Liu Hongmei, Xu Lin, Yan Ming, Lai Cangang, Ouyang Pingkai
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Sheng Wu Gong Cheng Xue Bao. 2008 Jun;24(6):1010-5. doi: 10.1016/s1872-2075(08)60048-5.
Global transcription machinery engineering (gTME) was employed to engineer xylose metabolism. Mutation of the transcription factor gene Sptl5 was introduced by error-prone PCR, followed by screening on media using xylose as the sole carbon source. One recombinant strain growing well on such media was chosen for further research. This strain showed modest growth rates in the media containing 50 g/L xylose or glucose at the condition of 30 degrees C, 200 r/min, 96 h, 94.0% and 98.9% of xylose and glucose were consumed, with the ethanol yield were 32.4% and 31.6%, respectively. The control strain had the ethanol yield of 44.3% under the glucose concentration of 50 g/L. When the carbon source was 50 g/L glucose/xylose (1:1), the utilization ratio of xylose and glucose was 91.7% and 85.9%, with the ethanol yield was 26%. Xylose was eventually exhausted. Concentration of the by-product xylitol was very low.
采用全局转录机制工程（gTME）对木糖代谢进行工程改造。通过易错PCR引入转录因子基因Sptl5的突变，随后在以木糖为唯一碳源的培养基上进行筛选。选择了一株在这种培养基上生长良好的重组菌株进行进一步研究。该菌株在30℃、200转/分钟、96小时的条件下，在含有50克/升木糖或葡萄糖的培养基中生长速度适中，木糖和葡萄糖的消耗率分别为94.0%和98.9%，乙醇产率分别为32.4%和31.6%。对照菌株在葡萄糖浓度为50克/升时乙醇产率为44.3%。当碳源为50克/升葡萄糖/木糖（1:1）时，木糖和葡萄糖的利用率分别为91.7%和85.9%，乙醇产率为26%。木糖最终耗尽。副产物木糖醇的浓度非常低。
