State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China.
BMC Biotechnol. 2023 Aug 29;23(1):33. doi: 10.1186/s12896-023-00794-6.
Dopamine is high-value compound of pharmaceutical interest, but its industrial scale production mostly focuses on chemical synthesis, possessing environment pollution. Bio-manufacturing has caused much attention for its environmental characteristic. Resting cells were employed to as biocatalysts with extraordinary advantages like offering stable surroundings, the inherent presence of expensive cofactors. In this study, whole-cell bioconversion was employed to convert dopa to dopamine. To increase the titer and yield of dopamine production through whole-cell catalysis, three kinds of aromatic amino acid transport protein, AroP, PheP and TyrP, were selected to be co-expressed. The effects of the concentration of L-dopa, pyridoxal-5'- phosphate (PLP), reaction temperature and pH were characterized for improvement of bioconversion. Under optimal conditions, dopamine titer reached 1.44 g/L with molar yield of 46.3%, which is 6.62 times than that of initial conditions. The catalysis productivity of recombinant E. coli co-expressed L-dopa decarboxylase(DDC) and AroP was further enhanced by repeated cell recycling, which maintained over 50% of its initial ability with eight consecutive catalyses. This study was the first to successfully bioconversion of dopamine by whole-cell catalysis. This research provided reference for whole-cell catalysis which is hindered by cell membrane.
多巴胺是具有医药价值的高附加值化合物，但工业规模生产主要集中在化学合成上，存在环境污染问题。生物制造因其环境友好的特点引起了广泛关注。固定化细胞作为生物催化剂具有许多独特的优势，如提供稳定的环境、固有存在昂贵的辅因子。在本研究中，采用全细胞生物转化法将多巴转化为多巴胺。为了通过全细胞催化提高多巴胺生产的产量和产率，选择了三种芳香族氨基酸转运蛋白 AroP、PheP 和 TyrP 进行共表达。考察了 L-多巴、吡哆醛-5'-磷酸（PLP）、反应温度和 pH 值对生物转化的影响，以优化条件。在最优条件下，多巴胺的产量达到 1.44 g/L，摩尔产率为 46.3%，是初始条件的 6.62 倍。通过重复细胞回收，进一步提高了共表达 L-多巴脱羧酶（DDC）和 AroP 的重组大肠杆菌的催化产率，连续 8 次催化后仍保持初始能力的 50%以上。本研究首次成功地实现了全细胞催化多巴胺的生物转化。本研究为全细胞催化提供了参考，克服了细胞膜的阻碍。
