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ABSTRACT: BACKGROUND: The number and diversity of uncultured ruminal bacterial and archaeal species revealed by 16S rRNA gene (rrs) sequences greatly exceeds that of cultured bacteria and archaea. However, the significance of uncultured microbes remains undetermined. The objective of this study was to assess the numeric importance of select uncultured bacteria and cultured bacteria and the impact of diets and microenvironments within cow rumen in a comparative manner. RESULTS: Liquid and adherent fractions were obtained from the rumen of Jersey cattle fed hay alone and Holstein cattle fed hay plus grain. The populations of cultured and uncultured bacteria present in each fraction were quantified using specific real-time PCR assays. The population of total bacteria was similar between fractions or diets, while total archaea was numerically higher in the hay-fed Jersey cattle than in the hay-grain-fed Holstein cattle. The population of the genus Prevotella was about one log smaller than that of total bacteria. The populations of Fibrobacter succinogenes, Ruminococcus flavefaciens, the genus Butyrivibrio, and R. albus was at least one log smaller than that of genus Prevotella. Four of the six uncultured bacteria quantified were as abundant as F. succinogenes, R. flavefaciens and the genus Butyrivibrio. In addition, the populations of several uncultured bacteria were significantly higher in the adherent fractions than in the liquid fractions. These uncultured bacteria may be associated with fiber degradation. CONCLUSIONS: Some uncultured bacteria are as abundant as those of major cultured bacteria in the rumen. Uncultured bacteria may have important contribution to ruminal fermentation. Population dynamic studies of uncultured bacteria in a comparative manner can help reveal their ecological features and importance to rumen functions. 相似文献
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甘露寡糖、果寡糖和大豆寡糖组合对锦江黄牛瘤胃液细菌多样性的影响 总被引：2，自引：0，他引：2
本试验旨在研究功能性寡糖(甘露寡糖、果寡糖和大豆寡糖)组合对锦江黄牛的瘤胃液细菌多样性的影响.选择3头健康且体重相近的安装有永久性瘤胃瘘管的锦江黄牛,采用自身对照方法,试验分2期进行,第1期:对照期,饲喂基础饲粮,不添加任何寡糖;第2期:添加期,饲喂基础饲粮+功能性寡糖(0.8％甘露寡糖+1.0％果寡糖+0.8％大豆寡糖),每期持续14 d.利用PCR-变性梯度凝胶电泳(DGGE)方法研究分析牛瘤胃液细菌多样性.结果表明:添加功能性寡糖组合后,牛瘤胃液细菌PCR-DGGE图谱条带数明显增加,3头牛增加了5个共同条带.经测序,其中2个是产琥珀酸丝状杆菌属,3个是未鉴定细菌.饲粮中添加功能性寡糖组合可使瘤胃液细菌菌群种类明显增加.结果提示,饲粮添加功能性寡糖组合能够影响瘤胃菌群区系,增强其稳定性. 相似文献
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《动物营养（英文）》2021,7(4):989-996
