耐高温酒精活性干酵母在玉米酒精生产中的应用

在玉米酒精生产中,利用耐高温酒精活性干酵母进行酒精发酵实验,确定发酵温度、发酵液初始pH、酵母添加量、发酵时间对酒精发酵的影响,然后进行正交实验,确定最佳工艺条件为发酵温度37℃,发酵液初始pH为5.0,酵母添加量为1.2‰,发酵时间48h。发酵残液中酒精浓度9.96%。     

食品企业中下脚料的生物学应用探讨

以碎粉丝为原料,以面粉厂下脚为辅料,质量比为4:1,料水比为l:4.添加尿素作为氮源促进酵母生长,且利于后续发酵,添加量为原料的0.15%;添加淀粉酶、糖化酶、活性干酵母进行糖化发酵生产酒精.通过单因素实验、正交试验得到最佳的发酵工艺为:液化酶加入量为30 U/g、糖化酶加入量为100 U/g,酵母加入量为原料量的0.5%.在10L的发酵罐中进行模拟中试,经过72 h的发酵,酒精得率可达47.9%.其中,糖化酶加入量对酒精得率影响最大.     

人参果果酒的研制

以人参果为原料研制人参果果酒.对人参果护色、酶解后取汁,添加酵母进行酒精发酵,并进行澄清等工艺制得人参果果酒.通过正交试验确定酒精发酵的工艺条件为发酵温度24℃,发酵时间8d,酵母液添加量为4％;防褐变处理采用0.4％VC效果最佳;澄清采用皂土0.2％和明胶0.02％效果最佳.采用本方法可酿制出澄清透明、风味醇正的人参果果酒.     

复合型酒精发酵促进剂在淀粉质原料酒精发酵废液回用中的应用

本文探讨添加复合型酒精发酵促进剂对淀粉质原料酒精发酵废液回用的影响,从发酵过程中酵母数、成熟醪酒份等方面进行对比,表明在废液回用生产酒精实验中添加复合型酒精发酵促进剂能使酵母在较恶劣的生存条件正常生长,保证酒精发酵的正常进行。     

湖北海棠叶饮料产品开发

以湖北海棠叶为原料,采用酵母发酵,开发酒精风味茶饮料。通过单因素和正交试验考察发酵和饮料调配过程中各因素对饮料感官的影响。试验结果表明海棠叶最佳发酵条件为发酵时间48 h,料液比1.5∶100(g/mL),白砂糖添加量11%,酵母添加量0.15%;饮料最佳调配配方为白砂糖添加量4%,柠檬酸添加量0.03%,β-环糊精添加量0.02%。     

淀粉酶废液在酒精生产中的应用研究

将中温α-淀粉酶和糖化酶的发酵废液添加到利用木薯粉生产酒精中,通过实验研究酶废液的添加对酒精产量以及对发酵过程中酿酒酵母的影响.实验证明,添加酶废液可以提高0.6％的酒精产量;在酒精发酵过程中,对酵母生长的负作用不明显.     

有机氮和酵母细胞壁对赤霞珠高糖原料酒精发酵的影响

以高糖度葡萄汁（总糖为286.2 g/L）为发酵原料,对比酵母源有机氮FN502和酵母细胞壁CW101的不同添加时期对葡萄酒酵母酒精发酵速度、乙酸产量、最终酒精度及葡萄糖、果糖残留量的影响。结果表明,在酒精发酵进行1/3时同时添加有机氮FN502和酵母细胞壁CW101（各200 mg/L）,或在酒精发酵进行1/3时添加有机氮FN502（200 mg/L）,进行2/3时添加酵母细胞壁CW101（200 mg/L）,对葡萄酒酵母的酒精发酵速度及果糖消耗促进作用均高于对照及二者分别单独使用,最终酒精度均为16.9%vol,总残糖分别为1.50 g/L和1.58 g/L。有机氮FN502和酵母细胞壁CW101的添加均可显著降低乙酸的产量（P＜0.05）。     

