CAJ | 학술논문

应用拉曼光谱和单细胞分析技术监测有机氮源尿素和酵母粉、无机氮源硝酸铵和硫酸铵对酿酒酵母乙醇发酵的影响及发酵过程胞内主要生物大分子的变化动态,以期从光谱学角度获知有机氮源促进乙醇发酵的机制。结果表明,利用酵母粉和尿素的乙醇发酵速度最快,14~18 h即可达到乙醇浓度的最大值；在有机氮源下,酵母细胞的RNA合成无明显的迟滞期,发酵前期,782 cm-1峰平均强度比无机氮源的高,其最大峰强是初始强度的1.9~2.1倍,而无机氮源仅为1.2~1.4倍；以酵母粉为氮源的不同发酵阶段,部分细胞的蛋白质二级结构以β折叠为主,而其它氮源的细胞则是以α螺旋为绝对主导。因此,尿素、酵母粉等有机氮源促进乙醇发酵的可能原因是缩短酵母的迟滞期,促进胞内RNA的快速合成,促进相关基因的快速转录和表达。
응용랍만광보화단세포분석기술감측유궤담원뇨소화효모분、무궤담원초산안화류산안대양주효모을순발효적영향급발효과정포내주요생물대분자적변화동태,이기종광보학각도획지유궤담원촉진을순발효적궤제。결과표명,이용효모분화뇨소적을순발효속도최쾌,14~18 h즉가체도을순농도적최대치；재유궤담원하,효모세포적RNA합성무명현적지체기,발효전기,782 cm-1봉평균강도비무궤담원적고,기최대봉강시초시강도적1.9~2.1배,이무궤담원부위1.2~1.4배；이효모분위담원적불동발효계단,부분세포적단백질이급결구이β절첩위주,이기타담원적세포칙시이α라선위절대주도。인차,뇨소、효모분등유궤담원촉진을순발효적가능원인시축단효모적지체기,촉진포내RNA적쾌속합성,촉진상관기인적쾌속전록화표체。
Nitrogen is an essential nutrient for yeast cells on ethanol fermentation. In order to reveal the promoting mechanisms of organic nitrogen sources on the ethanol fermentation by yeast, Saccharomyces cerevisiae, laser tweezers Raman spectroscopy and single-cell analysis techniques were used to monitored the kinetic of intracellular bio-macromolecules of individual cells during fermentation with urea, yeast extract, ammonium nitrate or ammonium sulfate as the sole nitrogen source. Major results from this work were as follows. (1) Organic nitrogen sources had a promoting effect on the ethanol fermentation, the fermentation with urea and yeast extract reached the maximum concentration of ethanol in 14-18 h. ( 2 ) There were no apparent lag phases for the RNA synthesis of yeast cells cultured with urea and yeast extract. The averaged Raman intensity of yeast cells at peak of 782 cm-1 in the early stage of fermentation was stronger than that of cultured with ammonium nitrate and ammonium sulfate. The maximum was about 1. 9-2. 1 times of the initial intensity for urea or yeast extract, but 1. 2-1. 4 times for ammonium nitrate and ammonium sulfate. (3) The secondary structure of proteins of partial cells cultured with yeast extract was dominated byβ-sheet, while cells cultured with other nitrogen sources were dominated by α-helix absolutely. These results bring us the conclusion that the improving effect of organic nitrogen sources such as urea and yeast extract on ethanol fermentation by Saccharomyces cerevisiae may be due to that the organic nitrogen sources can shorten the lag phase of yeast cells, promote the RNA synthesis, and promote the transcription and expression of related genes.