棕榈粕替代部分玉米对藏羊母羊小肠形态发育、消化酶活性及抗氧化功能的影响

试验旨在探究精料补充料中使用不同比例棕榈粕替代玉米对藏羊母羊肠道组织形态学、消化酶活性、pH、脂多糖以及抗氧化能力的影响。选取初始体重相近且健康的2～3月龄高原型藏羊母羊120只,随机分为4组,每组30只,每组6个重复,每个重复5只母羊,分别饲喂0%、15%、18%和21%水平的棕榈粕替代精料中玉米。试验期97d。结果显示：1)0%组与15%组间小肠各段的绒毛高度、绒毛宽度、隐窝深度、黏膜厚度以及绒毛高度/隐窝深度差异均不显著（P>0.05）;2)0%组空肠的α-淀粉酶、纤维素酶、脂肪酶及糜蛋白酶显著或极显著小于15%组（P<0.05或P<0.01）;3)0%组空肠的谷胱甘肽过氧化物酶、过氧化氢酶活性显著低于15%组与18%组（P<0.05）,相较于21%组差异不显著（P>0.05）;4)18%组与21%组空肠的脂多糖含量显著或极显著高于0%组（P<0.05或P<0.01）,与15%组相比差异不显著（P>0.05）。由此可见,棕榈粕可替代部分玉米饲喂藏羊母羊,推荐替代玉米的比例为15%。     

Taxonomic and Bioactivity Characterizations of Mameliella alba Strain LZ-28 Isolated from Highly Toxic Marine Dinoflagellate Alexandrium catenella LZT09

Microalgae host varied microbial consortium harboring cross-kingdom interactions with fundamental ecological significance in aquatic ecosystems. Revealing the complex biofunctions of the cultivable bacteria of phycosphere microbiota is one vital basis for deeply understanding the mechanisms governing these dynamic associations. In this study, a new light-yellow pigmented bacterial strain LZ-28 was isolated from the highly-toxic and harmful algal bloom-forming dinoflagellate Alexandrium catenella LZT09. Collective phenotypic and genotypic profiles were obtained to confidently identify this strain as a new Mameliella alba member. Comparative genomic analysis showed that strain LZ-28 shared highly similar functional features with other four marine algae-derived M. alba strains in spite of their distinctive isolation sources. Based on the bioactivity assaying, the mutual growth-promoting effects between bacterial strain LZ-28 and algal strain LZT09 were observed. After the culture conditions were optimized, strain LZ-28 demonstrated an extraordinary production ability for its bioflocculanting exopolysaccharides (EPS). Moreover, the portions of two monosaccharides glucose and fucose of the EPS were found to positively contribute to the bioflocculanting capacity. Therefore, the present study sheds light on the similar genomic features among the selected M. alba strains, and it also reveals the potential pharmaceutical, environmental and biotechnological implications of active EPS produced by this new Mameliella alba strain LZ-28 recovered from toxic bloom-forming marine dinoflagellate.     

氯磺隆与过氧化氢酶相互作用对其活性的影响

用油菜作为指示作物,采用高锰酸钾滴定法,通过水培试验研究了除草剂氯磺隆与过氧化氢酶相互作用对它们活性的相互影响。结果表明,除草剂氯磺隆与过氧化氢酶作用后,氯磺隆对过氧化氢酶的活性没有影响：而过氧化氢酶的存在使除草剂氯磺隆容易被植物体吸收,使氯磺隆与受体作用增强。     

22种植物提取液对杨分月扇舟蛾的生物活性的影响

对22种植物提取液的杀虫活性进行了初步筛选,结果表明苍耳植物提取液对杨分月扇舟蛾2龄幼虫有很强的拒食作用,其种子提取液对供饲叶碟24 h和48 h后的拒食率分别为82.83%和75.15%,茎提取液24 h和48 h后的拒食率分别为55.56%和65.87%。苍耳种子、地锦全株和牛膝叶提取液对杨分月扇舟蛾幼虫有非常强的毒杀作用,6 d后校正死亡率分别为91.94%、83.87%和81.13%。     

饲料中添加蛋白酶AG对鲤鱼鱼种生长和蛋白质消化酶活性的影响

通过2个试验研究了饲料中添加蛋白酶AG对鲤鱼生长和前肠蛋白质消化酶活性的影响.试验Ⅰ选用540尾均重11.7 g的鲤鱼,随机均分为6组,随机选取3组分别饲喂鱼粉含量为10%、15%、20%的3种等蛋白基础饲料,另外3组分别饲喂添加有175 mg/kg蛋白酶AG的以上3种饲料,试验期60 d.试验Ⅱ选取120尾均重48.7 g的鲤鱼,随机分为2组,一组饲喂鱼粉含量6%的基础饲料为对照组,另外一组饲喂添加175 mg/kg蛋白酶AG的基础饲料为试验组,试验期为30 d.试验Ⅰ结果表明:摄食10%鱼粉饲料和20%鱼粉 175 mg/kg蛋白酶AG饲料的鲤鱼分别具有最低和最高的增重率;在10%鱼粉饲料中添加蛋白酶AG显著提高了鱼体增重率(P<0.05),但在15%、20%鱼粉饲料中添加蛋白酶AG,对鱼体增重率没有显著影响.试验Ⅱ结果表明:相比于对照组,试验组鲤鱼增重率提高了6.4%(P<0.05),饲料系数降低了5.4%(P<0.05).试验Ⅰ和试验Ⅱ中,添加蛋白酶AG对鱼体肌肉水分、粗脂肪、粗蛋白质含量均无显著影响(P>0.05);对消化酶活性的测定表明,在鱼粉含量为10%、6%的基础饲料中添加蛋白酶AG,可显著提高前肠组织蛋白酶活性和食糜蛋白酶活性(P<0.05),但在鱼粉含量为15%、20%的基础饲料中添加蛋白酶AG,对前肠组织蛋白酶活性和食糜蛋白酶活性没有影响.综上所述,在鱼粉含量较低的饲料中添加蛋白酶AG,可提高鲤鱼消化道蛋白酶活性,改善生长性能.     

