Department of Civil Engineering, University of Calgary, Calgary, Canada.
Department of Civil Engineering, University of Calgary, Calgary, Canada.
Bioresour Technol. 2019 Jun;281:72-83. doi: 10.1016/j.biortech.2019.02.061. Epub 2019 Feb 13.
This study investigated functional dynamics of microbial community in response to different selection pressures, with a focus on denitrification. Suspended-biomass experiments demonstrated limited aerobic and relatively higher anoxic nitrate and nitrite reduction capabilities; the highest NO-N and NO-N removal rates were 1.3 ± 0.1 and 0.74 ± 0.01 in aerobic and 1.4 ± 0.05 and 3.4 ± 0.1 mg/L.h in anoxic media, respectively. Key potential denitrifiers were identified as: (i) complete aerobic denitrifiers: Dokdonella, Flavobacterium, and Ca. Accumulibacter; (ii) complete anoxic denitrifiers: Acinetobacter, Pseudomonas, Arcobacter, and Comamonas; (iii) incomplete nitrite denitrifier: Diaphorobacter (aerobic/anoxic), (iv): incomplete nitrate denitrifiers: Thauera (aerobic/anoxic) and Zoogloea (strictly-aerobic). Granular biomass removed 72 mg/L NH-N with no NO accumulation. Heterotrophic nitrification and aerobic denitrification were proposed as the principal nitrogen removal pathway in granular reactors, potentially performed by two key organisms Thuaera and Flavobacterium. Biodiversity analysis suggested that the selection pressure of nourishment condition was the decisive factor for microbial selection and nitrogen removal mechanism.
本研究旨在探究微生物群落对不同选择压力的功能动态响应，重点关注反硝化作用。悬浮生物实验表明，其具有有限的好氧和相对较高的缺氧硝酸盐和亚硝酸盐还原能力；在好氧和缺氧条件下，NO-N 和 NO-N 的最大去除率分别为 1.3±0.1 和 0.74±0.01mg/L.h 和 1.4±0.05 和 3.4±0.1mg/L.h。鉴定出的关键潜在反硝化菌为：（i）完全好氧反硝化菌：Dokdonella、Flavobacterium 和 Ca. Accumulibacter；（ii）完全缺氧反硝化菌：Acinetobacter、Pseudomonas、Arcobacter 和 Comamonas；（iii）不完全亚硝酸盐反硝化菌：Diaphorobacter（好氧/缺氧）；（iv）不完全硝酸盐反硝化菌：Thauera（好氧/缺氧）和Zoogloea（严格好氧）。颗粒生物量去除了 72mg/L 的 NH-N，没有 NO 积累。异养硝化和好氧反硝化被认为是颗粒反应器中主要的氮去除途径，可能由两个关键生物 Thauera 和 Flavobacterium 来完成。生物多样性分析表明，营养条件的选择压力是微生物选择和氮去除机制的决定性因素。
