Selenite-resistant Lactobacilli isolated from local cheeses made in the rural areas of Kurdistan and its application for the removal of selenite from water and wastewater

The presence of the high concentrations of selenite in the industrial wastewater that and subsequently entering water supply and the food chain are being health concerns. Thus, microbial bio-remediation has been considered as a safety tool for removing selenite. The aim of the current study was to evaluate the capability of selenite removal using Selenite-resistant Lactobacilli isolated from local cheeses made in the rural areas of Kurdistan.
25 local sample were collected from pristine areas kordestan provinceEnrichment was performed in the MRS media containing selenite (SeO3-2). Selenite tolerance pattern among bacterial isolates was performed by using the agar dilution test and broth dilution method.
The selenite content in the reaction medium was measured by a colorimetric assay. The One-factor-at-a- time method (OFAT) was used for the process optimization. Molecular characterization was performed by amplification of 16S rDNA gene and sequencing.
Findings:A total of 30 selenite-resistant bacteria were isolated and one of the strain, namedLactobacillus sp. Tra cheese 6, show the highest resistance to selenite (125 mM) along with bio-reduction efficiency. The maximum selenite removal was observed at the following conditions: initial biomass concentration 50 g/l, NaCl 4% (w/v), Temperature 37 C, pH 7.2 and agitation 100 rpm in the presence selenite with initial concentration of 45 mM. Under the optimal conditions, the concentration of SeO3-2 ion in the reaction supernatant decreased by 96% (from 45 to 1.8 mM) after 60 hours of incubation.
Discussion and Regarding the results obtained in the current investigation, isolation and determined of Lactobacilli as safety and economic catalysts and to develop suitable alternative methods for the removal of heavy metal oxyanions from water and wastewater are suggested.