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蝎子肠道内微生物多样性研究 总被引:2,自引:0,他引:2
蝎子是一种重要的药用动物,还具有很高的营养价值。分别采用非培养和纯培养方法研究蝎子肠道内的微生物群落,结果表明,非培养方法检测到的蝎子肠道内微生物大部分属于α,β,γ-Proteobacteria类群,纯培养法分离到的菌株多属于高G C含量的革兰氏阳性菌,两种方法都检测到肠杆菌属(Enterobacter)、沙雷氏菌属(Serratia)、苍白杆菌属(Ochrobactrum)菌株,综合两种方法检测结果,蝎子肠道微生物共包括23个属,分别是肠杆菌属(Enterobacter)、沙雷氏菌属(Serratia)、假单胞菌属(Pseudomonas)、不动杆菌属(Acinetobacter)、气单胞菌属(Aeromonas)、柠檬酸杆菌属(Citrobacter)、土地杆菌属(Pedobacter)、代尔夫特菌属(Delftia)、罗尔斯通氏菌属(Ralstonia)、苍白杆菌属(Ochrobactrum)、鞘鞍醇单胞菌属(Sphingomonas)、微小杆菌属(Exiguobacterium)、戈登氏菌属(Gordonia)、诺卡氏菌属(Nocardia)、红球菌属(Rhodococcus)、两面神菌属(Janibacter)、考克氏菌属(Kocuria)、微球菌属(Micrococcus)、壤霉菌属(Agromyces)、微杆菌属(Microbacterium)、土壤球菌属(Agrococcus)、异常球菌属(Deinococcus)、鸟氨酸微菌属(Ornithinimicrobium),还有一些属于不能培养的未知菌。 相似文献
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中国微生物物种多样性研究进展 总被引:7,自引:0,他引:7
微生物是分布最为广泛的生命形式,几乎分布到地球上的所有生境,具有丰富的物种多样性。我国地域辽阔,跨越热带至寒温带,气候条件多样,地理环境与生态系统类型复杂,是世界上生物多样性最丰富的国家之一。我国已开展了大量微生物多样性研究,并证实我国多样的生境蕴藏着丰富的微生物物种多样性。目前我国已报道真核微生物(菌物)约14,700种,其中包括真菌约14,060种、卵菌约300种、黏菌约340种,而真菌中有药用菌473种、食用菌966个分类单元。特别是近年来通过免培养的分子生物学技术发现我国存在丰富的原核微生物多样性。本文概述了传统方法和现代分子生物学技术在我国原核微生物(古菌、细菌)和真核微生物(真菌、卵菌、黏菌)物种多样性研究的最新进展。 相似文献
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科学家估计,目前大约只有不到1%的微生物能被纯培养,由于纯培养手段的局限,现在已相继发展有多种不同的方法用于探测微生物世界的多样性,如原位检测特异性的基因、基因组的分析,但这些研究方法对科学家认识微生物生态系统中的个体成员帮助不大。7月9日霍华德休斯医学研究所(HHM 相似文献
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污染土壤微生物群落结构多样性及功能多样性测定方法 总被引:18,自引:0,他引:18
土壤微生物在促进土壤质量和植物健康方面发挥着重要的作用,土壤微生物群落结构和组成的多样性及其变化在一定程度上反映了土壤质量.为了更好地了解土壤健康状况,非常有必要发展有效的方法来研究污染土壤微生物的多样性、分布以及行为等.回顾了近年来国内外污染土壤微生物群落结构多样性及功能多样性的测定方法,包括生物化学技术和分子生物学技术,现将它们的原理、优缺点、实用性及其发展动态作一阐述,同时指出结合这两种技术可为微生物群落分析提供一个更全面的、精确的方法. 相似文献
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【背景】野生棘线鲬(Grammoplites scaber)具有丰富的营养价值,但关于其胃肠道微生物方面的研究较少。【目的】研究棘线鲬胃肠道微生物群落特征,以揭示其潜在的益生菌和致病菌,为其健康生长的微生物群落调控提供依据。【方法】利用免培养和纯培养技术相结合的方式对来自珠江口的野生棘线鲬胃肠道样品进行了研究。【结果】通过对16S rRNA基因V3区高通量扩增测序,共得到456个操作分类单元(operational taxonomic units,OTU)。分析结果显示,在门水平上,棘线鲬胃肠道内的主要优势类群为变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)。在属级水平上,梭菌属(Clostridium)在棘线鲬胃肠道样品中普遍存在,综合占比为57.11%。基于16S rRNA基因进行表型和功能预测的结果表明,棘线鲬胃肠道内有益菌和潜在致病菌同时存在且有功能相互制约的趋势。纯培养实验采用12种不同的培养基进行选择性分离,共获得纯培养菌株99株,归类于3个门(Proteobacteria、Firmicutes和Actinobacteria) 4个纲10个目10个科13个属,其中优势类群为变形菌门(占比50.51%),实现纯培养最多的属级类群为嗜冷杆菌属(Psychrobacter)。【结论】揭示了野生棘线鲬胃肠道微环境微生物的物种组成与多样性,可以为硬骨鱼类核心肠道菌群的研究提供基础参考。此外,有益和有害菌群的揭示可为野生棘线鲬作为海洋食物资源利用的食品安全提供一定的借鉴,为发展海洋渔业养殖提供数据支撑。 相似文献
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Phylogenetic Approaches for Describing and Comparing the Diversity of Microbial Communities 总被引:28,自引:15,他引:13 下载免费PDF全文
Andrew P. Martin 《Applied microbiology》2002,68(8):3673-3682
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Cultivation-Dependent and -Independent Approaches for Determining Bacterial Diversity in Heavy-Metal-Contaminated Soil 总被引:16,自引:0,他引:16 下载免费PDF全文
Richard J. Ellis Philip Morgan Andrew J. Weightman John C. Fry 《Applied microbiology》2003,69(6):3223-3230
In recent years, culture-independent methods have been used in preference to traditional isolation techniques for microbial community analysis. However, it is questionable whether uncultured organisms from a given sample are important for determining the impact of anthropogenic stress on indigenous communities. To investigate this, soil samples were taken from a site with patchy metal contamination, and the bacterial community structure was assessed with a variety of approaches. There were small differences in microscopic epifluorescence bacterial counts. Denaturing gradient gel electrophoresis (DGGE) profiles of 16S rRNA gene fragments (16S-DGGE) amplified directly from soil samples were highly similar. A clone library