Engineering of pentose transport in Corynebacterium glutamicum to improve simultaneous utilization of mixed sugars
- First Online:
- Cite this article as:
- Sasaki, M., Jojima, T., Kawaguchi, H. et al. Appl Microbiol Biotechnol (2009) 85: 105. doi:10.1007/s00253-009-2065-x
- 634 Downloads
Corynebacterium glutamicum strains CRA1 and CRX2 are able to grow on l-arabinose and d-xylose, respectively, as sole carbon sources. Nevertheless, they exhibit the major shortcoming that their sugar consumption appreciably declines at lower concentrations of these substrates. To address this, the C. glutamicum ATCC31831 l-arabinose transporter gene, araE, was independently integrated into both strains. Unlike its parental strain, resultant CRA1-araE was able to aerobically grow at low (3.6 g·l−1) l-arabinose concentrations. Interestingly, strain CRX2-araE grew 2.9-fold faster than parental CRX2 at low (3.6 g·l−1) d-xylose concentrations. The corresponding substrate consumption rates of CRA1-araE and CRX2-araE under oxygen-deprived conditions were 2.8- and 2.7-fold, respectively, higher than those of their respective parental strains. Moreover, CRA1-araE and CRX2-araE utilized their respective substrates simultaneously with d-glucose under both aerobic and oxygen-deprived conditions. Based on these observations, a platform strain, ACX-araE, for C. glutamicum-based mixed sugar utilization was designed. It harbored araBAD for l-arabinose metabolism, xylAB for d-xylose metabolism, d-cellobiose permease-encoding bglF317A, β-glucosidase-encoding bglA and araE in its chromosomal DNA. In mineral medium containing a sugar mixture of d-glucose, d-xylose, l-arabinose, and d-cellobiose under oxygen-deprived conditions, strain ACX-araE simultaneously and completely consumed all sugars.