Metabolic Engineering of Bacillus licheniformis for Production of Acetoin.

Chuanjuan Lü,Peihai Liu,Xiaoting Guo,Yongsheng Ge,Chao Gao,Ping Xu,Menghao Cao,Cuiqing Ma

doi:10.3389/fbioe.2020.00125

Chuanjuan Lü, Peihai Liu + Show 6 more

Open Access

https://doi.org/10.3389/fbioe.2020.00125

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Abstract

Acetoin is a potential platform compound for a variety of chemicals. Bacillus licheniformis MW3, a thermophilic and generally regarded as safe (GRAS) microorganism, can produce 2,3-butanediol with a high concentration, yield, and productivity. In this study, B. licheniformis MW3 was metabolic engineered for acetoin production. After deleting two 2,3-butanediol dehydrogenases encoding genes budC and gdh, an engineered strain B. licheniformis MW3 (ΔbudCΔgdh) was constructed. Using fed-batch fermentation of B. licheniformis MW3 (ΔbudCΔgdh), 64.2 g/L acetoin was produced at a productivity of 2.378 g/[L h] and a yield of 0.412 g/g from 156 g/L glucose in 27 h. The fermentation process exhibited rather high productivity and yield of acetoin, indicating that B. licheniformis MW3 (ΔbudCΔgdh) might be a promising acetoin producer.

Highlights

Acetoin (3-hydroxy-2-butanone) is widely used as a common additive in food industry and a building block for various chemicals (Liu et al, 2011; Xiao and Lu, 2014; Yang et al, 2017)
Samples were collected by acetolactate decarboxylase (ALDC) might not be reduced to 2,3-butanediol and the periodically to determine the biomass, concentrations of glucose, strain B. licheniformis MW3 was used for acetoin
The concentrations of 2,3-butanediol and acetoin were analyzed by gas chromatography (GC; GC2014c, Shimadzu) with capillary GC columns

Summary

INTRODUCTION

Acetoin (3-hydroxy-2-butanone) is widely used as a common additive in food industry and a building block for various chemicals (Liu et al, 2011; Xiao and Lu, 2014; Yang et al, 2017). Many native or recombinant microorganisms, including the genera Serratia, Klebsiella, Saccharomyces, Gluconobacter, and Bacillus, have abilities to produce acetoin (Sun et al, 2012; Wang et al, 2013, 2017; Bae et al, 2016; Jia et al, 2017). Among these species, Bacillus species which can produce various industrial products have become the research hotspot for acetoin production (Zhang Y. et al, 2013; Fan et al, 2018; Liu et al, 2019). Considering its desirable characteristics, B. licheniformis MW3 ( budC gdh) may be a promising alternative for fermentative production of acetoin

MATERIALS AND METHODS

Analytical Methods

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT