不同精粗比日粮中添加甘露寡糖对绵羊体外发酵的影响

试验旨在研究不同精粗比日粮中添加甘露寡糖(MOS)对绵羊体外发酵的影响。采用4×6二因子析因试验设计,在4种精粗比日粮(20:80、30:70、40:60及50:50)中分别添加6个水平的MOS(0、0.4%、0.8%、1.2%、1.6%及2.0%),以体外产气法对各底物培养3、6、9、12和24h的产气量、甲烷(CH₄)产量、体外干物质消失率(IVDMD)、体外粗蛋白质消失率(IVCPD)、体外有机物质消失率(IVOMD)进行测定。结果表明:日粮精粗比对体外总产气量(除12、24h)和甲烷(CH₄)产量(除9h)均没有显著影响(P>0.05),日粮精粗比对IVDMD、IVOMD和IVCPD均产生了显著的影响(P<0.05);MOS仅对24h IVCPD产生了显著的影响(P<0.05);日粮精粗比和MOS的交互作用对体外产气量、CH₄产量、IVDMD、IVOMD和IVCPD均没有产生显著的影响(P>0.05)。随日粮中精饲料比例的上升,IVCPD下降而IVDMD和IVOMD在升高;随日粮中MOS比例的升高,IVCPD升高。综上所述,在精粗比为30:70的日粮中添加1.2% MOS效果最好。     

Effects on mortality and stress response in European sea bass, Dicentrarchus labrax (L.), fed mannan oligosaccharides (MOS) after Vibrio anguillarum exposure

The effects of dietary mannan oligosaccharides (MOS; 4 g kg^?1; Bio‐Mos, Alltech Inc, USA) in diets for European sea bass, Dicentrarchus labrax (L.), juveniles in relation to disease and stress resistance, combining intestinal infection with Vibrio anguillarum and stress challenge by confinement, were assessed in this study. After 8 weeks of MOS supplementation, fish were exposed to a pathogen challenge test against V. anguillarum by direct gut inoculation combined with a confinement stressor panel. Cumulative mortality of fish fed MOS caused by anally inoculated V. anguillarum decreased from 66% to 12.5% and from 54.1% to 25% in infected and infected + stressed fish, respectively, compared to fish fed control diet. Results for European sea bass revealed a positive effect of MOS dietary inclusion on disease resistance, in terms of cumulative mortality, against gut inoculated V. anguillarum, as well as reduced effects of stress on microbiota diversity. Both of these findings, together with the enhanced innate immune response and the higher gut mucus production and density of eosinophil granulocytes in gut mucosa obtained in previous studies after MOS supplementation ( Torrecillas et al. 2007, 2011a,b ) suggest that general reinforcement of the innate immune system, and particularly of the intestinal barrier efficiency, is the main defence mechanism of European sea bass fed MOS against pathogenic microorganisms.     

Conformational Analysis of the Oligosaccharides Related to Side Chains of Holothurian Fucosylated Chondroitin Sulfates

Anionic polysaccharides fucosylated chondroitin sulfates (FCS) from holothurian species were shown to affect various biological processes, such as metastasis, angiogenesis, clot formation, thrombosis, inflammation, and some others. To understand the mechanism of FCSs action, knowledge about their spatial arrangement is required. We have started the systematic synthesis, conformational analysis, and study of biological activity of the oligosaccharides related to various fragments of these types of natural polysaccharides. In this communication, five molecules representing distinct structural fragments of chondroitin sulfate have been studied by means of molecular modeling and NMR. These are three disaccharides and two trisaccharides containing fucose and glucuronic acid residues with one sulfate group per each fucose residue or without it. Long-range C–H coupling constants were used for the verification of the theoretical models. The presence of two conformers for both linkage types was revealed. For the Fuc–GlA linkage, the dominant conformer was the same as described previously in a literature as the molecular dynamics (MD) average in a dodechasaccharide FCS fragment representing the backbone chain of the polysaccharide including GalNAc residues. This shows that the studied oligosaccharides, in addition to larger ones, may be considered as reliable models for Quantitative Structure-Activity Relationship (QSAR) studies to reveal pharmacophore fragments of FCS.     

大豆糖蜜上清液中胰蛋白酶抑制剂的去除

胰蛋白酶抑制剂是广泛存在于大豆及大豆制品中的抗营养剂,主要有Kuntiz型和Bowman-Birk型两种,为了得到高品质的产品,需要在加工过程中将其灭活或去除。通过研究大豆糖蜜上清液中胰蛋白酶抑制剂的活性、鉴定抑制剂的种类,采用超滤法将其去除。经测定,固形物含量约10%的大豆糖蜜上清液中胰蛋白酶抑制剂活性约为5.05×105TIA·g-1蛋白,约为鲜豆奶的5倍。用截留分子量3 k Da的超滤膜将大豆糖蜜上清液中的大分子蛋白富集,通过还原-Tricine-SDS-PAGE分析,截留部分在图谱上显示为分子量约10 k Da的模糊的条带。通过用2%巯基乙醇还原再用NEM封闭游离巯基的方式处理样品,使得截留部分在电泳图上显示为分子量约7~8 k Da的两条清晰的条带。综合判断,大豆糖蜜上清液中主要含有Bowman-Birk型胰蛋白酶抑制剂。通过对比超滤效果,选择用截留分子量10k Da的超滤膜截留胰蛋白酶抑制剂,能够得到无抑制活性的透过液。     

