Water Desalination and Reuse Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia.
Microb Ecol. 2011 Apr;61(3):557-67. doi: 10.1007/s00248-010-9783-6. Epub 2010 Dec 14.
Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30 min IC(50) or the concentration of toxicant that results in a 50% reduction in oxygen utilization rate compared to a referential state represented by a control receiving no toxicant. Biodiversity of dominant bacterial taxa was assessed using polymerase chain reaction-terminal restriction fragment length polymorphism (PCR-T-RFLP) targeting the 16S ribosomal RNA (16S rRNA) gene. Statistical analysis of 30 min IC(50) values and PCR-T-RFLP data showed a significant positive correlation (P < 0.05) between functional resistance and microbial diversity for each of the three toxicants tested. To our knowledge, this is the first study showing a positive correlation between biodiversity of dominant bacterial taxa in activated sludge and functional resistance. In this system, activated sludge bacterial communities with higher biodiversity are functionally more resistant to disturbance caused by toxic shock loading.
考察生物多样性与受扰后活性污泥细菌群落功能稳定性（抵抗力和恢复力）之间的关系，是开发稳健生物废水处理系统设计策略的重要第一步。本研究通过用硫酸铜（Cu[II]）、3,5-二氯苯酚（3,5-DCP）或 4-硝基苯酚（4-NP）对具有不同生物多样性水平的活性污泥样品进行毒性冲击负荷处理，来研究功能抵抗力与优势细菌分类群生物多样性之间的关系。采用呼吸计量批实验来确定活性污泥细菌群落对三种毒物的功能抵抗力。功能抵抗力通过 30 分钟 IC（50）或毒物浓度来估计，该浓度导致与未受毒物影响的参照状态（以未受毒物影响的对照作为参照）相比，氧利用率降低 50%。采用聚合酶链反应-末端限制性片段长度多态性（PCR-T-RFLP）方法，针对 16S 核糖体 RNA（16S rRNA）基因，对优势细菌分类群的生物多样性进行评估。对 30 分钟 IC（50）值和 PCR-T-RFLP 数据的统计分析表明，对于测试的三种毒物中的每一种，功能抵抗力与微生物多样性之间存在显著正相关（P<0.05）。据我们所知，这是首次表明活性污泥中优势细菌分类群的生物多样性与功能抵抗力之间存在正相关关系的研究。在该系统中，生物多样性较高的活性污泥细菌群落对毒性冲击负荷引起的干扰具有更强的功能抵抗力。
