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航天诱变啤酒酵母菌株的复壮与筛选 总被引:4,自引:2,他引:2
对经航天诱变的啤酒酵母菌进行复壮,并对复壮后的酵母菌株从细胞大小、菌落形态、发酵力、增殖情况以及死灭温度等几方面进行了筛选.试验结果表明,诱变后菌株的发酵力、生长速度均优于出发菌株,死灭温度基本相同.并依此筛选出了l株各种生理性状都较好的诱变菌株,其适宜的生长培养基为麦芽汁培养基,适宜的培养时间为24h. 相似文献
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谷胱甘肽(GSH)在啤酒中具有抗老化作用,选育高产谷胱甘肽的啤酒酵母菌株有助于改善啤酒抗老化性能。以啤酒酵母S5为出发菌株,经紫外诱变和硫酸二乙酯(DES)诱变后,获得突变株SC67,其GSH胞内生成量为15.238mg/L,胞内含量为11.292mg/g,较S5分别提高91.4%和57.8%。SC67发酵所得啤酒中胞外谷胱甘肽含量(6.43mg/L)较S5(1.35mg/L)显著提高,啤酒抗氧化性能得到明显改善,DPPH自由基清除率较s5提高1312%;TBA值下降7.1%;RSV值提高49.2%。 相似文献
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啤酒酵母菌种复壮的技术措施 总被引:4,自引:0,他引:4
啤酒酵母菌种的复壮措施有控制少传代,避免种性衰退;模拟大生产复壮,恢复其原具备驻生罐种藏种复壮需先降压,排除发酵液,沉淀的酵母加入温度14℃的麦汁培养基培养复壮。此外,还好特殊情况的复壮处理,包括应急复壮法,酸处理法等。 相似文献
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鲜啤酒以其独特的风味、营养、时尚而流行于都市生活。啤酒酵母菌株的特性直接决定着鲜啤酒的质量,在生产中采用不同的菌株和生产工艺,可酿造出不同类型的啤酒。笔者根据实际经验,提出了啤酒屋酵母菌株分离的技术要点,并依此进行了啤酒屋酵母菌株的筛选。. 相似文献
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In the presence of glycerol or ethanol, SCPP (a strain of Saccharomyces cerevisiae that expresses pectinolytic activity) is capable of utilizing galacturonic acid or pectins for growth purposes. We now establish a relationship between the pectinolytic power of various strains of S. cerevisiae and their ability to grow on a pectin/glycerol-based medium. This property is further exploited for the detection of polygalacturonase-producing strains of S. cerevisiae. 相似文献
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对15株酿酒酵母菌株的外观发酵度、双乙酰生成和还原能力进行了比较,通过随机扩增多态性DNA(RAPD)和HSP150编码基因的长度多态性对不同酿酒酵母菌株的基因组DNA分子差异进行了分析。结果显示,菌株YZU-APK和SS-05的外观发酵度分别为77.2%和76.8%,双乙酰峰值分别为0.26mg/L和0.25mg/L,并在发酵第8d均降至0.09 mg/L。在46条随机引物中筛选出的2条引物P07和P42能够扩增出具有较好多态性的RAPD指纹图谱,可以将15个酵母菌株分成9个遗传型;对细胞壁热休克蛋白HSP150编码基因的PCR扩增,并根据扩增条带长度的不同可以将15株酵母分成6个遗传型。综合2种分析结果,并对低双乙酰酿酒酵母菌株YZU-APK和SS-05进行DNA分子标记,确定了其基因型分别是(P07:1,P42:1,hsp150:1)和(P07:1,P42:5,hsp150:2)。 相似文献
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为提高红曲中莫纳克林K含量,以实验室保藏紫色红曲霉(Monascus purpureus)MY-11为原始菌株,利用紫外诱变筛选红曲霉,并进行固态发酵制备红曲,采用高效液相色谱(HPLC)法对红曲中的莫纳克林K含量进行测定,选出高产莫纳克林K突变株,并与食源性菌株酿酒酵母(Saccharomyces cerevisiae)进行共酵。结果表明,通过紫外诱变筛选出2株高产莫纳克林K突变株M7和M8,固态发酵25 d后莫纳克林K含量分别为12.42 mg/g、12.49 mg/g,分别比原始菌株MY-11提高了26%、27%。将诱变菌株M7、M8分别继续与不同添加量的酿酒酵母共酵培养,结果发现加入酵母菌液添加量3%时莫纳克林K含量最高,分别为9.35 mg/g、8.94 mg/g,比对照组提高了2.63%、16.41%。紫外诱变筛选结合共酵培养方法可提高红曲中莫纳克林K含量。 相似文献
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应用基因突变技术向酿酒酵母APA1基因中引入同义突变,为进一步研究APA1表达量与酿酒酵母硫化氢产量的关系提供实验基础。从酿酒酵母S288c中利用聚合酶链式反应扩增APA1基因,与EGFP基因融合构建表达载体。以该载体为模板,通过一步法点突变技术向APA1基因中分别引入APA1-1/2/3/4 4 个突变。测序结果表明突变位点与预期结果一致。成功获得了APA1的4 个同义突变。一步法点突变技术是一种高效的定点突变方法。分别转化酿酒酵母YS59,荧光显微镜下可见绿色激发荧光,表明APA1-1/2/3/4与EGFP基因共表达。 相似文献
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Roman Mink Stephan Sommer Ralf Kölling Hans‐Georg Schmarr Louis Baumbach Maren Scharfenberger‐Schmeer 《Journal of the Institute of Brewing》2014,120(1):23-26
Microbially derived diacetyl accumulation during vinification imparts a buttery wine aroma, which has stylistic implications. However, at higher concentrations diacetyl induces an aromatic off‐flavour. Saccharomyces cerevisiae is able to reduce diacetyl to below the sensory threshold. Therefore, characterization of the diacetyl reduction in commercial wine yeasts creates new opportunities to manage the risk of wine associated off‐flavours. Diacetyl reduction by two commercial S. cerevisiae strains was characterized in Pinot blanc grape must of the vintage 2012 with different initial diacetyl concentrations (0–50 mg/L). Highest diacetyl reduction was found in the first two days after wine yeasts were inoculated. No further decrease in diacetyl content was observed after the fourth day. All assays in which diacetyl was added showed the same final diacetyl concentration of approximately 2 mg/L. However, a significantly lower amount of diacetyl was found in grape must without adding diacetyl. The present results indicate that commercial wine yeasts are able to reduce much higher amounts of diacetyl than normally expected during the vinification procedure. However, the constant final diacetyl concentration indicates that diacetyl accumulation may be the result of wine matrix binding effects, which prevent a complete reduction by active wine yeasts. Copyright © 2013 The Institute of Brewing & Distilling. 相似文献