芽孢杆菌对草鱼生长和肠粘膜抗氧化功能及养殖水质的影响

本试验研究了饲料中添加芽孢杆菌对草鱼生长、肠粘膜抗氧化功能及养殖水体水质的影响。选取平均体重为（51.0±2.3）g的健康草鱼300尾,随机分成3组（对照组、处理组1和处理组2）,每组3个重复,每个重复50尾鱼。其中对照组饲喂基础日粮,处理组1和2分别饲喂含复合芽孢杆菌（105 cfu/克饲料,枯草芽孢杆菌和解淀粉芽孢杆菌以1:1比例混合）和枯草芽孢杆菌（105 cfu/克饲料）的基础日粮。试验期为45d。结果表明,饲料中添加芽孢杆菌对养殖水体pH和硝酸盐氮含量无显著影响,但显著降低了从第21d到试验结束期间水体中亚硝酸盐氮的含量（处理组1第35d除外）。芽孢杆菌的添加同时显著降低草鱼的死亡率（P<0.05）,并提高了草鱼的增重率和特定生长率。与对照组相比,处理组1和2草鱼的增重率分别提高了52.93%（P<0.01）和21.78%（P<0.05）,特定生长率分别提高了44.44%（P<0.01）和16.67%（P<0.05）;而且处理组1草鱼增重率和特定生长率分别比处理组2提高了25.58%（P<0.01）和23.81%（P<0.01）。肠粘膜抗氧化活性研究表明,与对照组相比,饲料中添加芽孢杆菌能提高草鱼肠粘膜超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。以上结果提示,饲料中添加芽孢杆菌可以改善养殖水质和草鱼肠粘膜抗氧化功能,并显著促进草鱼生长并降低死亡率。     

芽孢杆菌对草鱼养殖水质的影响

为研究芽孢杆菌对草鱼养殖水质的影响,选取体重约45g的草鱼210尾,随机分为2组,每组设3个平行重复.对照组在水中不添加任何菌,处理组每隔7d分别向水中按照1×108 cfu/m3添加芽孢杆菌菌粉,二组均饲喂基础日粮.草鱼养殖水体水质测定结果表明:与对照组相比,第28天处理组氨氮含量比对照组下降29.17％(P＜0.05).亚硝酸盐氮含量无显著性差异且在0.39 mg/L以下.第14天时,处理组硝酸盐氮含量比对照组降低60.26％( P＜0.01),在第21天和第28天分别比对照组提高26.98％(P＜0.05)和67.85％(P＜0.01).处理组的总无机氮含量在21d内无显著差异,第28天时下降了15.39％(P＞0.05).养殖水体pH值维持在6.8～7.6,各组之间无显著差异.养殖水体中添加芽孢杆菌可降低氨氮含量,改善养殖水体水质.     

芽孢杆菌对草鱼养殖水质调控作用的研究

研究了芽孢杆菌(Bacillus)对草鱼养殖水质的调控.通过测定水体的氨氮、亚硝酸盐、硝酸盐氮和总无机氮值等来评价水质变化.测定结果表明,与对照组相比:第28天时,处理组1和2的氨氮含量分别下降13.18％ (P ＞0.05)和48.09％ (P ＜0.01),且处理组2比处理组1下降了26.71％ (P ＜0.05)...     

饲料中添加复合芽孢杆菌对草鱼消化道酶活性及肠道菌群的影响

用含复合芽孢杆菌(105 cfu/g饲料,枯草芽孢杆菌和解淀粉芽孢杆菌以1:1比例混合)的基础日粮,按体重3％的日投饵量,饲喂体重(51.37±0.58)g的草鱼(Ctenopharyngodon idellus),饲养实验45 d.结果表明:与对照组相比,处理组肠道内容物胰蛋白酶活性提高了79.46％ (P＜0.01);肝胰腺脂肪酶活性提高了16.82％(P＜0.01),肝胰腺淀粉酶和胰蛋白酶活性无显著差异(P＞0.05).肠道菌群数量分析显示,处理组肠道芽孢杆菌数均显著提高(P＜0.01),弧菌和大肠杆菌数显著降低(P＜0.01).结果提示,饵料中添加复合芽孢杆菌能够改善草鱼肠道菌群组成,并提高消化道特定消化酶活性.     

