Improving bio-desilication of a high silica bauxite by two highly effective silica-solubilizing bacteria
Improving bio-desilication of a high silica bauxite by two highly effective silica-solubilizing bacteria
复制标题
DOI：
10.1016/j.mineng.2018.08.041
复制
发表时间：
2018-11
影响因子：
4.8
通讯作者：
Qi Wang;X. Sheng;Linyan He;Y. Shan
中科院分区：
文献类型：
--
作者：
Qi Wang;X. Sheng;Linyan He;Y. Shan
细菌在高硅铝土矿的生物脱硅中发挥着重要作用。然而，生物脱硅效率低和机制未知限制了细菌在铝土矿生物脱硅中的应用。在本研究中，获得了两种高效的溶硅细菌（巴氏节杆菌 H19 和伯克霍尔德菌 G21），并表征了它们对高硅（18.1%）铝土矿中硅和铝释放的影响及其相关机制。在这些菌株存在的情况下，培养基中溶解的Si和Al浓度为3.3-13.9mM和0.04-0.41mM，从铝土矿中释放的总Si和Al分别为2.76-11.64mg和0.03-0.39mg。在实验结束时，菌株 G21 从铝土矿中释放的 Si 量比菌株 H19 多。这些菌株在生物脱硅过程中产生苹果酸 (791–1700μM)、柠檬酸 (94–447μM) 和琥珀酸 (228–494μM) 以及外多糖 (EPS) (39–420mgL−1)。此外，菌株 G21 比菌株 H19 产生更多的有机酸（19-65%），而菌株 H19 比菌株 G21 产生更多的 EPS（1.7-4.9 倍）。与对照相比，这些菌株的代谢物（发酵液、有机酸和 EPS）也显着增加了溶解的 Si 浓度。值得注意的是，菌株H19和G21处理的铝土矿中Al2O3与SiO2的比值分别为9.14和9.64，满足拜耳法生产氧化铝的要求。结果表明，这些菌株具有独特且高的生物脱硅效率，表明高效溶硅菌株通过产生有机酸和 EPS 来提高生物脱硅效率。
Bacteria play an important role in bio-desilication of high silica bauxites. However, low bio-desilication efficiency and unknown mechanisms limit the use of bacteria in bio-desilication of bauxite. In this study, two highly effective Si-solubilizing bacteria (Arthrobacter pascensH19 andBurkholderia anthinaG21) were obtained and characterized for their impact on Si and Al release from a high-silica (18.1%) bauxite and the mechanisms involved. Dissolved Si and Al concentrations in the culture medium were 3.3–13.9 mM and 0.04–0.41 mM, and total Si and Al released from the bauxite were 2.76–11.64 mg and 0.03–0.39 mg, respectively, in the presence of these strains. Strain G21 released more Si from the bauxite than strain H19 at the end of the experiment. These strains produced malic (791–1700 µM), citric (94–447 µM), and succinic (228–494 µM) acids, and expolyssaccharides (EPS) (39–420 mg L−1) during the bio-desilication processes. Furthermore, strain G21 produced more organic acids (19–65%) than strain H19, while strain H19 produced more EPS (1.7–4.9-fold) than strain G21. The metabolites (fermentation broth, organic acids, and EPS) of these strains also significantly increased dissolved Si concentration compared to the control. Notably, the ratios of Al2O3to SiO2in the bauxite treated with strains H19 and G21 were 9.14 and 9.64, respectively, which met the requirement in the Bayer process for alumina production. The results showed distinct and high bio-desilication effectiveness of these strains and suggested that the highly effective Si-solubilizing bacterial strains increased bio-desilication efficiency through the production of organic acids and EPS.