Wang Jianhua, He Yan, Zhu Jin, Guan Huimin, Huang Minsheng
Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
Department of Medical Laboratory in Chuxiong Medical College, Yunnan, 675005, China.
Appl Microbiol Biotechnol. 2017 Aug;101(15):6193-6203. doi: 10.1007/s00253-017-8318-1. Epub 2017 May 24.
The proper use of selective ammonia-oxidizing archaea (AOA) and/or ammonia-oxidizing bacteria (AOB) inhibitors is critical to distinguish AOA and AOB contribution. In this research, three inhibitors including ampicillin, dicyandiamide (DCD), and allylthiourea (ATU) were examined mainly focusing on inhibiting dosage, adaptability, and effects. The results showed that the optimized inhibitory dosage of ampicillin, DCD, and ATU was separately 1.5 g L, 1 mM, and 25 μM. Among the three inhibitors, ATU exhibited the strongest and persistent inhibition effects and resulted in up to 90% inhibition in the AOB-enriched culture. The seemingly weakening inhibiting effects of ATU in the simulated river systems can be attributed to the involved role of AOA, the uneven spatial distribution of ATU, and protection by sediment structure in complex malodorous rivers. The high-throughput pyrosequencing analysis showed the AOB-related genus Nitrosomonas and Nitrosococcus were mostly affected by ATU in the enrichments and the river systems, respectively. The inhibition of ATU was realized mainly by reducing the abundance and activity of AOB. The decrease of the ratio of AOB/AOA amoA gene copy numbers after addition of ATU further confirmed the inhibiting effectiveness of ATU in complex microbial community of malodorous rivers.
正确使用选择性氨氧化古菌（AOA）和/或氨氧化细菌（AOB）抑制剂对于区分AOA和AOB的作用至关重要。在本研究中，考察了氨苄青霉素、双氰胺（DCD）和烯丙基硫脲（ATU）这三种抑制剂，主要关注其抑制剂量、适应性和效果。结果表明，氨苄青霉素、DCD和ATU的优化抑制剂量分别为1.5 g/L、1 mM和25 μM。在这三种抑制剂中，ATU表现出最强且持久的抑制效果，在富含AOB的培养物中导致高达90%的抑制率。ATU在模拟河流系统中看似减弱的抑制效果可归因于AOA的参与作用、ATU的空间分布不均以及复杂恶臭河流中沉积物结构的保护作用。高通量焦磷酸测序分析表明，与AOB相关的亚硝化单胞菌属和亚硝化球菌属在富集培养物和河流系统中分别主要受ATU影响。ATU的抑制作用主要通过降低AOB的丰度和活性来实现。添加ATU后AOB/AOA氨单加氧酶基因拷贝数比值的降低进一步证实了ATU在恶臭河流复杂微生物群落中的抑制效果。
