Conversion of selenite to elemental selenium by indigenous bacteria isolated from polluted areas
Conversion of selenite to elemental selenium by indigenous bacteria isolated from polluted areas
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DOI：
10.1080/09542299.2015.1112751
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发表时间：
2015-01-01
影响因子：
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通讯作者：
Faisal, Muhammad
中科院分区：
文献类型：
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作者：
Javed, Saima;Sarwar, Arslan;Faisal, Muhammad
本研究以枯草芽孢杆菌、亚硒酸钠为原料，地衣芽孢杆菌和假产碱假单胞菌。通过改变不同的物理参数，如pH值，温度，不同的硒（Se）浓度水平（200，400，和600 μ g ml（-1）），通风，和培养时间增加亚硒酸盐还原的条件进行了优化。硒还原率随pH的增加而增加。平均而言，在pH 9时观察到28-90%的亚硒酸盐还原，而在pH 3时为15-33%。为了检查最适温度，所有菌株在32、37和42 ℃三个温度下培养。在不同温度下观察到亚硒酸盐还原，结果表明，每种菌株对最佳硒还原有不同的偏好。亚硒酸盐还原也监测使用不同的初始亚硒酸盐浓度和结果表明，在较低的初始浓度（200 μ g ml（-1））的最大硒减少。研究表明，亚硒酸盐还原菌在好氧和厌氧条件下均能修复土壤中的硒，且随着培养时间的延长，其还原能力下降。
The present research work is on the biotic transformation of highly soluble and toxic selenite to less toxic elemental selenium using bacterial strains Bacillus subtilis, Exiguobacterium sp., Bacillus licheniformis, and Pseudomonas pseudoalcaligenes. The conditions were optimized by changing different physical parameters such as pH, temperature, different Selenium (Se) concentration levels (200, 400, and 600 mu g ml(-1)), aeration, and incubation time for increased selenite reduction. The Se reduction rate increased with increase in pH. On average, 28-90% selenite reduction was observed at pH 9, while 15-33% at pH 3. To check the optimum temperature, all strains were cultured at three temperatures 32, 37, and 42 degrees C. Selenite reduction was observed at various temperatures and the results show that each strain has different preferences for optimum Se reduction. Selenite reduction was also monitored using different initial selenite concentrations and the results showed that at lower initial concentration (200 mu g ml(-1)) maximum Se was reduced. This study showed that selenite-reducing bacteria can remediate Se in both aerobic and anaerobic environments, as well as their reduction ability decreases with increase in incubation time.