UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal.
Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Denmark.
Water Res. 2017 Oct 1;122:159-171. doi: 10.1016/j.watres.2017.04.072. Epub 2017 Apr 29.
Tetrasphaera and Candidatus Accumulibacter are two abundant polyphosphate accumulating organisms in full-scale enhanced biological phosphorus removal (EBPR) systems. However, little is known about the metabolic behaviour and ecological niche that each organism exhibits in mixed communities. In this study, an enriched culture of Tetrasphaera and Ca. Accumulibacter was obtained using casein hydrolysate as sole carbon source. This culture was able to achieve a high phosphorus removal efficiency (>99%), storing polyphosphate while consuming amino acids anaerobically. Microautoradiography and fluorescence in situ hybridisation confirmed that more than 90% Tetrasphaera cells were responsible for amino acid consumption while Ca. Accumulibacter likely survived on fermentation products. Tetrasphaera performed the majority of the P removal (approximately 80%) in this culture, and batch tests showed that the metabolism of some carbon sources could actually lead to anaerobic orthophosphate (Pi) uptake (9.0 ± 2.1 mg-P/L) through energy generated by fermentation of glucose and amino acids. This anaerobic Pi uptake may lead to lower net Pi release to C uptake ratios and reduce the Pi needed to be removed aerobically in WWTPs. Intracellular metabolites such as amino acids, sugars, volatile fatty acids and small amines were observed as potential storage products, which may serve as energy sources in the aerobic phase. Evidence of the urea cycle was found, which could be involved in reducing the intracellular nitrogen content. This study improves our understanding of how phosphorus is removed in EBPR systems and can enable novel process optimisation strategies.
Tetrasphaera 和 Candidatus Accumulibacter 是两种在规模化强化生物除磷（EBPR）系统中丰富的多聚磷酸盐积累生物。然而，对于每种生物在混合群落中表现出的代谢行为和生态位知之甚少。在本研究中，使用水解酪蛋白作为唯一碳源获得了富集的 Tetrasphaera 和 Ca. Accumulibacter 培养物。该培养物能够实现高磷去除效率（>99%），在厌氧条件下消耗氨基酸时储存多聚磷酸盐。微量放射性自显影和荧光原位杂交证实，超过 90%的 Tetrasphaera 细胞负责消耗氨基酸，而 Ca. Accumulibacter 可能以发酵产物为食。在该培养物中，Tetrasphaera 完成了大部分磷的去除（约 80%），批试验表明，一些碳源的代谢实际上可以通过发酵葡萄糖和氨基酸产生的能量导致厌氧正磷酸盐（Pi）摄取（9.0±2.1mg-P/L）。这种厌氧 Pi 摄取可能导致净 Pi 释放与 C 摄取比降低，并减少 WWTP 中需要有氧去除的 Pi。观察到氨基酸、糖、挥发性脂肪酸和小胺等细胞内代谢物作为潜在的储存产物，它们可能在好氧阶段作为能源。发现了尿素循环的证据，它可能参与降低细胞内氮含量。本研究提高了我们对 EBPR 系统中磷去除方式的理解，并能够实现新的工艺优化策略。
