Elucidating the salt-tolerant mechanism of Halomonas cupida J9 and unsterile ectoine production from lignocellulosic biomass

作者：Yaping Chen, Yujie Liu, Yan Meng, Yuting Jiang, Weini Xiong, Shufang Wang, Chao Yang, Ruihua Liu · 发表于：Microbial Cell Factories · 年份：2024 · DOI：10.1186/s12934-024-02515-w · 被引用次数：18 · 研究领域：Microbial Metabolic Engineering and Bioproduction、Biofuel production and bioconversion、Enzyme Catalysis and Immobilization

BACKGROUND: Ectoine as an amino acid derivative is widely applied in many fields, such as the food industry, cosmetic manufacturing, biologics, and therapeutic agent. Large-scale production of ectoine is mainly restricted by the cost of fermentation substrates (e.g., carbon sources) and sterilization. RESULTS: In this study, Halomonas cupida J9 was shown to be capable of synthesizing ectoine using xylose as the sole carbon source. A pathway was proposed in H. cupida J9 that synergistically utilizes both WBG xylose metabolism and EMP glucose metabolism for the synthesis of ectoine. Transcriptome analysis indicated that expression of ectoine biosynthesis module was enhanced under salt stress. Ectoine production by H. cupida J9 was enhanced by improving the expression of ectoine biosynthesis module, increasing the intracellular supply of the precursor oxaloacetate, and utilizing urea as the nitrogen source. The constructed J9U-P8EC achieved a record ectoine production of 4.12 g/L after 60 h of xylose fermentation. Finally, unsterile production of ectoine by J9U-P8EC from either a glucose-xylose mixture or corn straw hydrolysate was demonstrated, with an output of 8.55 g/L and 1.30 g/L of ectoine, respectively. CONCLUSIONS: This study created a promising H. cupida J9-based cell factory for low-cost production of ectoine. Our results highlight the potential of J9U-P8EC to utilize lignocellulose-rich agriculture waste for open production of ectoine.