Highly accumulative production of l(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae

摘要: In order to produce microbiologically large amount of l (+)-lactic acid (LA) from glucose, batch and fed-batch (intermittent addition sterilized glucose powder aseptically) cultures Rhizopus oryzae NBRC 5384 (identical NRRL 395 ATCC 9363) whose mycelia were immobilized in situ within sponge-like cubic particles (3.5 mm edge long) carried out at 37°C a three baffled shake flask. Appropriately calculated fine powdery calcium carbonate (CaCO 3 ) was added initially or intermittently control pH the culture liquids. High accumulations LA (145 g/L 231 g/L, reality 176 g/L 280 g/L as anhydrous lactate) achieved by (glucose concentration = 150 g/L) (the initial concentration = 150 g/L intermittent equivalent 100 g/L). these yields productivities were, 95.0%, 1.42 g/L·h 92.5%, 1.83 g/L·h, respectively. Existence considerable amounts lactate (Ca(LA) 2 crystals broth experimentally proved two evidences: (i) heating up (70°C) followed quick low centrifugal force remove remaining CaCO solids then cooling down (37°C) incubation supernatant observe recrystallization Ca(LA) , (ii) measurement solubility media. It conceptually discussed be able avoid product inhibition means crystallization fermentation for high accumulation R. oryzae .