Expression, purification and characterization of a novel bis (hydroxyethyl) terephthalate hydrolase from <i>Hydrogenobacter thermophilus</i>.

Yangyang Chen; Jian Gao; Yipei Zhao; Hao Wang; Xu Han; Jie Zhang; Qun GU; Ying Hou; Weidong Liu

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Expression, purification and characterization of a novel bis (hydroxyethyl) terephthalate hydrolase from Hydrogenobacter thermophilus.

Author: Yangyang CHEN ¹ ; Jian GAO ² ; Yipei ZHAO ² ; Hao WANG ² ; Xu HAN ² ; Jie ZHANG ² ; Qun GU ² ; Ying HOU ¹ ; Weidong LIU ¹
Author Information

1. College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471000, Henan, China.
2. National Engineering Center for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Publication Type:Journal Article
Keywords: bis(hydroxyethyl) terephthalate (BHET); enzymatic properties; expression and purification; hydrolase
MeSH: Hydrolases/metabolism*; Bacteria/metabolism*; Hydrolysis; Polyethylene Terephthalates/metabolism*
From: Chinese Journal of Biotechnology 2023;39(5):2015-2026
CountryChina
Language:Chinese
Abstract: PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.