Gao Lin, She Menglin, Shi Jiao, Cai Dongbo, Wang Dong, Xiong Min, Shen Guoming, Gao Jiaming, Zhang Min, Yang Zhifan, Chen Shouwen
State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, China.
Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China.
Front Bioeng Biotechnol. 2022 Sep 9;10:974460. doi: 10.3389/fbioe.2022.974460. eCollection 2022.
Iturin A is a biosurfactant with various applications, and its low synthesis capability limits its production and application development. Fatty acids play a critical role in cellular metabolism and target product syntheses, and the relationship between fatty acid supplies and iturin A synthesis is unclear. In this study, we attempted to increase iturin A production strengthening fatty acid synthesis pathways in . First, acetyl-CoA carboxylase AccAD and ACP S-malonyltransferase were overexpressed promoter replacement, and iturin A yield was increased to 1.36 g/L by 2.78-fold in the resultant strain HZ-ADF1. Then, soluble acyl-ACP thioesterase derived from showed the best performance for iturin A synthesis, as compared to those derived from and , the introduction of which in HZ-ADF1 further led to a 57.35% increase of iturin A yield, reaching 2.14 g/L. Finally, long-chain fatty acid-CoA ligase LcfA was overexpressed in HZ-ADFT to attain the final strain HZ-ADFTL2, and iturin A yield reached 2.96 g/L, increasing by 6.59-fold, and the contents of fatty acids were enhanced significantly in HZ-ADFTL2, as compared to the original strain HZ-12. Taken together, our results implied that strengthening fatty acid supplies was an efficient approach for iturin A production, and this research provided a promising strain for industrial production of iturin A.
伊枯草菌素A是一种具有多种应用的生物表面活性剂，但其较低的合成能力限制了其生产和应用开发。脂肪酸在细胞代谢和目标产物合成中起着关键作用，而脂肪酸供应与伊枯草菌素A合成之间的关系尚不清楚。在本研究中，我们试图通过强化脂肪酸合成途径来提高伊枯草菌素A的产量。首先，通过启动子替换过表达乙酰辅酶A羧化酶AccAD和ACP S-丙二酰基转移酶，在所得菌株HZ-ADF1中伊枯草菌素A产量提高到1.36 g/L，提高了2.78倍。然后，与来源于其他菌株的可溶性酰基-ACP硫酯酶相比，来源于[具体菌株]的可溶性酰基-ACP硫酯酶对伊枯草菌素A合成表现出最佳性能，将其引入HZ-ADF1进一步使伊枯草菌素A产量提高57.35%，达到2.14 g/L。最后，在HZ-ADFT中过表达长链脂肪酸-CoA连接酶LcfA以获得最终菌株HZ-ADFTL2，伊枯草菌素A产量达到2.96 g/L，提高了6.59倍，与原始菌株HZ-12相比，HZ-ADFTL2中脂肪酸含量显著提高。综上所述，我们的结果表明强化脂肪酸供应是提高伊枯草菌素A产量的有效途径，本研究为伊枯草菌素A的工业化生产提供了一个有前景的菌株。
