魔芋软腐病拮抗菌BJ-1的鉴定

[目的]为魔芋软腐病的生物防治提供理论基础。[方法]采用平板对峙培养法从健、病魔芋植株及其根际土壤中进行拮抗菌的初筛和复筛,对筛选出的魔芋软腐病拮抗菌BJ-1进行形态学观察和生理生化鉴定。[结果]从发病植株中分离获得的BJ-1对魔芋软腐病有较强的拮抗作用,拮抗带宽度达10 mm。复筛试验表明,内生拮抗菌BJ-1具有广谱抗菌活性,对软腐病原菌的拮抗作用最强,拮抗带宽度达12 mm。形态学观察、生理生化试验发现BJ-1与芽孢杆菌属细菌的形态学特征和生理生化性状相似,初步认为魔芋软腐病拮抗菌BJ-1为芽孢杆菌属细菌。[结论]魔芋软腐病拮抗菌BJ-1为芽孢杆菌属细菌,对软腐病原菌有强拮抗作用。     

甘露寡糖对生长绵羊瘤胃发酵功能(体外)的影响

采用批次培养的方法,研究了体外条件下日粮添加甘露寡糖对生长绵羊瘤胃发酵功能的影响。甘露寡糖的添加水平为0,0.20%,0.40%,0.60%,0.80%以及1.00%。结果表明,日粮添加甘露寡糖可以提高培养液中的挥发性脂肪酸(VFA)含量;可以提高培养液中的菌体蛋白(BCP)含量,并以0.60%的添加量效果最佳;添加量在0.80%以上时,可以显著降低(P<0.05)培养液中的NH3-N含量;对培养残渣中的中性洗涤纤维(NDF)含量没有显著影响(P>0.05)。研究初步证明,日粮添加甘露寡糖可以在一定程度上提高生长绵羊的瘤胃发酵功能。     

魔芋葡甘聚糖在板栗保鲜中的应用

2002年10月—2003年4月,在西北农林科技大学林学院进行了魔芋葡甘聚糖保鲜板栗试验,通过四种处理对比,结果为,0.3%的魔芋葡甘聚糖水溶液和0.3%的魔芋葡甘聚糖水溶液 0.2%的丙酸钙两个处理分别比对照降低呼吸强度53.7%、54.1%,减少水分损耗34.1%、41.3%,处理后的板栗在0~2℃条件下贮藏6个月后无霉坏发生,保鲜效果较好。     

魔芋干制工艺参数的优化研究

应用多目标非线性优化理论与方法,对魔芋片单层热风干燥实验所得魔芋甘露聚糖、干燥速率、能耗回归模型进行了多目标综合优化研究与分析,得到魔芋优质、高效、节能干燥工艺参数为:风温81℃,风速1.4m/s,片厚5mm。     

魔芋甘露寡糖对黄颡鱼非特异性免疫功能及生长的影响

以健康黄颡鱼为试验鱼,按投喂饲料的不同分为5组,3个平行.对照组投喂基础饲料,试验组KM0.1、KM0.2、KM0.3、M0.3在基础饲料中分别添加0.1%、0.2%、0.3%的魔芋甘露寡糖及0.3%的酵母甘露寡糖,研究日粮中添加不同含量甘露寡糖对黄颡鱼非特异性免疫功能及生长的影响.结果表明:投喂0.2%魔芋甘露寡糖14~28 d,血液白细胞吞噬活性显著高于对照组,14 d吞噬百分率PP、吞噬指数PI达到最大值,分别为66.00%、5.24.在整个试验过程中,KM0.3、M0.3组与对照组之间PP、PI均无显著性差异.KM0.2组与对照组相比能显著增强血清溶菌酶、超氧化物歧化酶活性,在第35天时溶菌酶活性达到最大值(0.31),第7天时SOD活性达到最大值(136.67).除第42天外,KM0.3、M0.3组与对照组SOD活性无显著性差异.投喂不同含量魔芋甘露寡糖均能增加黄颡鱼头肾指数、后肾指数、脾体指数,促进生长、降低饵料系数.KM0.2组质量增加率最高(95.68%)、饵料系数最低(1.63).0.3%酵母甘露寡糖组与对照组相比也能显著促进黄颡鱼的生长,降低饵料系数,其中质量增加率为64.91%、饵料系数为1.84.     

Combined effects of dietary mannan oligosaccharides and total fish oil substitution by soybean oil on European sea bass (Dicentrarchus labrax) juvenile diets

This study evaluates the effects of dietary mannan oligosaccharides (MOS) on growth, tissue composition, fatty acid profiles and liver morphology of European sea bass (Dicentrarchus labrax) fed diets containing either soybean oil (SBO; SBOMOS) or fish oil (FO; FOMOS) as unique oil source for 8 weeks. Results showed that MOS supplementation enhanced specific growth rate, regardless of the oil source used, and that dietary oil source reduced fish length, regardless of dietary MOS supplementation. Dietary MOS favoured lipid accumulation in muscle and anterior intestine when supplemented in FO‐based diets compared to fish fed SBO diet and reduces it in liver in relation to lower hepatocyte area, particularly in fish fed SBOMOS diet. Dietary MOS favoured liver and not muscular ∑n‐3 PUFA, DHA, EPA and ARA deposition, when combined with FO but not when included in SBO‐based diets. Thus, MOS dietary supplementation favours fish performance and helps to minimize the side effects derived from high dietary SBO supplementation on liver lipid accumulation and hepatocyte vacuolization, which could be of especial interest on long‐term feeding trials; however, the effects on favoured deposition ∑n‐3 PUFA are limited to FO‐based diets.     

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。     

Prebiotic Mannan Oligosaccharide Diet Improves Health Status of the Digestive System of Marron,Cherax tenuimanus (Smith 1912)

The aim of this experiment was to determine the effects of dietary supplementation with mannan oligosaccharide (MOS; BioMos, Alltech, USA) on the gut microbiota and histology of marron, Cherax tenuimanus. Marron were fed six different diets supplemented with 0%, 0.05%, 0.1%, 0.2%, 0.4%, and 0.8% of MOS for a duration of 112 days. Total bacteria in the gut were highest when marron were fed diets which included 0.1% to 0.4% BioMos, whereas total bacteria/Vibrio spp. ratio was highest in the marron fed 0.4% BioMos diet only. The marron fed 0.2% and 0.4% BioMos diets showed normal morphology and higher densities of microvilli, and thicker layer of gut epithelium than other inclusion rates. The results suggest that application of 0.2% to 0.4% of MOS in the diet improves digestive system health in marron.     

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.