金黄果果汁酒精发酵研究

采用分离选育的金黄果酵母和葡萄酒酵母分别对金黄果果汁进行酒精发酵试验,试验表明金黄果酵母的最适宜的发酵条件为:发酵温度25℃,发酵液pH3.5,金黄果酵母接种量3%;葡萄酒酵母的最适宜发酵条件为:发酵温度20℃,发酵液pH3.5,葡萄酒酵母接种量9%。金黄果酵母耐受的最大SO2添加量为80 mg/L,葡萄酒酵母耐受的最大SO2添加量为100 mg/L。     

α—氨基酸在葡萄酒发酵中的变化

研究分析了葡萄酒原料之中的α－氨基酸的含量,以及添加酵母营养粉之后对α－氨基酸含量的影响;继而分析了新酒之中α－氨基酸的含量。α－氨基酸在发酵过程中的消耗,表明了酵母菌对α－氨基酸的利用情况。所以,为保证酒精发酵的顺利进行,在酒精发酵之前,往葡萄汁中添加酵母营养物质是必不可少的。     

发酵条件对5种产酯酵母酒精发酵和产酯的影响

该实验探讨了供氧情况、发酵pH和温度对各种产酯酵母酒精发酵和产酯的影响。 结果表明,供氧情况对产酯酵母的酒精发酵和产酯均有显著影响,其中对克鲁斯假丝酵母的酒精发酵影响最大,对球拟酵母产酯影响最大。 发酵pH对产酯酵母的酒精发酵和产酯有一定影响,其中卡特多菲毕赤酵母的最适产酒pH为5.0,克鲁斯假丝酵母和汉逊酵母最适产酒pH为4.0,球拟酵母最适产酒pH 为6.0～7.0;上述4种产酯酵母的最适产酯pH均为6.7,高产酯酿酒酵母的最适产酯pH为6.0～7.0。 温度对各种酵母的酒精发酵和产酯有一定影响,其中卡特多菲毕赤酵母、克鲁斯假丝酵母、汉逊酵母和球拟酵母的最适产酒温度均为28 ℃;卡特多菲毕赤酵母的最适产酯温度为20 ℃,克鲁斯假丝酵母、汉逊酵母和高产酯酿酒酵母为24 ℃,球拟酵母为28 ℃。     

咖啡渣酿酒酵母的筛选及氮源优化营养条件的研究

该文首先对比不同酵母菌酿造咖啡渣酒的产气、产酒精和产香能力,而后探究氮源的种类和浓度对酵母菌酿造咖啡渣酒的影响。结果表明,在备筛的4株酵母菌中,Saccharomyces cerevisiae D254产气能力、产酒精能力和发酵液的感官评分都较佳,适用于酿造咖啡渣酒;氮源的加入能有效解决咖啡渣酒发酵迟缓的问题,提高酵母菌生物量、酒体酒精度,降低残糖含量;其中添加0.20%磷酸氢二铵作氮源时效果最好,生物量由1.21 g/L增加至1.73 g/L,酒精度由7.3%vol增加至9.6%vol,残糖由19.52 g/L降低至5.73 g/L,且所得咖啡渣酒具有咖啡特有的芳香,酒体柔和协调。     

以大豆糖蜜为原料高产乙醇酵母的筛选鉴定及其发酵特性研究

从大豆糖蜜中进行高产乙醇酵母的筛选和鉴定,并对其发酵特性进行研究。从大豆糖蜜中通过菌种的富集分离,TTC平板法初筛,耐乙醇能力及乙醇发酵能力的测定,筛选出一株乙醇产量达9.07%(V/V)的菌株P14。通过个体形态、菌落特征、生理生化及26S rDNA D1/D2区序列分析将菌株P14鉴定为酿酒酵母。研究了大豆糖蜜浓度及添加氮源和无机盐对酿酒酵母P14发酵生产乙醇的影响及酿酒酵母P14对大豆糖蜜中低聚糖的利用,结果表明大豆糖蜜浓度、添加氮源和无机盐对乙醇发酵影响显著,最佳的大豆糖蜜浓度为40%,添加氮源为1.2 g/L的蛋白胨;补加的无机盐为0.4 g/L MgSO4。在此培养基中发酵72 h后,糖蜜中90.10%的葡萄糖,91.23%的蔗糖,92.56%的棉籽糖和96.97%的水苏糖被酵母利用。因此大豆糖蜜中筛选出来的酿酒酵母P14具有较强的利用大豆糖蜜中的大豆低聚糖发酵产生乙醇的能力。     

