Effects of different dietary copper sources on the growth and intestinal microbial communities of Pacific white shrimp (Litopenaeus vannamei)

An 8‐week feeding trial was conducted to evaluate the effects of dietary copper sources on growth performance and intestinal microbial communities of juvenile Pacific white shrimp (Litopenaeus vannamei). Four isonitrogenous (420 g/kg crude protein) and isolipidic (70 g/kg crude lipid) experimental diets were formulated to contain different copper sources, Diet NSC (no‐supplemented copper), Diet CS (copper sulphate), Diet Availa (copper amino acid complex from Availa^®Cu100) and Diet M (1:1, copper sulphate + copper amino acid complex). A total of 360 Pacific white shrimp juveniles (initial weight: 1.86 ± 0.03 g) were randomly allocated into four groups, with three replicates per group and 30 shrimps each replicate. An Illumina‐based sequencing method was used to analyse the intestinal bacterial composition of shrimp juveniles. The results revealed that shrimps fed Diet M had significantly higher percent weight gain (PWG) than that fed Diet NSC and Diet CS, while there were no significant differences between Diet M and Diet Availa. Survival was not affected by the dietary copper sources. Proteobacteria and Bacteroidetes were dominant in the intestines of Pacific white shrimp. Shrimps fed Diet M and Diet Availa had higher bacterial richness and diversity than those fed Diet NSC and Diet CS with no significant differences among all treatments. Furthermore, Diet M and Diet Availa which contained copper amino acid complex reduced the relative abundance of Vibrionaceae in shrimp intestinal tract. This study indicated that dietary copper sources could affect the intestinal microbial communities and diets supplemented with Availa^®Cu100 could have a positive impact on the growth performance and decrease the potential risk of disease in Pacific white shrimp.     

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(105cfu/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。     

大菱鲆仔稚鱼发育早期肠道菌群结构形成的影响因素

为研究鱼类发育早期肠道菌群结构的演变过程及影响因素,运用高通量测序技术,分析了处于不同发育阶段的大菱鲆(Scophthalmus maximus)仔稚鱼肠道、受精卵、不同类型的饵料和水源中的菌群结构,以及它们之间的相关性。结果显示,以不同的OTU(Operational Taxonomic Units,可操作分类单元)作为分类依据,发现大菱鲆仔稚鱼的肠道菌群结构在开口摄食后不久已趋于稳定,其优势菌与受精卵所携带的细菌关联较大。并且在大菱鲆仔稚鱼不同的发育时期,这一菌群的结构非常稳固,几乎不受水和饵料中优势细菌的影响而发生改变。乳球菌属的Lactococcus piscium菌株一直是大菱鲆仔稚鱼肠道中的优势菌种,在不同发育时期的优势度高达45%~65%。本研究还发现,大菱鲆仔稚鱼肠道可能对定植的菌种具有选择性,一些水环境和饵料中的非优势菌,如Streptococcus sp.,Pseudomonas sp.,Carnobacterium sp.等细菌也会定植于肠道,成为大菱鲆肠道中的次优势菌。     

鲫肠道上皮细胞原代培养方法的研究

探讨了健康鲫(Carassius auratus)幼鱼肠道上皮细胞的原代培养方法。结果显示,用含有抗生素、胶原蛋白酶Ⅰ、EDTA和胶原蛋白酶Ⅳ组成的D-Hanks液消化无菌分离的鲫肠道可以获得大量细胞团及绒毛隐窝;用含有抗生素、胎牛血清(FBS)、表皮生长因子(EGF)、胰岛素的DMEM培养液进行培养,并根据肠道上皮细胞与成纤维细胞贴壁时间的差异进一步纯化,连续培养12d后可以得到纯化的肠道上皮细胞。     

鹅肠道微生物研究进展

肠道微生物是当前研究的热点,鹅肠道微生物的组成与丰富程度不仅和鹅的生长性能密切相关,而且在鹅机体生理活动中具有一定的调节作用,同时与疾病的发生和发展具有密切的联系.通过研究鹅肠道微生物的调节,从而达到促生长或者治疗疾病的目的,是目前鹅研究探寻的新方向.文章主要综述了鹅肠道微生物的组成及其变化规律,以期为鹅产业生物饲料的...     

不同动物肠道微生物对黄豆苷原的转化研究

采用高效液相色谱技术,分析比较了32种不同动物肠道微生物菌群对黄豆苷原的转化情况。在全部供试动物中,只有大熊猫的肠道微生物菌群对黄豆苷原未表现转化能力,其余31种动物的代谢产物中均出现了去氧甲基安哥拉紫檀素;有14种动物对黄豆苷原的代谢产物中出现了高活性植物雌激素雌马酚。研究表明,不同动物对黄豆苷原的代谢能力强弱不仅与遗传因素有关,同时还与动物本身的饮食结构等环境因素有关。通过测定黄豆苷原在不同动物体内的代谢产物,确定了一些对黄豆苷原具有较强代谢能力的动物种类,尤其是确定了一些能将黄豆苷原高效转化为雌马酚的理想动物种类。     

辐照对瓜实蝇遗传区性品系成虫肠道微生物的影响

为研究辐照对瓜实蝇肠道微生物群落多样性和结构组成的影响,以100 Gy137Cs辐照来自瓜实蝇遗传区性品系(GSS)的5、8、11和13日龄的雌、雄成虫,并采用Illumina MiSeq测序技术分别对其肠道菌群进行测序分析。结果表明,瓜实蝇雌雄成虫的肠道中存在19个主要的菌属,包括17个属名已知,1个属名未知和1个属不可培养。其中,17个已知属分别属于4个细菌门,即变形菌门(Proteobacteria)(占总量的50%~98%)、厚壁菌门(Firmicutes)(占总量的2%~47%)、拟杆菌门(Bacteroidetes)(占总量的1%~16%)和1个至今微生物界还未确定的稀少菌门(unclassified rare phyla)(总量1%)。此外,辐照降低了瓜实蝇肠道中的微生物多样性以及优势菌的丰富度,且这种影响与瓜实蝇的性别和成虫日龄无关。本研究结果为评估和修复辐照对瓜实蝇的损伤提供了参考。     

