Sakuragawa Taku, Wakai Satoshi, Zhang Silai, Kawaguchi Hideo, Ogino Chiaki, Kondo Akihiko
Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan; Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
J Biosci Bioeng. 2021 Aug;132(2):140-147. doi: 10.1016/j.jbiosc.2021.03.017. Epub 2021 Apr 23.
Recently, a hyphae-dispersed type of filamentous fungus Aspergillus oryzae was constructed via genetic engineering, and industrial applications are expected due to the ease of handling and to the level of protein production properties. In this study, we constructed cellulase-expressing strains using wild-type and hyphae-dispersed strains to investigate the correlation between protein productivity and metabolism. Compared with the original strain, the hyphae-dispersed cellulase-expressing strain showed elevated cellulase activity, rapid glucose consumption, increased mycelial dry weight, an increased expression of cellulase genes, and activated respiration activity. Comparative metabolomic analysis showed fewer metabolites in the glycolysis and TCA cycles in the dispersed strains than in the original strains. These results indicate that the flux of carbohydrate metabolism in the hyphae-dispersed strains is smoother than that in the original strains. Such efficient metabolic flux would contribute to efficient energy conversion and to sufficient energy supply to anabolisms, such as mycelial growth and protein production. Our findings suggest that the hyphae-dispersed strains could be a useful host not only for protein production but also for the biological production of various chemicals such as organic acids.
最近，通过基因工程构建了一种菌丝分散型丝状真菌米曲霉，由于其易于操作和蛋白质生产特性水平，有望实现工业应用。在本研究中，我们使用野生型和菌丝分散型菌株构建了表达纤维素酶的菌株，以研究蛋白质生产力与代谢之间的相关性。与原始菌株相比，菌丝分散型纤维素酶表达菌株表现出纤维素酶活性升高、葡萄糖消耗迅速、菌丝干重增加、纤维素酶基因表达增加以及呼吸活性激活。比较代谢组学分析表明，分散菌株中糖酵解和三羧酸循环中的代谢物比原始菌株中的少。这些结果表明，菌丝分散型菌株中碳水化合物代谢通量比原始菌株中的更顺畅。这种高效的代谢通量将有助于高效的能量转换以及为合成代谢（如菌丝生长和蛋白质生产）提供充足的能量供应。我们的研究结果表明，菌丝分散型菌株不仅可以作为蛋白质生产的有用宿主，还可以作为各种化学品（如有机酸）生物生产的有用宿主。
