Hsu Chih-Ting, Kuo Yang-Cheng, Liu Yu-Cheng, Tsai Shen-Long
Department of Chemical Engineering, National Taiwan University of Science and Technology, No.43, Keelung Rd., Sec.4, Da'an Dist., Taipei City, 10607, Taiwan.
Chemical Division, Institute of Nuclear Energy Research, 1000 Wenhua Rd. Jiaan Village, Longtan District, Taoyuan City, 32546, Taiwan.
Microb Biotechnol. 2020 Jul;13(4):1094-1102. doi: 10.1111/1751-7915.13564. Epub 2020 Mar 31.
Transforming petrochemical processes into bioprocesses has become an important goal of sustainable development. The chemical synthesis of 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) is expensive and environmentally unfavourable. The study aims to investigate a whole-cell biocatalyst for efficient biotransformation of HMF to FDCA. For the first time, a genetically engineered Pseudomonas putida S12 strain expressing 5-hydroxymethylfurfural oxidase (HMFO) was developed for the biocatalytic conversion of HMF to FDCA. This whole-cell biocatalyst produced 35.7 mM FDCA from 50 mM HMF in 24 h without notable inhibition. However, when the initial HMF concentration was elevated to 100 mM, remarkable inhibition on FDCA production was observed, resulting in a reduction of FDCA yield to 42%. We solve this substrate inhibition difficulty by increasing the inoculum density. Subsequently, we used a fed-batch strategy by maintaining low HMF concentration in the culture to maximize the final FDCA titre. Using this approach, 545 mM of FDCA was accumulatively produced after 72 hs, which is the highest production rate per unit mass of cells to the best of our knowledge.
将石化过程转变为生物过程已成为可持续发展的一个重要目标。由5-羟甲基糠醛（HMF）化学合成2,5-呋喃二甲酸（FDCA）成本高昂且不利于环境。本研究旨在探究一种用于将HMF高效生物转化为FDCA的全细胞生物催化剂。首次构建了一种表达5-羟甲基糠醛氧化酶（HMFO）的基因工程恶臭假单胞菌S12菌株，用于将HMF生物催化转化为FDCA。这种全细胞生物催化剂在24小时内可从50 mM的HMF中产生35.7 mM的FDCA，且无明显抑制作用。然而，当初始HMF浓度提高到100 mM时，观察到对FDCA产生有显著抑制，导致FDCA产量降至42%。我们通过增加接种密度解决了这种底物抑制难题。随后，我们采用补料分批策略，在培养过程中维持低HMF浓度，以最大化最终的FDCA产量。采用这种方法，72小时后累计产生了545 mM的FDCA，据我们所知，这是单位质量细胞的最高生产率。
