Uncultivated Microorganisms
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Uncultivated Microorganisms
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Author : Slava S. Epstein
language : en
Publisher: Springer Science & Business Media
Release Date : 2009-09-01
Uncultivated Microorganisms written by Slava S. Epstein and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009-09-01 with Medical categories.
In 1898, an Austrian microbiologist Heinrich Winterberg made a curious observation: the number of microbial cells in his samples did not match the number of colonies formed on nutrient media (Winterberg 1898). About a decade later, J. Amann qu- tified this mismatch, which turned out to be surprisingly large, with non-growing cells outnumbering the cultivable ones almost 150 times (Amann 1911). These papers signify some of the earliest steps towards the discovery of an important phenomenon known today as the Great Plate Count Anomaly (Staley and Konopka 1985). Note how early in the history of microbiology these steps were taken. Detecting the Anomaly almost certainly required the Plate. If so, then the period from 1881 to 1887, the years when Robert Koch and Petri introduced their key inventions (Koch 1881; Petri 1887), sets the earliest boundary for the discovery, which is remarkably close to the 1898 observations by H. Winterberg. Celebrating its 111th anniversary, the Great Plate Count Anomaly today is arguably the oldest unresolved microbiological phenomenon. In the years to follow, the Anomaly was repeatedly confirmed by all microb- logists who cared to compare the cell count in the inoculum to the colony count in the Petri dish (cf., Cholodny 1929; Butkevich 1932; Butkevich and Butkevich 1936). By mid-century, the remarkable difference between the two counts became a universally recognized phenomenon, acknowledged by several classics of the time (Waksman and Hotchkiss 1937; ZoBell 1946; Jannasch and Jones 1959).
Accessing Uncultivated Microorganisms
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Author : Karsten Zengler
language : en
Publisher:
Release Date : 2008
Accessing Uncultivated Microorganisms written by Karsten Zengler and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008 with Science categories.
Providing a comprehensive overview and discussing developments in the field, this book details various innovative methods used in microbial ecology and environmental microbiology. It also includes all aspects of microbial diversity from bacteria and fungi to protists.
Uncultivated Microorganisms
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Author : Slava S. Epstein
language : en
Publisher: Springer
Release Date : 2009-07-23
Uncultivated Microorganisms written by Slava S. Epstein and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009-07-23 with Medical categories.
In 1898, an Austrian microbiologist Heinrich Winterberg made a curious observation: the number of microbial cells in his samples did not match the number of colonies formed on nutrient media (Winterberg 1898). About a decade later, J. Amann qu- tified this mismatch, which turned out to be surprisingly large, with non-growing cells outnumbering the cultivable ones almost 150 times (Amann 1911). These papers signify some of the earliest steps towards the discovery of an important phenomenon known today as the Great Plate Count Anomaly (Staley and Konopka 1985). Note how early in the history of microbiology these steps were taken. Detecting the Anomaly almost certainly required the Plate. If so, then the period from 1881 to 1887, the years when Robert Koch and Petri introduced their key inventions (Koch 1881; Petri 1887), sets the earliest boundary for the discovery, which is remarkably close to the 1898 observations by H. Winterberg. Celebrating its 111th anniversary, the Great Plate Count Anomaly today is arguably the oldest unresolved microbiological phenomenon. In the years to follow, the Anomaly was repeatedly confirmed by all microb- logists who cared to compare the cell count in the inoculum to the colony count in the Petri dish (cf., Cholodny 1929; Butkevich 1932; Butkevich and Butkevich 1936). By mid-century, the remarkable difference between the two counts became a universally recognized phenomenon, acknowledged by several classics of the time (Waksman and Hotchkiss 1937; ZoBell 1946; Jannasch and Jones 1959).
Microbial Evolution Diversity And Ecology
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Author : I M. Head
language : en
Publisher:
Release Date : 1998
Microbial Evolution Diversity And Ecology written by I M. Head and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1998 with categories.
