优良酿酒酵母菌的发酵性能研究

从甘肃武威产区美乐葡萄中筛选出3株优良酿酒酵母菌,对其发酵性能进行了比较.测定了3株酿酒酵母菌和对照菌株在葡萄汁小瓶发酵时的CO2失重量、产酒精能力和残糖量,并对其在酒精耐受性、SO2耐受性、高糖耐受性、酸耐受性、受温度变化的影响等各方面的指标进行了综合比较.结果显示菌株NJZGM1的综合性能最佳,具有应用于我国地区特色葡萄酒生产的潜能.     

中高温大曲发酵过程酿酒酵母的筛选与鉴定

为了确立一种简单且高效筛选中高温大曲发酵过程中酿酒酵母的方法,利用TTC显色实验对中高温大曲发酵过程中的22株酵母菌进行了产酒精能力初筛,并联合酵母菌麸曲发酵力和液态酒精发酵实验对初筛到的酵母菌株进行复筛和三级筛,最后通过分子生物学鉴定,确定4#和8#酵母菌株均为酿酒酵母(Saccharomyces cerevisiae)。首次对中高温大曲发酵全过程酵母菌的变迁做了较为细致的研究,将鉴定结果比对中高温大曲发酵过程酵母菌变迁表1可知,两株菌均分离自主发酵阶段。4#菌来自于主发酵2d曲心,8#菌分离于主发酵4d的曲皮。     

高产甘油低产H2S葡萄酒优良酵母菌株筛选及其酿酒特性

为获得中国本土优良酵母,提高葡萄酒感官特性,通过对采自新疆鄯善地区、宁夏广夏三基地的40 株野生酵母菌株进行实验室酿酒实验,筛选到两株高产甘油、低产H2S的葡萄酒优良酵母菌株H02、E22。分别于2010、2011年连续2 a对这2 株菌进行了10～20 L酒厂发酵实验并研究其酿酒特性。酒样理化指标结果符合国家标准GB 15037-2006《葡萄酒》要求,感官品尝分析结果与对照商业酵母VL1、RC212、C2C的差异性不显著（P＞0.05）,感官品质相当,筛选出的野生酵母菌株有着优良的酿酒特性。     

耐低pH酵母菌的分离及其对酸胁迫环境的适应性

为获得适用于高酸果汁发酵的酵母菌,本文从蓝莓和红树莓自然发酵的果汁中,分离筛选出2株在pH2.3、pH4.8时生长良好的酵母菌,经形态学、生理生化及分子生物学鉴定,编号J-23为季也蒙有孢汉逊酵母菌(Hanseniaspora guilliermondii),编号L-6为酿酒酵母菌(Saccharomyces cerevisiae)。在pH2.3、pH4.8酸环境下,以市售果酒酵母菌和葡萄汁有孢汉逊酵母菌为对照菌株,对J-23、L-6酵母菌的耐酸适应性进行研究,利用扫描电子显微镜(SEM)和透射电子显微镜(TEM),分别对细胞膜、细胞壁及胞内结构进行观察,并对酸胁迫中过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活力进行测定,结果显示:J-23和L-6酵母菌菌体形态无明显的凹陷、褶皱等现象,细胞结构清晰,且液泡变大;当pH2.3时,J-23酵母菌与对照菌1、L-6酵母菌与对照菌2中SOD酶活力分别为790.98、768.71、795.02、772.15 U/mL;CAT酶活力分别为389.81、370.85、385.17、373.31 U/mL。J-23和L-6菌株中2种酶活力均显著高于对照菌株,抗氧化能力增强,使菌株可以更好地适应酸胁迫环境。     

产β-糖苷酶菌株的筛选及酶活的研究

利用对硝基苯酚-β-D-葡萄糖苷为底物筛选酿酒酵母菌,得到1株高产糖苷酶的酿酒酵母菌。以该菌株作为实验菌株,研究该菌株的酶活特性,对酿酒酵母菌酶活性测定条件进行研究。通过单因子试验,确立了该菌株发酵对硝基苯酚-β-D-葡萄糖苷酶的最适培养条件：pH4．0,温度为40℃,发酵时间为6h。高浓度的葡萄糖、果糖对酶活没有抑制作用,酒精度超过14％vol时对产酶有抑制作用。     

适于生产生物柴油的产油酵母菌的筛选

该文从土壤中筛选出10株产油脂的酵母菌,经摇床培养复筛确定其中2株优良产油酵母菌JM-B、JM-D。通过对2株菌生理生化特性的试验,进一步对其发酵性能进行研究并对酵母菌株油脂脂肪酸组成进行测定。菌株JM-D油脂脂肪酸组成与植物油相似,适合用于发酵生产生物柴油,是今后发酵生产生物柴油的优良菌株。     

