Poster Presentations
|
Reduction of Selenite to Elemental Selenium through Bacterial Isolated from Polluted Areas
Saima Javed, PhD scholar, University of the Punjab
In this work highly toxic Selenite is transformed to less toxic element Selenium through biotic transformation using bacterial strain Bacillus Subtilis, Exiguobacterium sp., Bacillus licheniformis, and Pseudomonas Pseudoalcaligenes. Selenium is a metalloid which exists in different forms like reduced form (Selenide, Se2-), water dissolved form (Selenite, So3-2/Selenate SeO4-2) and in the form of element (Seo). Different parameters were changed for optimizing conditions like different Selenium (Se) concentration levels (200, 400 and 600 µg ml-1), temperature, pH, aeration and incubation time for increased reduction of Selenite. On average 15-33 % Selenite reduction was observed at pH 3, However it goes on increasing till 28-90% at pH 9. Three levels of tmperature (32°C, 37°C and 42°C) were selected for evaluating Selenite reduction. The reduction of Selenite was observed at different temperatures and the results showed that each strain has different preferences for optimum Selenite reduction. Selenite reduction was also examined by different initial Selenite concentration and the result showed that at lower initial concentration (200 µg ml-1) maximum Selenite was reduced as can be seen from the figure attached. This study showed that selenite-reducing bacteria can remediate Se in aerobic and anaerobic environments and reduction ability decreases with increase in incubation time
|
|
