Funding Information This research was supported by the National Natural Science Foundation (No. 50978028 and 51278050).
Glucose metabolic flux distribution of Lactobacillus amylophilus during lactic acid production using kitchen waste saccharified solution
Article first published online: 14 MAR 2013
© 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Thematic Issue on Biomaterials
Volume 6, Issue 6, pages 685–693, November 2013
How to Cite
Liu, J., Wang, Q., Zou, H., Liu, Y., Wang, J., Gan, K. and Xiang, J. (2013), Glucose metabolic flux distribution of Lactobacillus amylophilus during lactic acid production using kitchen waste saccharified solution. Microbial Biotechnology, 6: 685–693. doi: 10.1111/1751-7915.12046
- Issue published online: 11 OCT 2013
- Article first published online: 14 MAR 2013
- Manuscript Accepted: 27 JAN 2013
- Manuscript Revised: 31 DEC 2012
- Manuscript Received: 24 SEP 2012
- National Natural Science Foundation. Grant Numbers: 50978028, 51278050
The 13C isotope tracer method was used to investigate the glucose metabolic flux distribution and regulation in Lactobacillus amylophilus to improve lactic acid production using kitchen waste saccharified solution (KWSS). The results demonstrate that L. amylophilus is a homofermentative bacterium. In synthetic medium, 60.6% of the glucose entered the Embden–Meyerhof–Parnas (EMP) to produce lactic acid, whereas 36.4% of the glucose entered the pentose phosphate metabolic pathway (HMP). After solid–liquid separation of the KWSS, the addition of Fe3+ during fermentation enhanced the NADPH production efficiency and increased the NADH content. The flux to the EMP was also effectively increased. Compared with the control (60.6% flux to EMP without Fe3+ addition), the flux to the EMP with the addition of Fe3+ (74.3%) increased by 23.8%. In the subsequent pyruvate metabolism, Fe3+ also increased lactate dehydrogenase activity, and inhibited alcohol dehydrogenase, pyruvate dehydrogenase and pyruvate carboxylase, thereby increasing the lactic acid production to 9.03 g l−1, an increase of 8% compared with the control. All other organic acid by-products were lower than in the control. However, the addition of Zn2+ showed an opposite effect, decreasing the lactic acid production. In conclusion it is feasible and effective means using GC-MS, isotope experiment and MATLAB software to integrate research the metabolic flux distribution of lactic acid bacteria, and the results provide the theoretical foundation for similar metabolic flux distribution.