Recognition Of Chimeric Small Subunit Ribosomal Dna S Composed Of Genes From Uncultivated Microorganisms
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Author : Eric D. Kopczynski
language : en
Publisher:
Release Date : 1994
Recognition Of Chimeric Small Subunit Ribosomal Dna S Composed Of Genes From Uncultivated Microorganisms written by Eric D. Kopczynski and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1994 with Hot spring ecology categories.
When PCR was used to recover small-subunit (SSU) rRNA genes from a hot spring cyanobacterial mat community, chimeric SSU rRNA sequences which exhibited little or no secondary structural abnormality were recovered. They were revealed as chimeras of SSU rRNA genes of uncultivated species through separate phylogenetic analysis of short sequence domains.
Uncharted Microbial World
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Author :
language : en
Publisher:
Release Date : 2007
Uncharted Microbial World written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with categories.
Microbes are the foundation for all of life. From the air we breathe to the soil we rely on for farming to the water we drink, everything humans need to survive is intimately coupled with the activities of microbes. Major advances have been made in the understanding of disease and the use of microorganisms in the industrial production of drugs, food products and wastewater treatment. However, our understanding of many complicated microbial environments (the gut and teeth), soil fertility, and biogeochemical cycles of the elements is lagging behind due to their enormous complexity. Inadequate technology and limited resources have stymied many lines of investigation. Today, most environmental microorganisms have yet to be isolated and identified, let alone rigorously studied. The American Academy of Microbiology convened a colloquium in Seattle, Washington, in February 2007, to deliberate the way forward in the study of microorganisms and microbial activities in the environment. Researchers in microbiology, marine science, pathobiology, evolutionary biology, medicine, engineering, and other fields discussed ways to build on and extend recent successes in microbiology. The participants made specific recommendations for targeting future research, improving methodologies and techniques, and enhancing training and collaboration in the field. Microbiology has made a great deal of progress in the past 100 years, and the useful applications for these new discoveries are numerous. Microorganisms and microbial products are now used in industrial capacities ranging from bioremediation of toxic chemicals to probiotic therapies for humans and livestock. On the medical front, studies of microbial communities have revealed, among other things, new ways for controlling human pathogens. The immediate future for research in this field is extremely promising. In order to optimize the effectiveness of community research efforts in the future, scientists should include manageable systems with features like clear physical boundaries, limited microbial diversity, and manipulability with the goal of understanding fundamental principles that may apply to more complex systems. A great deal of microbial genetic and phenotypic diversity remains to be explored, and the commercial and medical potential locked up in these unknowns should compel the field to move forward. Future microbiology research will build on the successes of the past using new techniques and approaches. Uncultivated microbes hold great promise for industry, medicine, and the recycling of precious resources, and research and technology must make inroads in overcoming the barriers that prevent their study. In many cases, we will no longer be able to rely on isolated, pure cultures of microorganisms, but must use communities of microorganisms, which presently are poorly understood. Indeed, community-level studies can benefit from deconstructing microbial communities and analyzing the component members separately, but this is not feasible in every system. The effects of perturbation on microbial communities also require study. Humans rely on the services of microbes in innumerable ways, but we have little or no predictive understanding of how microbial communities respond to disturbance. Research must address current limitations in detecting microscale interactions among microbes by enhancing current technologies and fostering new microscopic tools, biosensors, and gas sensors for appropriate small scales. Genomics, which has enabled great progress in microbiology research of individual species, must be applied to communities of microorganisms. This will require improved methods of DNA extraction and amplification from environmental samples and improved strategies for DNA sequence assembly. In the future, genome sequencing efforts should continue the exploration of evolutionarily diverse microbes, as well as help reveal the mechanisms by which closely related microbes evolve. Technological advances have spurred every great leap in microbial biology, and in order to move forward, new methods for revealing the activities of microorganisms must be continually developed. Today, researchers need access to better techniques for enriching and isolating novel microorganisms, particularly approaches that enable them to mimic the low nutrient conditions to which many environmental microbes are adapted. Other outstanding needs include methods for performing in situ work and bioinformatics tools. Finally, there are several ways that training and education in microbiology are failing to adequately prepare the next generation of scientists for the challenges ahead. Training in some of the long-established disciplines, including enrichment and isolation, physiology, enzymology, and biochemistry, needs to be revitalized.
