rrndb: the Ribosomal RNA Operon Copy Number Database
TL;DR: This work has created a phylogenetically arranged report on rRNA gene copy number for a diverse collection of prokaryotic microorganisms in an attempt to understand the evolutionary implications of rRNA operon redundancy.
Abstract: The Ribosomal RNA Operon Copy Number Database (rrndb) is an Internet-accessible database containing annotated information on rRNA operon copy number among prokaryotes. Gene redundancy is uncommon in prokaryotic genomes, yet the rRNA genes can vary from one to as many as 15 copies. Despite the widespread use of 16S rRNA gene sequences for identification of prokaryotes, information on the number and sequence of individual rRNA genes in a genome is not readily accessible. In an attempt to understand the evolutionary implications of rRNA operon redundancy, we have created a phylogenetically arranged report on rRNA gene copy number for a diverse collection of prokaryotic microorganisms. Each entry (organism) in the rrndb contains detailed information linked directly to external websites including the Ribosomal Database Project, GenBank, PubMed and several culture collections. Data contained in the rrndb will be valuable to researchers investigating microbial ecology and evolution using 16S rRNA gene sequences. The rrndb web site is directly accessible on the WWW at http://rrndb.cme.msu.edu.
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TL;DR: The Ribosomal Database Project (RDP-II), previously described by Maidak et al. (2000), continued during the past year to add new rRNA sequences to the aligned data and to improve the analysis commands.
Abstract: The Ribosomal Database Project (RDP) is a curated database that offers ribosome-related data, analysis services and associated computer programs. The offerings include phylogenetically ordered alignments of ribosomal RNA (rRNA) sequences, derived phylogenetic trees, rRNA secondary structure diagrams, and various software for handling, analyzing and displaying alignments and trees. The data are available via anonymous FTP (rdp.life.uiuc.edu), electronic mail (server@rdp.life.uiuc.edu), gopher (rdpgopher.life.uiuc.edu) and WWW (http://rdpwww.life.uiuc.edu/ ). The electronic mail and WWW servers provide ribosomal probe checking, approximate phylogenetic placement of user-submitted sequences, screening for possible chimeric rRNA sequences, automated alignment, and a suggested placement of an unknown sequence on an existing phylogenetic tree.
2,106 citations
TL;DR: A quantitative PCR-based approach to estimating the relative abundances of major taxonomic groups of bacteria and fungi in soil provides a rapid and robust index of microbial community structure.
Abstract: Here we describe a quantitative PCR-based approach to estimating the relative abundances of major taxonomic groups of bacteria and fungi in soil. Primers were thoroughly tested for specificity, and the method was applied to three distinct soils. The technique provides a rapid and robust index of microbial community structure.
1,341 citations
Cites background from "rrndb: the Ribosomal RNA Operon Cop..."
...There are a number of reasons for this: DNA extraction bias may alter the estimated abundances of certain groups (16), heterogeneity in ribosomal operon number (11, 30) may affect relative estimates of group abundances, and the tested qPCR assays do not necessarily amplify rRNA genes belonging to all members of each targeted group....
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Joint Genome Institute1, Bigelow Laboratory For Ocean Sciences2, United States Department of Agriculture3, University of California, Merced4, Broad Institute5, Oak Ridge National Laboratory6, Michigan State University7, California State University, San Bernardino8, J. Craig Venter Institute9, Max Planck Society10, Argonne National Laboratory11, Pacific Northwest National Laboratory12, University of British Columbia13, University of Southern California14, Science for Life Laboratory15, University of Vermont16, Georgia Institute of Technology17, University of Illinois at Urbana–Champaign18, University of Texas at Austin19, University of Vienna20, University of California, Davis21, University of Nevada, Las Vegas22, University of Wisconsin-Madison23, Cooperative Institute for Research in Environmental Sciences24, University of California, San Diego25, European Bioinformatics Institute26, National Institutes of Health27, University of Queensland28, Saint Petersburg State University29, University of California, Berkeley30
TL;DR: Two standards developed by the Genomic Standards Consortium (GSC) for reporting bacterial and archaeal genome sequences are presented, including the Minimum Information about a Single Amplified Genome (MISAG) and the Minimum information about a Metagenome-Assembled Genomes (MIMAG), including estimates of genome completeness and contamination.
