DGGE技术的原理及其在动物胃肠道微生态系统研究中的应用

利用传统的培养方法很难将动物胃肠道的所有菌群进行培养,因此也很难鉴别各个时期动物胃肠道微生物之间的差异。变性梯度凝胶电泳(DGGE)技术可以避免传统方法的弊端,进而可以进一步确定动物胃肠道微生态系统的差别以及菌群的多样性。主要综述了DGGE技术的原理﹑优缺点以及在动物胃肠道微生态系统研究中的应用和前景。     

动物机体微生态系统和微生态制剂的研究进展

概述微生态系统的定义,口咽部微生态系统和胃肠道微生态的系统的研究现状和发展方向。尤其针对胃肠道微生态平衡的微生态制剂的定义、类型和作用机理、相对于传统抗生素的优势以及对其发展前景作了论述。     

微生态制剂对肠道菌群紊乱的调节作用

微生态制剂是根据微生态学基本原理研制,用于调节机体的微生态环境。动物微生态学是研究动物机体正常微生物群与宿主的相互关系。其研究内容主要包括口腔、胃肠道、泌尿生殖道和皮肤4个生态学领域。其中胃肠道微生态学在动物生产上的作用研究最多，也最深入。     

家兔胃肠道微生态系统和微生态制剂的研究进展

家兔作为一种小型的草食家畜,其胃肠道内环境和大量微生物的消化代谢方式与反刍动物瘤胃相似,平衡的家兔胃肠道菌群对其生长发育和提高抗病力具有十分重要的意义。随着生态养殖业的普及和发展,微生态制剂在生态养兔中的应用得到养殖业主的青睐,也成为了我们研究的主要方面。主要从家兔胃肠道微生态系统的组成、作用机制以及与家兔健康的密切关系等方面对胃肠道微生态系统及其微生态制剂的应用前景等问题进行了总结与探讨。     

微生态制剂对肠道菌群紊乱的调节作用

微生态制剂根据微生态学基本原理研制，用于调节机体的微生态环境。动物微生态学主要研究动物机体正常微生物群与宿主的相互关系。其研究内容包括口腔、胃肠道、泌尿生殖道和皮肤4个生态学领域。其中胃肠道微生态学在动物生产上的作用研究最多，也最深入。     

微生态制剂对肠道菌群紊乱的调节作用

微生态制剂是根据微生态学基本原理研制．用于调节机体的微生态环境。动物微生态学是研究动物机体正常微生物群与宿主相互关系。其研究内容主要包括口腔，胃肠道，泌尿生殖道和皮肤4个生态学领域。其中胃肠道微生态学在动物生产上的作用研究最多．也最深入．     

微生态制剂对肠道菌群紊乱的调节作用

微生态制剂是根据微生态学基本原理研制,用于调节机体的微生态环境.动物微生态学是研究动物机体正常微生物群与宿主相互关系.其研究内容主要包括口腔、胃肠道、泌尿生殖道和皮肤4个生态学领域.其中胃肠道微生态学在动物生产上的作用研究最多,也最深入.     

猪粪样DNA提取方法的比较

哺乳动物胃肠道中存在约30个属500多种不同的细菌,约1×1014个活细菌,其形成了复杂而动态平衡的微生态系统,对宿主营养物质的消化、吸收及免疫机制激活等起着十分重要的作用[1].这微生态平衡失调,机体正常的生理功能就会发生紊乱,导致疾病的发生、流行,对畜牧养殖业尤其是规模化养殖等带来极大的潜在威胁.因而,近年来对胃肠道微生物区系结构及其多样性研究成为热点,但由于胃肠道的特殊生存环境,目前有60%～80%的微生物是无法用传统的分离培养技术进行研究, 从而阻碍了人们对胃肠道微生物结构及其多样性的客观认识.     

