多诱变技术强化木醋杆菌木糖代谢及细菌纤维素生物合成

Enhancement of Xylose Metabolism and Bacterial Cellulose Biosynthesis in Komagataeibacter xylinus Through Multiple Mutagenesis Techniques

摘要:

【目的】针对木醋杆菌在木糖代谢效率低、细菌纤维素（bacterial cellulose，BC）合成能力受限的问题，探索多种物理诱变技术提升其木糖利用与BC合成性能。【方法】分别采用紫外（ultraviolet，UV）诱变、等离子体（atmospheric and room temperature plasma，ARTP）诱变及UV-ARTP复合诱变对木醋杆菌进行改良，并构建纯木糖与混合碳源两类发酵体系评估诱变菌株性能。通过比较诱变菌株的BC产量与木糖消耗量，筛选出高效稳定的突变菌株。【结果】ARTP诱变菌株ARTP-Mix-1的BC产量达5.07 g/L，木糖消耗量达4.06 g/L，较混合碳源培养基中的野生型菌株WT-Mix分别提高了73.04%及13.50倍，且均优于UV诱变菌株。而UV-ARTP复合诱变菌株CM-Mix-20的BC产量达6.00 g/L，木糖消耗量达4.70 g/L，较WT-Mix分别提高了104.78%和15.79倍。【结论】该研究为细菌纤维素工业化生产及木糖资源高效利用提供了新策略。

Abstract:

[Objective] This study aimed to address the low xylose metabolic efficiency and limited bacterial cellulose (BC) biosynthesis capacity of Komagataeibacter xylinus (K. xylinus) by exploring the use of multiple physical mutagenesis techniques to enhance xylose utilization and BC biosynthesis. [Method]Ultraviolet (UV) mutagenesis, atmospheric and room temperature plasma (ARTP) mutagenesis, and UV-ARTP combined mutagenesis were employed to improve K. xylinus. Pure xylose and mixed carbon-source fermentation systems were established to evaluate the fermentation performance of the mutant strains. Efficient and genetically stable mutants were screened by comparing BC yield and xylose consumption. [Result] The ARTP-mutagenized strain ARTP-Mix-1 achieved a BC yield of 5.07 g/L and xylose consumption of 4.06 g/L, which represented increases of 73.04% and 13.50 folds compared with those of the wild-type strain WT-Mix, respectively, and both values were higher than those of the UV-mutagenized strains. Furthermore, the mutant strain CM-Mix-20 produced by UV-ARTP achieved a BC yield of 6.00 g/L and xylose consumption of 4.70 g/L, which represented increases of 104.78% and 15.79 folds compared with those of WT-Mix, respectively. [Conclusion] This study provides a new strategy for the industrial production of BC and the efficient utilization of xylose resources.