Abstract
The byproduct of MOE-1-mediated rubber decomposition is an insoluble residue. We aimed to establish a method to utilize this residue as a biomass resource. We investigated the effects of rubber residues on the growth and nisin productivity of Lactococcus lactis NBRC 12007. Altering the concentration ratio of complete medium supplemented with glucose (CMG) (for the cultivation of NBRC 12007) to the hydrophobic fraction of rubber residues changed both growth and nisin productivity. When the rubber residue concentration was higher, nisin activity was significantly boosted, whereas bacterial growth was not. Growth and nisin activity of NBRC 12007 were proportional to the concentration of CMG. Nisin-stimulating effects reached a stationary phase at a rubber residue concentration of 6–7 mg/L. In diluted CMG, rubber residues could stimulate bacterial growth but not nisin activity. Overall, the findings suggested that the ratio of rubber residue concentration to that of the medium affects bacterial metabolism.
