Innovative submerged directed fermentation: Producing high molecular weight polysaccharides from Ganoderma lucidum.

Polysaccharides from Ganoderma lucidum (GLPs) exhibit unique bioactivity, but traditional cultivation yields low quantities and unstable quality, limiting their research and application. This study highlights how submerged fermentation processes enable the directed acquisition of structurally defined high molecular weight (MW) bioactive intracellular polysaccharides (IPS). The results showed that inoculation amount and fermentation scales had a significant effect on the content of high MW IPS. In the fermentor, by lowering the initial glucose concentration combined with fed-batch fermentation, the high MW IPS content was improved. The monosaccharide composition indicated that the high MW IPS obtained from different fermentation scales exhibited stability. This polysaccharide, which is a β-glucan with a β-1,3-Glcp backbone and β-1-Glcp attached at the O-6 position, demonstrated immunostimulatory effects in vitro. Overall, the consistent quality of GLPs during submerged fermentation underscores the feasibility of industrial-scale production, presenting a significant advancement over traditional cultivation methods and promising for biotechnological applications.