葡糖醋杆菌J2-1静态发酵生产细菌纤维素的培养基优化

为提高葡糖醋杆菌（Gluconacetobacter）J2-1发酵生产细菌纤维素的产量,采用静态发酵方式,利用单因素试验对发酵培养基的碳源、氮源、乙醇、有机酸及无机盐进行优化,并在此基础上选取葡萄糖、MgSO4·7H2O和酵母粉添加量进行正交试验优化。结果表明,发酵培养基最优组分为：葡萄糖80 g/L、酵母粉18 g/L、乙醇2%（V/V）、Na2HPO4·12H2O 3 g/L、乳酸2 g/L、MgSO4·7H2O 0.4 g/L。在此优化发酵培养基条件下,葡糖醋杆菌J2-1静态发酵生产细菌纤维素产量达到9.34 g/L,是优化前的1.89倍。     

紫甘薯α-淀粉酶酶解液中紫色素的分离与糖液发酵生产乙醇的研究

本文综合利用紫甘薯资源,同时获得紫色素和糖液,糖液发酵制备乙醇。以大孔树脂分离紫甘薯α-淀粉酶酶解液后获得紫色素与糖液,考察氮源种类与添加量、酵母接种量、发酵时间对糖液发酵产乙醇含量的影响,通过正交实验优化糖液发酵生产乙醇工艺。实验结果表明,紫甘薯酶解液经HPD400型大孔树脂分离,紫色素的色价(E_{1 cm}1%)达到86.3(波长为530 nm),糖液中总糖含量达到55.5 mg/L;(NH₄)₂SO₄作为发酵氮源,(NH₄)₂SO₄添加量为3.0 g/100 mL、酵母接种量为1.5 mL、发酵时间为7 d,可得到13.0%vol乙醇。此方法获得了紫甘薯色素,副产物糖液发酵可生产乙醇,为紫甘薯的综合利用提供了思路。     

Effect of Sugar Catabolite Repression in Correlation with the Structural Complexity of the Nitrogen Source on Yeast Growth and Fermentation

Biomass and ethanol production by industrial Saccharomyces cerevisiae strains were strongly affected by the structural complexity of the nitrogen source during fermentation in media containing galactose, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Diauxie was observed at low galactose concentrations independent of nitrogen supplementation. At high sugar concentrations altered patterns of galactose utilisation were observed. Biomass accumulation and ethanol production depended on the nature of the nitrogen source and were different for baking and brewing ale and lager strains. Baking yeast showed improved galactose fermentation performance in the medium supplemented with casamino acids. High biomass production was observed with peptone and casamino acids for the ale brewing strain, however high ethanol production was observed only in the presence of casamino acids. Conversely, peptone was the nitrogen supplement that induced higher biomass and ethanol production for the lager brewing strain. Ammonium salts always induced poor yeast performance. The results with galactose differed from those obtained with glucose and maltose which indicated that supplementation with a nitrogen source in the peptide form (peptone) was more positive for yeast metabolism, suggesting that sugar catabolite repression has a central role in yeast performance in a medium containing nitrogen sources with differing levels of structural complexity.     

添加外源物质对红曲霉固态发酵产酯化酶的影响

以作者所在实验室保藏的红曲霉HQ-3菌株为实验菌株,采用固态发酵方法生产酯化酶,研究添加外源物质对产酯化酶的影响。结果表明,葡萄糖可以作为速效碳源促进红曲霉产酯化酶能力;新鲜酵母破壁液对红曲霉产酯化酶具有诱导作用,添加酵母破壁液发酵4 d,酯化力是对照组的1.30倍,达到106.87 mg/g;添加乙醇与乳酸对酯化力的作用效果明显,添加乙醇使酯化力提高到123.32 mg/g。     

Altered Patterns of Maltose and Glucose Fermentation by Brewing and Wine Yeasts Influenced by the Complexity of Nitrogen Source

