Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Bioresour Technol. 2021 Feb;322:124530. doi: 10.1016/j.biortech.2020.124530. Epub 2020 Dec 11.
Microalga served as the promising bioresources due to the high efficiency of carbon dioxide conversion. However, the application of microalga is still restricted by low biomass, easier contamination, and high cost of production. To overcome the challenge, engineered Chlamydomonas reinhardtii CC-400 with pyridoxal kinase gene (pdxY) has demonstrated in this study. The results indicated CC-400 with pdxY reached enhanced algal biomass in three different systems, including flask, Two-layer Photo-Reactor (TPR) and airlift Photo-Bioreactor (PBR). The genetic strain PY9 cultured with 1% CO in the PBR showed a significant enhancement of biomass up to 1.442 g/L, a 2-times of that of the wild type. We also found the transcriptional levels of carbonic anhydrase (CA) dropped down in PY9 while higher levels of RuBisCo and pdxY occurred, thus the carbon dioxide assimilation under mixotrophic culture dramatically increased. We proofed that pdxY successfully mediated carbon dioxide utilization in CC-400.
微藻由于其高效的二氧化碳转化效率，被视为有前途的生物资源。然而，由于生物量低、易污染和生产成本高，微藻的应用仍然受到限制。为了克服这一挑战，本研究构建了带有吡哆醛激酶基因（pdxY）的工程化莱茵衣藻 CC-400。结果表明，在三种不同的系统（摇瓶、双层光生物反应器（TPR）和气升式光生物反应器（PBR））中，带有 pdxY 的 CC-400 能够提高藻类生物量。在 PBR 中用 1%CO2 培养的基因工程菌株 PY9 的生物量显著提高，达到 1.442 g/L，是野生型的 2 倍。我们还发现，在 PY9 中碳酸酐酶（CA）的转录水平下降，而 RuBisCo 和 pdxY 的水平升高，因此在混合营养培养下，二氧化碳的同化作用显著增加。我们证明了 pdxY 能够成功地介导 CC-400 中二氧化碳的利用。
