Enhanced butanol production by immobilized Clostridium beijerinckii TISTR 1461 using zeolite 13X as a carrier

Butanol production by cell immobilization onto porous materials—brick and zeolite 13X—was investigated using Clostridium beijerinckii TISTR 1461. Characterization results of two materials were completed to evaluate their potential as an immobilization carrier. Although zeolite has greater porosity than brick, it cannot be used for cell aggregation without treating with chemical. After immobilization, both materials can enhance butanol titers from 5.29 to 5.80 g/L and 8.58 g/L using brick and zeolite, respectively. Butanol to glucose yield also improved from 0.14 to 0.16 g/g after immobilization. It was found that butanol production significantly increased due to an increase in buffering capacity, strong bonding between the zeolite surface and cell, and butanol tolerance. In addition, repeated batch fermentation was performed, demonstrating that cells immobilized onto zeolite 13X have high stability and potential for long-term use in continuous fermentation.