低温下磁性载体 MBBR系统微生物群落特征和功能预测分析

为阐明低温下磁性载体对移动床生物膜反应器(MBBR)处理能力的影响，探究了反应器内生物膜的微生物多样性、群落结构、功能特征和氮代谢通路.结果表明，与商用载体反应器(对照组)相比，磁性载体反应器具有更高的污染物去除率，其对NH⁺₄-N和TN的平均去除率分别提高了16.2%和12.1%.Illumina高通量测序结果显示，磁性载体生物膜的微生物多样性和丰富度更高.由于不同微生物的磁化率不同，导致两种载体生物膜微生物群落结构存在显著差异.磁性载体生物膜中硝化菌属(如：Nitrosomonas、Nitrospira)和反硝化菌属(如：Sphaerotilus、Zoogloea)的相对丰度显著增多.PICRUSt2功能预测分析显示，磁性载体生物膜的整体基因功能表达水平更高，在信号传导机制和细胞内运输、分泌和囊泡运输等方面优势更明显.此外，大多数与氮代谢相关基因在磁性载体生物膜中丰度更高，如涉及硝化过程的基因amo、hao和反硝化过程基因nap、nor等，使得生物膜的低温脱氮潜力增强.以上结果从微观生物学角度更好地解释了反应器处理能力的差异，为磁性载体强...

Analysis of Microbial Community Characteristics and Function Prediction of MBBR with Magnetic Biocarriers at Low Temperature

In order to clarify effect of magnetic biocarriers on the performance of MBBR at low temperatures, the microbial diversity, community structure, functional characteristics, and nitrogen metabolism of biofilm in the reaction system were investigated. The results indicated that MBBR with magnetic biocarriers had a better pollutant removal efficiency, with the average removal rates of NH₄⁺-N and TN being 16.2% and 12.1% higher than those in the control group (commercial biocarriers), respectively. Illumina high-throughput sequencing analysis showed that higher diversity and richness of the bacterial community was established in the biofilm of magnetic biocarriers. There were obvious differences in microbial community structure of biofilm between the two biocarrier duos to bacterial magnetic susceptibility. The relative abundances of nitrifying bacteria (e.g., Nitrosomonas and Nitrospira) and denitrifying bacteria (e.g., Sphaerotilus and Zoogloea) were increased in the magnetic biocarriers. Functional prediction analysis with PICRUSt2 showed that the microorganism of magnetic biocarriers had a better total gene function expression level, which was significantly more increased than commercial biocarriers in gene-representing signal transduction mechanisms and intracellular trafficking, secretion, and vesicular transport. Furthermore, most of the abundances of nitrogen metabolism genes were raised in the biofilm of magnetic biocarriers (e.g., genes amo and hao, were responsible for nitrification, and genes nap and nor, which were responsible for denitrification). Magnetic biocarriers increased biofilm potential for denitrification at low temperatures. Our results explained the difference in performance between the two reactors from microbiology and provided the theoretical basis for magnetic biocarrier-enhanced performances of MBBR at low temperatures.