添加酸马奶源乳酸杆菌对犊牛肠道菌群和短链脂肪酸含量的影响

选取刚出生的健康荷斯坦犊牛20头,随机分为酸马奶组、正常组、腹泻组和抗生素组,每组5头。除正常组外,其他3组在相同哺乳的基础上均口服100 mL致病性E.coli O1菌悬液(2.5×10¹¹ CFU/mL)建立腹泻模型,抗生素组添加环丙沙星0.5 mg/kg,试验期15 d。结果表明：酸马奶组犊牛肠道微生物丰富度与多样性显著高于其他3组(P<0.05)。酸马奶源乳酸杆菌干预后显著提高了肠道内厚壁菌门、普雷沃氏菌科、毛螺菌科未确定菌属和拟普雷沃菌属的相对丰度,降低了拟杆菌门、变形菌门、梭杆菌门、放线菌门的相对丰度;酸马奶组犊牛粪便中乙酸、丙酸和丁酸含量显著高于其他3组(P<0.05)。由此可见,犊牛日粮中添加酸马奶源乳酸杆菌可显著提高肠道微生物多样性,增加肠道中有益菌的丰度,降低有害菌的丰度,并显著提高其粪便中乙酸、丙酸和丁酸的含量。     

甘露寡糖对肉鸡生产性能和肠道微生物以及免疫机能的影响

为探明甘露寡糖在肉鸡生产上的最佳使用剂量,选用11日龄广东岭南黄肉鸡1200只,随机分为6组,每组4个重复,每重复50只鸡,分别饲喂6种不同日粮,自由采食和饮水.第1组为空白对照组,第2,3,4,5,6组为试验组,在基础日粮的基础上分别添加1g/kgBio-MOS(甘露寡糖),4mg/kg黄霉素,1g/kgBio-MOS+4mg/kg黄霉素,0.5g/kgBio-MOS和1.5g/kgBio-MOS.结果表明:(1)添加Bio-MOS,提高了肉鸡的日增重和采食量,但与对照组之间差异不显著(p>0.05).(2)添加Bio-MOS1g/kg,盲肠中双歧杆菌显著高于对照组(p<0.05),但对回肠中双歧杆菌增殖效果不明显.与对照组相比,添加不同水平的Bio-MOS对盲、回肠乳酸杆菌增殖效果不明显,但不同程度地提高了盲肠中乳酸杆菌的含量;盲肠中大肠杆菌数量没有明显降低;回肠中除0.5g/kg组外,其余各组之间大肠杆菌含量差异不显著.(3)与对照组相比,添加Bio-MOS1g/kg极显著地提高了血液中T淋巴细胞的百分率(p<0.01).添加Bio-MOS对血清中新城疫抗体效价影响不明显,但以饲料中添加Bio-MOS1g/kg效果最好.饲料中添加Bio-MOS对血清中IgA,IgG,IgM影响不显著,但添加Bio-MOS1g/kg,其IgA,IgG,IgM的含量明显高于其他各组.(4)肉鸡日粮中同时添加甘露寡糖和黄霉素,两者表现出协同作用,但不及甘露寡糖单独使用时的效果.     

Phenethyl isothiocyanate as an anti-nutritional factor attenuates deoxynivalenol-induced IPEC-J2 cell injury through inhibiting ROSmediated autophagy

Deoxynivalenol(DON)is considered to be the most harmful mycotoxin that affects the intestinal health of animals and humans.Phenethyl isothiocyanate(PEITC)in feedstuff is an anti-nutritional factor and impairs nutrient digestion and absorption in the animal intestinal.In the current study,we aimed to explore the effects of PEITC on DON-induced apoptosis,intestinal tight junction disorder,and its potential molecular mechanism in the porcine jejunum epithelial cell line(IPEC-J2).Our results indicated that PEITC treatment markedly alleviated DON-induced cytotoxicity,decreasing the apoptotic cell percentage and pro-apoptotic mRNA/protein levels,and increasing zonula occludens-1(ZO-1),occludin and claudin-1 mRNA/protein expression.Meanwhile,PEITC treatment ameliorated DON-induced an increase of the inducible nitric oxide synthase(iNOS)and cyclooxygenase 2(COX-2)mRNA levels and intracellular reactive oxygen species(ROS)level,and a decrease of glutathione peroxidase 1(GPx1),superoxide dismutase 2(SOD2),catalase(CAT)and heme oxygenase 1(HO-1)mRNA levels.Additionally,PEITC treatment significantly down-regulated autophagy-related protein 5(ATG5),beclin-1 and microtubuleassociated protein 1 light chain 3B(LC3-II)mRNA/protein levels,decreased the number of green fluorescent protein-microtubule-associated protein 1 light-chain 3(GFP-LC3)puncta and phosphatidylinositol 3 kinase(PI3K)protein expression,and up-regulated phospho-protein kinase B(p-Akt)and phospho-mammalian target of rapamycin(p-mTOR)protein expression against DON.However,the activation of autophagy by rapamycin,an autophagy agonist,abolished the protective effects of PEITC against DON-induced cytotoxicity,apoptosis and intestinal tight junction disorder.Collectively,PEITC could confer protection against DON-induced porcine intestinal epithelial cell injury by suppressing ROSmediated autophagy.