Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece.
Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece.
Regul Toxicol Pharmacol. 2019 Jun;104:59-73. doi: 10.1016/j.yrtph.2019.03.004. Epub 2019 Mar 11.
The biological activity induced by the extractable organic matter (EOM) of size-segregated airborne Particulate Matter (PM) from two urban sites, urban traffic (UT) and urban background (UB), was assessed by using bacterial assays. The Gram-negative Escherichia coli (E. coli) coliform bacterium was used to measure the intracellular formation of Reactive Oxygen Species (ROS) by employing the Nitroblue tetrazolium (NBT) reduction assay and the lipid peroxidation by malondialdehyde (MDA) measurement. To the best of our knowledge, this is the first study using E. coli for assessing the bioactivity of ambient air in term of oxidative mechanism studies. E. coli BL21 cells were further used for DNA damage assessment by employing the reporter (β-galactosidase) gene expression assay. The bacterial strain S. typhimurium TA100 was used to assess the mutagenic potential of PM by employing the well-known mutation assay (Ames test). Four PM size fractions were assessed for bioactivity, specifically the quasi-ultrafine mode (<0.49 μm), the upper accumulation mode (0.49-0.97 μm), the upper fine mode (0.97-3 μm), and the coarse mode (>3.0 μm). The EOM of each PM sample included three organic fractions of successively increased polarity: the non-polar organic fraction (NPOF), the moderately polar organic fraction (MPOF), and the polar organic fraction (POF). The toxicological endpoints induced by each organic fraction were correlated with the concentrations of various organic chemical components determined in previous studies in an attempt to identify the chemical classes involved.
采用细菌测定法评估了来自两个城市地点（城市交通（UT）和城市背景（UB））的大小分离的空气颗粒物（PM）可提取有机物（EOM）所诱导的生物活性。革兰氏阴性大肠杆菌（E. coli）大肠埃希氏菌被用来通过使用硝基四氮唑蓝（NBT）还原测定法测量细胞内活性氧（ROS）的形成以及通过丙二醛（MDA）测量来测量脂质过氧化。据我们所知，这是首次使用大肠杆菌来评估环境空气中的生物活性，以进行氧化机制研究。进一步使用大肠杆菌 BL21 细胞通过使用报告（β-半乳糖苷酶）基因表达测定法评估 DNA 损伤。使用众所周知的突变测定法（Ames 测试），使用鼠伤寒沙门氏菌 TA100 菌株评估 PM 的致突变潜力。评估了四个 PM 粒径范围的生物活性，特别是准超细模式（<0.49μm）、上积累模式（0.49-0.97μm）、上细模式（0.97-3μm）和粗模式（>3.0μm）。每个 PM 样品的 EOM 包括三个有机部分，其极性依次增加：非极性有机部分（NPOF）、中等极性有机部分（MPOF）和极性有机部分（POF）。先前研究中确定的各种有机化学组分的浓度相关联，试图确定涉及的化学类别。
