Optimization of medium components for D-ribose production by transketolase-deficient Bacillus subtilis NJT-1507

Abstract

Statistical experimental designs were used to optimize the composition of culture media for the production of D-ribose by Bacillus subtilis. A fractional factorial design 2 (5-2) was used to determine medium components that significantly affected D-ribose production. The concentrations of glucose and (NH 4 ) 2 SO 4 were the significant factors. Central composite design and response surface methodology were then used to estimate the quadratic response surface and determine the factor levels for maximum production of D-ribose. Finally, the optimal medium composition was obtained (g/L): glucose, 172.75; (NH 4 ) 2 SO 4 , 13.2; yeast powder, 4; corn steep liquor, 8 and MnSO 4 , 0.5. This optimization strategy increased D-ribose production from 73.21 g/L to 88.57 g/L, an increase of 22% compared with the original conditions. The D-ribose production yield to glucose concentration was also enhanced from 0.37 g/g to 0.52 g/g. Confirmatory experiments were also performed to demonstrate the accuracy of the model. Under the optimal medium using ammonia to control pH in a 5 L fermenter, the D-ribose yield was increased to 95.28 g/L after 3 days of cultivation at 37 o C.

Efficient biosynthesis ofd-ribose using a novel co-feeding strategy inBacillus subtiliswithout acid formation

“…The strain used in this study was TKT‐deficient B. subtilis CGMCC 3720 which was named as NJT‐1507 in our previous article (Fang et al . ). The inoculation medium was composed of (g l −1 ): d ‐sorbitol 5, peptone 10, yeast extract 2, NaCl 2, at an initial pH 7·0.…”