Knocking-in the pentose transporter demonstrates the promotion of xylose utilization and L-ornithine production
In order to increase the rate of xylose consumption, the pentose transporter gene (araE ) from Bacillus subtilis was integrated into the genome locus ofiolR with the strong Peftu promoter, to generate the strain termed as XAB01. The pentose transporter AraE is not only extremely significant for the arabinose transportation, but also promotes the transportation of xylose to cells (Mao et al., 2018). As expected, the results showed that strain XAB01 demonstrated superior xylose consumption and L-ornithine synthesis than strain XAB (Fig.3a and 3b). strain XAB01 consumed 47.9 g/L xylose after 72h fermentation, with an average consumption rate of 0.665 g/(L·h). Through the rapid utilization of xylose, the growth and L-ornithine yield of strain were also improved. The output of L-ornithine increased by 12.5% (24.3 ± 0.23g/L) compared with strain XAB, and the xylose yield is 0.51 g/g.