Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Bioresour Technol. 2023 Nov;387:129599. doi: 10.1016/j.biortech.2023.129599. Epub 2023 Jul 31.
Chlorella sorokiniana (CS) is a prominent microalga with vast potential as a biocarrier for carbon mitigation toward a green process. However, challenges remain in achieving high biomass levels and production rates. Therefore, a systematic feeding strategy using 4-aminobutyric acid (GABA) and CRISPR technology was applied to improve microalgal productivity. At first, GABA increased protein content by 1.4-fold, while intermittent supplementation during cultivation resulted in a 1.58-fold and 2.13-fold increase in biomass and pigment content, respectively. Under halophilic conditions, the optimal approach involved repeated feeding of 5 mM GABA at the initial and mid-log phases of growth, resulting in biomass, protein, and pigment levels of 6.74 g/L, 3.24 g/L, and 49.87 mg/L. CRISPRa mediated glutamate synthase and using monosodium glutamate (MSG) as a cheap precursor for GABA has effectively enhanced the biomass, protein, and lutein content, thus offers a cost-effective approach to commercialize high-valued chemical using algae towards a low-carbon paradigm.
盐藻（Chlorella sorokiniana，CS）是一种重要的微藻，具有作为生物碳载体以实现绿色减排过程的巨大潜力。然而，要实现高生物质水平和生产速率仍然存在挑战。因此，采用 4-氨基丁酸（GABA）和 CRISPR 技术的系统喂养策略被应用于提高微藻的生产力。首先，GABA 将蛋白含量提高了 1.4 倍，而在培养过程中进行间歇性补充则使生物量和色素含量分别增加了 1.58 倍和 2.13 倍。在嗜盐条件下，最佳方法是在生长的初始和对数中期阶段重复添加 5 mM GABA，可得到 6.74 g/L 的生物量、3.24 g/L 的蛋白和 49.87 mg/L 的色素。通过 CRISPRa 介导的谷氨酸合酶和使用谷氨酸单钠（MSG）作为 GABA 的廉价前体，有效地提高了生物量、蛋白和叶黄素的含量，从而为利用藻类实现低碳范式下的高附加值化学品的商业化提供了一种具有成本效益的方法。