Abstract: We present two standards developed by the Genomic Standards Consortium (GSC) for reporting bacterial and archaeal genome sequences. Both are extensions of the Minimum Information about Any (x) Sequence (MIxS). The standards are the Minimum Information about a Single Amplified Genome (MISAG) and the Minimum Information about a Metagenome-Assembled Genome (MIMAG), including, but not limited to, assembly quality, and estimates of genome completeness and contamination. These standards can be used in combination with other GSC checklists, including the Minimum Information about a Genome Sequence (MIGS), Minimum Information about a Metagenomic Sequence (MIMS), and Minimum Information about a Marker Gene Sequence (MIMARKS). Community-wide adoption of MISAG and MIMAG will facilitate more robust comparative genomic analyses of bacterial and archaeal diversity.
1,171 citations
TL;DR: This review paper highlights differences between microbes and macroorganisms and generate hypotheses describing how these differences may be important for community assembly, and discusses the implications of microbial assembly processes for ecosystem function and biodiversity.
Abstract: SUMMARY Recent research has expanded our understanding of microbial community assembly. However, the field of community ecology is inaccessible to many microbial ecologists because of inconsistent and oftenconfusingterminologyaswellasunnecessarilypolarizingdebates. Thus,wereviewrecentliteratureonmicrobialcommunityassembly, using the framework of Vellend (Q. Rev. Biol. 85:183‐206, 2010) in an effort to synthesize and unify these contributions. We begin by discussingpatternsinmicrobialbiogeographyandthendescribefour basic processes (diversification, dispersal, selection, and drift) that contributetocommunityassembly.Wealsodiscussdifferentcombinations of these processes and where and when they may be most important for shaping microbial communities. The spatial and temporal scales of microbial community assembly are also discussed in relation to assembly processes. Throughout this review paper, we highlight differences between microbes and macroorganisms and generatehypothesesdescribinghowthesedifferencesmaybeimportantforcommunityassembly.Weendbydiscussingtheimplications ofmicrobialassemblyprocessesforecosystemfunctionandbiodiversity.
1,161 citations
TL;DR: The hypervariable sequence-specific dendrograms and the "MEGALIGN" files provided online will be highly useful tools for designing specific probes and primers for molecular assays to detect pathogenic bacteria, including select agents.
1,014 citations
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TL;DR: Analysis of the genomic DNA from a bacterial biofilm grown under aerobic conditions suggests that sulfate-reducing bacteria, despite their anaerobicity, were present in this environment.
Abstract: We describe a new molecular approach to analyzing the genetic diversity of complex microbial populations. This technique is based on the separation of polymerase chain reaction-amplified fragments of genes coding for 16S rRNA, all the same length, by denaturing gradient gel electrophoresis (DGGE). DGGE analysis of different microbial communities demonstrated the presence of up to 10 distinguishable bands in the separation pattern, which were most likely derived from as many different species constituting these populations, and thereby generated a DGGE profile of the populations. We showed that it is possible to identify constituents which represent only 1% of the total population. With an oligonucleotide probe specific for the V3 region of 16S rRNA of sulfate-reducing bacteria, particular DNA fragments from some of the microbial populations could be identified by hybridization analysis. Analysis of the genomic DNA from a bacterial biofilm grown under aerobic conditions suggests that sulfate-reducing bacteria, despite their anaerobicity, were present in this environment. The results we obtained demonstrate that this technique will contribute to our understanding of the genetic diversity of uncharacterized microbial populations.
11,380 citations
"rrndb: the Ribosomal RNA Operon Cop..." refers methods in this paper
...Molecular methods for microbial diversity assessment rely primarily on PCR-amplification of 16S rRNA genes from complex samples followed by (i) cloning and sequencing of unique amplicons, (ii) separation of amplicons based on chemical composition via denaturing- or temperature-gradient gel electrophoresis (10,11), or (iii) separation of amplicons after restriction digestion based on size via terminal restriction fragment length polymorphism analysis (12)....
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Book•
01 Jun 1987
4,940 citations
TL;DR: The number of prokaryotes and the total amount of their cellular carbon on earth are estimated to be 4-6 x 10(30) cells and 350-550 Pg of C (1 Pg = 10(15) g), respectively, which is 60-100% of the estimated total carbon in plants.
