Abstract：
The nutrients availability determines efficiency of biological treatment systems, along with the structure and metabolism of microbiota. Herein nutrients deficiencies on aerobic granular sludge were comparatively evaluated, treating wastewater with mass ratios of chemical oxygen demand : nitrogen : phosphorus being 200:20:4, 200:2:4, and 200:20:0.4 (deemed as nutrient-balanced, nitrogen-deficient, and phosphorus-deficient), respectively. Results revealed that both nitrogen and phosphorus deficiencies significantly raised the effluent qualities especially nitrogen removal. However, nitrogen deficiency aroused considerable growth of filamentous bacteria, while granules kept compact structure under phosphorus deficient condition. Extracellular polymeric substances (EPS) also varied in contents and structures in response to different wastewaters. Microbial community structure analysis demonstrated that nitrogen deficiency led to lower richness and higher diversity, while the reverse was observed under phosphorus deficient condition. Nitrogen deficiency mainly induced decrease of nitrifying bacteria, while similarly phosphorus deficiency led to loss of phosphorus accumulating organisms. Dramatic enrichment Candidatus_Competibacter and filamentous Thiothrix were found under nutrients deficiencies, in which the latter explained and indicated filamentous bulking potential especially under nitrogen limited condition. Bacterial metabolism patterns verified the functions of microbial community responding to nutrients via PICRUSt2 prediction mainly by up-regulating cell motility, and cellular processes and signaling. This study could aid understanding of long-term stability of aerobic granular sludge for low-strength wastewater treatment.
摘要：
营养物质的可用性决定了生物处理系统的效率，以及微生物群的结构和代谢。本文对好氧颗粒污泥的养分缺乏进行了比较评价，处理废水的化学需氧量：氮：磷的质量比为200：20：4，200：2：4和200：20：0.4（视为营养平衡，缺氮,和磷缺乏)，分别。结果表明，氮和磷的缺乏显着提高了出水水质，尤其是氮的去除。然而,氮缺乏引起丝状细菌的大量生长，在缺磷条件下，颗粒保持致密结构。胞外聚合物（EPS）的含量和结构也随不同的废水而变化。微生物群落结构分析表明,氮缺乏导致丰富度降低,多样性提高,而在缺磷条件下观察到相反的情况。氮缺乏主要导致硝化细菌减少，而类似的磷缺乏导致磷积累生物的损失。在营养缺乏的情况下发现了明显的富集念珠菌_竞争杆菌和丝状硫丝菌，其中后者解释并表明了特别是在氮限制条件下的丝状膨胀潜力。细菌代谢模式通过PICRUSt2预测主要通过上调细胞运动性来验证微生物群落对营养物质的反应功能，以及细胞过程和信号。这项研究可以帮助了解低强度废水处理的好氧颗粒污泥的长期稳定性。
