Department of Environmental Engineering, Korea Maritime and Ocean University, Busan, 49112, South Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, Busan, 49112, South Korea.
Department of Environmental Engineering, Korea Maritime and Ocean University, Busan, 49112, South Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, Busan, 49112, South Korea.
Environ Pollut. 2024 Mar 1;344:123450. doi: 10.1016/j.envpol.2024.123450. Epub 2024 Jan 25.
Several studies have focused on identifying and quantifying suspended plastics in surface and subsurface seawater. Microplastics (MPs) have attracted attention as carriers of antibiotic resistance genes (ARGs) in the marine environment. Plastispheres, specific biofilms on MP, can provide an ideal niche to spread more widely through horizontal gene transfer (HGT), thereby increasing risks to ecosystems and human health. However, the microbial communities formed on different plastic types and ARG abundances during exposure time in natural marine environments remain unclear. Four types of commonly used MPs (polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC)) were periodically cultured (46, 63, and 102 d) in a field-based marine environment to study the co-selection of ARGs and microbial communities in marine plastispheres. After the first 63 d of incubation (p < 0.05), the initial 16S rRNA gene abundance of microorganisms in the plastisphere increased significantly, and the biomass subsequently decreased. These results suggest that MPs can serve as vehicles for various microorganisms to travel to different environments and eventually provide a niche for a variety of microorganisms. Additionally, the qPCR results showed that MPs selectively enriched ARGs. In particular, tetA, tetQ, sul1, and qnrS were selectively enriched in the PVC-MPs. The abundances of intl1, a mobile genetic element, was measured in all MP types for 46 d (5.22 × 10 ± 8.21 × 10 copies/16s rRNA gene copies), 63 d (5.90 × 10 ± 2.49 × 10 copies/16s rRNA gene copies), and 102 d (4.00 × 10 ± 5.11 × 10 copies/16s rRNA gene copies). Network analysis indicated that ARG profiles co-occurred with key biofilm-forming bacteria. This study suggests that the selection of ARGs and their co-occurring bacteria in MPs could potentially accelerate their transmission through HGT in natural marine plastics.
已有多项研究聚焦于识别和量化海表和次表层海水中的悬浮塑料。微塑料（MPs）作为海洋环境中抗生素耐药基因（ARGs）的载体而备受关注。塑料球，即 MP 上的特定生物膜，可以提供一个理想的小生境，通过水平基因转移（HGT）更广泛地传播，从而增加对生态系统和人类健康的风险。然而，在自然海洋环境中，不同塑料类型和暴露时间下形成的微生物群落以及 ARG 丰度仍不清楚。本研究采用聚乙烯（PE）、聚丙烯（PP）、聚苯乙烯（PS）和聚氯乙烯（PVC）这四种常用的 MPs 类型，在基于野外的海洋环境中进行周期性培养（46、63 和 102 d），以研究海洋塑料球中的 ARG 和微生物群落的共同选择。在培养的前 63 d（p < 0.05），塑料球中微生物的 16S rRNA 基因丰度显著增加，随后生物量下降。这些结果表明 MPs 可以作为各种微生物迁移到不同环境的载体，最终为各种微生物提供小生境。此外，qPCR 结果表明 MPs 选择性富集 ARGs。特别是 tetA、tetQ、sul1 和 qnrS 选择性富集在 PVC-MPs 中。在所有 MPs 类型中，46 d（5.22×10±8.21×10 拷贝/16S rRNA 基因拷贝）、63 d（5.90×10±2.49×10 拷贝/16S rRNA 基因拷贝）和 102 d（4.00×10±5.11×10 拷贝/16S rRNA 基因拷贝）均检测到移动遗传元件 intl1 的丰度。网络分析表明，ARG 谱与关键的生物膜形成细菌共同发生。本研究表明，在 MPs 中 ARGs 的选择及其共存细菌可能通过 HGT 加速其在天然海洋塑料中的传播。
