精氨酸代谢途径抗酸关键基因对乳酸乳球菌Lactococcus lactis NZ9000胁迫抗性的影响

发布时间：2018-04-04 14:01

本文选题：Lactococcus　切入点：lactis　出处：《微生物学通报》2017年02期

【摘要】：【目的】寻找精氨酸代谢途径中与酸胁迫相关的关键作用因素。【方法】通过在Lactococcus lactis NZ9000中分别过量表达来源于Lactobacillus casei Zhang的精氨酰琥珀酸合成酶(ASS)和精氨酰琥珀酸裂解酶(ASL)改变精氨酸代谢提高酸胁迫抗性。【结果】与对照菌株对比,重组菌株在环境胁迫下表现了较高的生长性能、存活率和发酵性能。生理学分析发现,酸胁迫环境下,重组菌株细胞有较高的胞内NH4+、ATP含量和H+-ATPase活性,并显著提高了精氨酸脱亚胺酶(ADI)途径中的氨基酸浓度。进一步的转录分析发现,天冬氨酸合成、精氨酸代谢相关的基因转录水平上调。【结论】在L.lactis NZ9000中过量表达ASS或ASL可以引发精氨酸代谢流量的上调,进而提高了细胞的多种胁迫抗性。精氨酸合成途径广泛存在于多种微生物中,为微生物,尤其是工业微生物提高胁迫抗性提供了新思路。
[Abstract]:[Objective] to find the key factors associated with the effects of acid stress arginine metabolic pathways. [method] through Lactococcus lactis NZ9000 were overexpressed from Lactobacillus casei Zhang arginyl succinate synthase (ASS) and arginyl succinate lyase (ASL) changes in arginine metabolism improve the acid stress resistance. [results] with the control strain contrast, recombinant strains showed a high growth performance under environmental stress, survival rate and fermentation performance. The physiological analysis found that the acid stress environment, the recombinant strain cells had higher intracellular NH4+, ATP content and H+-ATPase activity, and significantly improve the arginine deiminase the concentration of amino acid (ADI) pathway. The transcription analysis revealed that aspartic acid synthesis, upregulation of gene transcription level of arginine metabolism. [Conclusion] overexpression of ASS or A in L.lactis NZ9000 SL can trigger the up regulation of arginine metabolic flux, and then enhance the multiple stress resistance of cells. Arginine synthesis pathway is widespread in many kinds of microbes. It provides a new idea for microorganisms, especially industrial microbes, to enhance stress resistance.

【作者单位】：江南大学工业生物技术教育部重点实验室;江南大学生物工程学院;江南大学糖化学与生物技术教育部重点实验室;江南大学粮食发酵工艺与技术国家工程实验室;
【基金】：国家自然科学基金项目(No.31470160) 国家重点基础研究发展规划项目(973计划)(No.2013CB733902) 中国博士后科学基金项目(No.2013M540538,114957) 国家高技术研究发展计划项目(863计划)(No.2011AA100901) 111计划项目(No.111-2-06)~~
【分类号】：Q93

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