浓香型白酒生产酵母菌筛选和特性研究

从四川省酿酒研究所生产基地采集的黄浆水、酒曲、窖泥等含菌材料中分离筛选得酒用酵母菌。经筛选得到产酒精能力强的2株酵母菌,对2株酒用酵母在麦芽汁小瓶发酵时的CO₂失重量和其对酸的耐受性等进行了综合比较。结果表明,菌株1的综合性能最好     

笃斯越桔中酿酒酵母菌的筛选、鉴定及特性研究

从口感好、自然发酵的笃斯越桔果汁中分离出140株酵母菌.经过对酵母菌产气、产酒精情况的测定以及发酵酿酒后感官评定,筛选出4株酵母菌,分别编号为C13、C18、D07和D15.对这4株酵母菌进行形态学和生理学特征鉴定以及26SrDNA D1/D2区序列分析,最终鉴定出4株酵母菌为同一种菌,即酵母属(Saccharomyces )中的酿酒酵母(Saccharomyces cerevisiae).结合商业葡萄酒活性干酵母进行比较分析,选择优良菌株D15作为实验菌株,测定其生物特性,结果表明D15具有较好的发酵特性、耐受特性和快速生长特性.D15在20°Bx、pH 3.5笃斯越桔果汁中24℃发酵9d,残糖量为2.8 g/L,酒精度(V/V)为12.5%,可以作为笃斯越桔酒酿造的优选菌株.     

中药淡豆豉不同发酵阶段微生物变化及优势菌的筛选

本文考察了中药淡豆豉不同发酵阶段微生物的动态变化规律,并筛选优势发酵菌,为淡豆豉生产标准化提供依据。分别采集淡豆豉不同发酵阶段(25%,50%,75%,100%)的样品,采用含青蒿、桑叶提取液的培养基培养发酵菌,通过对分离菌株的蛋白酶、β-葡萄糖苷酶和纤溶酶活性筛选优势发酵菌。结果显示,淡豆豉发酵过程首先是微球菌和酵母菌占优势,然后霉菌快速生长,细菌和酵母菌受抑制,发酵后期细菌和酵母菌再度生长;共分离筛选出9株菌,包含细菌1株,酵母菌4株和霉菌4株,其中1号酵母菌和2号毛霉的酶活总水平较高,分别为(29.510±0.008)IU/g和(29.578±0.012)IU/g。淡豆豉发酵过程菌群交替更迭,菌种多样,以霉菌和酵母菌为主,通过三种酶活测定结果初步筛选出优势菌。     

发酵米浆中高发酵性能酵母菌和乳酸菌的筛选和鉴定

为了实现传统米发糕的规范化工业生产,从传统米发糕的发酵米浆中筛选发酵性能较好的菌株,并进行种属鉴定。首先从发酵米浆中分离出40 株酵母菌的疑似菌和30 株乳酸菌的疑似菌。经杜氏小管产气、发酵液特性和生长曲线分析三级筛选,最终得到1 株高发酵性能的酵母菌。经革兰氏染色等初筛、pH 值和生长曲线分析,最终得到1 株高发酵性能的乳酸菌。最后对两株菌株进行菌落形态观察和生理生化种属鉴定,确定分别为卡斯特酒香酵母和植物乳杆菌。     

蛹虫草高产胞外虫草素和虫草多糖的诱变育种

通过诱变获得高产胞外虫草素和虫草多糖的蛹虫草菌株.采用紫外线诱变(UV)、化学诱变(LiCl)、复合诱变(UV-LiCl) 3种方式对蛹虫草孢子进行诱变;发酵检测存活菌株的胞外虫草素和虫草多糖的含量.结果:以胞外虫草素为指标,3种诱变方式的最大正突变率分别为化学突变(29.2％)＞紫外突变(28.6％)＞复合诱变(26.5％);以胞外多糖为指标,最大正突变率分别为紫外诱变(35.7％)＞复合诱变(33.3％)＞化学诱变(27.0％).紫外诱变突变株Z-5-1胞外虫草素产量达0.842g/L,比出发菌株高311％;紫外诱变突变株Z-4-7胞外虫草多糖产量达5.250g/L,比出发菌株高148％.在连续培养5代后,仍具有较好的遗传稳定性.紫外诱变能获得较高的蛹虫草正突变率,同时能获得高产虫草素、虫草多糖的突变株.     

