摘要：Fossil-based polypropylene (PP) is notoriously resistant to biodegradation. Limited studies have focused on degradation of PP by surface environment sourced microorganisms, following pretreatments to facilitate the biodegradation. In this study, the subterranean oil reservoir sourced strain Pseudomonas aeruginosa XJ16, was firstly applied to degrade an unpretreated polypropylene microplastic (PPMP) and an unpretreated agricultural polypropylene film (APPF). After 120 days, biodegradation ratios of the unpretreated PPMP and unpretreated APPF reached to 11.1 +/- 0.5 % and 23.5 +/- 0.5 %, respectively, with 98 % of the biodegraded parts were transferred into liquid organic compounds and only 0.2 % were transferred into CO2. Biofilm formation and microbial deterioration of the plastic surfaces were observed by scanning electron microscopy. Hydrophilic transformation of the polymers was observed using water contact angle, and confirmed by the oxidation-induced hydrophilic functional groups (-OH, C--O) detected by Fourier-transform infrared spectroscopy and pyrolysis-gas chromatography-mass spectrometry. Molecular weight reductions determined by high temperature gel permeation chromatography, together with various intermediate products containing alkanes, alcohols and acids detected by GC-MS, indicated the depolymerization and oxidation of carbon chains. The biodegradation induced thermal stability reductions were also monitored and verified by thermogravimetry analysis. Upmost, a novel oxidation mechanism occurring at the branched methyl groups (C6-C15) on the main polypropylene chain was confirmed based on the comprehensive characterizations. These results suggested that the bacterium P. aeruginosa XJ16 exhibited strong degradation ability and a novel degradation mechanism on unpretreated PP plastics, which may contribute new insight into the application of oil reservoir microorganisms to solve plastic pollutions in an underlying mechanism.

关键字：Polypropylene; Microplastics; Pseudomonas aeruginosa; Oil reservoir microorganisms; Branched methyl oxidation

ISSN号：2213-2929

卷、期、页：卷: 13期: 6

发表日期：2025-12-01

影响因子：0.000000

期刊分区（SCI为中科院分区）：二区

收录情况：SCIE（科学引文索引网络版）,EI（工程索引）

发表期刊名称：JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING

参与作者：Zhong, Zhe Ke

通讯作者：Li, Sheng Jin,Zhu, Ying Jia,Mu, Hong Mei

第一作者：万云洋,师生宝

论文类型：期刊论文

论文概要：Li, Sheng Jin,万云洋,Zhong, Zhe Ke,Zhu, Ying Jia,Mu, Hong Mei,师生宝，Biodegradation of unpretreated polypropylene microplastic and agricultural polypropylene film by a bacterium isolated from an oil reservoir，JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING，2025，卷: 13期: 6

论文题目：Biodegradation of unpretreated polypropylene microplastic and agricultural polypropylene film by a bacterium isolated from an oil reservoir