Production of highly pure R,R-2,3-butanediol for biological plant growth promoting agent using carbon feeding control of Paenibacillus polymyxa MDBDO

by Selleckchem | Nov 03 2023

Background: Chemical fertilizers have greatly contributed to the development of agriculture, but alternative fertilizers are needed for the sustainable development of agriculture. 2,3-butanediol (2,3-BDO) is a promising biological plant growth promoter.

Results: In this study, we attempted to develop an effective strategy for the biological production of highly pure R,R-2,3-butanediol (R,R-2,3-BDO) by Paenibacillus polymyxa fermentation. First, gamma-ray mutagenesis was performed to obtain P. polymyxa MDBDO, a strain that grew faster than the parent strain and had high production of R,R-2,3-BDO. The activities of R,R-2,3-butanediol dehydrogenase and diacetyl reductase of the mutant strain were increased by 33% and decreased by 60%, respectively. In addition, it was confirmed that the carbon source depletion of the fermentation broth affects the purity of R,R-2,3-BDO through batch fermentation. Fed-batch fermentation using controlled carbon feeding led to production of 77.3 g/L of R,R-2,3-BDO with high optical purity (> 99% of C4 products) at 48 h. Additionally, fed-batch culture using corn steep liquor as an alternative nitrogen source led to production of 70.3 g/L of R,R-2,3-BDO at 60 h. The fed-batch fermentation broth of P. polymyxa MDBDO, which contained highly pure R,R-2,3-BDO, significantly stimulated the growth of soybean and strawberry seedlings.

Conclusions: This study suggests that P. polymyxa MDBDO has potential for use in biological plant growth promoting agent applications. In addition, our fermentation strategy demonstrated that high-purity R,R-2,3-BDO can be produced at high concentrations using P. polymyxa.

Comments:

The study described aims to develop a strategy for the biological production of highly pure R,R-2,3-butanediol (R,R-2,3-BDO) through fermentation using a strain called Paenibacillus polymyxa MDBDO. R,R-2,3-BDO is considered a promising biological plant growth promoter, which could serve as an alternative to chemical fertilizers for sustainable agriculture

To achieve this, the researchers employed gamma-ray mutagenesis to generate the mutant strain P. polymyxa MDBDO, which exhibited faster growth and higher production of R,R-2,3-BDO compared to the parent strain. The mutant strain displayed a 33% increase in the activities of R,R-2,3-butanediol dehydrogenase, an enzyme involved in R,R-2,3-BDO production, and a 60% decrease in the activities of diacetyl reductase, another enzyme related to R,R-2,3-BDO synthesis.

The study also investigated the impact of carbon source depletion on the purity of R,R-2,3-BDO during batch fermentation. By implementing fed-batch fermentation with controlled carbon feeding, the researchers achieved a production of 77.3 g/L of R,R-2,3-BDO with high optical purity (> 99% of C4 products) within 48 hours. Furthermore, they explored the use of corn steep liquor as an alternative nitrogen source in fed-batch culture, resulting in a production of 70.3 g/L of R,R-2,3-BDO within 60 hours.

Importantly, the fermentation broth of P. polymyxa MDBDO, containing highly pure R,R-2,3-BDO, demonstrated significant growth stimulation in soybean and strawberry seedlings. This suggests that P. polymyxa MDBDO has the potential for applications as a biological plant growth promoting agent.

Overall, the study highlights the viability of using P. polymyxa as a producer of high-purity R,R-2,3-BDO and provides insights into the fermentation strategies employed to achieve this goal. The findings contribute to the development of alternative fertilizers and sustainable agricultural practices.