Efficient biosynthesis of d-ribose using a novel co-feeding strategy in Bacillus subtilis without acid formation

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• 作者：J. Cheng ; W. Zhuang ; N.N. Li ; C.L. Tang and H.J. Ying
• 刊名：Letters in Applied Microbiology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：64
• 期：1
• 页码：73-78
• 全文大小：201K
• ISSN：1472-765X

文摘

Normally, low d-ribose production was identified as responsible for plenty of acid formation by Bacillus subtilis due to its carbon overflow. An approach of co-feeding glucose and sodium citrate is developed here and had been proved to be useful in d-ribose production. This strategy is critical because it affects the cell concentration, the productivity of d-ribose and, especially, the formation of by-products such as acetoin, lactate and acetate. d-ribose production was increased by 59·6% from 71·06 to 113·41 g l⁻¹ without acid formation by co-feeding 2·22 g l⁻¹ h⁻¹ glucose and 0·036 g l⁻¹ h⁻¹ sodium citrate to a 60 g l⁻¹ glucose reaction system. Actually, the cell density was also enhanced from 11·51 to 13·84 g l⁻¹. These parameters revealed the importance of optimization and modelling of the d-ribose production process. Not only could zero acid formation was achieved over a wide range of co-feeding rate by reducing glycolytic flux drastically but also the cell density and d-ribose yield were elevated by increasing the hexose monophosphate pathway flux.