Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China.
Biomolecules. 2024 Jun 25;14(7):752. doi: 10.3390/biom14070752.
Safe and eco-friendly preservatives are crucial to preventing food spoilage and illnesses, as foodborne diseases caused by pathogens result in approximately 600 million cases of illness and 420,000 deaths annually. ε-Poly-L-lysine (ε-PL) is a novel food preservative widely used in many countries. However, its commercial application has been hindered by high costs and low production. In this study, ε-PL's biosynthetic capacity was enhanced in WG608 through metabolic engineering guided by multi-omics techniques. Based on transcriptome and metabolome data, differentially expressed genes (fold change >2 or <0.5; < 0.05) and differentially expressed metabolites (fold change >1.2 or <0.8) were separately subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The integrative analysis of transcriptome, metabolome, and overexpression revealed the essential roles of isocitrate lyase, succinate dehydrogenase, flavoprotein subunit, diaminopimelate dehydrogenase, polyphosphate kinase, and polyP:AMP phosphotransferase in ε-PL biosynthesis. Subsequently, a strain with enhanced ATP supply, L-lysine supply, and ε-PL synthetase expression was constructed to improve its production. Finally, the resulting strain, WME10, achieved an ε-PL production rate of 77.16 g/L in a 5 L bioreactor, which is the highest reported ε-PL production to date. These results suggest that the integrative analysis of the transcriptome and metabolome can facilitate the identification of key pathways and genetic elements affecting ε-PL synthesis, guiding further metabolic engineering and thus significantly enhancing ε-PL production. The method presented in this study could be applicable to other valuable natural antibacterial agents.
安全环保型防腐剂对于防止食物变质和疾病的发生至关重要，因为食源性病原体每年导致约 6 亿病例的疾病和 42 万例死亡。ε-聚赖氨酸（ε-PL）是一种新型食品防腐剂，在许多国家广泛应用。然而，其商业应用受到高成本和低产量的限制。在这项研究中，通过多组学技术指导的代谢工程，在 WG608 中增强了 ε-PL 的生物合成能力。基于转录组和代谢组数据，分别对差异表达基因（fold change >2 或 <0.5； < 0.05）和差异表达代谢物（fold change >1.2 或 <0.8）进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）途径富集分析。转录组、代谢组和过表达的综合分析揭示了异柠檬酸裂解酶、琥珀酸脱氢酶、黄素蛋白亚基、二氨基庚二酸脱氢酶、多磷酸盐激酶和多聚磷酸盐：AMP 磷酸转移酶在 ε-PL 生物合成中的重要作用。随后，构建了一个增强 ATP 供应、L-赖氨酸供应和 ε-PL 合成酶表达的菌株，以提高其产量。最终，所得菌株 WME10 在 5 L 生物反应器中实现了 77.16 g/L 的 ε-PL 生产速率，这是迄今为止报道的最高 ε-PL 生产速率。这些结果表明，转录组和代谢组的综合分析可以促进鉴定影响 ε-PL 合成的关键途径和遗传元件，指导进一步的代谢工程，从而显著提高 ε-PL 的产量。本研究提出的方法可适用于其他有价值的天然抗菌剂。