纳豆芽孢杆菌对鱼类非特异性免疫功能的影响

采用豆芽汁为培养基,按10%的接种量,在30℃1、20 r/min的培养条件下,纳豆芽孢杆菌培养8 h后便进入对数生长期,14 h达到生长顶峰,按一定的剂量每日投饵饲喂的方式摄入纳豆芽孢杆菌及其发酵产物,可促进受试鱼类血液NBT阳性细胞数量和血清溶菌酶活力显著上升(P<0.05),所不同的是培养时间短的纳豆芽孢杆菌培养液的作用效果要差一些。试验结果表明:纳豆芽孢杆菌及其发酵产物可明显提高鱼类的非特异性免疫功能。     

枯草芽孢杆菌对罗非鱼免疫功能和生长性能的影响

通过在养殖罗非鱼的水体里添加不同浓度的枯草芽孢杆菌,分别测定罗非鱼酸性磷酸酶、碱性磷酸酶、谷草转氨酶、谷丙转氨酶、溶菌酶五种免疫酶活性指标及生长性能指标,探讨在养殖水体中添加枯草芽孢杆菌对罗非鱼的免疫酶活性及生长性能的影响,目的为评价枯草芽孢杆菌在罗非鱼养殖过程中使用效果的生物学指标,以及为了推广枯草芽孢杆菌在罗非鱼养殖过程中提高罗非鱼免疫功能提供理论依据。     

饲喂枯草芽孢对草鱼粪便、养殖水体中芽孢数量和水质的影响

分别在饲料中添加不同含量的枯草(Bacillus subtilis)芽孢(A组实测芽孢数量为2.6×107 cfu/g,B组为4.4×106 cfu/g,空白组为0),饲喂静水水族箱中100 g左右的草鱼(Ctenopharyngodon idellus)10 d,测定饲喂枯草芽孢后草鱼粪便、养殖水体中芽孢数量和水质的变化.结果表明:(1)9 d内,水体中芽孢数量A组和B组在前6d时不断增加,在6d时达到稳定,其中A组和B组稳定时的含量分别为2.22×106 cfu/g和3.98×105 cfu/g.(2)10 d内,草鱼粪便干物质中的芽孢数量与饲料中的枯草芽孢含量相比,A组和B组粪便中的枯草芽孢损失率分别为89.76％ ～90.71％和83.83％～86.84％.(3)草鱼饲喂枯草芽孢后,A组和B组粪便中排出的枯草芽孢对水体中亚硝酸盐和氨氮有降低的趋势,但各组之间差异不显著(P＞0.05),对化学需氧量(COD)没有影响.     

地衣芽孢杆菌De在优质草鱼养殖中的应用研究

运用综合对比分析法探讨了地衣芽孢杆菌Bacillus licheniformis De在优质草鱼（Ctenopharyngodon idellus）养殖中的应用效果,其评价指标分别为成活率、水体pH、透明度、溶解氧及水中氨氮、硝酸盐浓度等。结果表明,施用地衣芽孢杆菌De可在一定程度上使水体环境和养殖生产性能得到优化,提高养殖草鱼的成活率,显著降低水体透明度及水中氨氮、硝酸盐含量（P〈0．05）,使水体pH、溶解氧有利于草鱼的生长。其中施菌组较对照组的成活率、水体pH、溶解氧分别提高了3．2％、3．9％、25．5％,而水体透明度、氨氮及亚硝氮浓度则分别降低了38．5％、74．6％、69．3％。     

枯草芽孢杆菌对养殖水体水质影响研究

在养殖水体中加入特定的芽孢杆菌及酵母菌 ,能使其定殖于养殖水体 ,生长繁殖后测定各项水质指标 ,证明其能迅速而有效的降低水中亚硝酸盐的含量 ,并对水中溶氧的影响较小 ,能够有效地改善养殖水体的水质状况。     

枯草芽孢杆菌表达柱状黄杆菌lip基因口服疫苗对草鱼免疫保护效果的研究

枯草芽孢杆菌(Bacillus subtilis)是一种水产益生菌,最近也被用作口服疫苗的投递载体。本研究利用前期筛选到的柱状黄杆菌(Flavobacterium columnare)保护性抗原基因lip,与pBE2R载体连接后,以质粒的方式转入枯草芽孢杆菌WB800中,构建了重组菌株WB800 (pBE2R-lip)。聚丙酰胺电泳和免疫印迹实验表明,枯草芽孢杆菌WB800 (pBE2R-lip)能表达lip蛋白,其分子量约为32 kDa。利用枯草芽孢杆菌WB800 (pBE2R-lip)口服免疫草鱼(Ctenopharyngodon idellus)后,通过酶联免疫吸附实验,在受免草鱼血清中检测到特异性抗体效价的上升,在人工感染实验中,受免草鱼的免疫保护率为52.4%。本研究表明,利用枯草芽孢杆菌能有效表达柱状黄杆菌的lip基因,以其作为口服疫苗能引起草鱼的免疫应答并提供免疫保护效果。     

Effect of dietary supplementation with Bacillus subtilis on the growth,performance, immune response and antioxidant activities of the shrimp (Litopenaeus vannamei)