generated from the most contaminated sample revealed a diverse bacterial community, which showed similarities to pristine soil communities from other studies. However, the proportion of bacteria from the soil samples that were culturable on standard plate-counting media varied between 0.08 and 2.2%, and these values correlated negatively with metal concentrations. The culturable communities from each sample were compared by 16S-DGGE of plate washes and by fatty acid profiling of individual isolates. Each approach indicated that there were considerable differences between the compositions of the culturable communities from each sample. DGGE bands from both culture-based and culture-independent approaches were sequenced and compared. These data indicated that metal contamination did not have a significant effect on the total genetic diversity present but affected physiological status, so that the number of bacteria capable of responding to laboratory culture and their taxonomic distribution were altered. Thus, it appears that plate counts may be a more appropriate method for determining the effect of heavy metals on soil bacteria than culture-independent approaches. 相似文献
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Luisa W. Hugerth Emilie E. L. Muller Yue O. O. Hu Laura A. M. Lebrun Hugo Roume Daniel Lundin Paul Wilmes Anders F. Andersson 《PloS one》2014,9(4)
High-throughput sequencing of ribosomal RNA gene (rDNA) amplicons has opened up the door to large-scale comparative studies of microbial community structures. The short reads currently produced by massively parallel sequencing technologies make the choice of sequencing region crucial for accurate phylogenetic assignments. While for 16S rDNA, relevant regions have been well described, no truly systematic design of 18S rDNA primers aimed at resolving eukaryotic diversity has yet been reported. Here we used 31,862 18S rDNA sequences to design a set of broad-taxonomic range degenerate PCR primers. We simulated the phylogenetic information that each candidate primer pair would retrieve using paired- or single-end reads of various lengths, representing different sequencing technologies. Primer pairs targeting the V4 region performed best, allowing discrimination with paired-end reads as short as 150 bp (with 75% accuracy at genus level). The conditions for PCR amplification were optimised for one of these primer pairs and this was used to amplify 18S rDNA sequences from isolates as well as from a range of environmental samples which were then Illumina sequenced and analysed, revealing good concordance between expected and observed results. In summary, the reported primer sets will allow minimally biased assessment of eukaryotic diversity in different microbial ecosystems. 相似文献
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Determining Diversity of Freshwater Fungi on Decaying Leaves: Comparison of Traditional and Molecular Approaches 总被引:4,自引:3,他引:4 下载免费PDF全文
Traditional microscope-based estimates of species richness of aquatic hyphomycetes depend upon the ability of the species in the community to sporulate. Molecular techniques which detect DNA from all stages of the life cycle could potentially circumvent the problems associated with traditional methods. Leaf disks from red maple, alder, linden, beech, and oak as well as birch wood sticks were submerged in a stream in southeastern Canada for 7, 14, and 28 days. Fungal biomass, estimated by the amount of ergosterol present, increased with time on all substrates. Alder, linden, and maple leaves were colonized earlier and accumulated the highest fungal biomass. Counts and identifications of released conidia suggested that fungal species