Lin Jingwei, Sun Kexin, Ma Li, Li Chunwang, Tong Haibin, Wang Zhanyong
College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China.
Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, China.
J Environ Manage. 2025 Feb;375:124288. doi: 10.1016/j.jenvman.2025.124288. Epub 2025 Jan 23.
Polybutylene succinate (PBS), a biodegradable plastic, can be used as an alternative to traditional plastics to effectively solve the growing plastic pollution. Although PBS is theoretically completely biodegradable, slow degradation remains a problem in practical applications, leading to the possibility of environmental pollution. In this study, after the PBS degradation ability of the fungus Paraphoma chrysanthemicola was determined, a P. chrysanthemicola cutinase (PCC) gene was cloned and expressed in Pichia pastoris and its PBS degradation ability was further characterized. With a molecular weight of approximately 20 kDa, PCC showed good PBS degradation activity at pH 6.0-8.0 and 20-40 °C. Metal ions have different effects on PCC activity. Specifically, Ca, Zn, and Co promoted enzyme activity, whereas Cu, Fe, and Ni inhibited enzyme activity. The weight loss of the PBS films was greater than 50% after 60 h of PCC treatment, and scanning electron microscopy revealed the appearance of cracks on the surface of the PBS films during the degradation process, which deepened with the progression of degradation time. This PBS degradation by PCC occurs via surface erosion, with the resulting degradation products being mainly 1,4-succinic acid and succinic acid butanediyl ester. This study provides a preliminary elucidation of the enzymatic mechanisms involved in PBS degradation by PCC and offers insights into the development of more effective biotechnological approaches to address the environmental challenges associated with plastic waste.
聚丁二酸丁二醇酯（PBS）是一种可生物降解的塑料，可作为传统塑料的替代品，有效解决日益严重的塑料污染问题。尽管PBS理论上可完全生物降解，但在实际应用中降解缓慢仍是一个问题，这可能导致环境污染。在本研究中，测定了真菌菊苣拟茎点霉对PBS的降解能力后，克隆了菊苣拟茎点霉角质酶（PCC）基因并在毕赤酵母中表达，进一步表征了其对PBS的降解能力。PCC分子量约为20 kDa，在pH 6.0 - 8.0和20 - 40°C条件下表现出良好的PBS降解活性。金属离子对PCC活性有不同影响。具体而言，Ca、Zn和Co促进酶活性，而Cu、Fe和Ni抑制酶活性。经PCC处理60小时后，PBS薄膜的失重超过50%，扫描电子显微镜显示在降解过程中PBS薄膜表面出现裂缝，且随着降解时间的推移裂缝加深。PCC对PBS的降解通过表面侵蚀发生，产生的降解产物主要是1,4 - 琥珀酸和丁二酸丁二醇酯。本研究初步阐明了PCC降解PBS的酶促机制，并为开发更有效的生物技术方法以应对与塑料垃圾相关的环境挑战提供了见解。
