The concentrations of free amino ac

The concentrations of free amino acids indicated the supply of nitrogen source in the medium. The fermentation with (NH4)2SO4 addition in the rice fermentation medium was conducted. As
shown at Table 3, the concentrations of tyramine, cadaverine and histamine were not detected with (NH4)2SO4 addition, and the concentrations of corresponding tyrosine, lysine and histidine were also undetected. Our results indicated that the concentrations of free amino acids was decreased when (NH4)2SO4 were added into the medium, perhaps this is because the nitrogen source in the fermentation medium was adequate, which can reduced the proteinase
activity of yeast. Amino acid are the precursors of biogenic amines, which can synthesize biogenic amines by the decarboxylation reaction. Although it was difficult to establish a direct connection between amines and amino acids, our results showed that elevated levels of tyramine, cadaverine and histamine correlated with a decrease in tyrosine, lysine and histidine, confirming that higher concentrations of amino acid precursors could result
in more biogenic amine production, although the detailed mechanism is not clear.

結果 (中文) 1:

游离氨基酸浓度表示介质中的氮源的供应。大米发酵培养基 (NH4) 2SO4 加发酵进行。作为显示在表 3，浓度的酪胺、 尸胺、 组胺未检测到 (NH4) 2SO4 另外，与相应，浓度赖氨酸和组氨酸是酪氨酸的还未被发现。我们的研究结果表明，游离氨基酸浓度时 (NH4) 2SO4 被添加到介质中，这也许是因为在发酵培养基中的氮源是充分的这可以减少蛋白酶活性的酵母。氨基酸是可以通过脱羧反应合成生物胺的生物胺的前体。虽然很难建立胺和氨基酸之间的直接连接，我们的研究结果表明，酪胺、 尸胺、 组胺水平升高相关酪氨酸、 赖氨酸和组氨酸，确认可能导致更高的浓度的氨基酸前体的跌幅在更多的生物胺生产中，虽然详细的机制尚不清楚。

結果 (中文) 3:

游离氨基酸的浓度表明，在培养基中的氮源的供应。随着发酵（NH4）2SO4添加在大米发酵培养基进行了。作为在表3所示，酪胺的浓度，尸胺和组胺均未检出与（NH4）2SO4添加，和相应的酪氨酸的含量，赖氨酸和组氨酸还未被发现的。我们的研究结果表明，游离氨基酸浓度降低时，（NH4）2SO4添加到培养基中，或许这是因为在发酵培养基中的氮源充足，可降低蛋白酶酵母活性。氨基酸是生物胺的前体，可以通过脱羧反应合成生物胺。虽然这是很难建立胺类和氨基酸之间有直接的联系，我们的研究结果表明，酪胺水平升高，尸胺和组胺与减少酪氨酸、赖氨酸和组氨酸，证实高浓度的氨基酸前体的可能结果在更多的生物胺生产，虽然详细的机制是不明确的。