Methanogens: reevaluation of a unique biological group.
01 Jun 1979-Microbiological Research (American Society for Microbiology)-Vol. 43, Iss: 2, pp 260-296
TL;DR: The present study focuses on the development and outline of a new treatment based on 16-year-old ribonucleic acid, as well as evidence in support of the new taxonomic treatment.
About: This article is published in Microbiological Research.The article was published on 1979-06-01 and is currently open access. It has received 2745 citations till now.
Citations
More filters
TL;DR: Amorphous metal alloys are employed in acoustic devices dependent upon the properties of low acoustic velocity and low attenuation, such as wire, strip and bulk delay lines.
Abstract: Because a natural entity “species” cannot be recognized as a group of strains that is genetically well separated from its phylogenetic neighbors, a pragmatic approach was taken to define a species by a polyphasic approach (L. G. Wayne, D. J. Brenner, R. R. Colwell, P. A. D. Grimont, O. Kandler, M. I. Krichevsky, L. H. Moore, W. E. C. Moore, R. G. E. Murray, E. Stackebrandt, M. P. Starr, and H. G. Truper, Int. J. Syst. Bacteriol. 37:463-464, 1987), in which a DNA reassociation value of about 70% plays a dominant role. With the establishment of rapid sequence analysis of 16S rRNA and the recognition of its potential to determine the phylogenetic position of any prokaryotic organism, the role of 16S rRNA similarities in the present species definition in bacteriology needs to be clarified. Comparative studies clearly reveal the limitations of the sequence analysis of this conserved gene and gene product in the determination of relationships at the strain level for which DNA-DNA reassociation experiments still constitute the superior method. Since today the primary structure of 16S rRNA is easier to determine than hybridization between DNA strands, the strength of the sequence analysis is to recognize the level at which DNA pairing studies need to be performed, which certainly applies to similarities of 97% and higher.
6,188 citations
TL;DR: The physiological characteristics of Geobacter species appear to explain why they have consistently been found to be the predominant Fe(III)- and Mn(IV)-reducing microorganisms in a variety of sedimentary environments.
2,633 citations
TL;DR: An analysis of aligned sequences of the four nuclear and two mitochondrial rRNA genes identified regions of these genes that are likely to be useful to address phylogenetic problems over a wide range of levels of divergence.
Abstract: Ribosomal DNA (rDNA) sequences have been aligned and compared in a number of living organisms, and this approach has provided a wealth of information about phylogenetic relationships. Studies of rDNA sequences have been used to infer phylogenetic history across a very broad spectrum, from studies among the basal lineages of life to relationships among closely related species and populations. The reasons for the systematic versatility of rDNA include the numerous rates of evolution among different regions of rDNA (both among and within genes), the presence of many copies of most rDNA sequences per genome, and the pattern of concerted evolution that occurs among repeated copies. These features facilitate the analysis of rDNA by direct RNA sequencing, DNA sequencing (either by cloning or amplification), and restriction enzyme methodologies. Constraints imposed by secondary structure of rRNA and concerted evolution need to be considered in phylogenetic analyses, but these constraints do not appear to impede seriously the usefulness of rDNA. An analysis of aligned sequences of the four nuclear and two mitochondrial rRNA genes identified regions of these genes that are likely to be useful to address phylogenetic problems over a wide range of levels of divergence. In general, the small subunit nuclear sequences appear to be best for elucidating Precambrian divergences, the large subunit nuclear sequences for Paleozoic and Mesozoic divergences, and the organellar sequences of both subunits for Cenozoic divergences. Primer sequences were designed for use in amplifying the entire nuclear rDNA array in 15 sections by use of the polymerase chain reaction; these "universal" primers complement previously described primers for the mitochondrial rRNA genes. Pairs of primers can be selected in conjunction with the analysis of divergence of the rRNA genes to address systematic problems throughout the hierarchy of life.
2,439 citations
TL;DR: This is the first demonstration that microorganisms can completely oxidize organic compounds with Fe(III) or Mn(IV) as the sole electron acceptor and that oxidation of organic matter coupled to dissimilatory Fe( III), Mn( IV), or Mn (IV) reduction can yield energy for microbial growth.
Abstract: A dissimilatory Fe(III)- and Mn(IV)-reducing microorganism was isolated from freshwater sediments of the Potomac River, Maryland. The isolate, designated GS-15, grew in defined anaerobic medium with acetate as the sole electron donor and Fe(III), Mn(IV), or nitrate as the sole electron acceptor. GS-15 oxidized acetate to carbon dioxide with the concomitant reduction of amorphic Fe(III) oxide to magnetite (Fe(3)O(4)). When Fe(III) citrate replaced amorphic Fe(III) oxide as the electron acceptor, GS-15 grew faster and reduced all of the added Fe(III) to Fe(II). GS-15 reduced a natural amorphic Fe(III) oxide but did not significantly reduce highly crystalline Fe(III) forms. Fe(III) was reduced optimally at pH 6.7 to 7 and at 30 to 35 degrees C. Ethanol, butyrate, and propionate could also serve as electron donors for Fe(III) reduction. A variety of other organic compounds and hydrogen could not. MnO(2) was completely reduced to Mn(II), which precipitated as rhodochrosite (MnCO(3)). Nitrate was reduced to ammonia. Oxygen could not serve as an electron acceptor, and it inhibited growth with the other electron acceptors. This is the first demonstration that microorganisms can completely oxidize organic compounds with Fe(III) or Mn(IV) as the sole electron acceptor and that oxidation of organic matter coupled to dissimilatory Fe(III) or Mn(IV) reduction can yield energy for microbial growth. GS-15 provides a model for how enzymatically catalyzed reactions can be quantitatively significant mechanisms for the reduction of iron and manganese in anaerobic environments.
2,233 citations
TL;DR: In this paper, the carbon and hydrogen stable isotope composition of the methane as a function of the coexisting carbon dioxide and formation water precursors is used to distinguish two primary methanogenic pathways.
1,756 citations
References
More filters
TL;DR: A method has been described for the isolation of DNA from micro-organisms which yields stable, biologically active, highly polymerized preparations relatively free from protein and RNA, and Representative samples have been characterized for their thermal stability and sedimentation behaviour.
11,573 citations
TL;DR: A phylogenetic analysis based upon ribosomal RNA sequence characterization reveals that living systems represent one of three aboriginal lines of descent: the eubacteria, comprising all typical bacteria, the archaebacteria, and the urkaryotes, now represented in the cytoplasmic component of eukaryotic cells.
Abstract: A phylogenetic analysis based upon ribosomal RNA sequence characterization reveals that living systems represent one of three aboriginal lines of descent: (i) the eubacteria, comprising all typical bacteria; (ii) the archaebacteria, containing methanogenic bacteria; and (iii) the urkaryotes, now represented in the cytoplasmic component of eukaryotic cells.
3,522 citations
TL;DR: This article corrects the article on p. 100 in vol.
Abstract: [This corrects the article on p. 100 in vol. 41.].
3,345 citations
Book•
01 Jan 1977
TL;DR: The anaerobe laboratory manual is one of the literary work in this world in suitable to be reading material and it will show the amazing benefits of reading a book.
Abstract: Now, we come to offer you the right catalogues of book to open. anaerobe laboratory manual is one of the literary work in this world in suitable to be reading material. That's not only this book gives reference, but also it will show you the amazing benefits of reading a book. Developing your countless minds is needed; moreover you are kind of people with great curiosity. So, the book is very appropriate for you.
2,925 citations