Regulatory mechanisms and cell membrane properties of Candida glycerinogenes differ under 2-phenylethanol addition or fermentation conditions
Regulatory mechanisms and cell membrane properties of Candida glycerinogenes differ under 2-phenylethanol addition or fermentation conditions
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DOI：
10.1002/biot.202300181
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发表时间：
2023-10-27
影响因子：
4.7
通讯作者：
Zhuge，Bin
中科院分区：
文献类型：
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作者：
Wang，Yuqin;Liu，Fang;Zhuge，Bin
2-苯基乙醇（2-PE）的高产率和效价的生物合成通常受到其毒性的限制。在这项研究中，我们描述了2-PE耐受性的分子机制，在多应力耐受工业酵母，产甘油假丝酵母。它们在2-PE添加或发酵条件下是不同的。在细胞外添加2-PE后，C.产甘油细胞变圆、变大，比表面积减小。然而，在2-PE发酵C.产甘油细胞较小，比表面积增大。通过分析细胞膜的组成和分子参数，研究了耐受机制的其他差异。细胞外2-PE胁迫导致不饱和脂肪酸合成基因转录表达下调。这增加了细胞膜中饱和脂肪酸的比例，从而增加了细胞膜的刚性并减少了2-PE进入细胞。然而，细胞内2-PE应激导致不饱和脂肪酸合成基因的转录表达上调，并增加细胞膜中不饱和脂肪酸的比例;这反过来又增强了细胞膜的柔韧性，从而加速了2-PE的外排。这些相反的机制是由转录因子Hog 1和Swi 5介导的。在2-PE添加下，C.甘油原激活Hog 1并抑制Swi 5以上调erg 5和derg 4表达，从而增加细胞膜刚性并抵抗2-PE输入。在2-PE发酵过程中，C.甘油原激活Hog 1并抑制Swi 5以上调2-PE转运蛋白scdr 1和酰基辅酶A去饱和酶1 ole 1以增加2-PE输出，从而降低2-PE细胞内毒性。这些结果为细胞膜水平上的2-PE耐受机制提供了新的见解，并提出了一种通过工程抗应激基因来提高2-PE产量的新策略。
The biosynthesis of 2‐phenylethanol (2‐PE) at high yields and titers is often limited by its toxicity. In this study, we describe the molecular mechanisms of 2‐PE tolerance in the multi‐stress tolerant industrial yeast,Candida glycerinogenes. They were different under 2‐PE addition or fermentation conditions. After extracellular addition of 2‐PE,C. glycerinogenescells became rounder and bigger, which reduced specific surface area. However, during 2‐PE fermentationC. glycerinogenescells were smaller, which increased specific surface area. Other differences in the tolerance mechanisms were studied by analyzing the composition and molecular parameters of the cell membrane. Extracellular 2‐PE stress resulted in down‐regulation of transcriptional expression of unsaturated fatty acid synthesis genes. This raised the proportion of saturated fatty acids in the cell membrane, which increased rigidity of the cell membrane and reduced 2‐PE entry to the cell. However, intracellular 2‐PE stress resulted in up‐regulation of transcriptional expression of unsaturated fatty acid synthesis genes, and increased the proportion of unsaturated fatty acids in the cell membrane; this in turn enhanced flexibility of the cell membrane which accelerated efflux of 2‐PE. These contrasting mechanisms are mediated by transcriptional factors Hog1 and Swi5. Under 2‐PE addition,C. glycerinogenesactivated Hog1 and repressed Swi5 to upregulateerg5anderg4expression, which increased cell membrane rigidity and resisted 2‐PE import. During 2‐PE fermentation,C. glycerinogenesactivated Hog1 and repressed Swi5 to upregulate 2‐PE transporter proteinscdr1and Acyl‐CoA desaturase 1ole1to increase 2‐PE export, thus reducing 2‐PE intracellular toxicity. The results provide new insights into 2‐PE tolerance mechanisms at the cell membrane level and suggest a novel strategy to improve 2‐PE production by engineering anti‐stress genes.