Li Ya-Wen, Yang Cai-Ling, Peng Hui, Nie Zhi-Kui, Shi Tian-Qiong, Huang He
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, 210023, People's Republic of China.
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
Bioresour Bioprocess. 2022 Oct 5;9(1):106. doi: 10.1186/s40643-022-00595-3.
Gibberellic acid (GA3) is a plant growth hormone that plays an important role in the production of crops, fruits, and vegetables with a wide market share. Due to intrinsic advantages, liquid fermentation of Fusarium fujikuroi has become the sole method for industrial GA3 production, but the broader application of GA3 is hindered by low titer. In this study, we combined atmospheric and room-temperature plasma (ARTP) with ketoconazole-based screening to obtain the mutant strain 3-6-1 with high yield of GA3. Subsequently, the medium composition and fermentation parameters were systematically optimized to increase the titer of GA3, resulting in a 2.5-fold increase compared with the titer obtained under the initial conditions. Finally, considering that the strain is prone to substrate inhibition and glucose repression, a new strategy of fed-batch fermentation was adopted to increase the titer of GA3 to 575.13 mg/L, which was 13.86% higher than the control. The strategy of random mutagenesis combined with selection and fermentation optimization developed in this study provides a basis for subsequent research on the industrial production of GA3.
赤霉素（GA3）是一种植物生长激素，在具有广泛市场份额的农作物、水果和蔬菜生产中发挥着重要作用。由于自身优势，藤仓赤霉菌的液体发酵已成为工业生产GA3的唯一方法，但GA3的更广泛应用受到低产量的阻碍。在本研究中，我们将常压室温等离子体（ARTP）与基于酮康唑的筛选相结合，获得了GA3高产突变株3-6-1。随后，系统优化了培养基组成和发酵参数以提高GA3产量，与初始条件下获得的产量相比提高了2.5倍。最后，考虑到该菌株易于受到底物抑制和葡萄糖阻遏，采用了补料分批发酵的新策略，将GA3产量提高到575.13 mg/L，比对照高13.86%。本研究中开发的随机诱变结合筛选和发酵优化策略为后续GA3工业化生产研究提供了依据。
