Han Ya-Nan, Yi Yang, Su Jian-Yu, Fang Chao, Sardans Jordi, Peñuelas Josep, Yang Fang-Kun
School of Life Sciences, Ningxia University, Yinchuan, 750021, China.
School of Life Sciences, Ningxia University, Yinchuan, 750021, China.
Environ Pollut. 2025 Aug 11;384:126977. doi: 10.1016/j.envpol.2025.126977.
Re-used plastic-film (RUPF) mulching has emerged as an innovative and practical agricultural practice to reduce plastic use and the buildup of plastic waste in drylands in China. However, alterations in bacterial community colonisation mechanisms and ecological processes due to plastic contamination in RUPF mulching systems remain unclear. In this study, we examined the distribution and assembly of soil bacterial communities under two RUPF exposure scenarios, weathered plastic film plastisphere (WPS) and soil-buried plastic film plastisphere (BPS), and compared them to no-mulching ambient soil (CK). The findings revealed that WPS differed significantly from CK and BPS in terms of soil bacterial alpha- and beta-diversity. Bacterial diversity was reduced in WPS, while BPS showed no significant change compared to CK. Moreover, stochastic processes primarily influenced bacterial community assembly across all environments, whereas deterministic processes had a more pronounced effect on plastispheres than on CK. In WPS, the migration and diffusion of colonising bacteria was slow, whereas bacterial competition was more pronounced in BPS. The co-occurrence networks in the plastispheres were more intricate and unstable than those in CK. There were notable differences in bacterial functions between the plastisphere and CK soils, carbohydrate metabolism, amino acid metabolism, lipid metabolism, and xenobiotic biodegradation and metabolism decreased in WPS; whereas lipid metabolism and xenobiotic biodegradation and metabolism increased in BPS compared to that in CK. Notably, the profiles of human disease-related pathways, virulence factors, and pathogens were significantly higher in the plastisphere than that in CK, with WPS showing higher levels than BPS. Overall, our results emphasise that WPS has a more distinct bacterial composition and function, heightening the potential ecological risks compared to CK and BPS. These findings highlight the need for effective strategies to mitigate the risks of reusing plastic films in agricultural environments.
废旧塑料薄膜（RUPF）覆盖已成为一种创新且实用的农业实践，可减少中国干旱地区的塑料使用量和塑料废弃物的积累。然而，RUPF覆盖系统中由于塑料污染导致的细菌群落定殖机制和生态过程的变化仍不清楚。在本研究中，我们研究了两种RUPF暴露情景下土壤细菌群落的分布和组装情况，即风化塑料薄膜生物球（WPS）和土壤掩埋塑料薄膜生物球（BPS），并将它们与无覆盖的环境土壤（CK）进行比较。研究结果表明，WPS在土壤细菌的α-和β-多样性方面与CK和BPS存在显著差异。WPS中的细菌多样性降低，而BPS与CK相比没有显著变化。此外，随机过程在所有环境中对细菌群落组装起主要影响，而确定性过程对生物球的影响比对CK更为显著。在WPS中，定殖细菌的迁移和扩散缓慢，而在BPS中细菌竞争更为明显。生物球中的共现网络比CK中的更为复杂和不稳定。生物球土壤和CK土壤之间的细菌功能存在显著差异，WPS中碳水化合物代谢、氨基酸代谢、脂质代谢以及外源生物降解和代谢减少；而与CK相比，BPS中脂质代谢以及外源生物降解和代谢增加。值得注意的是，生物球中与人类疾病相关的途径、毒力因子和病原体的谱显著高于CK，其中WPS的水平高于BPS。总体而言，我们的结果强调WPS具有更独特的细菌组成和功能，与CK和BPS相比，其潜在生态风险更高。这些发现凸显了需要采取有效策略来减轻农业环境中重复使用塑料薄膜的风险。
