Aspergillus oryzae is a common starter in the soy sauce industry and struggles to grow under complex fermentation conditions. However, little is known about the flavor formation mechanism under osmotic conditions (low-temperature and high-salt) in A. oryzae. This work investigated the flavors and the relative protein expression patterns by gas chromatography-mass spectrometry (GC-MS) and proteomic analysis. Low-temperature and a high-salt content are unfavorable to the secretion of hydrolases and the formation of fragrant aldehydes. The aldehyde contents under osmotic conditions were reduced to 1.4-3.7 times lower than that of the control. Besides, copper amine oxidases which decreased under low-temperature stress and salt stress were shown to be important in catalyzing the oxidative deamination of several amine substrates to fragrant aldehydes. Furthermore, alcohol dehydrogenase and polyketide synthase are beneficial to the formation of alcohols and aromatic flavors under low-temperature stress and salt stress. Particularly, the ethanol content under 16 °C stress was 3.5 times higher than that under 28 °C.

中文翻译：

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通过蛋白质组学分析探索米曲霉在酱油发酵过程中渗透条件下的风味形成机理。

米曲霉是酱油行业中常见的发酵剂，并且在复杂的发酵条件下难以生长。然而，对于米曲霉在渗透条件下（低温和高盐）的风味形成机理知之甚少。这项工作通过气相色谱-质谱（GC-MS）和蛋白质组学分析研究了风味和相对蛋白质表达模式。低温和高盐含量不利于水解酶的分泌和芳香醛的形成。渗透条件下的醛含量比对照降低了1.4-3.7倍。此外，在低温胁迫和盐胁迫下减少的铜胺氧化酶被证明在催化几种胺底物氧化脱氨成芳香醛方面也很重要。此外，醇脱氢酶和聚酮化合物合酶有利于在低温胁迫和盐胁迫下形成醇和芳香族风味剂。特别是，在16°C胁迫下的乙醇含量比28°C下的乙醇含量高3.5倍。