State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
Sci Total Environ. 2019 Dec 15;696:133809. doi: 10.1016/j.scitotenv.2019.133809. Epub 2019 Aug 6.
Although adding long-term acyl homoserine lactone (AHL) over one month was highly instructive for the development of an AHL-based anaerobic granulation strategy, the role of long-term exogenous AHL at different concentrations in the granulation process was poorly understood due to commercial exogenous AHL's extremely high cost. In this study, organic synthesis of N-decanoyl-homoserine lactone (C10-HSL) was employed for the first time to drastically reduce the cost of the AHL addition. Daily dosages of exogenous C10-HSL at 50 nM, 500 nM and 5000 nM were separately added into anaerobic bioreactors to promote the granulation process for as long as 168 days. 50 nM C10-HSL showed a negligible effect on the granulation process while 5000 nM C10-HSL achieved the best performance with the highest chemical oxygen demand (COD) removal, largest granule size and best extracellular polymeric substance production. Bacterial analysis indicated that exogenous C10-HSL showed a concentration-related effect in bacterial community organization. Besides, addition of 5000 nM C10-HSL resulted in the greatest promotion of Methanosaeta which was extremely important to the formation of anaerobic granule. This study provides a foundation for the future application of long-term exogenous AHL manipulation to improve the granulation process in an engineered ecosystem.
虽然在一个月以上的时间内添加长链酰基高丝氨酸内酯（AHL）对基于 AHL 的厌氧颗粒化策略的发展非常有指导意义，但由于商业外源性 AHL 的成本极高，长期不同浓度的外源性 AHL 在颗粒化过程中的作用仍不清楚。在本研究中，首次采用 N-癸酰基高丝氨酸内酯（C10-HSL）的有机合成来大幅降低 AHL 添加的成本。每天分别向厌氧生物反应器中添加 50 nM、500 nM 和 5000 nM 的外源性 C10-HSL，以促进颗粒化过程长达 168 天。50 nM 的 C10-HSL 对颗粒化过程几乎没有影响，而 5000 nM 的 C10-HSL 表现出最佳性能，具有最高的化学需氧量（COD）去除率、最大的颗粒尺寸和最佳的胞外聚合物产量。细菌分析表明，外源性 C10-HSL 在细菌群落组织方面表现出浓度相关的影响。此外，添加 5000 nM 的 C10-HSL 可最大程度地促进 Methanosaeta 的生长，这对厌氧颗粒的形成极为重要。本研究为未来应用长期外源性 AHL 操纵来改善工程生态系统中的颗粒化过程提供了基础。
