包埋法固定化对硫氧化微生物菌群结构和功能的影响

【目的】为探讨包埋法固定化过程对硫氧化菌群硫化物去除能力及菌群微生物群落结构的影响,【方法】以聚乙烯醇-海藻酸钠-活性炭为载体,对硫氧化菌群进行了固定化,并采用富含硫化物的无机盐培养基,对比固定化与非固定化硫氧化菌群对硫化物的氧化去除能力。同时,利用PCR-DGGE技术,探讨硫氧化菌群在固定化前后以及在硫化物氧化去除过程中微生物群落结构变化。【结果】在对硫氧化菌群进行固定化之后,12 h之内对硫化物的最大去除能力从1000 mg/L下降为600 mg/L。硫氧化菌群的微生物群落结构发生了明显变化,但菌群中的硫氧化菌Catenococcus thiocycli未受影响,硫氧化菌Thioclava pacifica在菌群中的地位反而得到了强化。【结论】受制于底物在载体材料中的扩散迁移效率,硫氧化菌群对硫化物的氧化去除能力在固定化之后有所下降。由于不同微生物对固定化形成的微环境的适应能力以及对载体附着能力的不同,固定化对硫氧化菌群的微生物群落结构产生较大影响。

Effects of immobilization on community structure and function of sulfide oxidizing microbiota

Objective] To study the effects of cell immobilization on sulfide degradation ability and microbial community structure.Methods] Sulfide oxidizing microbiota was immobilized by entrapment on polyvinyl alcoholsodium alginate-activated carbon carrier. Sulfide degradation ability of the immobilized and free sulfide oxidizing microbiota was compared in sulfide-rich minimal medium. PCR-DGGE technique was used to reveal the effects of immobilization on microbial community structure.Results] The maximum sulfide degradation ability of the sulfide oxidizing microbiota in 12 h decreased from 1000 to 600 mg/L after immobilization. Community structure of the sulfide oxidizing microbiota changed after immobilization, but Catenococcus thiocycli was little affected. Thioclava pacifica was even strengthened in the microbiota after immobilization and sulfide degrading.Conclusion] In conclusion, limited by substrate diffusion and transfer in carrier material, sulfide degradation ability of the sulfide oxidizing microbiota under high sulfide concentration decreased after immobilization. Also, immobilization could affect the microbial community structure of sulfide oxidizing microbiota due to different adaptation ability to the microenvironment and adhesion ability to the carrier material.