ε-Poly-L-lysine production by immobilized cells of Kitasatospora sp. MY 5-36 in repeated fed-batch cultures

The production of ε-PL by Kitasatospora sp. MY 5-36 through entrapment or adsorption on bagasse, synthetic sponge, macroporous silica gel, and loofah sponge was investigated in shake flask cultures, and immobilization on loofah sponge gave the highest ε-PL production. Repeated fed-batch cultures for ε-PL production were also carried out in a stirred bioreactor and final ε-PL concentrations and productivity of 34.11 g L−1 and 9.34 g L−1 d−1, respectively were achieved by cells immobilize in loofah sponge. These values exceeded those for cultures with free cells (22.53 g L−1 and 3.30 g L−1 d−1). The immobilized cells were reused five times over a period of 526 h. These results suggest that the immobilization approach is promising for industrial applications.