Contribution of YthA, a PspC Family Transcriptional Regulator of Lactococcus lactis F44 Acid Tolerance and Nisin Yield: a Transcriptomic Approach
Contribution of YthA, a PspC Family Transcriptional Regulator of Lactococcus lactis F44 Acid Tolerance and Nisin Yield: a Transcriptomic Approach
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YthA（乳酸乳球菌 F44 酸耐受性和乳链菌肽产量的 PspC 家族转录调节因子）的贡献：转录组学方法
DOI：
10.1128/aem.02483-17
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发表时间：
2018-01
影响因子：
4.4
通讯作者：
Qiao Jianjun
中科院分区：
文献类型：
--
作者：
Wu Hao;Liu Jingui;Miao Sen;Zhao Yue;Zhu Hongji;Qiao Mingqiang;Saris Per Erik Joakim;Qiao Jianjun
摘要为了克服环境胁迫对乳酸乳球菌生长的不利影响，乳酸乳球菌可以激活不同的适应性调节机制。本研究对L. lactis subsp.乳酸菌F44在酸胁迫下进行了定量逆转录-PCR分析。然后构建了8株基因过表达菌株，以研究它们对耐酸能力的影响。在致死pH 3.0的酸休克中，过表达PspC家族转录调节因子ythA使存活率增加了3.2倍。乳酸链球菌素产量提高了45.50%。过表达菌株FythA具有较高的细胞内pH稳定性和耐乳链菌肽能力。随后，转录组分析显示，绝大多数与氨基酸生物合成相关的基因，包括精氨酸，丝氨酸，苯丙氨酸和酪氨酸，主要在FythA中上调。精氨酸生物合成（argG和argH）、精氨酸脱亚胺酶途径和极性氨基酸转运（ysfE和ysfF）被认为是YthA的主要调控机制。此外，与嘧啶和胞外多糖生物合成相关的基因的转录上调。nisIPRKFEG基因在FythA中的转录水平显著较高，这直接有助于nisin的产量和抗性。通过计算机分析，预测了三个潜在的DNA结合序列的基因的上游区域的显着变化。本研究表明，YthA能提高乳酸链球菌素的产量和耐酸性，揭示了YthA的调控机制。乳链菌肽由乳酸乳球菌乳酸亚种（Lactococcus lactis subsp.）乳酸，广泛用作安全的食品防腐剂。酸胁迫成为乳酸链球菌生长和产乳链菌肽的主要限制因子。本研究发现，转录调控因子YthA有利于提高乳酸菌的耐酸性。乳酸菌F44。过量表达ythA可显著提高存活率和乳链菌肽产量。细胞内pH的稳定性和乳酸链球菌素的抗性也有所提高。转录组分析表明，乳酸链球菌素的免疫和一些氨基酸，嘧啶，胞外多糖的生物合成在工程菌增强。本研究阐明了YthA的调控机制，为构建健壮的工业乳酸菌提供了新的策略。乳酸菌菌株
ABSTRACT To overcome the adverse impacts of environmental stresses during growth, different adaptive regulation mechanisms can be activated in Lactococcus lactis. In this study, the transcription levels of eight transcriptional regulators of L. lactis subsp. lactis F44 under acid stress were analyzed using quantitative reverse transcription-PCR. Eight gene-overexpressing strains were then constructed to examine their influences on acid-resistant capability. Overexpressing ythA, a PspC family transcriptional regulator, increased the survival rate by 3.2-fold compared to the control at the lethal pH 3.0 acid shock. Moreover, the nisin yield was increased by 45.50%. The ythA-overexpressing strain FythA appeared to have higher intracellular pH stability and nisin-resistant ability. Subsequently, transcriptome analysis revealed that the vast majority of genes associated with amino acid biosynthesis, including arginine, serine, phenylalanine, and tyrosine, were predominantly upregulated in FythA. Arginine biosynthesis (argG and argH), arginine deiminase pathway, and polar amino acid transport (ysfE and ysfF) were proposed to be the main regulation mechanisms of YthA. Furthermore, the transcription of genes associated with pyrimidine and exopolysaccharide biosynthesis were upregulated. The transcriptional levels of nisIPRKFEG genes were substantially higher in FythA, which directly contributed to the yield and resistance of nisin. Three potential DNA-binding sequences were predicted by computer analysis using the upstream regions of genes with prominent changes. This study showed that YthA could increase acid resistance and nisin yield and revealed a putative regulation mechanism of YthA. IMPORTANCE Nisin, produced by Lactococcus lactis subsp. lactis, is widely used as a safe food preservative. Acid stress becomes the primary restrictive factor of cell growth and nisin yield. In this research, we found that the transcriptional regulator YthA was conducive to enhancing the acid resistance of L. lactis F44. Overexpressing ythA could significantly improve the survival rate and nisin yield. The stability of intracellular pH and nisin resistance were also increased. Transcriptome analysis showed that nisin immunity and the biosynthesis of some amino acids, pyrimidine, and exopolysaccharides were enhanced in the engineered strain. This study elucidates the regulation mechanism of YthA and provides a novel strategy for constructing robust industrial L. lactis strains.
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影响因子：
--
作者：
Toni T;Jovanovic G;Huvet M;Buck M;Stumpf MP
通讯作者：
Stumpf MP
影响因子：
3.6
作者：
Kingston AW;Liao X;Helmann JD
通讯作者：
Helmann JD
影响因子：
4.4
作者：
ENGELKE, G;GUTOWSKIECKEL, Z;ENTIAN, KD
通讯作者：
ENTIAN, KD
影响因子：
4.4
作者：
Ercan, Onur;Wels, Michiel;Kleerebezem, Michiel
通讯作者：
Kleerebezem, Michiel
影响因子：
4.1
作者：
J. Tramer;G. G. Fowler-G.
通讯作者：
J. Tramer;G. G. Fowler-G.