2,3-Butanediol

2,3-Butanediol (2,3-BDO) is a chiral compound that can exist in three isomeric forms: L-butanediol (dextro-or (2S, 3S)-(+)-), D-butanediol (levo-or (2R, 3R)-(-)-) and meso-butanediol (2R, 3R-), as shown in figure 1. It is considered as an important microbial metabolite and has been widely used in many fields such as food, medicine, chemical, and so on.

Common practice for 2,3-butanediol production is the pyrolysis of diacetate. However, its industrial production and usage are limited by the fairly high cost of its petrol-based production. Considering the over climate change and finiteness of fossil reserves, the preparation of 2,3-butanediol obtained from renewable resources has drawn more and more attention.

Fig. 1 Stereoisomers of butanediol

Synthesis of 2,3-Butanediol

Generally, there are three consecutive metabolic conversion steps in the biosynthesis of 2,3-butanediol for most microorganisms: pyruvate → α-acetolactate → acetoin and/or diacetyl → 2,3-butanediol. First, under the catalysis of an α-acetolactate synthase, pyruvate from glycolysis is converted to α-acetolactate via decarboxylation. Next, under the action of α-acetolactate decarboxylase, α-acetolactate is anaerobically converted to R-acetoin. Meanwhile, α-acetolactate also produces diacetyl as a minor byproduct via a spontaneous reaction due to instability under aerobic conditions. Diacetyl is further reduced to S-acetoin via a butanediol dehydrogenase or a diacetyl reductase with consumption of one NADH equivalent. Acetoin is an intermediate compound prior to the formation of 2,3-butanediol. From these two types of acetoin (R-acetoin and S-acetoin), three types of 2,3-butanediol, namely (2R,3R), (2S,3S), and (2R,3S)-butanediol are determined by stereospecific termination enzymes such as a butanediol dehydrogenase and an acetoin reductase.

Fig. 2 Metabolic pathway and regulation mechanism of butanediol

Strains of Klebsiella and Enterobacter genera mainly form (2S,3S)-butanediol and (2R,3S)-butanediol, while members of Bacillus genus form (2R,3R)-butanediol and (2R,3S)-butanediol. Microorganisms that can produce 2,3-butanediol are listed as followings:

Our 2,3-Butanediol

Our biosynthetic 2,3-butanediol is obtained by fermentation of glycerol generated from palm oil. Basic properties are listed in the following table:

Alfa Chemistry is a professional supplier of biosynthetic 2,3-butanediol. For high quality products, professional technical service, use suggestion and latest industry news, please feel free to contact us.

References

1. Song, C. W., Park, J. M., Chung, S. C., et al. Microbial production of 2,3-butanediol for industrial applications. Journal of Industrial Microbiology & Biotechnology. 2019.
2. Maina, S., Prabhu, A. A., Vivek, N., Vlysidis, A., Koutinas, A., & Kumar, V. Prospects on bio-based 2,3-butanediol and acetoin production: Recent progress and advances. Biotechnology Advances, 2021, 107783.

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