State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China 214122.
J Agric Food Chem. 2012 Feb 29;60(8):2033-8. doi: 10.1021/jf204270h. Epub 2012 Feb 14.
Although Maotai flavor liquor is exclusive due to its soy sauce flavor, knowledge of its key compound and production mechanism is still scarce until now. To gain insight into the production mechanism of soy sauce flavor, a soy sauce flavor producing strain with high efficiency and heat-resistant capability was obtained, and the metabolic mechanism of the strain was investigated with the technique of microarray profiling. Because high temperature was a key factor for soy sauce flavor production, the global gene expression of this heat-resistant strain fermented at 55 °C was analyzed. Except for the responsive increase of heat shock proteins, which maintained cell survival during heat stress, biosynthesis of cysteine was also up-regulated. In addition, some metabolites were significantly increased when cysteine was added to the fermentation medium, such as 2,3-butanediol, 3-hydroxy-2-butanone, and tetramethylpyrazine, which were important flavor compounds in soy sauce flavor liquor and might be related with soy sauce flavor. The results indicated that cysteine might play an important role in the formation of soy sauce flavor compound, and it might act as an indirect precursor or stimulator of soy sauce flavor formation. This was the first use of the microarray profiling tool to investigate the fermentative strains for Chinese traditional liquor, which would allow a deeper insight into the mechanism of the formation of soy sauce flavor compound.
尽管茅台酒的风味独特，带有酱油味，但直到现在，人们对其关键化合物和生产机制仍知之甚少。为了深入了解酱油风味的生产机制，我们获得了一株高效、耐热的酱油风味产生菌，并利用微阵列分析技术研究了该菌株的代谢机制。由于高温是酱油风味生产的关键因素，我们分析了耐热菌株在 55°C 发酵时的全基因表达情况。除了响应性增加的热休克蛋白（在热应激期间维持细胞存活）外，半胱氨酸的生物合成也被上调。此外，当向发酵培养基中添加半胱氨酸时，一些代谢物的含量显著增加，如 2,3-丁二醇、3-羟基-2-丁酮和四甲基吡嗪，它们是酱油风味白酒中的重要风味化合物，可能与酱油风味有关。结果表明，半胱氨酸可能在酱油风味化合物的形成中发挥重要作用，它可能作为酱油风味形成的间接前体或刺激物。这是首次利用微阵列分析工具研究中国传统白酒的发酵菌株，这将使我们更深入地了解酱油风味化合物形成的机制。
