TOXICITY OF SILVER NANOPARTICLES TO ACHROMOBACTER DENITRIFICANS
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摘要: 为研究纳米银(AgNPs)对反硝化无色杆菌(Achromobacter denitrificans)的毒性作用,选择室内培养方式,探究纳米银对Achromobacter denitrificans的生长抑制、氨化作用、同化吸收NH4+-N、细胞膜表面结构和活性氧生成的影响。研究发现,纳米银可抑制细菌生长,抑制效果与浓度和暴露时间呈正相关。添加10 mg/LAgNPs在硝化培养基中,Achromobacter denitrificans生长抑制率12h后达38.2%,而添加1 mg/LAgNPs时生长抑制率仅为11.5%。不同AgNPs暴露浓度条件下,4~6 h后生长抑制率均趋于稳定。暴露培养后的细菌生化活性降低,AgNPs投加浓度从1 mg/L提高到10 mg/L时,NH+4-N生成速率从2.77 mg/(L·h)降低至2.07 mg/(L·h),降低了25.3%;NH4+-N同化速率从5.52 mg/(L·h)降低至1.71 mg/(L·h),降低了69.1%。pH是影响毒性作用的重要因素,弱酸(pH 5.0)与弱碱(pH 9.0)均不利于细菌生存。通过毒性作用机理分析可知,纳米银可导致细胞膜表面凹陷破裂,膜内物质泄漏流出,细胞内发生活性氧的累积。Abstract: The indoor culture method was selected to study the toxic mechanism of AgNPs to Achromobacter denitrificans and the effects of silver nanoparticles on the growth inhibition, ammoniation, assimilation and absorption of NH4+-N, cell membrane surface structure and the accumulation of the reactive oxygen species. The study found that AgNPs could inhibit bacterial growth, and the inhibitory effect was positively related to concentration and exposure time. In the nitrification medium supplemented with 10 mg/LAgNPs, the growth inhibition rate of Achromobacter denitrificans reached 38.2% after 12 h, while the growth inhibition rate was only 11.5% when 1 mg/LAgNPs was added. Under different AgNPs exposure concentrations, the growth inhibition rates tended to be stable after 4~6 h. The biochemical activity of bacteria after exposure to AgNPs decreased. When the dosage of AgNPs increased from 1 mg/L to 10 mg/L, the NH+4-N generation rate decreased by 25.3%, from 2.77 mg/(L·h) to 2.07 mg/(L·h); NH4+-N assimilation rate decreased by 69.1%, from 5.52 mg/(L·h) to 1.71 mg/(L·h). Besides, pH was an important factor affecting the toxicity. Both weak acid(pH=5.0) and weak alkaline(pH=9.0) were not conducive to bacterial survival. Through the analysis of the mechanism of toxicity, we found that AgNPs can cause the depression and rupture of the cell membrane surface, the leakage of substances in the membrane, and the accumulation of reactive oxygen species in the cells.
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[1] VANCE M E,TODD K,VEJERANO E P,et al.Nanotechnology in the real world:redeveloping the nanomaterial consumer products inventory[J].Blstn Journal of Nanotechnology,2015,6:69-80. [2] STENSBERG M C,WEI Q S,MCLAMORE E S,et al.Toxicological studies on silver nanoparticles:challenges and opportunities in assessment,monitoring and imaging[J].Nanomedicine,2011,6(5):879-898. [3] CHEMOUSOVAS S,EPPLE M.Silver as antibacterial agent:ion,nanoparticle,and metal[J].Angewandte Chemie International Edition,2013,44(6):1636-1653. [4] LIU J Y,SONSHIN D A,SHERVANI S,et al.Controlled release of biologically active silver from nanosilver surfaces[J].ACS Nano,2010,4(11):6903-6913. [5] HWANG E T,JIN H L,YUN J C,et al.Analysis of the toxic mode of action of silver nanoparticles using stress-specific bioluminescent bacteria[J].Small,2010,4(6):746-750. [6] PARK E J,YI J,KIM Y,et al.Silver nanoparticles induce cytotoxicity by a Trojan-horse type mechanism[J].Toxicology in Vitro,2010,24(3):872-878. [7] JIANG X M,MICHU T,WANG L M,et al.Fast intracellular dissolution and persistent cellular uptake of silver nanoparticles in CHO-K1 cells:implication for cytotoxicity[J].Nanotoxicology,2015,9(2):181-189. [8] CHOI O,HU Z.Size dependent and reactive oxygen species related nanosilver toxicity to nitrifying bacteria[J].Environmental Science & Technology,2008,42(12):4583-4588. [9] 范俊楠,赵建伟,朱端卫.湖泊氮素氧化及脱氮过程研究进展[J].生态学报,2012,32(15):4924-4931. [10] LIANG Z H,DAS A,HU Z Q.Bacterial response to a shock load of nanosilver in an activated sludge treatment system[J].Water Research,2010,44(18):5432-5438. [11] YANG Y,CHEN Q,WALL J D,et al.Potential nanosilver impact on anaerobic digestion at moderate silver concentrations[J].Water Research,2012,46(4):1176-1184. [12] 伍玲丽,张晓雪,舒昆慧,等.两种粒径纳米银对Nitrosomonas europaea的毒性效应[J].中国环境科学,2019,39(10):4401-4408. [13] YANG Y,WANG J,XIU Z M,et al.Impacts of silver nanoparticles on cellular and transcriptional activity of nitrogen-cycling bacteria[J].Environmental Toxicology and Chemistry,2013,32(7):1488-1494. [14] DONG B,LIU G F,ZHOU J T,et al.Transformation of silver ions to silver nanoparticles mediated by humic acid under dark conditions at ambient temperature[J].Journal of Hazardous Materials,2020,383(Feb.5):121190.1-121190.9. [15] PERETYAZHKO T S,ZHANG Q B,COLVIN V L.Size-controlled dissolution of silver nanoparticles at neutral and acidic pH conditions:kinetics and size changes[J].Environmental Science & Technology,2014,48(20):11954-11961. [16] BORCH T,KRETZSCHMAR R,KAPPLER A,et al.Biogeochemical redox processes and their impact on contaminant dynamics[J].Environmental Science & Technology,2010,44(1):15-23. [17] RASOOL K,LEE D S.Inhibitory effects of silver nanoparticles on removal of organic pollutants and sulfate in an anaerobic biological wastewater treatment process[J].Journal of Nanoscience & Nanotechnology,2016,16(5):4456-4463. [18] YUAN Z H,LI J W,CUI L,et al.Interaction of silver nanoparticles with pure nitrifying bacteria[J].Chemosphere,2013,90(4):1404-1411. [19] LOO S L,KRANTZ W B,FANE A G,et al.Bactericidal mechanisms revealed for rapid water disinfection by superabsorbent cryogels decorated with silver nanoparticles[J].Environmental Science & Technology:ES&T,2015,49(4):2010-2018. [20] GORDON O,SLENTERS T V,BRUNETTO P S,et al.Silver coordination polymers for prevention of implant infection:thiol interaction,impact on respiratory chain enzymes,and hydroxyl radical induction[J].Antimicrobial Agents and Chemotherapy,2010,54(10):4208-4218. [21] YANG E J,KIM S,KIM J S,et al.Inflammasome formation and IL-1β release by human blood monocytes in response to silver nanoparticles[J].Biomaterials,2012,33(28):6858-6867.
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