cells were processed according to standard procedures for scanning electron microscopy (SEM). Briefly, the samples were washed in phosphate buffer, dehydrated through a graded series of ethanol, dried in hexamethyldisilizane (HMDS) and transferred onto coverslips. Dry samples were subsequently placed onto aluminium stubs and carbon coated before imaging the samples with the Zeiss Crossbeam 540 FEG SEM using the InLens detector at 0.5 kV. The EDS analysis (Oxford Instruments, United Kingdom) was done using 20kV and Backscatter detector on at least three areas on the sample. The As content in cells of Stenotrophomonas sp. and Consortium exposed to arsenite and arsenate was compared. Statistical analyses were carried out using Statistica 13.3 software (TIBCO Software Inc.). For pairwise comparisons ordinary t-test for independent variables was used. Decisions regarding statistical significance were made at p < 0.05.