Department of Biotechnology, Pukyong National University, Busan, 48513, Republic of Korea.
Department of Chemistry, Umeå University, SE-90187, Umeå, Sweden.
Appl Biochem Biotechnol. 2021 Feb;193(2):577-588. doi: 10.1007/s12010-020-03434-3. Epub 2020 Oct 12.
This study was aimed at enhancing galactose consumption from the red seaweed Kappaphycus alvarezii. The optimal pretreatment condition of thermal acid hydrolysis was treated with 350 mM HNO for 60 min at 121 °C. The enzymatic saccharification with a 1:1 mixture of Celluclast 1.5 L and Viscozyme L showed the maximum yield of glucose; 42-g/L monosaccharide concentration was obtained with the highest yield of pretreatment and enzymatic saccharification (E) and the lowest inhibitory compound concentration. The deletion of the GAL80, MIG1, CYC8, or TUP1 gene was performed to improve the galactose consumption rate. The strains with the deletion of the MIG1 gene (mig1Δ) showed higher galactose consumption rate and ethanol yield than other strains. High transcription levels of regulatory genes revealed that the mig1Δ relieved glucose repression. These results show that the mig1Δ enhances galactose consumption rate from K. alvarezii.
本研究旨在提高红海藻 Kappaphycus alvarezii 中半乳糖的消耗量。经 350 mM HNO3 在 121°C 下预处理 60 分钟，是热酸水解的最佳预处理条件。用 1:1 的纤维素酶 1.5 L 和木聚糖酶 L 的混合物进行酶解，可获得最大的葡萄糖产量；用预处理和酶解（E）的最高产率和最低抑制化合物浓度获得 42 g/L 的单糖浓度。通过删除 GAL80、MIG1、CYC8 或 TUP1 基因来提高半乳糖的消耗率。删除 MIG1 基因（mig1Δ）的菌株比其他菌株具有更高的半乳糖消耗率和乙醇产率。调控基因的高转录水平表明 mig1Δ 缓解了葡萄糖的抑制作用。这些结果表明 mig1Δ 提高了 K. alvarezii 对半乳糖的消耗率。
