Lee Yen-Ju, Yi Ying-Chen, Lin Yu-Chieh, Chen Chao-Chung, Hung Jia-Horung, Lin Jia-Yi, Ng I-Son
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.
Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Bioresour Bioprocess. 2022 Jun 16;9(1):68. doi: 10.1186/s40643-022-00557-9.
5-Aminolevulinic acid (5-ALA) is a non-proteinogenic amino acid which has involved in heme metabolism of organisms, and has been widely applied in agriculture, and medical fields nowadays. 5-ALA is used in the elimination of pathogens or cancer cells by photodynamic therapy (PDT) owing to the photosensitizer reaction which releases the reactive oxygen species (ROS). Currently, biofabrication of 5-ALA is regarded as the most efficient and eco-friendly approach, but the complicated ingredient of medium causes the nuisance process of purification, resulting in low recovery and high producing cost. In this study, hydrogen chloride, sodium acetate, and ammonia were examined to maximize the recovery of 5-ALA from ion-exchange chromatography (IEC), thus a 92% recovery in 1 M ammonia at pH 9.5 was obtained. Afterward, the activated carbon was used for decolorization to further remove the pigments from the eluent. Four organic solvents, i.e., diethyl ether, methanol, ethanol, and acetone were compared to extract and form 5-ALA precipitation. The purified 5-ALA was verified to eliminate 74% of A549 human lung cancer and 83% of A375 melanoma skin cancer cell. Moreover, Proteus hauseri, Aeromonas hydrophila, Bacillus cereus, and Staphylococcus aureus were killed via anti-microbial PDT with 1% 5-ALA and reached 100% killing rate at optimal condition. With the addition of 0.05% 5-ALA during the culture, the growth of microalgae Chlorella sorokiniana was improved to against a common aquatic pathogen, A. hydrophila. The broad application of 5-ALA was demonstrated in this study for the first time.
5-氨基乙酰丙酸（5-ALA）是一种非蛋白质氨基酸，参与生物体的血红素代谢，如今已广泛应用于农业和医学领域。由于光动力疗法（PDT）中5-ALA作为光敏剂会释放活性氧（ROS），因此可用于消除病原体或癌细胞。目前，5-ALA的生物制造被认为是最有效且环保的方法，但培养基成分复杂导致纯化过程繁琐，回收率低且生产成本高。在本研究中，对氯化氢、醋酸钠和氨进行了考察，以最大化从离子交换色谱（IEC）中回收5-ALA，从而在pH 9.5的1 M氨中获得了92%的回收率。随后，使用活性炭进行脱色，以进一步去除洗脱液中的色素。比较了四种有机溶剂，即乙醚、甲醇、乙醇和丙酮，用于萃取并形成5-ALA沉淀。经证实，纯化后的5-ALA可消除74%的人肺癌A549细胞和83%的黑色素瘤皮肤癌A375细胞。此外，通过1%的5-ALA进行抗菌光动力疗法可杀死豪氏变形杆菌、嗜水气单胞菌、蜡样芽孢杆菌和金黄色葡萄球菌，在最佳条件下杀灭率达到100%。在培养过程中添加0.05%的5-ALA，可促进小球藻对常见水生病原体嗜水气单胞菌的抗性生长。本研究首次证明了5-ALA的广泛应用。
