Co-production of polysaccharides, ginsenosides and succinic acid from Panax ginseng residue: A typical industrial herbal waste

Co-production of polysaccharides, ginsenosides and succinic acid was achieved from Panax ginseng residue (PGR) in this study. Physico-chemical separation was first applied to recover the released polysaccharides and ginsenoside. Enzymatic hydrolysis was then conducted to covert the left PGR into mono-sugars which was following transformed into succinic acid by constructing a succinic acid-producing strain of Escherichia coli—ZW333. Results indicated that the yields of polysaccharides and ginsenosides increased according to the increase of deconstruction content of PGR. A total sugar yield reached 52 g/L at 10% PGR loading and increased to 94.33 g/L following fed-batch enzymatic hydrolysis. Finally, 56.28 g/L succinic acid was produced. In total, 18 g ginseng polysaccharides, 230 mg ginsenosides and 39 g succinic acid were produced from 100 g PGR. Accordingly, the total economic output could reach RMB 80,149 from 1 t PGR, illustrating the great value increasement of PGR by this industrially possible process.