热带海洋学报

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一株海洋来源可降解聚氨酯的伊朗假单胞菌SCSIO 85019的分离鉴定及其降解特性

刘雨晴1,2,吴挺标3,邓诗静1,2,樊婷婷3,田新朋1,李青连1,4   

  1. 1. 热带海洋环境国家重点实验室(中国科学院南海海洋研究所), 广东 广州 510301;

    2. 中国科学院大学,北京,100049

    3. 医药健康技术与工程研究所(深圳湾实验室),广东,深圳,518132

    4. 广东药科大学生命科学与生物制药学院,广东 广州 510006

  • 收稿日期:2025-06-20 修回日期:2025-10-07 接受日期:2025-10-17
  • 通讯作者: 李青连
  • 基金资助:

    国家重点研发计划青年科学家项目(2023YFC3903300)

Isolation, Identification and Degradation Characteristics of a Marine-Derived Polyurethane-Degrading Pseudomonas iranensis Strain SCSIO 85019

LIU Yuqing 1,2, WU Tingbiao 3, DENG Shijing 1,2, FAN Tingting 3, TIAN Xinpeng 1, LI Qinglian1,4

2. 中国科学院大学,北京,100049

3. 医药健康技术与工程研究所(深圳湾实验室),广东,深圳,518132

4. 广东药科大学生命科学与生物制药学院,广东 广州 510006   

  1. 1. State Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture(South China Sea Institute of Oceanology), Guangzhou 510301, China

    2. University of Chinese Academy of Sciences, Beijing 100049, China

    3. Institute of Biomedical Health Technology and Engineering (Shenzhen Bay Laboratory), Shenzhen, 518132, China

    4. School of Life Science and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China

  • Received:2025-06-20 Revised:2025-10-07 Accepted:2025-10-17
  • Contact: Li, Qinglian
  • Supported by:
    National Key Research and Development Program of China for Young Scientists(2023YFC3903300)

摘要: 聚氨酯(polyurethane, PU)塑料凭借其独特的性质被广泛应用于各行各业,但其海洋环境中的积累产生了大量的微塑料,给海洋生态环境和人体健康带来了严重威胁。本研究从惠州大亚湾海洋沉积物中到一株能够降解PU的菌株SCSIO 85019,经过菌落形态观察和16S rRNA基因序列分析,鉴定为伊朗假单胞菌(Pseudomonas iranensis)。降解性能评价表明,该菌在最小无机盐培养基(minimal salt medium, MSM)平板上可同时降解水性聚酯型聚氨酯 ImpranilTM DLN 和固态聚酯型聚氨酯聚1,4-丁二醇己二酸酯基PU(Poly1,4-butylene adipate-based PU, PBA-PU),分别形成透明圈直径(H)与菌落直径(C)的比值(H/C)为1.6和2.0的显著透明水解圈。在液体MSM培养基中,菌株SCSIO 85019在30℃、pH 7.0条件下培养4天,对 0.1% (v/v) 的ImpranilTM DLN的降解率达到82.04%。以PBA-PU为底物,对菌株SCSIO 85019的降解上清液进行LC-MS分析,鉴定出己二酸、1,4-丁二醇以及4,4'-二氨基二苯甲烷衍生物等5个降解中间体产物,表明该菌可同时水解PBA-PU的酯键和氨酯键。通过胞外酶活实验和基因组生物信息学分析,筛选出3个可能参与PU酯键水解的酯酶(QXI20836.1、QXI21523.1和QXI24368.1)以及氨酯键断裂的1个脲酶(QXI23417.1)和1个蛋白酶(QXI23233.1),并推导了菌株SCSIO 85019降解PBA-PU的可能途径。本研究首次报道伊朗假单胞菌具有聚氨酯降解能力,并对菌株SCSIO 85019的降解特性进行表征,为海洋环境中微塑料的治理提供了菌种资源。

关键词: 聚氨酯, 海洋微塑料, 生物降解, 脲酶, 酯酶

Abstract: Polyurethane (PU) plastics are widely utilized across various industries owing to their unique properties. However, their accumulation in marine environments has resulted in the generation of substantial amounts of microplastics, posing serious threats to marine ecosystems and human health. In this study, a PU-degrading strain SCSIO 85019 was isolated and purified from marine sediments collected from Daya Bay, Huizhou. Based on colony morphological characteristics and 16S rRNA gene phylogenetic analysis, the strain was identified as Pseudomonas iranensis. Degradation capability assessment showed that this strain could degrade both aqueous polyester-polyurethane Impranil™ DLN and solid polyester-polyurethane (poly1,4-butylene adipate-based PU, PBA-PU) on minimal salt medium (MSM) plates, forming distinct hydrolysis zones with ratios of halo diameter (H) to colony diameter (C) of 1.6 and 2.0, respectively. In liquid MSM culture, after 4 days of incubation at 30°C and pH 7.0, strain SCSIO 85019 achieved a degradation rate of 82.04% for 0.1% (v/v) Impranil™ DLN. LC-MS analysis of PBA-PU degradation products identified five intermediate metabolites, including adipic acid, 1,4-butanediol, and 4,4'-methylenedianiline derivatives, indicating this strain could hydrolyze both ester and urethane bonds of PBA-PU. Through extracellular enzyme activity assays and genomic bioinformatics analysis, we identified three putative esterases (QXI20836.1, QXI21523.1, and QXI24368.1) potentially involved in ester bond hydrolysis, along with one urease (QXI23417.1) and one protease (QXI23233.1) likely responsible for urethane bond cleavage. A potential pathway for PBA-PU degradation by strain SCSIO 85019 was proposed. This study not only reports the first evidence of polyurethane degradation by Pseudomonas iranensis but also characterizes the degradation properties of its strain SCSIO 85019, thereby providing a valuable microbial resource for marine microplastic remediation.

Key words: Polyurethane, Marine microplastics, Biodegradation, Urease, Lipase.