浅议动物微生态营养理论的发展

1动物微生态营养学发展概况 微生态营养学是以动物微生态学和动物营养学为基础的一门交叉学科,其研究重点为动物微生态环境与宿主关系、菌群平衡及代谢产物与动物(消化吸收)代谢机能关系和饲料因子与动物胃肠道微生态环境的关系. 动物消化道中的微生物数量级为100万亿,微生物间及微生物与动物间形成了相互依存和相互作用的不可分割的整体.胃肠道微生物按其在肠道内生存定居的特点可分为固定群落和过路群落.前者是指在胃肠道内占有特定区域的微生物,后者则指那些不能在健康动物胃肠道内长期生长的微生物.     

微生态制剂的研究进展及其在奶牛生产上的应用

微生态制剂可直接饲喂动物并在动物消化道内起有益作用,它以活的形式在动物消化道中与病原菌进行竞争抑制,增强动物机体的免疫功能,并直接参与胃肠道微生物的平衡,达到胃肠道功能正常变化的目的。作者概述了微生态制剂的作用机理及在奶牛生产上的应用,为微生态制剂的进一步研究奠定理论基础。     

DGGE/TGGE技术在微生物生态学中的应用

变性梯度凝胶电泳(deaturing grad ien t ge l e lectrophores is,DGGE)和温度梯度凝胶电泳(tem perature grad ien t ge le lectrophores is,TGGE)可以直接分离PCR扩增片段,作为一种分子指纹技术而逐渐被人们应用于微生态研究中。通过DGGE/TGGE对微生物组成的遗传特性进行表征,不但省去了菌种分离耗时耗力的工作量,更可鉴定出根据传统方法无法分离出来的菌种。作者重点描述了DGGE/TGGE的基本原理以及在胃肠道微生态研究中的应用。     

Fecal microbial diversity and putative function in captive western lowland gorillas (Gorilla gorilla gorilla), common chimpanzees (Pan troglodytes), Hamadryas baboons (Papio hamadryas) and binturongs (Arctictis binturong)

Microbial populations in the gastrointestinal tract contribute to host health and nutrition. Although gut microbial ecology is well studied in livestock and domestic animals, little is known of the endogenous populations inhabiting primates or carnivora. We characterized microbial populations in fecal cultures from gorillas (Gorilla gorilla gorilla), common chimpanzees (Pan troglodytes), Hamadryas baboons (Papio hamadryas) and binturongs (Arctictis binturong) to compare the microbiomes associated with different gastrointestinal morphologies and different omnivorous feeding strategies. Each species was fed a distinct standardized diet for 2 weeks prior to fecal collection. All diets were formulated to reflect the species' feeding strategies in situ. Fresh fecal samples were pooled within species and used to inoculate in vitro batch cultures. Acetate, propionate, butyrate and valerate were measured after 24 h of incubation. Eubacterial DNA was extracted from individual fecal samples, pooled, and the cpn60 gene region was amplified and then sequenced to identify the major eubacterial constituents associated with each host species. Short chain fatty acids (P < 0.001) and methane (P < 0.001) were significantly different across species. Eubacterial profiles were consistent with fermentation data and suggest an increase in diversity with dietary fiber.     

微生物脂肪酶概况及其动物营养效应的研究进展

微生物脂肪酶是工业用脂肪酶的重要来源,是生物技术和有机化学应用中广泛使用的酶类之一。文章从微生物脂肪酶来源、酶学特性、在动物消化道中的营养效应和作用机理方面进行综述,主要介绍国内外关于脂肪酶应用在动物饲料方面所取得的一些研究成果,为微生物脂肪酶在饲料中的开发与应用提供参考。     

Effects of supplementing freeze-dried Mitsuokella jalaludinii phytase on the growth performance and gut microbial diversity of broiler chickens

