Li Ke, Fang Senbiao, Zhang Xiao, Wei Xiaodi, Wu Pingle, Zheng Rong, Liu Lijuan, Zhang Haibo
College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China.
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Microorganisms. 2024 Mar 26;12(4):663. doi: 10.3390/microorganisms12040663.
2-Phenylethanol (2-PE) and indole-3-acetic acid (IAA) are important secondary metabolites produced by microorganisms, and their production are closely linked to the growth state of microorganisms and environmental factors. CGMCC 5087 can produce both 2-PE and IAA depending on α-ketoacid decarboxylase KDC4427. This study aimed to investigate the effects of different environment factors including osmotic pressure, temperature, and pH on the synthesis of 2-PE and IAA in sp. CGMCC 5087. The bacteria exhibited an enhanced capacity for 2-PE synthesis while not affecting IAA synthesis under 5% NaCl and pH 4.5 stress conditions. In an environment with pH 9.5, the synthesis capacity of 2-PE remained unchanged while the synthesis capacity of IAA decreased. The synthesis ability of 2-PE was enhanced with an increase in temperature within the range of 25 °C to 37 °C, while the synthesis capacity of IAA was not affected significantly. Additionally, the expression of varied under stress conditions. Under 5% NaCl stress and decreased temperature, expression of the gene was increased. However, altering pH did not result in significant differences in gene expression levels, while elevated temperature caused a decrease in gene expression. Furthermore, molecular docking and molecular dynamics simulations suggested that these conditions may induce fluctuation in the geometry shape of binding cavity, binding energy, and especially the value, which played key roles in affecting the enzyme activity. These results provide insights and strategies for the synthesis of metabolic products 2-PE and IAA in bacterial fermentation, even under unfavorable conditions.
2-苯乙醇（2-PE）和吲哚-3-乙酸（IAA）是微生物产生的重要次生代谢产物，它们的产生与微生物的生长状态和环境因素密切相关。中国普通微生物菌种保藏管理中心5087（CGMCC 5087）能够依靠α-酮酸脱羧酶KDC4427产生2-PE和IAA。本研究旨在探究不同环境因素，包括渗透压、温度和pH值，对CGMCC 5087菌株中2-PE和IAA合成的影响。在5% NaCl和pH 4.5的胁迫条件下，该细菌表现出增强的2-PE合成能力，同时不影响IAA的合成。在pH 9.5的环境中，2-PE的合成能力保持不变，而IAA的合成能力下降。在25℃至37℃范围内，随着温度升高，2-PE的合成能力增强，而IAA的合成能力没有受到显著影响。此外，在胁迫条件下基因表达有所变化。在5% NaCl胁迫和温度降低的情况下，基因的表达增加。然而，改变pH值并未导致基因表达水平出现显著差异，而温度升高导致基因表达下降。此外，分子对接和分子动力学模拟表明，这些条件可能会引起结合腔几何形状、结合能尤其是值的波动，这些在影响酶活性方面起着关键作用。这些结果为细菌发酵中代谢产物2-PE和IAA的合成提供了见解和策略，即使在不利条件下也是如此。