Maltose and glucose fermentations by industrial brewing and wine yeasts strains were strongly affected by the structural complexity of the nitrogen source. In this study, four Saccharomyces cerevisiae strains, two brewing and two wine yeasts, were grown in a medium containing maltose or glucose supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Diauxie was observed at low sugar concentration for brewing and wine strains, independent of nitrogen supplementation, and the type of sugar. At high sugar concentrations altered patterns of sugar fermentation were observed, and biomass accumulation and ethanol production depended on the nature of the nitrogen source and were different for brewing and wine strains. In maltose, high biomass production was observed under peptone and casamino acids for the brewing and wine strains, however efficient maltose utilization and high ethanol production was only observed in the presence of casamino acids for one brewing and one wine strain studied. Conversely, peptone and casamino acids induced higher biomass and ethanol production for the two other brewing and wine strains studied. With glucose, in general, peptone induced higher fermentation performance for all strains, and one brewing and wine strain produced the same amount of ethanol with peptone and casamino acids supplementation. Ammonium salts always induced poor yeast performance. The results described in this paper suggest that the complex nitrogen composition of the cultivation medium may create conditions resembling those responsible for inducing sluggish/stuck fermentation, and indicate that the kind and concentration of sugar, the complexity of nitrogen source and the yeast genetic background influence optimal industrial yeast fermentation performance.     

Structural Complexity of the Nitrogen Source and Influence on Yeast Growth and Fermentation

The structural complexity of the nitrogen source strongly affects both biomass and ethanol production by industrial strains of Saccharomyces cerevisiae, during fermentation in media containing glucose or maltose, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Diauxie was observed at low glucose and maltose concentrations independent of nitrogen supplementation. At high sugar concentrations diauxie was not easily observed, and growth and ethanol production depended on the nature of the nitrogen source. This was different for baking and brewing ale and lager yeast strains. Sugar concentration had a strong effect on the shift from oxido‐fermentative to oxidative metabolism. At low sugar concentrations, biomass production was similar under both peptone and casamino acid supplementation. Under casamino acid supplementation, the time for metabolic shift increased with the glucose concentration, together with a decrease in the biomass production. This drastic effect on glucose fermentation resulted in the extinction of the second growth phase, probably due to the loss of cell viability. Ammonium salts always induced poor yeast performance. In general, supplementation with a nitrogen source in the peptide form (peptone) was more positive for yeast metabolism, inducing higher biomass and ethanol production, and preserving yeast viability, in both glucose and maltose media, for baking and brewing ale and lager yeast strains. Determination of amino acid utilization showed that most free and peptide amino acids present, in peptone and casamino acids, were utilized by the yeast, suggesting that the results described in this work were not due to a nutritional status induced by nitrogen limitation.     

不同有机氮源对葡萄酒发酵的影响

分别使用酵母浸粉和混合氨基酸作为模拟葡萄汁（36 °Bx）的有机氮源发酵葡萄酒,以保证葡萄酒的正常发酵和最终产品品 质。 通过测定发酵过程中的二氧化碳生成量、还原糖、可同化氮、甘油和挥发性化合物含量变化,比较酵母浸粉和混合氨基酸对葡萄酒 品质的影响。 结果表明,使用酵母浸粉耗还原糖量为295.7 g/L,生成乙醇97.20 g/L、甘油26.50 g/L、乙酸1.08 g/L和乙酸乙酯46.05 mg/L, 与使用混合氨基酸相比,多消耗还原糖130.47 g/L,多生成乙醇46.14 g/L、甘油7.95 g/L和乙酸0.54 g/L,增幅分别为78.95%、90.38%、 42.84%和99.35%。 使用酵母浸粉比混合氨基酸的发酵程度大,速度快。 因此,可用适量酵母浸粉替代混合氨基酸作为葡萄酒发酵的 氮源补充。     

Sucrose Fermentation by Brazilian Ethanol Production Yeasts in Media Containing Structurally Complex Nitrogen Sources

Four Saccharomyces cerevisiae Brazilian industrial ethanol production strains were grown, under shaken and static conditions, in media containing 22% (w/v) sucrose supplemented with nitrogen sources varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Sucrose fermentations by Brazilian industrial ethanol production yeasts strains were strongly affected by both the structural complexity of the nitrogen source and the availability of oxygen. Data suggest that yeast strains vary in their response to the nitrogen source's complex structure and to oxygen availability. In addition, the amount of trehalose produced could be correlated with the fermentation performance of the different yeasts, suggesting that efficient fuel ethanol production depends on finding conditions which are appropriate for a particular strain, considering demand and dependence on available nitrogen sources in the fermentation medium.