Wang Zhongwei, Dunne Aislinn, van Loosdrecht Mark C M, Saikaly Pascal E
Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands.
Front Microbiol. 2018 Mar 16;9:479. doi: 10.3389/fmicb.2018.00479. eCollection 2018.
Saline wastewater is known to affect the performance of phosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) process. However, studies comparing the effect of salinity on different PAO clades are lacking. In this study, 'Candidatus Accumulibacter phosphatis' Clade I and II (hereafter referred to as PAOI and PAOII) were highly enriched (∼90% in relative abundance as determined by quantitative FISH) in the form of granules in two sequencing batch reactors. Anaerobic and aerobic batch experiments were conducted to evaluate the effect of salinity on the kinetics and stoichiometry of PAOI and PAOII. PAOI and PAOII communities showed different priority in using polyphosphate (poly-P) and glycogen to generate ATP in the anaerobic phase when exposed to salt, with PAOI depending more on intracellular poly-P degradation (e.g., the proportion of calculated ATP derived from poly-P increased by 5-6% at 0.256 mol/L NaCl or KCl) while PAOII on glycolysis of intracellularly stored glycogen (e.g., the proportion of calculated ATP derived from glycogen increased by 29-30% at 0.256 mol/L NaCl or KCl). In the aerobic phase, the loss of phosphate uptake capability was more pronounced in PAOII due to the higher energy cost to synthesize their larger glycogen pool compared to PAOI. For both PAOI and PAOII, aerobic conversion rates were more sensitive to salt than anaerobic conversion rates. Potassium (K) and sodium (Na) ions exhibited different effect regardless of the enriched PAO culture, suggesting that the composition of salt is an important factor to consider when studying the effect of salt on EBPR performance.
众所周知，含盐废水会影响强化生物除磷（EBPR）工艺中聚磷菌（PAOs）的性能。然而，缺乏比较盐度对不同聚磷菌进化枝影响的研究。在本研究中，“聚磷菌属（Candidatus Accumulibacter phosphatis）”的I型和II型（以下简称PAOI和PAOII）在两个序批式反应器中以颗粒形式高度富集（通过定量FISH测定，相对丰度约为90%）。进行了厌氧和好氧批次实验，以评估盐度对PAOI和PAOII动力学和化学计量学的影响。当暴露于盐环境时，PAOI和PAOII群落利用多聚磷酸盐（poly-P）和糖原在厌氧阶段产生ATP的优先级不同，PAOI更多地依赖细胞内多聚磷酸盐的降解（例如，在0.256 mol/L NaCl或KCl条件下，计算得出的源自多聚磷酸盐的ATP比例增加了5-6%），而PAOII则依赖细胞内储存糖原的糖酵解（例如，在0.256 mol/L NaCl或KCl条件下，计算得出的源自糖原的ATP比例增加了29-30%）。在好氧阶段，与PAOI相比，PAOII由于合成其更大糖原库的能量成本更高，其磷吸收能力的损失更为明显。对于PAOI和PAOII而言，好氧转化率比厌氧转化率对盐更敏感。无论富集的PAO培养物如何，钾（K）离子和钠（Na）离子都表现出不同的影响，这表明在研究盐度对EBPR性能的影响时，盐的组成是一个需要考虑的重要因素。