Inefficient dietary nitrogen (N) conversion to microbial proteins, and the subsequent use by ruminants, is a major research focus across different fields. Excess bacterial ammonia (NH3) produced due to degradation or hydrolyses of N containing compounds, such as urea, leads to an inefficiency in a host's ability to utilize nitrogen. Urea is a non-protein N containing compound used by ruminants as an ammonia source, obtained from feed and endogenous sources. It is hydrolyzed by ureases from rumen bacteria to produce NH3 which is used for microbial protein synthesis. However, lack of information exists regarding urea hydrolysis in ruminal bacteria, and how urea gets to hydrolysis sites. Therefore, this review describes research on sites of urea hydrolysis, urea transport routes towards these sites, the role and structure of urea transporters in rumen epithelium and bacteria, the composition of ruminal ureolytic bacteria, mechanisms behind urea hydrolysis by bacterial ureases, and factors influencing urea hydrolysis. This review explores the current knowledge on the structure and physiological role of urea transport and ureolytic bacteria, for the regulation of urea hydrolysis and recycling in ruminants. Lastly, underlying mechanisms of urea transportation in rumen bacteria and their physiological importance are currently unknown, and therefore future research should be directed to this subject. 相似文献
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瘤胃微生物在木质纤维素价值化利用的研究进展 总被引：1，自引：0，他引：1
瘤胃是反刍动物消化的第一个腔室，各种微生物（细菌、真菌和原生动物）相互作用将木质纤维素植物生物降解为易于代谢的化合物。瘤胃也是目前自然界公认的木质纤维素高效降解和利用的天然反应器，其真菌和细菌可分泌多种木质纤维素降解酶，在木质纤维素生产生物燃料和化学用品方面具有潜在的价值。因此，本研究在瘤胃内木质纤维降解的微生物及其降解木质纤维素相关酶的基础上，重点综述了瘤胃微生物在木质纤维素生物转化为乙醇、生物化学（有机酸）及沼气等方面的研究进展，旨在为瘤胃微生物和瘤胃酶在木质纤维素价值化利用方面的研究和应用提供新的方法和思路。 相似文献
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生命早期消化道中的微生物定植可影响动物机体，且具有长期健康效应，详细了解早期瘤胃微生物的定植状况对动物健康及生长发育有重要意义。反刍动物自出生后开始与外界微生物接触，其瘤胃微生物菌群结构发生剧烈变化，且易受动物日龄、品种以及饮食结构的影响。反刍动物瘤胃含有复杂的微生物菌群，主要由厌氧细菌、古生菌、真菌和原虫构成。本文综述了反刍动物幼龄阶段瘤胃细菌、古生菌、真菌和原虫的定植组成及其变化，同时阐述了饲粮组成和饲料添加剂对幼龄反刍动物瘤胃微生物菌群的影响，旨在为幼龄反刍动物实现分阶段的营养调控提供理论基础。 相似文献
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减少瘤胃甲烷排放措施的研究已成为当前的研究热点之一。本研究以酒、面包和畜禽专用酿酒酵母产品为原材料,从中分离到三株酵母菌,将其制成冻干粉,通过体外产气试验,筛选出了一株抑制瘤胃甲烷排放效果最为显著的酵母菌株。然后以该酵母菌株作为研究对象,进行分子生物学鉴定;采用分光光度计比浊法测定该酵母菌株的生长曲线,确定菌体生长规律;并以此为依据,设计单因素试验考察该酵母菌株最适宜的生长条件。结果表明,分离得到的酵母菌株均为酿酒酵母saccharomyces cerevisiae;抑制瘤胃体外甲烷排放效果最显著的1株酵母菌分离自面包中;该酿酒酵母菌株的对数生长期为8～24h,其最佳培养条件为:生长温度30℃,pH 5.5,培养基中葡萄糖的浓度4.0%。 相似文献
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《The Journal of Applied Poultry Research》2005,14(2):444-453
Bacteria colonize practically every habitat in the nature. Bacterial community of the gastrointestinal tract (GIT) is one of the major metabolic tissues of animals. Still, its species composition is not known, because methods that have been previously used for bacterial analysis do not capture the species present. The bacterial community within the GIT not only has intracommunity interactions, but it also interacts with the host tissues. For the host, it is essential to tolerate commensal bacteria and to recognize and fight intestinal pathogens. In addition to recognized pathogens, there are many functional bacterial groups, which produce metabolites considered harmful for the host. Such functional bacterial groups include protein-fermenting bacteria that produce toxic end products in their amino acid metabolism, which is why a high-protein diet is often considered unhealthy. Carbohydrates are preferred substrates for gastrointestinal bacteria, but in the distal colon, they may become depleted, and putrefaction becomes the dominating type of fermentation. This largely accounts for the health effects of slowly fermenting dietary fibers.Microbial communities in the GIT of different animals have developed hand-in-hand with their digestion strategy. In monogastric animals, bacterial fermentation has concentrated in the lower GIT, whereas in ruminants bacteria are responsible for the initial digestion of the diet. Rumen-like sites with intense bacterial fermentation are found in most animals, but no other group of animals totally depends on bacteria. The response of rumen bacteria to feed components can be evaluated by an in vitro rumen simulation, which measures relevant fermentation parameters, such as the yield of bacterial biomass (protein) and volatile fatty acids (energy). In monogastric animals, it is essential that the host has measures to prevent bacterial competition for substrates in regions in which absorption takes place; the use of prophylactic antibiotics for production animals has aided this.Availability of good methods for monitoring the total bacterial communities and their metabolism is a prerequisite for informative studies in the future. 相似文献
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Halima SULTANA Hazizul HUSSAIN‐YUSUF Toshihiro TAKAHASHI Tetsuo MORITA Ryoji ONODERA 《Animal Science Journal》2003,74(1):11-16
The catabolism of arginine (Arg) by mixed rumen bacteria (B), mixed rumen protozoa (P), and their mixture (BP) was quantitatively investigated in an in vitro system in order to confirm the metabolic pathway of Arg and provide basic information for enzymatic and molecular studies as well as an understanding of the quantitative distribution of metabolites. Rumen microbial suspensions (B, P, and BP) collected from fistulated goats were anaerobically incubated with or without 1 mmol/L Arg at 39°C for 12 h. Arg and other related compounds such as citrulline (Cit), ornithine (Orn), proline (Pro) and 5‐aminovaleric acid (5AV) in both supernatant and hydrolyzates of B, P, and BP suspensions were analyzed by HPLC. The metabolic pathways of Arg in mixed rumen bacteria and mixed rumen protozoa were considered to be as follows: rumen bacteria, Arg → Cit → Orn → Pro → 5AV → VFAs + NH3; rumen protozoa, Arg → Cit → Orn → Pro → 5AV. The disappearance of Arg (1 mmol/L) was approximately 52.9 and 88.2% in B, 33.9 and 55.6% in P, and 52.8 and 85.2% in