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چکیده
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Background and Aim: Heavy metals are considered as important toxic pollutants and they are serious threat to the aquatic and terrestrial ecosystems as well as human health. Soluble form of selenium includes selenite (SeO3-2) is more toxic and exhibits higher bio-accumulation. The bio-remediation of selenite into less toxic forms is important from the standpoint of hygiene and environmental health. Methods: Fifty-six samples were collected from local dairy products, including yoghurt, buttermilk, curd and tarhana in the West of Iran. M17, MRS and KAA media containing 10mM of selenite were used for selective isolation strains of Lactobacillus, Lactococcus and Enterococcus spp. Minimum inhibitory concentration (MIC) and inhibitory effects of selenite on acid lactic bacteria were determined with the disk diffusion and the agar dilution methods. Results: The results showed that the isolated strain of Lactococcus sp. seD2b had a maximum MIC (110 mM) as well as the lowest inhibitory effect with the average diameter of the inhibition zone (26.6 mm) in the presence of selenite. MIC values for other isolated bacteria were in the range of 55-90 mM. The highest inhibitory effect of selenite oxyanion was seen in a strain of Lactobacillus sp. seD5 with an average diameter of 42.2 mm. Conclusion: Bioremediation is one of the green technologies for treating wastewater containing selenite. Considering the potential of lactic acid bacteria for converting the toxic forms of selenium into a harmless, they can be recruited as an efficient tool for enhancing food and water safety.
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