UASB反应器中产甲烷菌对温度胁迫的响应

采用间歇培养方式探讨了升流式厌氧污泥床(UASB)反应器中不同营养类型产甲烷菌对温度胁迫的响应规律.研究结果表明,产甲烷螺旋菌(Methanospirillum)是该反应器的主要氢营养型产甲烷菌,而主要乙酸营养型产甲烷菌为产甲烷丝状菌(Methanosaeta).在35℃条件下,氢营养型和乙酸营养型产甲烷菌的累计甲烷产量分别为24.7,11.7mL,而最大产甲烷速率分别为0.74,0.18mL/h.当温度从35℃分别降低至30,25,20,15℃时,导致氢营养型产甲烷菌的累计产甲烷量分别减少了14.2%,34.0%,47.0%,57.5%,而乙酸营养型产甲烷菌的累计产甲烷量分别减少了5.1%,23.9%,45.3%,95.7%.由此可见,在20~30℃时氢营养型产甲烷菌对温度胁迫更加敏感,而在15℃以下时乙酸营养营养型产甲烷菌对温度胁迫更加敏感.

Response of methanogens on temperature stress in an UASB reactor

The effects of temperature stress on different nutrition type methanogens in an upflowed anaerobic sludge blanket(UASB) reactor was investigated by batch culture. The results showed that the dominant hydrogenotrophic and acetotrophic methanogens in this reactor were Methanospirillum and Methanosaeta, respectively. Under 35℃ condition, the accumulative methane production from hydrogenotrophic and acetotrophic methanogens were 24.7 and 11.7mL, separately. And the maximum methane production rate(R_max) were 0.74 and 0.18mL/h, respectively. Temperature decreases, from 35℃ to 30, 25, 20, 15℃, resulted in accumulative methane productions from hydrogenotrophic methanogens were decreased by 14.2%, 34.0%, 47.0%, 57.5%, respectively. While those from acetotrophic methanogens were reduced by 5.1%, 23.9%, 45.3%, 95.7%, separately. These results indicated that hydrogenotrophic methanogens are more sensitive to temperature tress at 20~30℃, while acetotrophic methanogens are more sensitive at ≤15℃.