Inclusion of phytase in animal feedstuff is a common practice to enhance nutrients availability. However, little is known about the effects of phytase supplementation on the microbial ecology of the gastrointestinal tract. In this study, freeze-dried Mitsuokella jalaludinii phytase (MJ) was evaluated in a feeding trial with broilers fed a low available phosphorus (aP) diet. A total of 180 male broiler chicks (day-old Cobb) were assigned into three dietary treatments: Control fed with 0.4% (w/w) of available phosphorus (aP); Group T1 fed low aP [0.2% (w/w)] supplemented with MJ; and T2 fed low aP and deactivated MJ. The source of readily available P, dicalcium phosphate (DCP), was removed from low aP diet, whereby additional limestone was provided to replace the amount of Ca normally found in DCP. For each treatment, 4 replicate pens were used, where each pen consisted of 15 animals. The animals' energy intake and caecal bacterial community were monitored weekly for up to 3 weeks. The apparent metabolizable energy (AME) and apparent digestibility of dry matter (ADDM) of broilers fed with different diets were determined. In addition, the caecal microbial diversities of broilers were assessed using high-throughput next-generation sequencing targeting the V3-V4 region of bacterial 16S rRNA. The results showed that broilers fed with T1 diet have better feed conversion ratio (FCR) when compared to the Control (p < .05) and T2 diets (p < .05), demonstrating the efficiency of MJ as a supplement to low aP diet. Nevertheless, MJ did not significantly affect the microbial population and diversity in broilers' caeca, which mainly consists of members from Bacteroidetes, Firmicutes, and Proteobacteria. Regardless, significant variations in the caecal bacterial composition were observed over time, probably due to succession as the broilers aged. This is the first reported study on the effect of MJ on the microbial diversity of broiler's caeca.     

膨化秸秆微生物发酵饲料对杜寒杂交肉羊生长性能和胃肠道发育的影响

[目的] 研究膨化秸秆微生物发酵饲料对杜寒杂交肉羊生长性能和胃肠道发育的影响。[方法] 选择81只3月龄、体重为（23.0±1.0）kg的杜寒杂交羔羊,随机分为对照组（70%精料+30%干秸秆）、试验Ⅰ组（70%精料+30%膨化秸秆微生物发酵饲料）和试验Ⅱ组（70%精料+30%膨化秸秆微生物发酵饲料,添加占日粮总蛋白浓度10%的膨化缓释尿素,NPN≥100%）。试验期为75 d,预饲期为15 d,正饲期为60 d。分析育肥羊的增重,胃肠道组织重量和表观形态。[结果] 膨化秸秆微生物发酵饲料极显著（P<0.01）提高试验组羊的采食量和日增重。试验组羊的大肠重,消化道总重和瘤胃容积均显著（P<0.05）高于对照组,试验Ⅱ组羔羊瘤胃内壁颜色优于其他组。[结论] 膨化秸秆微生物发酵饲料促进了育肥羊生长性能和胃肠道发育,试验Ⅱ组的作用更明显。     

镉、汞、铅污染及其微生物修复研究进展

随着人类活动的增强,重金属的应用越来越广,同时造成的环境污染问题愈发严重,特别是重金属镉、汞、铅。利用微生物技术修复环境污染中的重金属,以其成本低、效率高等特点,已经成为环境污染修复领域的研究热点。作者综述镉、汞、铅污染及其微生物修复的研究进展,并提出利用微生物细胞表面展示技术构建高效吸附重金属的基因工程菌,在微生物修复方面应用的重要价值。     

Microbial diversity and structure in the gastrointestinal tracts of two stranded short-finned pilot whales (Globicephala macrorhynchus) and a pygmy sperm whale (Kogia breviceps)

