Lin De-Shun, Yen Hong-Wei, Kao Wei-Chen, Cheng Chieh-Lun, Chen Wen-Ming, Huang Chieh-Chen, Chang Jo-Shu
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.
Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan.
Biotechnol Biofuels. 2015 Oct 13;8:168. doi: 10.1186/s13068-015-0352-6. eCollection 2015.
Clostridium pasteurianum CH4 was used to produce butanol from glycerol. The performance of butanol fermentation was improved by adding butyrate as the precursor to trigger the metabolic pathway toward butanol production, and by combining this with in situ butanol removal via vacuum membrane distillation (VMD) to avoid the product inhibition arising from a high butanol concentration.
Adding 6 g L(-1) butyrate as precursor led to an increase in the butanol yield from 0.24 to 0.34 mol butanol (mol glycerol)(-1). Combining VMD and butyrate addition strategies could further enhance the maximum effective butanol concentration to 29.8 g L(-1), while the yield was also improved to 0.39 mol butanol (mol glycerol)(-1). The butanol concentration in the permeate of VMD was nearly five times higher than that in the feeding solution.
The proposed butyrate addition and VMD in situ butanol removal strategies are very effective in enhancing both butanol titer and butanol yield. This would significantly enhance the economic feasibility of fermentative production of butanol. The VMD-based technology not only alleviates the inhibitory effect of butanol, but also markedly increases butanol concentration in the permeate after condensation, thereby making downstream processing easier and more cost-effective.
巴氏梭菌CH4被用于从甘油生产丁醇。通过添加丁酸盐作为前体来触发丁醇生产的代谢途径，并将其与通过真空膜蒸馏（VMD）进行原位丁醇去除相结合，以避免高丁醇浓度引起的产物抑制，从而提高了丁醇发酵性能。
添加6 g L(-1)丁酸盐作为前体导致丁醇产率从0.24提高到0.34 mol丁醇（mol甘油）(-1)。将VMD和丁酸盐添加策略相结合可进一步将最大有效丁醇浓度提高到29.8 g L(-1)，同时产率也提高到0.39 mol丁醇（mol甘油）(-1)。VMD渗透液中的丁醇浓度几乎比进料溶液中的高五倍。
所提出的丁酸盐添加和VMD原位丁醇去除策略在提高丁醇滴度和丁醇产率方面非常有效。这将显著提高丁醇发酵生产的经济可行性。基于VMD的技术不仅减轻了丁醇的抑制作用，而且还显著提高了冷凝后渗透液中的丁醇浓度，从而使下游加工更简便且更具成本效益。