桑黄菌原生质体诱变及发酵菌株选育

对桑黄菌原生质体进行紫外线与He-Ne激光复合诱变处理,经过3代筛选,筛选出了5株变异株SJ1～SJ5。5株变异株都具有较稳定的遗传性,多糖发酵产量比出发菌株均有所提高,其中SJ4比出发菌株增产57.74%,表现最优,酯酶同工酶分析表明SJ4与出发菌株相比酯酶酶谱发生了变化。     

Release of cell wall polysaccharides from Saccharomyces cerevisiae thermosensitive autolytic mutants during alcoholic fermentation

In order to increase the release of cell wall polysaccharides during alcoholic fermentation, a wine strain of Saccharomyces cerevisiae was subjected to UV mutagenesis to obtain thermosensitive autolytic mutants affected in cell wall integrity. Five mutants and the parental strain were utilized in fermentation trials conducted at 28, 32 and 34 degrees C. Results showed that at all temperatures the mutant strains released into the medium a higher polysaccharide quantity than the parental strain. In particular, at 28 degrees C there was a doubling of these macromolecules. At the end of alcoholic fermentation, all strains showed at 28 degrees C elevated and similar levels of viable cells; at 32 degrees C this parameter remained high for mutant strains ts16 and ts39 and the parental strain; at 34 degrees C all strains underwent a drop in cell viability, which was less intense in the case of strain ts16. As a relationship between cell viability and the quantity of polysaccharides released by the yeast strain was not found, it can be assumed that the mutation led to cells with a less stable wall and thus an easier release of macromolecules into the medium.     

Analysis of β-glucans and chitin in a Saccharomyces cerevisiae cell wall mutant using high-performance liquid chromatography

We have previously shown that mutations in the yeast KNR4 gene resulted in pleiotropic cell wall defects, including resistance to killer 9 toxin, elevated osmotic sensitivity to SDS and increased resistance to zymolyase, a (1→3)-β-glucanase. In this report, we further demonstrated that knr4 mutant cells were more permeable to a chromogenic substrate, X-GAL, suggesting that the mutant cell walls were leakier to certain non-permeable molecules. To determine if these defects resulted from structural changes in the cell walls, we analysed the alkali-insoluble cell wall components using HPLC assays developed for this purpose. Comparative analysis using four isogenic strains from a ‘knr4 disrupted’ tetrad demonstrated that mutant cell walls contained much less (1→3)-β-glucan and (1→6)-β-glucan; however, the level of chitin, a minor cell wall component, was found to be five times higher in the mutant strains compared to the wild-type strains. The data suggested that the knr4 mutant cell walls were dramatically weakened, which may explain the pleiotropic cell wall defects.     

常压室温等离子体诱变技术选育高产Monacolin K紫色红曲霉突变株

采用常压室温等离子体（atmospheric and room temperature plasma,ARTP）射流诱变技术处理紫色红曲霉菌株M-1,选育高产Monacolin K突变株,为Monacolin K的发酵生产提供优良菌株。确定等离子体处理条件,采用稀释平板培养法挑选突变株,高效液相色谱法分析突变株发酵液的Monacolin K产量,借助扫描电子显微镜观察诱变处理前后菌体微结构特征。结果表明：ARTP对紫色红曲霉菌株具有较强的致死和致突变效应,ARTP处理30 s紫色红曲霉菌株诱变致死率达到84%,处理90 s时其致死率约为92.6%,可获得较高的正突变率（23.8%）;筛选得到突变株23的Monacolin K产量达到428.14 mg/L,较初始菌株M-1提高了111%。ARTP作用于紫色红曲霉,可引起菌株形态学特征发生改变,突变株的菌落色泽、菌丝体和孢子形态等特征均有一定变化;ARTP产生的活性粒子可透过细胞膜作用于DNA物质,引起DNA发生多样性损伤、不完全修复突变,形成遗传稳定的突变株。     

紫外诱变法选育酒酒球菌乙醇胁迫耐受菌株及其发酵性能研究

该研究以酒酒球菌（Oenococcus oeni）SD-2a为研究对象,采用紫外诱变法选育乙醇胁迫耐受突变菌株,评价其在乙醇胁迫条件下的生长能力,并测定其产β-葡萄糖苷酶活性及其在模拟酒中苹果酸、乳酸含量及活菌数的变化。结果表明,分离筛选到3株乙醇胁迫耐受性好的突变菌株,分别编号为UVe1、UVe2、UVe3,在高体积分数乙醇（12%和14%）胁迫环境下,3株突变菌株的生长速度均显著高于出发菌株SD-2a（P＜0.05）;突变菌株UVe2的β-葡萄糖苷酶活性显著高于出发菌株SD-2a和对照菌株L-450（P＜0.05）;在模拟酒中,3株突变菌株的苹果酸降解与乳酸生成速度均显著高于出发菌株SD-2a（P＜0.05）,且突变菌株UVe1和UVe2的存活率显著高于出发菌株SD-2a（P＜0.05）;综上,突变菌株UVe2具有优良商业酒酒球菌的潜力。     

