马克斯克鲁维酵母菌生长条件的优化及其代谢分泌物分析

应用1株藏灵菇（kefir粒）分离菌株——马克斯克鲁维酵母菌的优化培养,筛选了在设计条件下的最适培养发酵时间、pH值、温度及主要培养基成分比例,优化了该菌生长发酵的生态环境,获得了一种优化的培养发酵基料;通过对该基料营养及健康活性因子的检测分析,评估了该基料对人体提供营养和保健作用的可能性及应用前景。     

The enrichment and retention of ascorbic acid in rotifers fed microalgal diets

The enrichment and retention of ascorbic acid (AA) was investigated in rotifers Brachionus plicatilis fed on microalgae ( Nannochloropsis oculata and Isochrysis sp. (T.ISO)) and baker's yeast Saccharomyces cerevisiae . The concentrations of AA of the rotifer diets used in the study differed significantly: 4200 μg g⁻¹ of dry weight in Isochrysis sp. (T.ISO), 2600 μg g⁻¹ in N. oculata and only 77 μg g⁻¹ in S. cerevisiae . Rotifers contained 620 μg AA g⁻¹ prior to the experimental feeding. When subsequently fed for 3 h on microalgae at a ration of 0.13 mg dry microalgae per 10⁶ rotifers rapidly and efficiently increased their content of AA: Isochrysis sp.-fed rotifers contained 1600 μg AA g⁻¹ and N. oculata -fed rotifers contained 1100 μg AA g⁻¹. Concentrations were boosted by a further feeding of a second ration of algae at three times the initial feeding ration; 21 h later, Isochrysis sp.-fed rotifers contained 2500 μg AA g⁻¹ and N. oculata -fed rotifers contained 1700 μg AA g⁻¹. This represented a 180% and 310% increase in the pre-feeding vitamin concentrations in Isochrysis sp. and N. oculata -fed rotifers, respectively. There were no significant changes in AA concentration in rotifers fed a similar ration of yeast throughout the feeding period (520-620 μg AA g⁻¹). Rotifers retained AA during a subsequent 24 h non-feeding period, with no significant changes in the concentrations in any of the rotifer groups. The production of rotifers rich in AA may be particularly valuable for the culture of fish larvae that have a high requirement for the vitamin.     

临沂市富硒小麦优质高产栽培技术

为推动临沂富硒小麦的生产发展,对小麦的播种、田间管理、病虫害防治、施硒技术和适期收获等一系列的栽培技术进行了介绍.     

塔式发酵罐连续培养面包酵母的研究

以糖密为原料用塔式发酵罐连续培养面包酵母,单位时间内干酵母的产量是间歇发酵法的2～3倍．且具有明显的设备投资少,占地面积小,质量稳定,节省人力、物力,管理方便等特点。     

酵母硒和枣粉对白羽肉鸡肌原纤维蛋白构象、功能及消化特性的影响

本试验旨在研究酵母硒和枣粉对白羽肉鸡肌原纤维蛋白构象、功能及消化特性的影响.选用1日龄、体重相近、健康的白羽肉鸡180只,随机分成6组,每组3个重复,每个重复10只.6个组分别为CK组(基础饲粮)、J组(基础饲粮+8％枣粉替换8％玉米)、0.3S组(基础饲粮+0.3 mg/kg酵母硒)、0.6S组(基础饲粮+0.6 m...     

酵母硒和亚硒酸钠对育肥湖羊组织硒含量、抗氧化能力、肉品质及货架期的影响

本研究旨在比较饲粮中添加酵母硒和亚硒酸钠对育肥湖羊组织硒含量、抗氧化能力、肉品质及货架期的影响.选取24只湖羊公羔[初始体重(31.99±3.60)kg],随机分为3组,每组8只.3组湖羊分别饲喂基础饲粮(含硒0.54 mg/kg DM,对照组)以及在基础饲粮中分别添加0.4 mg/kg(以硒计)酵母硒(SY组,饲粮实...     

牙鲆酵母双杂交cDNA文库的构建及文库质量鉴定

为了研究牙鲆(Paralichthys olivaceus)免疫及抗病相关蛋白和大分子物质的功能及相互作用机制,构建了牙鲆酵母双杂交cDNA文库.原始文库滴度为1.6×106 CFU/mL,随机选取单克隆菌落进行PCR扩增,根据PCR扩增结果表明插入片段大部分大于500 bp,平均长度约为1.5 kb,随机调取了115个EST进行了序列测定.扩增后放大文库库容约为1.8×1012CFU.转化酵母后,文库转化效率为3.6×105CFU/μg,文库库容为5.4×106CFU.牙鲆酵母双杂交文库的构建成功为鲆蝶类免疫机理的研究,尤其是信号分子通路研究提供有效的工具.     

Growth,nitrogen gain and indispensable amino acid retention of pacu (Piaractus mesopotamicus,Holmberg 1887) fed different brewers yeast (Saccharomyces cerevisiae) levels

A feeding‐and‐digestibility trials were carried out to evaluate the efficacy of replacing fishmeal with brewers yeast Saccharomyces cerevisiae in diets of pacu, Piaractus mesopotamicus, juveniles. The feeding trial was conducted during 54 days with 450 fish (26.6 ± 1.7 g) testing six isonitrogenous (270 g kg^?1 crude protein) and isoenergetic (19 MJ kg^?1 crude energy) diets, with increasing yeast level to replace 0 (control), 30, 35, 50, 70 or 100% of dietary fishmeal. Growth performance and feed utilization increased with increasing dietary yeast level until 50% fishmeal replacement. Protein retention efficiency was higher in fish fed 35 and 50%. Protein digestibility and the fillet hue (the red/green chromaticity) were not significantly different among all treatments. Nitrogen gains were significantly improved in fish fed 35% replacement diet compared to fish fed the control diet. The retentions of indispensable amino acids tended to increase with increasing dietary yeast levels, with maximum retention at 35–50%. On the basis of our results, replacing 50% fishmeal by yeast in pacu diets successfully improved feed efficiency and growth performance, and reduced nitrogen losses, thereby reducing the nitrogen outputs from fish farms.     

夏季日粮中添加酵母硒对柴鸡生产性能及蛋中硒沉积的影响

选用30周龄河北柴鸡360只,随机分成5组,每组3个重复,基础日粮含硒(Se)0.08 mg/kg,试验组Se的添加水平分别是0、0.15、0.3、0.5、1.0 mg/kg;预试期1周,试验期为7周。探讨在夏季,添加不同水平的酵母硒对产蛋柴鸡生产性能及蛋中硒沉积的影响。结果表明,日粮中添加0.5 mg/kg Se,产蛋率极显著高于其它试验组(P<0.01),而蛋重差异不显著(P>0.05);日粮中添加1 mg/kg Se时,蛋中硒含量达到最高,为1.91μg/g。     

水稻条纹病毒外壳蛋白自身互作的活性区段研究

水稻条纹病毒(Rice stripe virus,RSV)的外壳蛋白(coat protein,CP)参与病毒转录、复制等多个生物学过程。病毒蛋白之间的互作对病毒侵染活性非常重要,在明确RSV外壳蛋白CP能够自身互作的基础上,通过构建CP蛋白N端、M区段和C端(CP-N、CP-M和CP-C)的酵母表达载体,利用酵母双杂交系统确定外壳蛋白CP自身互作的活性区段。结果表明,N端和C端第1~81个氨基酸是参与水稻条纹病毒CP蛋白自身互作的活性区段。这一研究结果不仅有助于加深理解RSV CP蛋白在病毒基因组稳定、复制过程中的作用,也有助于加深了解RSV、寄主和传播介体之间关系。