Effect of temperature and surfactant on biomass growth and higher-alcohol production during syngas fermentation by Clostridium carboxidivorans P7

• Main Authors: Shaohuang Shen, Guan Wang, Ming Zhang, Yin Tang, Yang Gu, Weihong Jiang, Yonghong Wang, Yingping Zhuang
• Format: Article
• Language: English
• Published: SpringerOpen 2020-10-01
• Series: Bioresources and Bioprocessing
• Subjects: Clostridium carboxidivorans P7; Higher alcohol; Two-step temperature culture; Surfactant; Comparative transcriptome
• Online Access: http://link.springer.com/article/10.1186/s40643-020-00344-4

Abstract Hexanol–butanol–ethanol fermentation from syngas by Clostridium carboxidivorans P7 is a promising route for biofuel production. However, bacterial agglomeration in the culture of 37 °C severely hampers the accumulation of biomass and products. To investigate the effect of culture temperature on biomass growth and higher-alcohol production, C. carboxidivorans P7 was cultivated at both constant and two-step temperatures in the range from 25 to 37 °C. Meanwhile, Tween-80 and saponin were screened out from eight surfactants to alleviate agglomeration at 37 °C. The results showed that enhanced higher-alcohol production was contributed mainly by the application of two-step temperature culture rather than the addition of anti-agglomeration surfactants. Furthermore, comparative transcriptome revealed that although 37 °C promoted high expression of genes involved in the Wood–Ljungdahl pathway, genes encoding enzymes catalyzing acyl-condensation reactions associated with higher-alcohol production were highly expressed at 25 °C. This study gained greater insight into temperature-effect mechanism on syngas fermentation by C. carboxidivorans P7.