The objective of this study was to evaluate the effect of dietary supplementation of a probiotic bacterium, Bacillus subtilis, on the growth, immune response and antioxidant activities of shrimp (Litopenaeus vannamei). Shrimps with an average initial weight of 2.11±0.17 g were randomly assigned to four groups with three replicates. The control group was fed a basal diet, and three treated groups were fed diets supplemented with B. subtilis at doses of 1 × 10⁴, 5 × 10⁴ and 10 × 10⁴ colony‐forming unit (CFU) g^?1 feed respectively. After 40 days of culture, 10 shrimps from each replicate were taken randomly for the determination of immune response and oxidization resistance indices. The results showed that the shrimps fed with B. subtilis at a dose of 1 × 10⁴, 5 × 10⁴ CFU g^?1 feed showed significantly better growth than that of the control diet. The phenoloxidase activities showed a tendency to increase with an increased dose of B. subtilis in diets but there was no significant difference among the three treated groups. In addition, phenoloxidase activities were found to be significantly higher (P<0.05) in the groups treated with B. subtilis than that of the control group. Shrimps treated with 5 × 10⁴ CFU g^?1 feed probiotic bacterium showed the highest lysozyme activity and it was significantly higher (P<0.05) than the other groups. However, there was no significant difference in acid phosphatase and alkaline phosphatase activity across all the groups. The total antioxidant capacity, superoxide dismutase and glutathione peroxidase activities in the probiotic‐treated groups were significantly increased (P<0.05) as compared with the control groups. Both maleic dialdehyde concentration and superoxide anion activities in the probiotic‐treated groups were significantly lower (P<0.05) than those of the control. The probiotic did not affect the nitric oxide synthase and the catalase activity in any of the control and treated groups. These results indicated that the probiotic B. subtilis could significantly promote the growth rate of shrimp by increasing the immune function and antioxidant capacity. The most effective dose of B. subtilis in the diet was 5 × 10⁴ CFU g^?1 feed.     

草鱼对CFRV疫苗免疫应答的研究

本文研究了草鱼对ＣＦＲＶ疫苗的免疫应答水平,规律性,免疫效应期及免疫持久性。用该疫苗免疫后的草鱼能产生很强的应答反应,免疫保护力可达８０％以上,血清中和抗体效价非常明显地高于对照组。它的免疫效应期在５天以内,第１０天血清中和抗体达到较高水平,第２０天处于峰值,并可维持２０余天,以后在第１０天的水平上波动。草鱼对ＣＦＲＶ疫苗的免疫持久性在１３个月以上。     

Effects of dietary glutamine supplementation on growth performance,antioxidant status and intestinal function in juvenile grass carp (Ctenopharyngodon idella)

Glutamine (Gln) is a conditionally essential free amino acid that has been widely used in aquaculture. The present study showed that appropriate levels of dietary Gln could significantly improve growth performance and increase lipase and trypsin activity, mucosal thickness (MT) and the number of lymphocytes. The levels of glycine (Gly) in the 6 g/kg Gln group, threonine (Thr) in the 12 g/kg group and lysine (Lys) in the 6 and 9 g/kg group were increased significantly, while glutamate (Glu) and serine (Ser) concentrations decreased significantly with increasing dietary Gln levels from 3 to 12 g/kg. Moreover, the 12 g/kg dietary Gln level could improve the concentration of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH‐PX) and the total antioxidant capacity (T‐AOC). In addition, 3 g/kg Gln upregulated the gene expression of aminopeptidase N (APN), caudal‐related homeobox gene (CDX2), L‐type amino acid transporter 2 (LAT2), oligopeptide transporter 1 (PEPT1), specificity proteins 1 (SP1) and 3 (SP3), and peroxisome proliferator‐activated receptor α (PPAR‐α) but downregulated PPAR‐γ gene expression compared to that in the control group. Taken together, these findings suggest that Gln could improve the growth performance, antioxidant status and intestinal function of grass carp.     

草鱼肠道芽孢杆菌的鉴定及产酶能力分析

从100 g左右的健康草鱼(Ctenopharyngodon idellus)肠道中分离出3株疑似芽孢杆菌(Bacillus)菌株(G1、G2、G3),并通过对其进行生理生化特征、16S rDNA全序列和产酶能力的分析,筛选出1株高产酶能力的益生菌株.结果显示:G1、G2和G3菌株与枯草芽孢杆菌在16S rDNA序列相似性≥99％的水平上聚为同一分支,结合形态观察和生理生化特征,最终鉴定G1、G2和G3菌株均为枯草芽孢杆菌(Bacillus subtilis);以水解圈直径/菌落直径比值评定了G1、G2和G3菌株的产纤维素酶、淀粉酶和蛋白酶的能力,其中G1菌株产纤维素酶、淀粉酶和蛋白酶能力(比值分别为2.9、2.2和3.3)均高于G2、G3菌株,具有作为益生菌的潜力.     

