Isopropanol-butanol-ethanol (IBE) production in repeated-batch cultivation of Clostridium beijerinckii DSM 6423 immobilized on sugarcane bagasse

摘要: Abstract The IBE mixture is a potential automotive fuel, and its production by Clostridium beijerinckii DSM 6423, the best known natural producer, hindered low productivity butanol titer. To alleviate this problem, we cultivated C. 6423 in repeated batches using sugarcane bagasse as low-cost immobilization agent. Experiments were conducted 250-mL bottles containing 150 mL P2 medium, glucose, bagasse. In fermentation with seven batch cycles (257 h) 7.5 g bagasse, glucose (60 g/L) conversion varied between 38% 98%. four of cycles, was 0.22 0.28 g/L∙h, titer reached 6.7–8.6 g/L. contrast, free-cell single-batch cultivation, limited to 35%, slower (0.13 g IBE/L∙h), did not exceed 4.8 g/L. Despite gains titer, further research needed elucidate factors mechanisms that caused yield decline during repeated-batch cultivation 6423.