Effects of Yeast Oligosaccharide Diet Supplements on Growth and Disease Resistance in Juvenile Nile Tilapia,Oreochromis niloticus

Commercially available yeast and yeast subcomponents consisting mainly of β-glucan or oligosaccharide feed additives were added to diets of juvenile (12–18g) Nile tilapia (Oreochromis niloticus) at rates recommended by suppliers. Three experiments were conducted following a basic protocol with varied rates of supplementation, duration of feeding, and stocking densities. Experimental diets were fed twice daily to apparent satiation for a period of two or four weeks, at the end of which feed consumption and weight gain were measured. Following the experimental feeding period, serum components, including protein and immunoglobulin concentrations, as well as lysozyme and complement activities, were measured. A disease challenge was conducted with pathogenic isolates of Streptococcus iniae or Edwardsiella tarda. Weight gains were not significantly different in fish fed the supplemented diets when compared to the control diet. There were significant differences in fed intake within individual experiments; however, this effect was not consistent in all three experiments. Overall feed efficiency was not significantly affected by diet. There were no differences in serum components of fish sampled at two or four weeks. Fish fed the experimental diets did not have lower mortality or morbidity after disease challenge compared to fish fed the control diets. Specific antibody against S. iniae or E. tarda measured by ELISA did not reveal differences in the fish surviving the challenge. We conclude that the incorporation of these commercial yeast component products into the diet of juvenile Nile tilapia at these rates and for these feeding periods had no effect on growth, serum components, antibody responses, or survival following S. iniae or E. tarda infection.     

壳寡糖对月季切花的保鲜效果

为延长月季切花的保鲜期,以月季切花为材料,研究壳寡糖对月季切花的保鲜效果。同时利用分光光度计法检测壳寡糖对月季切花抗氧化酶活性和抗氧化物质含量的影响,进一步探讨其保鲜机理。结果表明:壳寡糖能够延长月季切花瓶插寿命6.4d。与对照相比,壳寡糖瓶插期月季切花的抗氧化酶(SOD)和过氧化氢酶(CAT)的活性分别提高11.8%~109.3%和32.6%~194.9%,且脯氨酸的含量提高13.0%~98.2%。壳寡糖可提高月季切花的抗氧化能力,能有效延长月季切花瓶插寿命。     

补光和寡糖添加处理对罗汉松苗木生长的影响

以罗汉松当年生实生苗为对象,通过人工补光延长每天育苗的光照时间,施肥时添加寡糖处理,翌年在控制条件下对越冬苗木进行模拟倒春寒处理,取样调查苗木春季生长和干物质。结果表明,添加寡糖处理对苗高、地径和新生根系数量无影响。添加寡糖、延长光照处理地径和当年生叶长分别提高17%和79%,补光对促进苗高的生长和新生根数量的增加具显著影响;延长光照和添加寡糖对地上部和地下根系的干物质积累均有显著促进,补光并添加寡糖处理的茎干干物质较少,根系干物质较大;添加寡糖、延长光照处理的苗木质量提高。     

牛蒡提取物对菠菜生长及品质的影响

通过盆栽试验,研究了牛蒡粗提液、牛蒡寡糖两种牛蒡提取物对菠菜生长及品质的影响。结果表明,喷施牛蒡粗提液和牛蒡寡糖均可增加菠菜鲜重,分别比清水处理的高38.3%、24.7%;同时,提高菠菜Vc、总糖含量,降低菠菜体内硝酸盐、草酸含量。说明牛蒡粗提液和牛蒡寡糖不仅能促进菠菜生长,而且能改善菠菜品质。牛蒡粗提液和牛蒡寡糖相比,牛蒡粗提液的效果优于牛蒡寡糖,而且牛蒡粗提液的成本约为牛蒡寡糖的1/10～1/15。因此,从使用效果及经济效益考虑,牛蒡粗提液的应用前景更佳。     

Structural Characterization and Heparanase Inhibitory Activity of Fucosylated Glycosaminoglycan from Holothuria floridana

Unique fucosylated glycosaminoglycans (FG) have attracted increasing attention for various bioactivities. However, the precise structures of FGs usually vary in a species-specific manner. In this study, HfFG was isolated from Holothuria floridana and purified by anion exchange chromatography with the yield of ~0.9%. HfFG was composed of GlcA, GalNAc and Fuc, its molecular weight was 47.3 kDa, and the -OSO₃⁻/-COO⁻ molar ratio was 3.756. HfFG was depolymerized by a partial deacetylation–deaminative cleavage method to obtain the low-molecular-weight HfFG (dHfFG). Three oligosaccharide fragments (Fr-1, Fr-2, Fr-3) with different molecular weights were isolated from the dHfFG, and their structures were revealed by 1D and 2D NMR spectroscopy. HfFG should be composed of repeating trisaccharide units -{(L-FucS-α1,3-)d-GlcA-β1,3-d-GalNAc_4S6S-β1,4-}-, in which sulfated fucose (FucS) includes Fuc_2S4S, Fuc_3S4S and Fuc_4S residues linked to O-3 of GlcA in a ratio of 45:35:20. Furthermore, the heparanase inhibitory activities of native HfFG and oligosaccharide fragments (Fr-1, Fr-2, Fr-3) were evaluated. The native HfFG and its oligosaccharides exhibited heparanase inhibitory activities, and the activities increased with the increase of molecular weight. Additionally, structural characteristics such as sulfation patterns, the terminal structure of oligosaccharides and the presence of fucosyl branches may be important factors affecting heparanase inhibiting activity.     

