脱硫混合菌系在传代和硫化氢脱除中的稳定性

Stability of Desulfurated Mixed Bacterial Culture During Succession Cultivation and Hydrogen Sulfide Removal

为研究由嗜酸氧化亚铁硫杆菌[Acidithiobacillus ferrooxidans(A.ferrooxidans)]和嗜酸氧化硫硫杆菌[Acidithiobacillus thiooxidans(A.thiooxidans)]按数量1∶2配比的一组脱硫混合菌系的硫化氢脱除效果及在传代和硫化氢脱除过程中的稳定性,采用ATP分析法和qRT-PCR分别检测ATP浓度和细菌gyr B基因拷贝数及其比例。结果表明,在传代培养中,ATP含量较为稳定,其值在1.09×10-6~1.54×10-6mol·L^(-1)的小范围内变化,A.ferrooxidans和A.thiooxidans的gyr B基因拷贝数也相对稳定,在最佳脱硫条件下,硫化氢的脱除效率可达99.4%。在脱硫过程中,体系p H值为2.29~2.62。此外,不同时间点的ATP含量和细菌基因拷贝数也相对稳定。在传代培养和硫化氢脱除的过程中,A.ferrooxidans和A.thiooxidans的gyr B基因拷贝数的比例一直维持在1∶2左右。本研究结果为脱硫混合菌系在生物燃气脱除硫化氢中的应用提供了依据。

A desulfurated mixed bacterial culture consisting of A. ferrooxidans and A. thiooxidans with number ratio 1 ： 2 was used to remove hydrogen sulfide. To investigate its removal efficiency of hydrogen sulfide and stability during succession cultivation and hydrogen sulfide removal process, the ATP titer, bacterial gyrB gene copy number and its number ratio of A. ferrooxidans and A. thiooxidans were monitored by ATP assay and qRT-PCR. Results indicated that the ATP content varied in a small range of 1.09 × 10 -6 to 1.54 × 10 -6 mol·L-1, maintaining relatively stable throughout subculture. The change of A. ferrooxidans and A. thiooxidans quantity in terms of the gyrB gene number were also relatively stable. The removal efficiency of hydrogen sulfide reached to 99.4% under the optimal condition. The pH of each time point was more or less constant, ranging from 2. 29 to 2. 62 during hydrogen sulfide removal. Additionally, the ATP titer and bacterial numbers at different time points remained relatively stable during the process. The number ratio of A. ferrooxidans and A. thiooxidans always remained around 1：2 during subcultivation and desulfurization processes. Results provide a basis for applying the mixed bacterial culture in removal of hydrogen sulfide from biogas.