Abstract
Clostridium acetobutylicum has been used as a microbial platform for the production of butanol, acetone, and butyrate from biomass. This study examined the effect of nutritional enrichment on the production of acetate and butyrate by C. acetobutylicum in culture, and tested whether this nutritional change could shift metabolic flux in these microbial cells. The degenerated (non-solventogenic) C. acetobutylicum M5 strain, which lacks the pSOL1 plasmid that contains genes responsible for solvent production, was cultured in the rich medium, C. acetobutylicum medium 1 (CAM1). As a control, M5 strain was also cultured in clostridial growth medium (CGM). Batch fermentation of M5 strain in CAM1 achieved a cell density of 23.7 (OD600), which was 2.55 times that obtained when these cells were cultured in CGM. Fermentation in CAM1 yielded volumetric acetate and butyrate productivities of 0.42 g/L/h and 1.06 g/L/h, respectively, which were 2.33 and 1.33 times the values obtained in CGM. Nutritional enrichment also increased the acetate-to-butyrate ratio, which was 0.39 g/g for M5 cells grown in CAM1 and 0.25 g/g for those grown in CGM. These findings demonstrate that the tested nutritional enrichment triggers a metabolic shift in the acid production of a degenerated C. acetobutylicum in culture.
Highlights
Clostridium acetobutylicum produces various metabolites from C5 and C6 sugars in nature [1]
2 Department of Chemical and Biomolecular Engineering (BK21 Plus Program), BioProcess Engineering Research Center, Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea which was 0.39 g/g for M5 cells grown in C. acetobutylicum medium 1 (CAM1) and 0.25 g/g for those grown in clostridial growth medium (CGM). These findings demonstrate that the tested nutritional enrichment triggers a metabolic shift in the acid production of a degenerated C. acetobutylicum in culture
We examined the effect of nutritional enrichment on solvent production in C. acetobutylicum ATCC 824 [13]
Summary
Clostridium acetobutylicum produces various metabolites (e.g., butanol, acetone, ethanol, butyrate, acetate, and hydrogen) from C5 and C6 sugars in nature [1]. The major products of the acidogenic phase are acetate and butyrate, which are reassimilated during the solventogenic phase and used to produce solvents, such as acetone, butanol, and ethanol [2, 5, 6]. A well-known degenerated (non-solventogenic) strain is C. acetobutylicum M5 [10, 11]; in this strain, complementation of the adhE1 gene was found to recover the ability to produce butanol [12]. Our group recently designed a new rich medium, CAM1, and used it to examine the effect of nutritional enrichment on solvent production during the phase transition of C. acetobutylicum ATCC 824 [13]. No previous study has examined the effect of nutritional enrichment on the production of acetate and butyrate by C. acetobutylicum. We cultured M5 strain in CAM1 and examined how the rich medium affected the culture of this acidogenic (degenerated) C. acetobutylicum
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
