Ko Kyung-Seok, Ha Kyoochul, Kong In Chul
Groundwater Department, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 34132, Korea.
Department of Environmental Engineering, Yeungnam University, Gyeongbuk 38541, Korea.
Int J Mol Sci. 2015 Nov 24;16(11):27967-77. doi: 10.3390/ijms161126066.
The potential effects of monotypic and binary metal oxide nanoparticles (NPs, ZnO, NiO, Co₃O₄ and TiO₂) on microbial growth were evaluated in sandy soil collected from artificial recharge sites. Microbial growth was assessed based on adenosine triphosphate (ATP) content, dehydrogenase activity (DHA), and viable cell counts (VCC). Microbial growth based on ATP content and VCC showed considerable differences depending on NP type and concentration, whereas DHA did not significantly change. In general, ZnO NPs showed the strongest effect on microbial growth in all measurements, showing an EC50 value of 10.9 mg/L for ATP content. The ranking (EC50) of NPs based on their effect on microbial growth assessed by ATP content and VCC was ZnO > Co₃O₄ > NiO > TiO₂. Upon exposure to binary NP mixtures, synergistic and additive modes of action were observed for ATP content and VCC, respectively. The ranges of observed (P(O)) and expected (P(E)) activity were 83%-92% and 78%-82% of the control (p-value 0.0010) based on ATP content and 78%-95% and 72%-94% of the control (p-value 0.8813) based on VCC under the tested conditions, respectively. The results indicate that the effects of NP mixtures on microbial growth in the sandy soil matrix were as great, or greater, than those of single NPs. Therefore, understanding the effects of single NPs and NP mixtures is essential for proper ecological risk assessment. Additionally, these findings demonstrate that the evaluation of NP effects may be profoundly influenced by the method of microbial growth measurement.
在从人工补给点采集的沙质土壤中，评估了单金属和双金属氧化物纳米颗粒（NPs，氧化锌、氧化镍、四氧化三钴和二氧化钛）对微生物生长的潜在影响。基于三磷酸腺苷（ATP）含量、脱氢酶活性（DHA）和活细胞计数（VCC）评估微生物生长情况。基于ATP含量和VCC的微生物生长情况因纳米颗粒类型和浓度的不同而存在显著差异，而DHA没有显著变化。总体而言，在所有测量中，氧化锌纳米颗粒对微生物生长的影响最强，ATP含量的半数效应浓度（EC50）值为10.9mg/L。基于ATP含量和VCC评估，纳米颗粒对微生物生长影响的排名（EC50）为氧化锌>四氧化三钴>氧化镍>二氧化钛。暴露于双金属纳米颗粒混合物后，ATP含量和VCC分别观察到协同和相加作用模式。在测试条件下，基于ATP含量，观察到的（P(O)）和预期的（P(E)）活性范围分别为对照的83%-92%和78%-82%（p值0.0010），基于VCC则分别为对照的78%-95%和72%-94%（p值0.8813）。结果表明，纳米颗粒混合物对沙质土壤基质中微生物生长的影响与单一纳米颗粒的影响相当，甚至更大。因此，了解单一纳米颗粒和纳米颗粒混合物的影响对于进行恰当的生态风险评估至关重要。此外，这些发现表明，纳米颗粒影响的评估可能会受到微生物生长测量方法的深刻影响。