Information on the gut microbiome composition of different mammals could provide novel insights into the evolution of mammals and succession of microbial communities in different hosts. However, there is limited information on the gut microbiome composition of marine mammals, especially cetaceans because of sampling constraints. In this study, we investigated the diversity and composition of microbial communities in the stomach, midgut, and hindgut of 2 stranded short-finned pilot whales (Globicephala macrorhynchus) and hindgut of a stranded pygmy sperm whale (Kogia breviceps) by using 16S rRNA gene amplicon sequencing technology. On the basis of the 50 most abundant operational taxonomic units, principal coordinate analysis, and non-metric multidimensional scaling analysis, we confirmed that the gut microbial communities of the 3 whales were different. Our results revealed that the gut microbiome of 1 stranded short-finned pilot whale GM16 was dominated by Firmicutes (mainly Clostridium) and Fusobacteria; whereas that of the other pilot whale GM19 was composed of Gammaproteobacteria and Bacteroidetes (mainly Vibrio and Bacteroides, respectively), probably caused by intestinal disease and antibiotic treatment. The gut microbiome of the pygmy sperm whale was dominated by Firmicutes and Bacteroidetes. Moreover, different gastrointestinal tract regions harbored different microbial community structures. To our knowledge, this is the first report of the gut microbiome of short-finned pilot whales, and our findings will expand our current knowledge on microbial diversity and composition in the gastrointestinal tract of cetaceans.     

Dietary shifts affect the gastrointestinal microflora of the giant panda (Ailuropoda melanoleuca)

Giant pandas exhibit seasonal changes in bamboo plant part preference. The influences on the gastrointestinal tracts (GIT) microbial populations were evaluated during a 14‐month period for a pair of adult male and female giant pandas housed at the Memphis Zoo using traditional culturing methods to enumerate eight bacterial groups (total anaerobes, total aerobes (TAR), streptococci (STR), total enterics, Escherichia coli, Bacteroides spp., lactobacilli and Clostridium spp.). Both the male and female pandas altered bamboo consumption behaviours, with a sharp decrease in leaf preference in April 2010 and returning to high levels of leaf preference from June to October, corresponding to significant shifts in the densities of TAR, STR, and lactobacilli and Bacteroides spp. These findings indicate seasonal changes in food preference affect the assemblages of microbial populations within the GIT of the giant panda and contribute to a better understanding of the importance of bamboo in this species’ foraging strategy.     

胃肠道褪黑素的合成及其对消化道微生物群体影响的研究进展

胃肠道褪黑素主要是由肠嗜铬细胞分泌,具有一定昼夜节律性。褪黑素通过调控细胞因子或NF-κB等调控肠道微生物及其代谢,进而影响动物肠道微生物群体结构以及某些细菌的昼夜节律。本文主要对近几年胃肠道褪黑素的合成分泌及其生理功能、肠道微生物节律性以及褪黑素对肠道微生物的调控作用等研究进行综述,以期为胃肠道褪黑素与菌群之间调控关系的研究提供一定参考。     

荒漠区不同大小灌丛周围土壤微生物生物量及活性特征

为了解不同大小灌丛对荒漠区土壤生物学性状的影响与作用,本研究在东阿拉善荒漠区选择两组不同大小的红砂灌丛,研究其周围土壤资源的空间异质性和土壤微生物特性的变化规律。结果表明,红砂灌丛下沙堆土壤有机碳和全氮含量显著大于其内部和外部土壤,随灌丛增大,沙堆有机碳和全氮含量无显著变化,而土壤水分含量显著增加;另外,灌丛周围土壤微生物生物量碳氮含量较低,分别为55.23~113.81 mg/kg和5.46~7.66 mg/kg,其中,灌丛内部土壤微生物生物量碳含量和微生物熵(qMB)显著高于灌丛外部与沙堆,而土壤微生物呼吸熵(qCO₂)变化与之相反;随灌丛增大,内部土壤微生物生物量与微生物活性保持稳定,变化较小。以上结果说明红砂灌丛对风蚀拦截形成的沙堆富含大量养分,但沙堆养分含量与灌丛大小无关,同时沙堆的形成对维持灌丛内部土壤微环境的稳定与健康具有重要作用。