State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
Int J Environ Res Public Health. 2020 Mar 23;17(6):2118. doi: 10.3390/ijerph17062118.
Chromium contamination has been an increasing threat to the environment and to human health. Cr(VI) and Cr(III) are the most common states of chromium. However, compared with Cr(III), Cr(VI) is more toxic and more easily absorbed, therefore, it is more harmful to human beings. Thus, the conversion of toxic Cr(VI) into Cr(III) is an accepted strategy for chromium detoxification. Here, we isolated two strains with a high chromium tolerance and reduction ability, named D and 332, respectively. Both strains demonstrated a strong pH and temperature adaptability and survival under 8 mM Cr(VI). D achieved 87.8% Cr(VI) removal in 24 h with an initial 2 mM Cr(VI). Cu(II) was found to increase the removal rate of Cr(VI) significantly. With the addition of 0.4 mM Cu(II), 99.9% of Cr(VI) in the culture was removed by 332 in 24 h. This is the highest removal efficiency in the literature that we have seen to date. The immobilization experiments found that sodium alginate with diatomite was the better method for immobilization and was more efficient in immobilized cells. Our research provided valuable information and new, highly effective strains for the bioremediation of chromium pollution.
铬污染对环境和人类健康构成了日益严重的威胁。Cr(VI)和 Cr(III)是铬的两种最常见形态。然而，与 Cr(III)相比，Cr(VI)毒性更大，更容易被吸收，因此对人类的危害更大。因此，将有毒的 Cr(VI)转化为 Cr(III)是一种公认的铬解毒策略。在这里，我们分别分离到两株具有高铬耐受和还原能力的菌株，命名为 D 和 332。这两株菌均表现出较强的 pH 和温度适应性，在 8 mM Cr(VI)下仍能存活。D 菌株在 24 小时内可将初始浓度为 2 mM 的 Cr(VI)去除 87.8%。Cu(II)的添加可显著提高 Cr(VI)的去除率。在添加 0.4 mM Cu(II)的情况下，332 菌株在 24 小时内可将 99.9%的 Cr(VI)去除。这是迄今为止我们所见过的文献中最高的去除效率。固定化实验发现，硅藻土固定化海藻酸钠是一种更好的固定化方法，固定化细胞的效率更高。我们的研究为铬污染的生物修复提供了有价值的信息和新的、高效的菌株。
