Effects of a long-term periodic substrate perturbation on an anaerobic community
Effects of a long-term periodic substrate perturbation on an anaerobic community
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长期周期性底物扰动对厌氧群落的影响
DOI：
10.1016/s0043-1354(97)00064-x
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发表时间：
1997
期刊：
影响因子：
12.8
通讯作者：
R. Hickey
中科院分区：
文献类型：
--
作者：
J. Xing;C. Criddle;R. Hickey
研究了葡萄糖喂养的厌氧菌群对长期(400天)周期性底物扰动的反应。一个完全混合的“母体”反应器稳定运行，水力停留时间(HRT)为10天，葡萄糖进料恒定为8g/L，作为“子体”反应器的微生物来源。子反应器最初的运行方式与母反应器相同，即在10天的水力停留时间和恒定的8g/升葡萄糖进料条件下运行。在达到稳定状态后，子体反应器采用周期性有机负荷模式，即进水葡萄糖浓度在16~0g/L(仅限矿物介质)之间交替变化，周期为6d。在启动扰动后，葡萄糖发酵中间产物迅速积累。出水化学需氧量(COD)从约400 mg/L上升到6000 mg/L的峰值，沼气中甲烷含量从50%下降到20%以下，pH从7.0下降到6.2。随后是230天的亚稳“稳定状态”，在此期间，出水COD浓度在5000毫克/升的新中值上下波动，醋酸盐和丁酸盐浓度以循环的反模式变化。在亚稳期结束时，挥发性脂肪酸浓度迅速下降。在约40天内，建立了一个新的稳定状态。这些观察表明，厌氧系统能够通过微生物群落的长期变化来适应周期性的底物扰动。
The response of a glucose-fed anaerobic community to a long-term (>400 days) periodic substrate perturbation was examined. A completely mixed “mother” reactor operated at steady state with a 10-day hydraulic retention time (HRT) and constant 8 g/liter glucose feed served as the source of organisms for a “daughter” reactor. The daughter reactor was initially operated in the same manner as the mother reactor, i.e. at a 10-day HRT and a constant 8 g/liter glucose feed. After reaching steady state, the daughter reactor was subjected to a periodic organic loading pattern in which the influent glucose concentration was alternately varied from 16 to 0 g/liter (mineral media only) on a 6-day cycle. A rapid accumulation in glucose fermentation intermediates occurred immediately after initiating the perturbation. Effluent chemical oxygen demand (COD) increased from ca 400 to a peak level of 6000 mg/liter, methane content of the biogas decreased from 50 to less than 20% and the pH decreased from 7.0 to 6.2. This was followed by a 230-day metastable “steady state” during which the effluent COD concentration fluctuated about a new median value of 5000 mg/liter and the acetate and butyrate concentrations varied in a cyclic, inverse pattern. At the end of the metastable period, volatile fatty acid concentrations decreased rapidly. Within ca 40 days, a new steady state was established. These observations indicate that the anaerobic system was able to adapt to the periodic substrate perturbation through a long-term change in microbial community.