BP during 6 and 12 h incubations, respectively. When expressed in units of ‘per gram (g) of microbial nitrogen (MN)’, the net degradation rate of Arg in BP (50.3 µmol/g MN/h) was approximately 46% lower than that of B during a 12 h incubation period. The presence of protozoa tended to inhibit the production of Orn from Cit and the production of 5AV from Pro which were thought to be rate‐limiting steps of Arg metabolism in rumen microorganisms. As a result, protozoa appeared to have a saving effect on Arg metabolism, that is, protozoa protected Arg from wasteful exhaustion in the rumen. 相似文献
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瘤胃微生物如细菌、原虫以及纤毛虫等的研究一直是反刍动物研究的重要方面。它们不仅可以对饲料纤维、淀粉进行降解,日粮蛋白质也是它们的发酵底物之一,此外,内源性的含氮物质和日粮中添加的氮源物质都可被它们代谢利用。在瘤胃微生物产生的各种降解酶的作用下,饲料养分被逐级降解进行转化,但它们的作用机理及相互作用尚不完全清楚,一直是反刍动物营养研究的重点。为此,文章对瘤胃微生物对宿主动物氮源物质的作用及其需求作一介绍,以便为深入研究作一参考。 相似文献
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《畜牧与生物技术杂志(英文版)》2017,(3)
Background: Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods: To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet(HFD) or a high energy diet(HED) were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results: Rumen bacterial diversity was mainly affected by diet and individual cow(P 0.05) rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers(using LEf Se analysis) were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions: Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study. 相似文献
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大蒜素是一种从大蒜中提取的含硫化合物，具有安全性高、无残留、不产生耐药性、抗菌谱广、无配伍禁忌等优点。大蒜素的生理功能包括降低血糖和血压、抗氧化、增强免疫力和抑制有害细菌等，并且在动物生产中发挥着维持动物肠道健康、改善肠道菌群、调节脂肪沉积等作用。作为饲料添加剂的大蒜素主要为化学合成类型。首先合成二烯丙基二硫醚，再通过氧化反应合成大蒜素，在实验室中大蒜素还可以通过过氧化氢、过氧邻苯二甲酸镁或氯代苯甲酸氧化二烯丙基二硫化物来合成。在实际生产中，大蒜素对反刍动物有促生长、提高饲料消化率、改善瘤胃发酵等诸多功能。大蒜素还可以通过抑制瘤胃内产甲烷菌活性和减少产甲烷菌数量来降低瘤胃甲烷产量。作者主要介绍了大蒜素的合成、理化特性及其生理功能，并阐述了在反刍动物中应用大蒜素的研究成果，以期为大蒜素在反刍动物生产中的应用提供参考。 相似文献
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Allicin is a sulfur compound extracted from garlic,which has the advantages of high safety,no residue,no drug resistance,wide antibacterial spectrum,no incompatibility and so on.The physiological functions of allicin include reducing blood sugar and blood pressure,anti-oxidation,enhancing immunity and inhibiting harmful bacteria,and plays a role in maintaining animal intestinal health,improving intestinal flora and regulating fat deposition in animal production.Allicin,as a feed additive,is mainly of chemical synthesis type.Diallyl disulfide is synthesized at first,and then allicin is synthesized by oxidation reaction.Allicin can also be synthesized by hydrogen peroxide,magnesium peroxy phthalate or chlorobenzoic acid oxidizing diallyl disulfide in the laboratory.In actual production,allicin can promote the growth of ruminants,improve feed digestibility,improve rumen