Abstract:In order to understand the effects of silver and gold nanoparticles (nano-silver and nano-gold) on ammoxidation in the environment and its mechanisms involved, the AOB (ammonia-oxidizing bacteria) enrichment cultures, from surface sediments in Jiulong River estuary wetland in Fujian Province, China, were inoculated in media with different concentrations of nano-silver and nano-gold.Then the changes of ammonium nitrogen and nitrite nitrogen concentrations, and the ammoxidation rate were measured, and the AOB biodiversity and abundance were analyzed using the methods of molecular fingerprint technology of PCR-DGGE and qPCR.Results showed that nano-silver significantly inhibited ammoxidation in the environment, of which the average ammoxidation rate and the transformation of ammonium nitrogen decreased with increasing nano-silver concentration.Interestingly, the average ammoxidation rate was significantly correlated to AOB diversity indices (Shannon index and Simpson index) and AOB abundance.Obviously, the ammoxidation inhibition resulted primarily from the reduction of AOB biodiversity and abundance, which caused by the bactericidal ability of nano-silver.However, there was insignificant correlation between the AOB biodiversity and the abundance and ammoxidation average rate under the nano-gold treatment.And there was not inhibition upon AOB and ammoxidation average rate, yet a slight promotion of ammoxidation with nano-gold.The DNA sequencing found that the AOB tested in this study was belonged to b-Proteobacteria, closing to Nitrosospira or Nitrosomonas.Undoubtedly, the species of AOB in the environment is complicated, and the ambient conditions are various as well.Therefore, more attention is still needed to be paid to how and to what extent different nanomaterials impact AOB diversity and abundance and in turn ammoxidation.
陈铮, 罗专溪, 邱昭政, 颜昌宙. 纳米金、银对氨氧化细菌及其氨氧化作用的影响[J]. 中国环境科学, 2014, 34(3): 705-712.
CHEN Zheng, LUO Zhuan-Xi, QIU Zhao-Zheng, YAN Chang-Zhou. Effects of silver and gold nanoparticles on ammonia-oxidizing bacteria and its ammoxidation. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(3): 705-712.