耐冷嗜酸硫杆菌的生长特性和固定化培养

为解决氧化亚铁硫杆菌、嗜铁钩端螺旋菌等中温菌在低温和高酸的吸附尾液中作氧化剂时生长繁殖慢、氧化Fe²⁺速率低等问题,以耐冷嗜酸硫杆菌为研究对象,结合新疆某地浸采铀现场生产实际,对该菌的生长特性、耐酸驯化和固定化培养进行了探索。结果表明,该菌的接种量以10%为宜;当初始Fe²⁺浓度为0.3~0.5 g/L时,细菌仍能较快氧化Fe²⁺;在5~25℃条件下,耐冷嗜酸硫杆菌氧化Fe²⁺的速率均高于氧化亚铁硫杆菌,即耐冷嗜酸硫杆菌更适于溶浸液低温环境;耐冷嗜酸硫杆菌耐酸驯化后能在pH=0.31的培养液中保持较好的氧化活性;从生物陶粒表面电镜图片中可以观察出较厚的生物膜,固定化细菌和游离态细菌协同氧化Fe²⁺的速率是游离态细菌单独氧化的3.4倍。

Growth Characteristics of Acidithiobacillus Ferrivorans and Its Immobilization Culture

In order to solve problems that the mesophilic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum have slow growth and reproduction and have a low oxidation rate of Fe²⁺ as oxidant agent at low temperature in high acidity leaching-finished solution,such issues as the growth characteristics of acidithiobacillus ferrivorans and its acid tolerance domestication and immobilization culture were preliminarily studied,combining with the actual production situation of in-situ leaching uranium in Xinjiang.The experimental result indicated that the inoculum quantity of this bacterium was controlled at about 10%;When the initial concentration of Fe²⁺ was 0.3～0.5 g/L,the bacteria still maintained a fast rate of oxidation with Fe²⁺;At the temperature of 5～25 ℃,Fe²⁺oxidation rate of Acidithiobacillus ferrivoran was higher than that of Acidithiobacillus ferrooxidans,namely Acidithiobacillus ferrivorans was more suitable for leaching solution at low temperature environment;Acidithiobacillus ferrivorans could keep better oxidation activity in nutrient fluid after domesticated in acid condition (pH=0.31);A thicker biofilm could be observed in the SEM images of the Bio-ceramic,and the Fe²⁺ oxidation rate of synergistic interaction between immobilized bacteria and dissociative bacteria was about 3.4 times as much as that of dissociative bacteria.