Furfural-tolerant Zymomonas mobilis derived from error-prone PCR-based whole genome shuffling and their tolerant mechanism
Furfural-tolerant Zymomonas mobilis derived from error-prone PCR-based whole genome shuffling and their tolerant mechanism
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DOI：
10.1007/s00253-018-8817-8
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发表时间：
2018-04-01
影响因子：
5
通讯作者：
Zhang, Minhua
中科院分区：
文献类型：
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作者：
Huang, Suzhen;Xue, Tingli;Zhang, Minhua
糠醛耐受菌株是利用木质纤维素生物质发酵生产生物燃料或化学品的关键。本研究首次对运动发酵单胞菌CP4进行了基于易错PCR的全基因组改组，获得了耐受3 g/L糠醛的突变株F211和F27。F211在各种糠醛胁迫条件下，当糠醛浓度降至1 g/L时，均能快速生长。同时，这两株突变株对高浓度葡萄糖的耐受性也比对照菌株CP4强。基因组重测序显示，F211和F27有12和13个单核苷酸多态性。活性测定结果表明，在糠醛胁迫下，突变体F211和CP 4的NADH依赖性糠醛还原酶活性均升高，且突变体的活性达到峰值的时间早于对照。此外，F211培养物中的糠醛水平也更快速地降低。这些结果表明，在对数生长期早期依赖于NADH的糠醛还原酶活性增强，从而加速了糠醛的解毒过程，从而提高了突变体对糠醛的耐受性。总之，我们得到了Z。结果表明，该菌株对糠醛和高浓度葡萄糖的耐受性均有所提高，为糠醛耐受机制和菌株选育提供了有价值的线索。
Furfural-tolerant strain is essential for the fermentative production of biofuels or chemicals from lignocellulosic biomass. In this study, Zymomonas mobilis CP4 was for the first time subjected to error-prone PCR-based whole genome shuffling, and the resulting mutants F211 and F27 that could tolerate 3 g/L furfural were obtained. The mutant F211 under various furfural stress conditions could rapidly grow when the furfural concentration reduced to 1 g/L. Meanwhile, the two mutants also showed higher tolerance to high concentration of glucose than the control strain CP4. Genome resequencing revealed that the F211 and F27 had 12 and 13 single-nucleotide polymorphisms. The activity assay demonstrated that the activity of NADH-dependent furfural reductase in mutant F211 and CP4 was all increased under furfural stress, and the activity peaked earlier in mutant than in control. Also, furfural level in the culture of F211 was also more rapidly decreased. These indicate that the increase in furfural tolerance of the mutants may be resulted from the enhanced NADH-dependent furfural reductase activity during early log phase, which could lead to an accelerated furfural detoxification process in mutants. In all, we obtained Z. mobilis mutants with enhanced furfural and high concentration of glucose tolerance, and provided valuable clues for the mechanism of furfural tolerance and strain development.