CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Bioresour Technol. 2018 Feb;249:605-611. doi: 10.1016/j.biortech.2017.10.070. Epub 2017 Oct 20.
To investigate the effects of temperature shock on NO emissions, four treatments with rapidly changing incubation temperature from the control (20 °C) to 4, 12, 25, or 34 °C were conducted. Results showed that higher NO emissions (0.023-0.37%) were observed when reactor contents received temperature shocks. NO emissions increased as the temperature interval increased. Nitrate, nitrite, and nitrous oxide reduction rates generally followed the order: 34 °C > 25 °C > 20 °C > 12 °C > 4°C. Overall, the low-temperature shocks down-regulated and high-temperature shocks up-regulated the expression of denitrifying genes. However, the transcription rate of norB/nosZ and nirS/nosZ could not explain higher NO emission. The increased NO emissions might be more related to post-transcriptional regulation and enzyme activity (Q value). The results of cDNA sequencing showed that the active microbial community was relatively stable. Among the members of top 15 genera with active transcripts, Flavobacterium, Comamonadaceae and Xanthomonadales were the dominant denitrifying bacteria.
为了研究温度冲击对 NO 排放的影响，进行了四个处理，即将培养温度从对照（20°C）快速变化到 4°C、12°C、25°C 或 34°C。结果表明，当反应器内容物受到温度冲击时，会观察到更高的 NO 排放（0.023-0.37%）。NO 排放随着温度间隔的增加而增加。硝酸盐、亚硝酸盐和氧化亚氮还原率通常遵循以下顺序：34°C > 25°C > 20°C > 12°C > 4°C。总的来说，低温冲击下调了脱氮基因的表达，而高温冲击上调了脱氮基因的表达。然而，norB/nosZ 和 nirS/nosZ 的转录率并不能解释更高的 NO 排放。增加的 NO 排放可能与转录后调控和酶活性（Q 值）有关。cDNA 测序的结果表明，活性微生物群落相对稳定。在具有活性转录本的前 15 个属的成员中，黄杆菌属、丛毛单胞菌科和黄单胞菌目是主要的脱氮细菌。
