CAJ | 학술논문

为明晰纳米金、银对环境中氨氧化细菌(AOB)的氨氧化作用影响机制,本文通过对驯化培养河口湿地表层沉积物所得到的氨氧化细菌(AOB)富集培养物进行纳米材料不同浓度的处理试验,测定氨氮、亚硝氮浓度和氨氧化速率的变化特征,并利用PCR-DGGE分子指纹图谱技术和qPCR方法分析不同试验中AOB的多样性与丰度信息,确定纳米金、银对氨氧化速率、氨氧化细菌多样性与丰度的影响规律.结果表明,纳米银对环境中氨氮的转化具有浓度抑制效应,随着浓度增加,氨氧化平均速率越低,氨氮转化越少.纳米银处理之间的氨氧化平均速率同氨氧化细菌(AOB)的香农与辛普森多样性指数、amoA 基因丰度存在显著正相关关系.因而纳米银对环境中氨氧化作用的抑制效应主要通过其杀菌能力影响了氨氧化菌的多样性和丰度而起作用.纳米金氨氧化平均速率则和AOB的多样性指数以及amoA基因丰度均无显著相关.纳米金对氨氧化细菌、氨氧化速率却不呈现浓度抑制效应,甚至出现略微促进氨氧化作用的趋势.DNA测序结果发现实验的氨氧化细菌都属于β-Proteobacteria,同Nitrosospira、Nitrosomonas亲源性较近.环境中的氨氧化微生物种类复杂,环境条件多变.不同纳米材料是如何影响氨氧化微生物进而影响氨氧化作用,仍需进行深入研究.
위명석납미금、은대배경중안양화세균(AOB)적안양화작용영향궤제,본문통과대순화배양하구습지표층침적물소득도적안양화세균(AOB)부집배양물진행납미재료불동농도적처리시험,측정안담、아초담농도화안양화속솔적변화특정,병이용PCR-DGGE분자지문도보기술화qPCR방법분석불동시험중AOB적다양성여봉도신식,학정납미금、은대안양화속솔、안양화세균다양성여봉도적영향규률.결과표명,납미은대배경중안담적전화구유농도억제효응,수착농도증가,안양화평균속솔월저,안담전화월소.납미은처리지간적안양화평균속솔동안양화세균(AOB)적향농여신보삼다양성지수、amoA 기인봉도존재현저정상관관계.인이납미은대배경중안양화작용적억제효응주요통과기살균능력영향료안양화균적다양성화봉도이기작용.납미금안양화평균속솔칙화AOB적다양성지수이급amoA기인봉도균무현저상관.납미금대안양화세균、안양화속솔각불정현농도억제효응,심지출현략미촉진안양화작용적추세.DNA측서결과발현실험적안양화세균도속우β-Proteobacteria,동Nitrosospira、Nitrosomonas친원성교근.배경중적안양화미생물충류복잡,배경조건다변.불동납미재료시여하영향안양화미생물진이영향안양화작용,잉수진행심입연구.
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 β-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.