Engineered for the Enhancement of Glucosamine Accumulation by the Consumption of Glucose and Ammonium Based on Synthetic Biological Pathways.

Glucosamine (GlcN) is a high-value compound with significant health applications. GlcN is widely used in the food and health industry as a food additive or functional food. The development of a green, efficient, and safe method for GlcN production is of great significance due to the complexity of traditional production methods, environmental pollution, and sensitization of raw materials. In this study, genes , , , , and were knocked out using the Clustered Regularly Interspaced Short Palindromic Repeats Cas9 (CRISPR-Cas9) method. In addition, three key enzyme genes, glucosamine-6-phosphate deaminase , glucosamine-6-phosphate phosphatase , and ammonium transporter , were introduced to construct engineered strains for GlcN synthesis in the presence of high-concentration inorganic ammonium ions. The results indicated that HPG5 with , , and integration and simultaneous deletion of , , , , and achieved the highest GlcN yield (1.95 ± 0.02 g/L) during fermentation with 10 g/L (NH)SO, which was 2.47-fold higher than the control. The conversion rate of glucose to GlcN in HPG5 was 9.75% in liquid YPD medium containing 20 g/L of glucose and 10 g/L of (NH)SO. Thus, the results indicated that HPG5 could effectively produce GlcN in the presence of high-concentration ammonium sulphate. This study provides a promising alternative, HPG5, for GlcN production.