橡胶树树皮中ACC氧化酶基因(HbACO7)的表达特性及功能探究

天然橡胶是重要的工业原材料,主要来自橡胶树树皮中的乳管。乙烯能促进橡胶树乳管产胶和排胶,在树皮上施用乙烯利（一种乙烯释放剂）或乙烯可显著提高胶乳产量。基于本课题组前期获得的橡胶树基因组和转录组数据,克隆橡胶树中乙烯合成通路关键酶——1-氨基环丙烷基-1-羧酸（ACC）氧化酶基因家族（HbACOs）的全部8个家族基因,研究其组织表达模式。结果表明：在分析的7种组织中,尽管HbACO基因存在不同程度的冗余表达,但每种基因的组织表达模式具有明显的特异性,其中HbACO7是树皮中表达量最高的家族基因。HbACO7基因的表达在割胶季节的不同月份发生明显变化,其中在8月的表达量最高。成功构建了HbACO7基因的原核表达载体,实现其在大肠杆菌BL21中的诱导表达。纯化后的HbACO7重组蛋白具有明显的ACO酶催化活性,成功地催化了乙烯的体外合成。该结果将为后续橡胶树树皮中的乙烯生物合成调控机制研究提供参考。     

Antihypertensive Effects of IGTGIPGIW Peptide Purified from Hippocampus abdominalis: p-eNOS and p-AKT Stimulation in EA.hy926 Cells and Lowering of Blood Pressure in SHR Model

The aim of this study was to assess the potential hypertensive effects of the IGTGIPGIW peptide purified from Hippocampus abdominalis alcalase hydrolysate (HA) for application in the functional food industry. We investigated the antihypertensive effects of IGTGIPGIW in vitro by assessing nitric oxide production in EA.hy926 endothelial cells, which is a major factor affecting vasorelaxation. The potential vasorelaxation effect was evaluated using 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate, a fluorescent stain. IGTGIPGIW significantly increased the expression of endothelial-derived relaxing factors, including endothelial nitric oxide synthase and protein kinase B, in EA.hy926 cells. Furthermore, oral administration of IGTGIPGIW significantly lowered the systolic blood pressure (183.60 ± 1.34 mmHg) and rapidly recovered the diastolic blood pressure (143.50 ± 5.55 mmHg) in the spontaneously hypertensive rat model in vivo. Our results demonstrate the antihypertensive activity of the IGTGIPGIW peptide purified from H. abdominalis and indicate its suitability for application in the functional food industry.     

Fucose-Rich Sulfated Polysaccharides from Two Vietnamese Sea Cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera: Structures and Anticoagulant Activity

Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→]_n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues.     

Ce对UV-B辐射胁迫下大豆幼苗光合作用影响:Ⅰ对光合色素与希尔反应活性的影响

用水培法研究Ce(Ⅲ)对紫外辐射(UV-B,280￣320nm)胁迫下油菜幼苗光合色素含量与希尔反应活性变化对光合作用的影响。静态数据表明,20mg·L-1CeCl3能有效减缓紫外辐射(T1/0.15W·m-2和T2/0.45W·m-2)胁迫所导致的光合速率下降,叶绿素与类胡萝卜素含量减少及Hill反应活性降低,使得Ce UV-B组各项指标虽低于CK,但明显优于UV-B组。动态曲线显示,Ce减缓了UV-B胁迫期各项指标的下降趋势,加快恢复期的上升速度,且最终达到较好的恢复效果。通过对Chl含量、Hill反应活性与Pn的相关统计学分析发现,Ce对UV-B辐射胁迫下Hill反应活性和叶绿素含量的调节具有改善光合功能的作用,且对Hill反应活性的调节作用大于叶绿素含量。     

丛枝菌根真菌对元宝枫生长及其根系形态的影响

【目的】阐明丛枝菌根（arbuscular mycorrhizal,AM）真菌对元宝枫生长状况及根系形态特性的影响,探讨元宝枫根系形态与其生长发育的关系。【方法】在元宝枫幼苗生长基质中接种摩西斗管囊霉（Funneliformis mosseae）和根内根孢囊霉（Rhizophagus intraradices）2种AM真菌,以不接种AM真菌为对照,通过盆栽试验,培养90 d后,测定元宝枫的生长状况、根系活力及根系形态指标,利用单因素方差分析和多重比较方法,分析接菌与不接菌处理之间的差异,采用envfit ()函数、冗余度分析和变差分解分析元宝枫生长状况与其他指标间的关系。【结果】①接种2种AM真菌后,元宝枫株高、地径、茎干质量和根系活力较对照显著提高,根冠比下降。根内根孢囊霉对元宝枫的促生作用比摩西斗管囊霉显著。②与对照相比,接种2种AM真菌后,元宝枫根表面积和根体积显著增大,粗根根长占总根长的比例增加,细根根长占总根长的比例显著降低。根内根孢囊霉对元宝枫根系形态的影响比摩西斗管囊霉显著。③元宝枫生长状况与其根系活力和根系形态密切相关。【结论】接种AM真菌有助于增强元宝枫的根系活力,改善其根系形态,促使其汲取更多养分,进而提高其生物量。