richness increased, while community evenness decreased, with time (up to 11 species on day 28). Conidia of Articulospora tetracladia dominated. Modifications of two molecular methods—denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis—suggested that both species richness and community evenness decreased with time. The dominant ribotype matched that of A. tetracladia. Species richness estimates based on DGGE were consistently higher than those based on T-RFLP analysis and exceeded those based on spore identification on days 7 and 14. Since traditional and molecular techniques assess different aspects of the fungal organism, both are essential for a balanced view of fungal succession on leaves decaying in streams. 相似文献
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Diversity of seed proteins and isozymes has been widely used for identification of crop cuhivars and evaluation of seed qualities, such as the bread-making potential of wheat, malting and brewing capacity of barley. After elucidation of the rationale for the use of biochemical methods, more attention was paid to various electrophoretic and electrofocusing methods used in identification of different crops which were arranged in the following sequence: selfed or inbred species, out-or cross- pollinating species, Fi hybrids and asexually propagated clones. Recent progress on the application of some new techniques including monoclonal antibody, high performance liquid chromatography and restriction fragment length polymorphism was briefly described. 相似文献
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A useful measure of diversity was calculated for microbial communities collected from lake water and sediment samples using the Shannon index (H′) and rarefaction [E(S)]. Isolates were clustered by a numerical taxonomy approach in which limited (<20) tests were used so that the groups obtained represented a level of resolution other than species. The numerical value of diversity for each sample was affected by the number of tests used; however, the relative diversity compared among several sampling locations was the same whether 11 or 19 characters were examined. The number of isolates (i.e., sample size) strongly influenced the value of H′ so that unequal sized samples could not be compared. Rarefaction accounts for differences in sample size inherently so that such comparisons are made simple. Due to the type of sampling carried out by microbiologists, H′ is estimated and not determined and therefore requires a statement of error associated with it. Failure to report error provided potentially misleading results. Calculation of the variance of H′ is not a simple matter and may be impossible when handling a large number of samples. With rarefaction, the variance of E(S) is readily determined, facilitating the comparison of many samples. 相似文献
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Karolina Tomczyk-Żak 《Geomicrobiology journal》2016,33(1):20-38
Relatively stable physical conditions in caves allow for the examination of the relationship between geochemical processes and the activity of microorganisms, reflected in substantial rock alterations, formation of new structures, surface deterioration and cave expansion. Although caves are considered as extreme environments, they are inhabited by microbial communities with unexpected diversity. While Proteobacteria and Actinobacteria are the most ubiquitous groups, also the presence of Archaea has been frequently noted recently. Here, we present a summary of results on diversity of cave microorganisms in the context of taxon distribution as well as the contribution and role of individual taxa in cave ecosystems. 相似文献