利用水解淀粉高产衣康酸菌株的诱变育种

利用葡萄糖产衣康酸的土曲霉为出发株,通过紫外、Co^60等诱变方法的处理,筛选得到能利用部分水解的不溶性淀粉的菌株。同时研究诱变剂的处理剂量、致死率;并进行产酸情况的测定,糖的利用率和传代稳定性的研究。最后得到几株能够高产的土曲霉菌株。其中FZ—12—4菌株产酸率达到6．30g／100ml,产酸率比出发菌株提高45％。     

利用易错PCR构建酱油酿造用T酵母spt15突变库

为得到酱油酿造优良性状的微生物,对酱油酿造用T酵母进行研究。首先利用易错聚合酶链式反应（polymerase chain reaction,PCR）技术构建spt15（可编码TATA结合蛋白）的突变基因库,然后重组于表达载体YEplac195中,并导入尿嘧啶营养缺陷型菌株W303和WM2中筛选。结果表明：在不同盐质量分数的固体培养基中经筛选获得4?个最佳突变菌株,其具有耐盐优势,在酱油发酵中可产生较高的氨基酸态氮。经PCR产物测序可知,重组质粒中目的基因的序列有碱基的增添、缺失和替换。     

Impact of lignin composition on cell‐wall degradability in an Arabidopsis mutant

An Arabidopsis mutant that does not deposit syringyl‐type lignin was used to test the hypothesis that lignin composition impacts cell‐wall degradability. Two lines of the ferulate‐5‐hydroxylase‐deficient fah1 mutant and the wild‐type control line were grown in the greenhouse. In Experiment 1, the plants were harvested at the mature seed stage. For Experiment 2, plants were harvested 5, 6, 7 and 8 weeks after sowing. In both experiments stems were collected and analysed for cell‐wall concentration and composition, and in vitro degradability of cell‐wall polysaccharide components by rumen micro‐organisms. The absence of syringyl‐type lignin was confirmed for the mutant lines by nitrobenzene oxidation and pyrolysis‐GC‐MS. Lignin concentration was the same for all three Arabidopsis lines, at all stages of maturity. The Arabidopsis stems were similar to forage legumes in that the potentially degradable cell‐wall fraction was very quickly degraded. Cell‐wall polysaccharide degradability did not differ among the Arabidopsis lines in the first experiment after 24‐h fermentations, but the cell‐wall polysaccharides of the fah1‐2 mutant line were less degradable after 96‐h than either the wild‐type or the fah1‐5 mutant. In contrast, in Experiment 2 no differences among lines were found for cell‐wall polysaccharide degradability after either 24‐ or 96‐h fermentations; however, signficantly higher levels of ester‐bound ferulic acid were found in the walls of the fah1 mutant lines. As expected, increasing stem maturity was correlated with reduced degradation of cell‐wall polysaccharides. These experiments indicate that either lignin composition, as measured by syringyl‐to‐guaiacyl ratio, does not alter cell‐wall degradability in Arabidopsis, or that the fah1 mutation has other effects on the cell walls of these mutants such that the impact of the change in syringyl‐to‐guaiacyl ratio is masked. © 1999 Society of Chemical Industry     

真姬菇液体培养用菌种及其营养因子筛选

以菌体生长速度和多糖产量为依据,从5株真姬菇菌种中筛选出1株在液体培养中生长良好、多糖产量高的菌株,用于营养条件优化,并分析了各菌株在液体培养中的生长与多糖产生特点。采用Plackett-Burman试验设计,对影响真姬菇生长及产多糖的相关因子进行了筛选。在培养过程中,所有菌株均呈Logistic生长,胞内多糖和胞外多糖均呈先上升后下降的趋势,在菌体的对数生长期达到峰值。菌株ZJ-029的生长速度和多糖产量最大。在11种营养因子中,葡萄糖、麦芽糖、玉米淀粉和豆粕粉对真姬菇菌丝生长有显著影响;葡萄糖、麦芽糖和MgSO_4对胞外多糖产量有显著影响;葡萄糖、玉米淀粉和MgSO_4对胞内多糖产量有显著影响。在PB设计的水平范围内,各因子对各指标的影响均为正效应。