School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China.
Sci Total Environ. 2023 Jan 15;856(Pt 2):159211. doi: 10.1016/j.scitotenv.2022.159211. Epub 2022 Oct 5.
Microfibers (MFs) are widely existed in indoor air; however, characteristic of microbiota on MFs is largely unknown. In this study, air-borne MFs were collected from fallout or air-conditioner (AC) filter dust in three types of indoor space including living room, dormitory and office. Both plastic and natural MFs were identified by Fourier transform infrared spectroscopy. Ultramicroscopic observation showed dense biofilms adhering on surfaces of MFs. Fallout MFs contained more bacteria but fewer fungi than MFs from AC filter dust. MFs-loaded bacteria were of highest abundance in living rooms, following dormitories and offices. Bacterial community and its diversity were further analyzed by 16S rRNA High-throughput sequencing. Up to 4540 of bacterium OTUs were shared in these MFs samples, unique OTUs in fallout and AC filter samples accounting for 26.3 % and 25.7 % of the total. Compared to MFs fallout, AC filter MFs contained more species of pathogenic bacteria, such as Betaproteobacteriales and Ralstonia, with obviously different β-diversity between two groups. Phenotypic analysis showed that fallout and AC filter MFs bacteria presented high index values of film formation, oxidative stress tolerance and potential pathogenicity. Overall, these results suggest that abundant bacteria including pathogen can be loaded on MFs, and would pose health risks through delivery of indoor MFs.
微纤维（MFs）广泛存在于室内空气中；然而，MFs 上微生物的特征在很大程度上是未知的。在这项研究中，从客厅、宿舍和办公室三种室内空间的沉降物或空调（AC）过滤器灰尘中收集了空气传播的 MFs。傅里叶变换红外光谱法鉴定了塑料和天然 MFs。超微观察表明，密集的生物膜附着在 MFs 的表面上。沉降 MFs 中含有的细菌比来自 AC 过滤器灰尘的 MFs 多，但真菌少。负载 MFs 的细菌在客厅中丰度最高，其次是宿舍和办公室。通过 16S rRNA 高通量测序进一步分析了细菌群落及其多样性。这些 MFs 样本中共有 4540 个细菌 OTUs，沉降和 AC 过滤器样本中的特有 OTUs 分别占总数的 26.3%和 25.7%。与沉降 MFs 相比，AC 过滤器 MFs 含有更多种类的致病菌，如β变形菌纲和罗尔斯通氏菌，两组之间的β多样性明显不同。表型分析表明，沉降和 AC 过滤器 MFs 细菌的成膜、氧化应激耐受和潜在致病性指数值较高。总的来说，这些结果表明，大量的细菌，包括病原体，可以负载在 MFs 上，并通过室内 MFs 的传播对健康构成威胁。
