Issue 21, 2023

Systematic metabolic engineering of Bacillus licheniformis for hyperproduction of the antioxidant hydroxytyrosol

Abstract

Hydroxytyrosol (HT) is a natural antioxidant that exhibits various health-related properties. In this work, we focused on establishing and optimizing the production of HT in Bacillus licheniformis. Through protein engineering ketoacid decarboxylase, boosting the phosphoenolpyruvate (PEP) supply, releasing feedback inhibition, and blocking competing pathways, HT production increased to 2078 mg L−1 from zero. Remarkably, the tyrosol catabolic pathway was identified and deletion of the alcohol dehydrogenase gene adhA significantly reduced tyrosol degradation. Next, multiple rate-liming factors were identified, including insufficiency of PEP, erythrose-4-phosphate and 4-hydroxyphenylpyruvate supply, and imbalance of KivDV461I and HpaBC expression levels. The carbon flux toward HT was significantly improved by modulating the glucose transport system, fine-tuning the expression levels of kivDV461I and hpaBC, and enhancing the expression of tyrAfbr, tkt, and zwf, which increased the HT titer to 6299 mg L−1. Finally, the final strain DHT23 produced 9475 mg L−1 HT under fed-batch conditions, with a yield and productivity of 135.4 mg g−1 glucose and 395 mg (L h)−1, respectively, which represents the highest HT production to date. Taken together, this study establishes B. licheniformis as a framework for HT hyperproduction and paves the way for achieving the industrial production of HT in the future.

Graphical abstract: Systematic metabolic engineering of Bacillus licheniformis for hyperproduction of the antioxidant hydroxytyrosol

Supplementary files

Article information

Article type
Paper
Submitted
24 May 2023
Accepted
31 Aug 2023
First published
02 Oct 2023

Green Chem., 2023,25, 8718-8729

Systematic metabolic engineering of Bacillus licheniformis for hyperproduction of the antioxidant hydroxytyrosol

Y. Zhan, F. Zhou, W. Ruan, H. Yin, Z. Li, H. Wang, T. Li, D. Cai, S. Yang, X. Ma and S. Chen, Green Chem., 2023, 25, 8718 DOI: 10.1039/D3GC01773G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements