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Engineering Lactococcus lactis for D-Lactic Acid Production from Starch.
Yuji Aso1, Ayaka Hashimoto2, Hitomi Ohara2
1Department of Biobased Materials Science, Kyoto Institute of Technology, 1 Hashigami-cho, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan. aso@kit.ac.jp.
Current Microbiology
|July 15, 2019
Summary
Engineered Lactococcus lactis can now produce D-lactic acid directly from starch. This novel bioprocess enhances D-lactic acid production efficiency using genetically modified bacteria.
Area of Science:
- Biotechnology
- Microbial Engineering
- Metabolic Engineering
Background:
- Global demand for D-lactic acid necessitates improved bioprocess development.
- Current methods for D-lactic acid production require optimization for efficiency and sustainability.
Purpose of the Study:
- To engineer Lactococcus lactis for direct D-lactic acid production from starch.
- To develop a novel bioprocess for enhanced D-lactic acid yield.
Main Methods:
- Genetic modification of L. lactis NZ9000 by replacing L-lactate dehydrogenase (L-Ldh) with a heterologous D-Ldh gene.
- Introduction of a heterologous α-amylase gene into the engineered L. lactis strain.
- Cultivation of engineered strains with glucose and starch as carbon sources.
Main Results:
- Engineered strain AH1 exhibited D-lactate dehydrogenase activity (1.54 U/mL) and produced D-lactic acid with 93.8% purity from glucose.
- Engineered strain AH2 demonstrated amylolytic activity (0.26 U/mL) and produced 15.0 g/L of D-lactic acid directly from starch within 24 hours.
- The developed bioprocess achieved direct D-lactic acid production from starch using engineered L. lactis.
Conclusions:
- Lactococcus lactis can be successfully engineered for direct D-lactic acid production from starch.
- This study presents the first report of D-lactic acid production in engineered L. lactis.
- The developed bioprocess offers a promising route for efficient and sustainable D-lactic acid manufacturing.
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