利用酵母双杂交法检测甘蓝SCR与SRK之间的相互作用

为深入研究甘蓝S位点受体激酶(SRK)和S位点富含半胱氨酸蛋白(SCR)间相互识别的分子机理,以具有典型自交不亲和性的甘蓝D3为材料,利用巢式PCR分别扩增SRK胞外域(eSRK)和SCR,通过酵母双杂交检测二者之间的相互作用。并利用同源重组技术将eSRK与GAL4报告基因DNA活化域融合(pGADT7eSRK)以及SCR与GAL4报告基因DNA结合域融合(pGBKT7SCR)。两种重组质粒分别转化酵母Y187和Y2HGold后未出现自激活现象。融合的二倍体酵母(pGADT7eSRK× pGBKT7SCR)能在选择性固体培养基(SD/–Ade/–His/–Leu/–Trp/X-a-Gal/AbA)上生长,并且菌落呈蓝色。结果表明, eSRK与SCR蛋白能够相互结合, 为深入研究二者作用位点成功建立了一个技术平台。     

利用酵母双杂交系统鉴定羽衣甘蓝臂重复蛋白(ARC1)与结球甘蓝S位点受体激酶(SRK)激酶结构域的相互作用

S位点受体激酶(SRK)和臂重复蛋白(ARC1)是芸薹属植物自交不亲和反应的两种重要的信号元件,SRK-ARC1之间的互作决定着自交不亲和反应的进程。本研究利用PCR技术获得结球甘蓝(Brassicaoleracea var.capitata)SRK激酶结构域(SRKJ)的编码区以及羽衣甘蓝(B.oleracea var.acephala)ARC1基因不同片段长度的基因组DNA与编码区,分别构建以pGBKT7为载体的长度依次递减的ARC1a、ARC1b、ARC1c和ARC1d的重组诱饵质粒和以pGADT7为载体的SRKJ的重组猎物质粒,并将重组质粒转化酵母菌株进行蛋白质相互作用检测。结果显示:羽衣甘蓝ARC1存在5个连续的臂重复区,与结球甘蓝ARC1的氨基酸序列一致性达到98%;构建的重组表达载体在酵母细胞中无毒性和自激活作用产生;3个实验组Y2HGold[pGBKT7-ARC1a]×Y187[pGADT7-SRKJ]、Y2HGold[pGBKT7-ARC1c]×Y187[pGADT7-SRKJ]和Y2HGold[pGBKT7-ARC1d]×Y187[pGADT7-SRKJ]同时激活了4种报告基因AUR1-C...     

Yeast extract, brewer’s yeast and spirulina in diets for Labeo rohita fingerlings affect haemato-immunological responses and survival following Aeromonas hydrophila challenge

A feeding trial was conducted for 60 days to study the immunomodulatory role of three different immunostimulants yeast extract (YE), brewer’s yeast (BY) and spirulina (SP) in Labeo rohita fingerlings. Four hundred and fifty fingerlings (avg. wt 3.35 ± 0.15 g) were randomly distributed in ten treatments and fed with either of ten iso-nitrogenous and iso-caloric semi-purified diets, prepared with three incremental levels (1%, 2% and 4%) of different immunostimulants except the control. Growth parameters did not vary significantly (p > 0.05) among the experimental groups. Haematology and serum parameters was performed before Aeromonas hydrophila challenge whereas respiratory burst activity was analysed following challenge. The respiratory burst activity, total leucocyte count, serum total protein and globulin was significantly higher (p < 0.05) in YE 1% supplemented group. The survival (%) after challenging with A. hydrophila was also highest in the YE fed groups. The results indicate that among the different sources and levels of immunostimulants, YE at lower inclusion level is more effective in promoting the immune status of L. rohita fingerlings.     

酵母蛋白促杂交瘤细胞和骨髓瘤细胞克隆化和诱生腹水的作用

从隐球酵母科酵母菌提取的酵母蛋白对杂交瘤细胞和骨髓瘤细胞具有促生长、促克隆率和诱生腹水的作用.在单个细胞克隆化不加饲养细胞的情况下,克隆率在50％以上.酵母蛋白对抗李氏杆菌杂交瘤细胞促生长作用为对照组的9.8倍,应用ELISA法测定培养上清抗体反应结果,吸光度值平均增加0.20.在不预先注射液体石蜡的情况下,将杂交瘤细胞或骨髓癌细胞悬于含酵母蛋白的培养液中,直接注入BALB/c小鼠腹腔,无论腹水出现时间还是产量收获均与预先注射液体石蜡常规对照组相似(P>0.05),且腹水效价实验组较常规液体石蜡对照组增加近1倍.     

酵母双杂交表达载体pGBKT7_NPR1与pGADT7_NPR1的构建及酵母菌的转化

NPR1是水杨酸介导的系统获得性抗性（SAR）途径中不可或缺的一个转录辅助因子。在SA诱导下,NPR1被转运至细胞核内并与一些转录因子结合,以启动下游基因的表达。本研究通过PCR扩增获得拟南芥中NPR1基因CDS序列,经过限制性内切酶酶切后在T4连接酶作用下分别克隆至pGBKT7与pGADT7酵母表达载体上,并成功将其转化至Gold酵母菌株中。为利用酵母双杂交筛选NPR1参与形成的转录复合体中其它可能存在的蛋白质并阐明其在植物防御信号传导途径中的互作模式奠定了基础。     