fermentation.Allicin can also reduce rumen methane production by inhibiting the activity of methanogenic bacteria in the rumen and reducing the number of methanogenic bacteria.The authors mainly introduced the synthesis,physical and chemical properties and physiological functions of allicin,and expounded the research results and prospects of the application of allicin in ruminants,in order to provide reference for the better application of allicin in ruminant production. 相似文献
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有关瘤胃酸中毒发生机制研究表明,瘤胃乳酸的累积可能对酸中毒诱导起重要作用,而高精料日粮下瘤胃乳酸累积主要取决于瘤胃乳酸产生菌和乳酸利用菌间的平衡程度。本文综述了瘤胃微生物对乳酸的代谢机制,包括主要乳酸产生菌[溶纤维丁酸弧菌(Butyrivibrio fibrisolvens)、牛链球菌(Streptococcus bovis)、乳酸杆菌(Lactobacillus)]和主要乳酸利用菌[反刍兽新月单胞菌(Selenomonus ruminantium)、埃氏巨型球菌(Megasphaera elsdenii)],并简要概述了酸中毒的调控方法,旨在为反刍动物瘤胃酸中毒的乳酸中毒机制深入解析提供参考。 相似文献
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试验旨在探讨不同的饲养环境及日粮结构对牦牛瘤胃菌群结构的影响，应用高通量测序技术分析了青海牦牛引进山东后的瘤胃菌群变化情况。结果表明，青海牦牛瘤胃液可见物种（Observed species）及Chao1指数（Chao1 index）与引进牦牛瘤胃液相比差异极显著（P<0.01），ACE指数差异显著（P<0.05）；青海牦牛菌群丰度显著高于引进牦牛，说明青海牦牛引进山东后瘤胃菌群丰度发生了显著变化，而引进前后牦牛瘤胃液香浓指数（Shannon index）以及辛普森指数（Simpson index）差异不显著（P>0.05），说明青海牦牛引进山东后瘤胃菌群多样性未显著改变。测序数据表明，牦牛瘤胃液中丰度较高的菌群依次是拟杆菌门、厚壁菌门、变形菌门、疣微菌门、互养菌门、软壁菌门、纤维杆菌门；青海牦牛引进山东后菌群结构比例变化显著的门是浮霉菌门和装甲菌门（P<0.05），变化显著的属是颤杆菌克属和帕匹杆菌属（P<0.05）。数据分析得出，拟杆菌和理研菌科在青海牦牛瘤胃液中起重要作用，而普雷沃氏菌科、琥珀酸弧菌科和产气单胞菌在引进山东牦牛瘤胃液中起主要的作用，推测饲养环境及日粮结构的改变导致了瘤胃菌群及其相关功能的改变。本研究为地域和日粮结构的变化对牦牛瘤胃菌群结构的影响提供了理论依据。 相似文献
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蛋白质来源对瘤胃细菌和原虫群体结构的影响 总被引：1，自引：0，他引：1
以4只瘘管山羊为试验动物,采用4×4拉丁方设计,使用克隆测序、遗传指纹以及细胞显微计数等技术,研究以羽毛粉(A)、玉米蛋白粉(B)、豆粕(C)和鱼粉(D)4种蛋白补充料分别配合的混合日粮对瘤胃细菌和原虫群体结构的影响。结果表明:细菌的R.flavefaciens、R.bromii、R-7、Roseburia faecalis、Uncultured T33H60F48、Uncultured GRANT42及1个尚不能定性的类群在组间存在显著差异(P<0.05);原虫的内毛虫、前毛虫、头毛虫、等毛虫4个类群在处理间差异显著(P<0.05)。综上可见,蛋白质源对瘤胃细菌和原虫类群结构有显著影响。 相似文献
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2008-2009年反刍动物营养研究进展 Ⅱ.外源添加剂对瘤胃发酵的调控 总被引：3，自引：2，他引：1
作者综述了2009年在ADSA-ASAS大会和CNKI、PubMed等数据库中外源添加剂(离子载体、酶制剂、植物提取物、饲用微生物)对瘤胃发酵调控的相关文献39篇。离子载体如莫能菌素主要通过促进瘤胃丙酸的产生,抑制生物氢化菌,促进长链脂肪酸在瘤胃内发生不完全氢化等瘤胃调控作用,从而缓解反刍动物的能量负平衡,减少甲烷排放,降低乳中脂肪含量。酶制剂(包括纤溶酶和淀粉酶等)在饲喂前加入日粮中能够免受瘤胃蛋白酶的降解,并保持酶活性,促进饲料的消化。植物提取物中皂角甙通过抑制原虫生长降低甲烷的排放,动物长期采食富含单宁的植物可产生单宁耐受菌,并且单宁的植物提取物可影响瘤胃的生物氢化作用,植物精油对瘤胃的调控作用包括减少淀粉和蛋白的降解,以及通过对某种瘤胃微生物的选择性作用抑制氨氮的降解。饲用微生物(主要有酵母菌、乳酸菌、芽孢杆菌等)能增加营养物质消化率,改变瘤胃发酵模式,增加瘤胃微生物菌群,但其益生效果与泌乳阶段、日粮类型、环境条件有关。 相似文献
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慢性瘤胃酸中毒状态下奶山羊瘤胃细菌内几种相关细菌数量变化的研究 总被引：1，自引：0，他引：1
研究慢性瘤胃酸中毒（subacute rumen acidosis,SARA）状态下,相关瘤胃微生物数量的变化。将6只体重相近,体况良好,并安装有永久性瘤胃瘘管的泌乳期关中奶山羊作为试验对象,以逐渐增加精料的方式诱导动物发生SARA。试验分4期进行,4期日粮的精粗比分别为5∶5、6∶4、7∶3和8∶2。分别采用16S rRNA 探针杂交法和传统培养法对SARA状态下瘤胃内微生物数量变化进行测定。随着日粮精料比例的增加,牛链球菌、乳酸杆菌、反刍兽新月单胞菌、埃氏巨型球菌和淀粉分解菌的数量出现不同程度的增加,而3种主要纤维分解菌的数量有所下降,其中淀粉分解菌的数量极显著增加（P<0.01）。在SARA状态下瘤胃细菌总数、乳酸产生菌和乳酸利用菌数量均有所增长,同时3种主要纤维分解菌的数量明显下降。 相似文献