Work

Augmentation of exopolysaccharide synthesis and its influence on biofunctional properties of polysaccharide in Sanghuangporus vaninii via targeted overexpression of phosphoglucomutase

Year: 2025

Type: article

Abstract: Phosphoglucomutase (PGM) is considered an essential catalyst in polysaccharide biosynthesis , plays a pivotal role in the early stage of carbon metabolism and the synthesis of nucleotide sugars . Polysaccharides are important active components of Sanghuangporus vaninii . Based on the transcriptomic data, the successful cloning and re-annotation of the putative 1353 - bp PGM took place, which encodes a protein of 49.45 kDa. In order to elucidate the function of this gene, overexpression and interference transformation systems were constructed in S. vaninii . The results revealed that the PGM is primarily responsible for regulating the interconversion between glucose-1-phosphate and glucose-6-phosphate. An up - regulation of PGM expression resulted in a significant increase in extracellular polysaccharide content, quantified at 7.72 % and 15.15 %, whereas a down - regulation of PGM expression resulted in a significant increase in intracellular polysaccharide content (33.68 % and 38.24 %). The antioxidant capacity of intracellular polysaccharide in strain, including hydroxyl radical scavenging, superoxide anion radical scavenging, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, ABTS + radical scavenging and FRAP scavenging was significantly increased by RNA interference with the expression of PGM , while the overexpression of PGM was found to enhance the antioxidant capacity of extracellular polysaccharide to a certain degrees. Furthermore, the modulation of PGM expression had a significant impact on polysaccharide metabolic pathways, resulting in alterations in monosaccharide composition and impacting the content of cell wall components , and the microstructure of polysaccharides. These findings elucidate the polysaccharide biosynthetic pathway in S. vaninii , highlighting the PGM as a prime target for the propagation of high-yield polysaccharide-producing strains. This study stands as a basic reference for amplifying polysaccharide production via strategic metabolic regulation .

Source: International Journal of Biological Macromolecules

DOI: 10.1016/j.ijbiomac.2025.141182