Abstract: The number of prokaryotes and the total amount of their cellular carbon on earth are estimated to be 4-6 3 10 30 cells and 350-550 Pg of C (1 Pg 5 10 15 g), respectively. Thus, the total amount of prokaryotic carbon is 60-100% of the estimated total carbon in plants, and inclusion of prokaryotic carbon in global models will almost double estimates of the amount of carbon stored in living organisms. In addition, the earth's prokaryotes contain 85-130 Pg of N and 9-14 Pg of P, or about 10-fold more of these nutrients than do plants, and represent the largest pool of these nutrients in living organisms. Most of the earth's prokaryotes occur in the open ocean, in soil, and in oceanic and terrestrial subsurfaces, where the numbers of cells are 1.2 3 10 29 , 2.6 3 10 29 , 3.5 3 10 30 , and 0.25-2.5 3 10 30 , respectively. The numbers of het- erotrophic prokaryotes in the upper 200 m of the open ocean, the ocean below 200 m, and soil are consistent with average turnover times of 6-25 days, 0.8 yr, and 2.5 yr, respectively. Although subject to a great deal of uncertainty, the estimate for the average turnover time of prokaryotes in the subsurface is on the order of 1-2 3 10 3 yr. The cellular production rate for all prokaryotes on earth is estimated at 1.7 3 10 30 cellsyyr and is highest in the open ocean. The large population size and rapid growth of prokaryotes provides an enormous capacity for genetic diversity. Although invisible to the naked eye, prokaryotes are an essential component of the earth's biota. They catalyze unique and indispensable transformations in the biogeochemical cy- cles of the biosphere, produce important components of the earth's atmosphere, and represent a large portion of life's genetic diversity. Although the abundance of prokaryotes has been estimated indirectly (1, 2), the actual number of pro- karyotes and the total amount of their cellular carbon on earth have never been directly assessed. Presumably, prokaryotes' very ubiquity has discouraged investigators, because an esti- mation of the number of prokaryotes would seem to require endless cataloging of numerous habitats. To estimate the number and total carbon of prokaryotes on earth, several representative habitats were first examined. This analysis indicated that most of the prokaryotes reside in three large habitats: seawater, soil, and the sedimentysoil subsur- face. Although many other habitats contain dense populations, their numerical contribution to the total number of pro- karyotes is small. Thus, evaluating the total number and total carbon of prokaryotes on earth becomes a solvable problem. Aquatic Environments. Numerous estimates of cell density, volume, and carbon indicate that prokaryotes are ubiquitous in marine and fresh water (e.g., 3-5). Although a large range of cellular densities has been reported (10 4 -10 7 cellsyml), the
4,405 citations
"rrndb: the Ribosomal RNA Operon Cop..." refers background in this paper
...Microbes are the most abundant and most diverse forms of life on earth (1)....
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TL;DR: Computer-simulated analysis of terminal restriction fragment length polymorphisms (T-RFLP) for 1,002 eubacterial sequences showed that with proper selection of PCR primers and restriction enzymes, 686 sequences could be PCR amplified and classified into 233 unique terminal restriction fragments lengths or "ribotypes."
Abstract: A quantitative molecular technique was developed for rapid analysis of microbial community diversity in various environments. The technique employed PCR in which one of the two primers used was fluorescently labeled at the 5' end and was used to amplify a selected region of bacterial genes encoding 16S rRNA from total community DNA. The PCR product was digested with restriction enzymes, and the fluorescently labeled terminal restriction fragment was precisely measured by using an automated DNA sequencer. Computer-simulated analysis of terminal restriction fragment length polymorphisms (T-RFLP) for 1,002 eubacterial sequences showed that with proper selection of PCR primers and restriction enzymes, 686 sequences could be PCR amplified and classified into 233 unique terminal restriction fragment lengths or "ribotypes." Using T-RFLP, we were able to distinguish all bacterial strains in a model bacterial community, and the pattern was consistent with the predicted outcome. Analysis of complex bacterial communities with T-RFLP revealed high species diversity in activated sludge, bioreactor sludge, aquifer sand, and termite guts; as many as 72 unique ribotypes were found in these communities, with 36 ribotypes observed in the termite guts. The community T-RFLP patterns were numerically analyzed and hierarchically clustered. The pattern derived from termite guts was found to be distinctly different from the patterns derived from the other three communities. Overall, our results demonstrated that T-RFLP is a powerful tool for assessing the diversity of complex bacterial communities and for rapidly comparing the community structure and diversity of different ecosystems.
2,383 citations
"rrndb: the Ribosomal RNA Operon Cop..." refers methods in this paper
...Molecular methods for microbial diversity assessment rely primarily on PCR-amplification of 16S rRNA genes from complex samples followed by (i) cloning and sequencing of unique amplicons, (ii) separation of amplicons based on chemical composition via denaturing- or temperature-gradient gel electrophoresis (10,11), or (iii) separation of amplicons after restriction digestion based on size via terminal restriction fragment length polymorphism analysis (12)....
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TL;DR: The potentials and limitations of these techniques will be discussed, and it will be indicated why their use in ecological studies has become so important.
Abstract: Here, the state of the art of the application of denaturing gradient gel electrophoresis (DGGE) and temperature gradient gel electrophoresis (TGGE) in microbial ecology will be presented. Furthermore, the potentials and limitations of these techniques will be discussed, and it will be indicated why their use in ecological studies has become so important.
2,181 citations