甘露寡糖对肠道健康和免疫的调控机制及其在畜禽生产中的应用

过去几十年来,由于饲用抗生素在畜牧养殖业中的滥用,导致畜禽正常的肠道菌群被破坏并引起肠道细菌耐药性和环境污染等一系列问题,严重损害了畜禽的肠道健康。同时,近年来集约化养殖已经成为畜牧业的发展方向,养殖规模越来越大,如何有效地提高畜禽免疫力已然成为重点的研究方向。健康的肠道是保障畜禽健康生长的基础,保持健康的肠道菌群,能有效提高动物机体的免疫力和抗病能力。甘露寡糖是一种绿色新型饲料添加剂,作为一类功能性寡糖,具有改善畜禽肠道健康和提高免疫应答等作用。在猪生产中,添加甘露寡糖能够提高断奶仔猪的生长性能和免疫力。在家禽生产中,添加甘露寡糖能够改善家禽肠道菌群并提高生产性能和肉品质。作者主要介绍了甘露寡糖的结构及理化性质、改善肠道健康和免疫调控机制及其在断奶仔猪、育肥猪、蛋鸡和肉鸡生产中的应用效果。重点总结了甘露寡糖对畜禽肠道健康和免疫的调控机制及免疫途径,旨在为甘露寡糖在肠道健康和免疫调控方面的深入研究及其在畜禽养殖中的应用提供理论依据。     

具有农业生物活性壳寡糖的研究进展

壳寡糖是一类由N-乙酰氨基葡萄糖或氨基葡萄糖通过β-(1,4)-糖苷键连接起来的低聚合度水溶性的糖类,在食品、医药、化妆品等方面具有广泛用途。主要评述了壳寡糖在植物生长调节(诱导抗性)、杀菌作用以及杀虫活性方面的应用,表明壳寡糖是一种对环境友好的、良好的生物源农药。     

钕和牛蒡寡糖对秦艽种子萌发的影响

研究了两种诱导物钕和牛蒡寡糖对秦艽种子萌发的影响。结果表明:不同浓度的钕溶液对秦艽种子萌发都具有促进作用。6 mg/L的钕溶液培养的秦艽种子,种子发芽势和发芽率最高,发芽势与发芽率达到60%和89%,比对照高25%和26%,且芽苗长势好。牛蒡寡糖溶液对秦艽种子萌发的影响表现为高浓度抑制,低浓度促进。在不同浓度的牛蒡寡糖溶液中,3 g/L牛蒡寡糖溶液对秦艽种子萌发促进作用强,发芽率达到87.5%,比对照发芽率高22%,芽苗长势好。     

The Microstructure,Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives

Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.     

Enzymatic degradation of FODMAPS via application of β-fructofuranosidases and α-galactosidases- A fundamental study

Cereals and pulses often contribute to the intake of Fermentable Oligo-, Di-, Monosaccharides, and Polyols (FODMAPs) due to high amounts of fructans or galactooligosaccharides (GOS). FODMAPs can trigger symptoms of Irritable Bowel Syndrome (IBS) and therefore, the development of foods and beverages with a lower FODMAP-content are favourable for IBS patients. Enzyme technology is a promising tool to reduce the FODMAP-content in foods and to maintain product quality. This fundamental study investigates the efficiency of invertase, inulinase, and α-galactosidase as potential food additives to reduce the total FODMAP content of food ingredients. Extracts of high FODMAP ingredients, such as wheat and lentil, and standard solutions of various fructans and GOS were incubated with invertase, inulinase and α-galactosidase for 1 h and 2 h. Contents of oligosaccharides before and after treatment and related IBS-triggering reaction products were quantified using ion chromatography. Inulinase showed a high degradation yield (over 90% of degradation) for both GOS and fructans. For invertase only low degradation yields were measured. α-Galactosidase showed the highest efficiency in decomposing GOS (100% of degradation) and led to non-IBS triggering degradation products. This indicates a high potential for a combined inulinase/α-galactosidase treatment for products containing both fructans and GOS.