Department of Environmental Engineering, School of Environmental and Geographical Science, Shanghai Normal University, Shanghai 200234, PR China.
Department of Environmental Engineering, School of Environmental and Geographical Science, Shanghai Normal University, Shanghai 200234, PR China.
Sci Total Environ. 2019 Nov 25;693:133622. doi: 10.1016/j.scitotenv.2019.133622. Epub 2019 Jul 26.
It is common that biological wastewater-treatment processes are exposed to inputs of toxic compounds, such as phenolics. Due to their slow growth rate, nitrifying bacteria are most susceptible to inhibition that can lead to loss of nitrification capacity. Here, a microbial community containing nitrifying bacteria was acclimated to phenol, and it developed resistance to phenol inhibition and maintained nitrification activity. For the phenol-acclimated biomass, the NH-N removal rates were almost unaffected when it was suddenly exposed to phenol. Heterotrophic synthesis and nitrification rates contributed 76% and 24% of the total NH-N removal respectively during phenol removal, but the nitrification rate increased significantly once phenol was removed and mineralized. In contrast, the NH-N removal rates decreased sharply for normal (unacclimated) nitrifying biomass when it was exposed to phenol. The phenol-acclimated biomass retained its resistance to phenol inhibition for at least two months after acclimation, and addition of the phenol-acclimated biomass to the normal biomass conferred resistance to phenol inhibition. Community analysis of the phenol-acclimated biomass showed an increase in families known to contain strains able to biodegrade phenolics. Taken together, the results indicate that the main impact of phenol acclimation was enrichment of phenol-biodegrading bacteria, which allowed rapid removal and mineralization of phenol and, consequently, alleviation of phenol's inhibition of nitrification.
生物废水处理过程经常会受到有毒化合物（如酚类化合物）的输入，这是很常见的。由于硝化细菌的生长速度较慢，因此它们最容易受到抑制，从而导致硝化能力丧失。在这里，含有硝化细菌的微生物群落被驯化以耐受酚类化合物，并且它对酚类化合物的抑制作用产生了抗性并保持了硝化活性。对于酚类驯化的生物量，当突然暴露于酚类化合物时，NH3-N 去除率几乎不受影响。在去除酚类化合物的过程中，异养合成和硝化速率分别贡献了总 NH3-N 去除的 76%和 24%，但一旦去除和矿化酚类化合物，硝化速率就会显著增加。相比之下，当正常（未驯化）硝化生物量暴露于酚类化合物时，NH3-N 去除率急剧下降。酚类驯化的生物量在驯化后至少两个月内保留了对酚类化合物抑制的抗性，并且将酚类驯化的生物量添加到正常生物量中赋予了对酚类化合物抑制的抗性。对酚类驯化生物量的群落分析表明，能够降解酚类化合物的菌株所包含的家族数量有所增加。总之，结果表明，酚驯化的主要影响是富集了能够降解酚类化合物的细菌，这使得酚类化合物能够快速去除和矿化，从而减轻了酚类化合物对硝化的抑制作用。
