The overwhelming amount of cassava residues and okara are a foremost challenge for the food processing industry environmental loading. The purpose of this article is to utilize Pleurotus ostreatus mycelium to ferment solid cassava and soybean residue, resulting in mycelial biomass with nutritional values and promising prebiotic activities from fermented waste sources. By blending a ratio of 80% cassava and 20% soybean residues, the mycelium spread rapidly after 3 days of culture, from 1.73 mm on the first day to 13.32 mm on the third day, and completely covered the surface after 9 days of culture (120 mm). Using the solid-state fermentation (SSF) method allowed us to improve the content of substances isolated from mycelium biomass, where polysaccharide content rose by 2.1 times to 3.44 mg/g, and the protein content increased by 1.84 times over the initial substrate. The prebiotic activity of extracted PS was greatest in P. acidilactici NBD8 (1.58); for L. pentosus NH1, L. argentoraten NH15, and L. plantarum WCFS1 strains, the indices were 0.11, 0.17, and 0.3, respectively. The SSF process with P. ostreatus mycelium has the potential to be an effective method for improving the nutrition and digestibility of soybean and cassava residues for application in the production of nature-derived animal feed, as well as contributing to fully utilized agricultural residue, agriculture’s circular economy, reducing environmental issues, and achieving the net-zero carbon emissions target by 2050, as the Vietnam government committed to achieving during the COP26 World Leaders’ Summit in 2021.

This investigation involved the addition of Trametes versicolor mycelium to Pleurotus ostreatus extract, which was subsequently fermented using Lactobacillus plantarum to improve the quality of the fermented beverage. The concentration of total dissolved solids (^oBrix) generally diminishes with prolonged fermentation time, whereas it increases with the addition of T. versicolor mycelium. The pH values markedly decreased after 12 h, thereafter stabilizing after 24 and 48 h of fermentation, oscillating between 3.04 and 3.32. The total acid content (TAC) escalated in direct correlation with the mycelium ratio and fermentation length, with TAC values spanning from 6.617 to 10.678 g/L at a 1.0% mycelium addition. The ABTS+ antioxidant capacity ascended in direct correlation with the quantity of T. versicolor mycelium incorporated, attaining values of 58.13%, 49.63%, and 48.44% after 12, 24, and 48 h in CT6, respectively. Nonetheless, this ability exhibited a progressive decline over the fermenting period. The addition of T. versicolor mycelium effectively stimulated the proliferation of L. plantarum WCFS1, achieving a high cell density in the treatment supplemented 0.6% T. versicolor mycelium (CT4) after 12, 24, and 48 h of fermentation. The capacity of inhibiting harmful bacteria was maximized with the addition of 1.0% mycelium, resulting in an inhibition zone width of 13.42 mm for Escherichia coli ATCC 85922 after 48 h and 16.65 mm for Staphylococcus aureus ATCC 25023 after 24 h of fermentation. The fermented beverage had the greatest sensory score with the addition of 0.6% mycelium after 24 h of fermentation. The findings revealed significant potential for the manufacture of natural-based functional beverage industry.

The overwhelming amount of cassava residues and okara is a foremost challenge for the food processing industry environmental loading. The purpose of this article is to utilize Pleurotus ostreatus mycelium to ferment solid cassava and soybean residue, resulting in mycelial biomass with nutritional values and promising prebiotic activities from fermented waste-sources. By a blending ratio of 80% cassava and 20% soybean residues, the mycelium spread rapidly after 3 days of culture, from 1.73 mm on the first day to 13.32 mm on the third day, and completely covered the surface after 9 days of culture (120 mm). Using the SSF method allowed us to improve the content of substances isolated from mycelium biomass, where polysaccharide content rose by 2.1 times to 3.44 mg/g, and the protein content increased by 1.84 times over the initial substrate. The prebiotic activity of isolated-PS was greatest in P. acidilactici NBD8 (1.58); for L. pentosus NH1, L. argentoraten NH15, and L. plantarum WCFS1 strains, the indices were 0.11, 0.17, and 0.3, respectively. SSF process with P. ostreatus mycelium has the potential to be an effective method for improving the nutrition and digestibility of soybean and cassava residues for application in the production of nature-derived animal feed, as well as contributing to fully utilize agricultural residue, agriculture's circular economy, reducing environmental issues, and achieve net-zero carbon emissions target by 2050, as Vietnam government committed during the COP26 World Leaders' Summit in 2021.