Fermentative production of gluconic acid: A membrane-integrated Green process

Abstract On integrating downstream membrane based separation modules with conventional fermentation unit, gluconic acid representing a class of industrially important organic acids could be produced from fermentation of sugar cane juice—a renewable cheap carbon source in an environmentally benign process. Using Gluconobacter oxydans as microbial agents in the bioconversion, the membrane-integrated hybrid fermentation system succeeded in producing 93 g/L gluconic acid of 98% purity with yield of 0.94 g/g and productivity of 6.7 g/L/h. The system performance parameters establish superiority of this novel technology over the existing ones. Against the overwhelmingly practiced batch or semi-batch processes involving multiple energy-intensive unit operations, this continuous production scheme ensures efficient bio-conversion without substrate–product inhibitions in a quite simplified plant characterized by high degree of process intensification.