海藻酸钠寡糖对菜心类囊体膜组成及特性的影响

采用溶液培养,研究海藻酸钠寡糖对菜心(Brassica chinensis L.)类囊体膜组成和特性的影响。结果表明:海藻酸钠寡糖处理可不同程度提高细胞色素b559、细胞色素b563和光系统Ⅱ浓度,从而提高光合电子传递效率。海藻酸钠寡糖处理还可提高亚油酸(C18∶2)含量,降低棕榈酸(C16∶1)和硬脂酸(C18∶0)含量,从而增加膜脂的不饱和度,有利于维持类囊体膜的流动性和稳定性。此外,海藻酸钠寡糖处理的菜心希尔反应活力在第2、4、6和8天时,分别为对照的2.91、3.88、2.48和2.18倍。Mg2+-ATP酶和Ca2+-ATP酶活性也有不同程度的提高。海藻酸钠寡糖提高植物光合效率可能归因于其对类囊体膜结构的改变和功能的改善。     

Carbohydrate Concentration in Lentils (Lens culinaris Medikus.): Genotypic and Environmental Effects

Lentils contain a range of prebiotic carbohydrates; however, genotypic and environmental implications of these components have not been well understood. The objective of this study was to determine the genetic and environmental variation of carbohydrate concentrations in three commonly grown lentil cultivars in South Dakota, USA at two locations over two growing seasons. Significant genetic and environmental variation was found for most of the constituents evaluated. Raffinose-family oligosaccharides (RFO) ranged from 3161 mg 100g^?1 at Bison and 3670 mg 100g^?1 at Wall and from 3217 mg 100g^?1 to 3650 mg 100g^?1 between cultivars. Moreover, RFO content was strongly correlated to a simple plant stress index (SI) in which higher estimated plant stress (e.g., low precipitation) produced higher levels of RFO. These results demonstrate important differences in prebiotic concentrations, which can be used for future lentil breeding efforts when matching cultivars to diverse growing climates with highly variable growing season precipitation.     

功能性寡糖及其在断奶仔猪饲养中的应用研究

寡糖是一种新型的饲料添加剂,具有非常广泛的使用价值和巨大的应用前景。本文就寡糖的特点及在断奶仔猪饲料中的应用作一综述。     

琼胶寡糖对黄瓜抗性及啶虫脒残留的影响

为探究琼胶寡糖作为激发子对植物的影响,本研究以碧翠18号黄瓜为试验材料,在其生长过程中喷施不同浓度琼胶寡糖,测定黄瓜的生长指标、抗性相关酶活和基因表达,以及农药啶虫脒残留量。结果表明,喷施琼胶寡糖可显著促进黄瓜植株生长,提高果实产量;提高黄瓜叶片超氧化物歧化酶、过氧化物酶、多酚氧化酶、过氧化氢酶活性,降低丙二醛含量;并上调几丁质酶与病程相关蛋白1基因的表达,最高表达量分别为对照组的10.4倍和14.5倍。此外,喷施琼胶寡糖有效降低了啶虫脒在黄瓜上的半衰期,加速其降解。浸果试验结果也显示,琼胶寡糖可显著降低农药残留,100 μg·mL^-1琼胶寡糖溶液可减少农残68.29%。因此,琼胶寡糖具有促进黄瓜植株生长、提高抗性及减少果实农药残留的效果,在农业生产中具有良好的开发价值。     

褐藻双寡糖（AFOD）和岩藻寡糖(FOS)预防草莓叶斑病的影响

本试验的目的是筛选出对草莓叶斑病有高效防治效果且绿色的防治方法。试验以“红颜”草莓品种为材料,分别采用不同浓度的褐藻双寡糖和岩藻寡糖单施以及与不同浓度的阿泰灵混合喷施,测定草莓的SPAD值和防治效果。结果表明,在整个生育期内70%褐藻双寡糖和岩藻寡糖能增加草莓叶片SPAD值,对草莓有促生长的作用,还可以预防草莓叶斑病,且高浓度70%褐藻双寡糖、岩藻寡糖与减量阿泰灵混用可提高阿泰灵的防治效果。     

几丁质寡糖诱导小麦抗白粉病作用的研究

试验表明 ,应用工业化生产的几丁质寡糖液 (COS)可以减轻小麦白粉病的发生。随着COS浓度的增加 ,其诱导小麦产生抗白粉病的效果越好。通过不同施用方式的比较 ,表明小麦的抗性是由于植株吸收COS后 ,引发体内系统诱导抗性而表达的。