投喂阿维拉霉素对鲤免疫应答的影响

将阿维拉霉素按照一定的浓度添加到饲料中,投喂经注射接种福尔马林灭活的嗜水气单胞菌(Aerom onashydrophila)菌苗的鲤,于免疫后的第7 d、14 d、21 d、28 d和35 d检测供试鲤血液中的白细胞吞噬活性、血清中溶菌酶活性、抗体效价、补体C3含量及免疫保护率(RPS),探讨了阿维拉霉素对受免鲤免疫应答的影响。结果表明,饲料中添加阿维拉霉素(4 mg/kg和8 mg/kg),投喂较长时间(≥28 d)会降低受免鲤的血液白细胞吞噬活性、血清中的溶菌酶活性和抗体效价,减少受免鲤血清中补体C3的含量,减弱鲤抵抗嗜水气单胞菌人工感染的能力,每公斤饲料中添加8 mg的阿维拉霉素其免疫抑制作用更强。     

Improvement of Antioxidant Activity of Grass Carp (Ctenopharyngodon idella) Protein Hydrolysate by Washing and Membrane Removal Pretreatments and Ultrasonic Treatment

To improve the antioxidant activity of grass carp hydrolysate, washing and membrane removal pretreatments and ultrasonic treatment were applied in this study. Various pretreatment methods (washing methods and membrane removal methods) for removing the prooxidants and phospholipid in minced fish were evaluated. The effects of ultrasonic treatment prior to enzyme hydrolysis on the antioxidant activities of minced carp hydrolysate were investigated. The minced carp subjected to washing with 0.4% NaCl solution and subsequent membrane removal with CaCl₂ and citric acid solution had the lowest content of prooxidants and phospholipid remaining in the minced fish. The hydrolysate produced from washing/membrane removal pretreated carp with ultrasonic treatment for 20 min had the highest ferric reducing antioxidant power and scavenging activities against 1,1-diphenyl-2-picrylhydrazyl and 2,2?-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. This suggested that the combination approach of washing/membrane removal pretreatment and ultrasonic treatment could improve the antioxidant activity of carp hydrolysate, and this hydrolysate could be a potential antioxidant ingredient for functional foods.     

鱼腥草或枳实对草鱼淋巴细胞转化率影响的比较研究

在草鱼基础饵料中分别添加0.1%、0.2%、0.3%、0.4%鱼腥草或枳实,45d后测定各试验组和对照组的淋巴细胞转化率,0.1%、0.2%、0.3%、0.4%试验组中,添加鱼腥草平均分别为60.15%±8.44%、66.03%±8.21%、63.36%±6.52%和53.96%±10.35%,添加枳实平均分别为67.04%±3.93%、71.23%±5.77%、72.57%±5.65%和63.15%±2.33%,对照组为54.98%±2.69%。统计结果表明添加枳实0.2%、0.3%组与对照组差异非常显著(P<0.01)、与添加0.1%鱼腥草组差异显著(P<0.05);添加枳实0.1%组、鱼腥草0.2%组与对照组差异显著(P<0.05);添加枳实0.3%组与0.4%组差异显著(P<0.05);其余各组比较,差异不显著。表明在饲料中添加一定量的枳实和鱼腥草可明显提高草鱼的淋巴细胞转化率,增强草鱼的免疫功能,是两种新的中草药免疫增强剂。     

Mo~(6+)对草鱼组织器官及抗氧化酶活性的影响

通过不同质量浓度Mo~(6+)(0、30.67、122.66mg/L)对(10.0±3.0)g草鱼幼鱼脑、肝脏、肾脏、心脏及性腺的组织学以及对肝胰脏抗氧化酶活性的影响,探讨了重金属Mo~(6+)的毒性积累和毒性机制。结果表明,草鱼Mo~(6+)中毒后,脑组织出现异常,表现为细胞破裂、细胞核聚集程度严重;肾脏充血,肾小管上皮细胞核肥大,肾小球明显萎缩;心脏肌纤维细胞体积增大,单位视野内细胞数变少,细胞核形态异常,以及局部的细胞空泡变性,出现少量细胞核偏移和密集并且细胞轮廓模糊,肌纤维有轻微断裂现象;肝脏的肝细胞出现严重的水样变性,伴随着细胞溶解、浑浊变性和轮廓模糊,血窦扩张,形成局部的点状病灶;卵巢中卵母细胞出现核变形,胞质中出现小的空泡,细胞核膨胀,扩张和核仁空泡化;精巢中生精小管畸形,含不同发育阶段的精原细胞、精母细胞、精子细胞,精细胞体积增大,精子数量明显减少。随着Mo~(6+)质量浓度的升高和时间延长,草鱼肝胰脏中的超氧化物歧化酶活性和丙二醛含量降低。