热刺激对酵母属酵母甘油产量的影响

Effect of Heat Shock on Glycerol Production of Yeasts

酵母属酵母酒精发酵过程中甘油的生成量受多种因素的影响。研究选用1株贝酵母(Saccharomyces bayanus)和6株酿酒酵母(Saccharomyces cerevisiae)(编号依次为X1、X2、X3、X4、X5、X6、X7),分别在15℃、20℃、25℃、30℃和35℃下发酵模拟葡萄汁,考察酵母的产甘油能力。7株酵母在15℃、20℃、25℃、30℃下发酵良好,35℃发酵,受到不同程度的抑制。相同发酵温度下不同酵母间产甘油能力具有极显著差异性(P<0.01);同一酵母在不同发酵温度下甘油产量也具有极显著差异性(P<0.01),其中X2酵母甘油产量最高,且随着温度的升高甘油产量增幅最高,在30℃下发酵时达到最高值10.95g/L,较15℃发酵时增加3.40g/L。以产甘油能力最高的酿酒酵母X2为试验菌株,研究热刺激温度(30℃、35℃、40℃、45℃、50℃)与热刺激时间(10min、20min)对甘油产量的影响。20min/50℃甘油产量最高为14.76g/L。在各处理温度下,将热刺激时间由10min延长至20min,酵母甘油产量均有极显著提高(P<0.01),最高增幅为4.54g/L;相同热刺激时间下提高温度,酵母甘油产量也有极显著提高(P<0.01),最高增幅为3.79g/L。因此热刺激处理为提高酵母属酵母甘油产量的有效措施之一。

The production of glycerol was affected by many factors. In this paper, one strain of Saccharomyces bayanus and six strains of Saccharomyces cerevisiae （followed by the number X1, X2 , X3 , X4 , X5 , X6 , and X7 ） were selected to ferment synthetic grape juice at 15℃ , 20℃ , 25℃ , 30℃ , and 35℃ to study the ability of yeast on glycerol production. The results showed that seven strains of yeasts had good fermentation at 15℃, 20℃, 25℃, 30℃, while at 35℃ they were inhibited at different degrees. During same fermentation temperature, there was signifi- cant difference between different yeasts about the production ability of glycerol （P 〈 0.01 ） , and same phenomenon was happened for same yeast at different fermentation temperatures （P 〈 0.01 ）. Among the seven strains of yeast, X2 produced the highest content of glycerol, which was increased with the improving of temperature. For example, it can produce 10.95 g/L of glycerol at 30℃ , which was 3.40 g/L more than that at 15℃. Following the results above, we chose yeast X2 as the test yeast to study the effects of heat shock temperature （30℃, 35℃ , 40℃ , 45℃ , and 50℃ ）, and heat shock time （10 min and 20 min） on the production of glycerol. The results showed that the highest glycerol content was achieved at 50℃/20min, which was 14.76 g/L. During different heat stimulating temperatures, by in- creasing the heat stimulating time from 10 min to 20 min, the production of glycerol was significantly increased （P 〈 0.01 ）, the maximum increase was 4.54 g/L. Also, during the same heat shock time, by increasing the heat shock temperature, the glycerol production was significantly increased （P 〈 0.01 ） ; the maximum increase was 3.79 g/L. Therefore, the results showed that heat shock treatment was the effective way to increase the production of glycerol.