初始菌株HY-7是从河南省三门峡矿区的铝土矿矿坑水中分离出来的硅酸盐杆菌。根据试验结果,该菌的最佳生长温度为30℃和pH值是7.0,紫外诱变改良时的最佳紫外照射时间为20s,此时的正突变率为23.0%。紫外诱变前后菌株的生长曲线对比表明,诱变后菌株达到稳定状态的时间为144 h,比诱变前提早24h。细菌的序列同源性分析表明,该群落组成主要可以分为两大支,一支与类芽孢杆菌属有较高的同源性,另一支与乳酸芽孢乳杆菌属有较高的同源性。生物脱硅试验结果表明,经过7d的生物浸出脱硅过程后,金红石精矿中TiO2的品位从78.21%提高到91.80%,其回收率达到95.24%。该生物脱硅工艺不仅有效地提高了金红石精矿的品位,同时还很环保。
The original strain HY-7 was isolated from the bauxite mine drainage(BMD) taken from a reservoir in Sanmenxia Mine,Henan Province,China.The optimum temperature and pH for the growth of strain HY-7 were 30 ℃ and 7.0,respectively.The optimum UV radiating time was 20 s and the positive mutation rate was 23.0%.The growth curves show that strain HY-7 needs144 h to reach the stationary phase after its mutagenesis,which is 24 h earlier than that of the original strain.Sequence homology analysis indicated that this community consisted of mainly two branches:one sharing high homology with Paenibacillus stellifer and the other sharing high homology with Sporolactobacillus laevolacticus.The experimental results showed that the TiO2 grade of mtile concentrate increased from 78.21%to 91.80%and the recovery of TiO2 reached 95.24%after 7 d of bioleaching.The bio-desilication process can not only effectively improve the TiO2 grade of rutile concentrate but also meet the requirements of environmental protection.