冰葡萄酒发酵过程中成分变化的研究

[目的]研究冰葡萄酒的品质及发酵过程中成分的变化。[方法]以辽宁五女山米兰酒业有限公司提供的威代尔(Vidal)冰葡萄汁为酿酒材料,基于3种发酵温度、3种菌株和9种接种量,设计正交试验,对酿造冰葡萄酒发酵过程中的成分进行分析。[结果]冰葡萄酒成品的理化指标为:酒精度11%、糖度27.8°Brix、干浸出物244.3 mg/L、游离SO236.4 mg/L、总SO265.0 mg/L、氨基酸367.8 mg/L、总酸11.4 mg/L,挥发酸561.0 mg/L。根据冰葡萄酒的实际酿造结果和品质综合评价,冰葡萄酒的发酵温度为12℃,莱蒙特D47为酿造冰葡萄酒质的最佳的酒酵母。[结论]研究可为冰葡萄酒发酵条件的优化及加工技术的提高提供理论依据,同时为其他冰冻类水果的加工研究奠定基础。     

酵母β-葡聚糖对早期断奶羔羊瘤胃氮代谢的影响

选用甘肃肉用绵羊新品种选育群初生公羔20只,随机分为5组,观测了饲粮中添加不同剂量（0、37．50、75．00、112．50、150．00mg／kg）酵母β-葡聚糖对早期断奶羔羊瘤胃氮代谢参数的影响,结果表明,添加酵母β-葡聚糖对日龄82d的羔羊瘤胃液中总氮、氨氮和蛋白氮含量均没有显著影响（P〉0.05）,75．00mg／kg的添加剂量组尿素氮含量有高于对照组的趋势（P=0．091）,食前150．00mg／kg添加剂量组血清尿素氮显著低于对照组（P〈．05）。     

Effect of concentrate level and live yeast (Saccharomyces cerevisiae) supplementation on Texel lamb performance and carcass characteristics

An alternative additive that improves the nutrient use by ruminants and reduces the use of antibiotics is desirable in order to promote a sustainable and ecological animal production. The objective of the study was to evaluate the supplementation of live yeast (Saccharomyces cerevisiae) in diets of finishing lambs fed with different concentrate levels on their performance, carcass traits, metabolic profile and eating pattern. The trial was carried out at Institute of Animal Science and Pastures, in Nova Odessa city, Brazil, with 24 Texel lambs, 18.0 Kg±1.14 Kg of initial live weight, and averaging 70 days-old, kept in individual pens. The animals were fed with diets comprising hay and concentrate rations in two different proportions (80 or 60%, on DM basis), supplemented or not with live yeast. A completely randomized blocks design, on a 2×2 factorial arrangement (2 concentrate levels with presence or absence of live yeast), was used to compare the means. Supplementation with live yeast did not affect (P>0.05) DM intake, feed conversion, daily live weight gain, total live weight gain and final live weight, although it increased cold carcass weight (P=0.0135) and external carcass length (P=0.0104) regardless of the concentrate feed proportion in the diet. On carcass traits, supplementation with live yeasts did not modify (P>0.05) cold carcass dressing percentage, compactness index, leg length, external chest depth, buttock circumference, carcass fat cover score, and conformation score. Lambs fed diets with greater concentrate level (80%) significantly increased (P<0.05) DM intake, feed conversion, daily live weight gain, total and final live weight gains, cold carcass weight, compactness index, external carcass length, external chest depth, and buttocks circumference and did not modify (P>0.05) the cold dressing percentage, degree of carcass fat cover score and conformation. The live yeast decreased plasmatic lactate (P<0.05), did not affect (P>0.05) plasmatic glucose, and reduced (P<0.05) serum urea, only on the higher concentrate diets. The proportion of concentrate did not affect (P>0.05) the plasmatic glucose and lactate. Supplementation of live yeasts did not improve (P>0.05) the rib eye dimensions and the carcass subcutaneous fat thickness measured by ultrasound. Lambs on diet with greater concentrate level had smaller (P<0.05) ingestion and rumination time. The supplementation with live yeast increased the rumination time and did not modify the ingestion time. It can be concluded that live yeast supplementation increases the weight and the carcass length, regardless of the amount of concentrate added to the diet.     

海藻中产油脂酵母菌的分离与鉴定

[目的]从湛江海藻中分离筛选产油脂酵母菌。[方法]通过稀释凃布法及苏丹黑染色法,从海藻中分离产油脂酵母菌,对目标菌进行菌落及显微形态观察,同时做碳源同化试验、氮源同化试验、产类淀粉化合物试验、产酯试验、产酸试验、脲酶试验等生理生化试验进行进一步分析,再通过26S rDNA D1/D2区域的系统发育树分析进行分子生物学水平鉴定。[结果]共筛选到2株油脂产生菌,经多相分类鉴定,菌株HY12属于Rhodotorula mucilaginosa;菌株HY16属于Pseudozyma antarctica。[结论]该研究可为开发海藻中产油脂酵母菌提供理论依据。     

乳酸菌和酵母菌混合培养条件优化研究

对乳酸链球菌和酿酒酵母菌进行混合培养发酵,通过讨论溶氧、温度、pH值、接种量、接种比例和培养基对其发酵结束时活菌数的影响,确定两种菌在前期28℃摇床150 r/min培养24h,后期37℃静置24h,初始pH为7.5,接种量为0.5%,接种比例乳酸菌:酵母菌为1%:0.5%,培养基为YEPD时,两者的活菌数水平达到最高值,乳酸菌达5.0×108CFU/mL,酵母菌达1.0×108CFU/mL。