Enhancement of pigment and proximate values of intergeneric hybrid of protoplast fusion of Monascus ruber and Pleurotus ostreatus

Abstract Protoplast fusion is a crucial technique for strain enhancement that brings genetic recombination to filamentous fungus and creates hybrid strains. In this present study, the intergenic fusion between M. ruber and P. ostreatus has been carried out to enhance pigments, secondary metabolites, and proximate values. Protoplasts from M. ruber and P. ostreatus were isolated and an equal amount of protoplast was taken and performed protoplast fusion. The regenerated colonies were plated in potato dextrose agar with selected biological markers (nystatin and fluconazole) for the confirmation of the hybrid. In a standardized condition, the protoplast yield of M. ruber and P. ostreatus was 2.31×107 cells/ml and 2.33×107 cells/ml, respectively. Acidic pH yielded high amounts of protoplasts than neutral and alkaline pH. KCl showed a high yield of protoplasts 2.36×106 cells /ml from M. ruber and 2.46×107cells/ml from P. ostreatus. The colony resistance to nystatin and fluconazole was confirmed that the obtained regenerated colonies were fusant. The fusant has no septation in its transverse walls with lipid droplets. Fusion of protoplast from M. ruber and P. ostreatus resulted in genetic inference at the metabolic levels, explaining the elevation of pigment in fusant colonies. The proximate composition of fusant strains was higher. In conclusion, we have developed a new strain with genetic variance capable of producing an increased level of pigment with nutritional value through protoplast fusion that allows the generation of fusant with the characteristics of parent strains and elucidates the effectiveness of fusant for commercial applications.