Orimaco Rhys, Donnelly Pauric, Sexton Seán, McLoughlin Aoife, Kelly Sophie, O'Connor Kevin E, Wierckx Nick, Narančić Tanja
UCD Earth Institute and School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland.
BiOrbic - Bioeconomy Research Centre, Ireland, University College Dublin, Dublin 4, Ireland.
Microb Biotechnol. 2025 May;18(5):e70159. doi: 10.1111/1751-7915.70159.
In the search for biobased alternatives to traditional fossil plastics, 2,5-furandicarboxylic acid (FDCA) represents a potential substitute to terephthalic acid (TPA), a monomer of the ubiquitous polyester, polyethylene terephthalate (PET). Pseudomonas umsongensis GO16, which can metabolise TPA and ethylene glycol (EG), can also oxidise 5-hydroxymethylfurfural (HMF), a precursor to FDCA. The enzymes involved in the oxidation to FDCA, PsfA and PsfG, were identified and characterised. Deletion of FDCA decarboxylase HmfF involved in the conversion of FDCA to furoic acid, and subsequently to a central metabolic intermediate, 2-ketoglutarate, allowed for the accumulation of FDCA. GO16 ΔhmfF cells were grown on glycerol, TPA, EG or mock PET hydrolysate, and the catalyst was then used for the biotransformation of HMF to FDCA. When TPA was used as a growth substrate and to power the biotransformation, the transport of 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) into the cytoplasm represented a rate-limiting step in HMF oxidation. De-bottlenecking transport limitations through in trans overexpression of the HMFCA transporter (HmfT) along with the PsfA aldehyde dehydrogenase and PsfG alcohol dehydrogenase allowed 100% conversion of 50 mM HMF to FDCA within 24 h when TPA, EG or mock PET hydrolysate were used to grow the biocatalyst and subsequently to power the biotransformation. This expands the repertoire of valuable products obtained from engineered P. umsongensis GO16 in the strategy to bio-upcycle post-consumer PET.
在寻找传统化石塑料的生物基替代品的过程中，2,5-呋喃二甲酸（FDCA）是对苯二甲酸（TPA）的潜在替代品，TPA是无处不在的聚酯聚对苯二甲酸乙二酯（PET）的一种单体。能代谢TPA和乙二醇（EG）的温宋假单胞菌GO16也能氧化5-羟甲基糠醛（HMF），HMF是FDCA的前体。鉴定并表征了参与氧化生成FDCA的酶PsfA和PsfG。删除参与将FDCA转化为糠酸并随后转化为中心代谢中间体2-酮戊二酸的FDCA脱羧酶HmfF，可使FDCA积累。GO16 ΔhmfF细胞在甘油、TPA、EG或模拟PET水解产物上生长，然后将该催化剂用于HMF向FDCA的生物转化。当使用TPA作为生长底物并为生物转化提供能量时，5-羟甲基-2-呋喃甲酸（HMFCA）向细胞质的转运是HMF氧化的限速步骤。通过反式过表达HMFCA转运蛋白（HmfT）以及PsfA醛脱氢酶和PsfG醇脱氢酶消除转运限制，当使用TPA、EG或模拟PET水解产物培养生物催化剂并随后为生物转化提供能量时，可在24小时内将50 mM HMF 100%转化为FDCA。这扩展了从工程化温宋假单胞菌GO16获得的有价值产品的种类，用于生物循环利用消费后PET的策略。