High Resolution Phylogenetic Microbial Community Profiling
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Author :
language : en
Publisher:
Release Date : 2014
High Resolution Phylogenetic Microbial Community Profiling written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
The representation of bacterial and archaeal genome sequences is strongly biased towards cultivated organisms, which belong to merely four phylogenetic groups. Functional information and inter-phylum level relationships are still largely underexplored for candidate phyla, which are often referred to as microbial dark matter. Furthermore, a large portion of the 16S rRNA gene records in the GenBank database are labeled as environmental samples and unclassified, which is in part due to low read accuracy, potential chimeric sequences produced during PCR amplifications and the low resolution of short amplicons. In order to improve the phylogenetic classification of novel species and advance our knowledge of the ecosystem function of uncultivated microorganisms, high-throughput full length 16S rRNA gene sequencing methodologies with reduced biases are needed. We evaluated the performance of PacBio single-molecule real-time (SMRT) sequencing in high-resolution phylogenetic microbial community profiling. For this purpose, we compared PacBio and Illumina metagenomic shotgun and 16S rRNA gene sequencing of a mock community as well as of an environmental sample from Sakinaw Lake, British Columbia. Sakinaw Lake is known to contain a large age of microbial species from candidate phyla. Sequencing results show that community structure based on PacBio shotgun and 16S rRNA gene sequences is highly similar in both the mock and the environmental communities. Resolution power and community representation accuracy from SMRT sequencing data appeared to be independent of GC content of microbial genomes and was higher when compared to Illumina-based metagenome shotgun and 16S rRNA gene (iTag) sequences, e.g. full-length sequencing resolved all 23 OTUs in the mock community, while iTags did not resolve closely related species. SMRT sequencing hence offers various potential benefits when characterizing uncharted microbial communities.
Molecular Investigation Of Chloroethene Reductive Dehalogenation By The Mixed Microbial Community Kb1
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Author : Alison Sara Waller
language : en
Publisher:
Release Date : 2009
Molecular Investigation Of Chloroethene Reductive Dehalogenation By The Mixed Microbial Community Kb1 written by Alison Sara Waller and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
Bioaugmentation with Dehalococcoides-containing cultures is a successful technology for the remediation of chlorinated ethene-contaminated groundwater. The overall goal of this research was to identify and characterize genes that are used by a Dehalococcoides-containing culture, KB-1, during degradation of Trichloroethene (TCE) to ethene, via cis-Dichloroethene (cDCE) and vinyl chloride. Firstly, the diversity and dynamics of the microbial populations within KB1 was assessed using 16S rRNA clone libraries and quantitative PCR analyses. Secondly, reductive-dehalogenase-homologous- (RDH) genes in KB1 were identified, sequenced and their transcription compared through RNA-generated RDH cDNA clone libraries. Finally, to elucidate functionally important genes within the community, Shotgun metagenome microarrays were constructed and used to investigate transcription during dechlorination. Results of the phylogenetic analyses indicated that KB1 is a diverse community of microorganisms whose stability is enhanced by functional redundancy within the culture. To fully understand this diverse community of uncultivated microorganisms a metatranscriptome approach was used. Experiments with shotgun metagenome microarrays identified spots which were statistically significantly differentially expressed during dechlorination. These spots were then sequenced, revealing Dehalococcoides and non-Dehalococcoides -genes which are important during dechlorination. These results demonstrated that shotgun microarrays can be constructed without prior sequence knowledge and used to effectively examine differential transcription within an uncultivated community. Subsequently, all of the spots of the array were sequenced, and additional array experiments were conducted. Sequencing identified 24 reductive dehalogenase genes in the culture, and analysis of the microarray results indicated that many of these RDH genes were differentially expressed in response to certain chlorinated compounds. Interspecies interactions were also highlighted as results suggested that non-Dehalococcoides microorganisms provide partial corrinoids which Dehalococcoides salvages to synthesize cobalamin which is essential for reductive dehalogenation. Transcription of CRISPR-associated genes also indicated interaction between phage and other microorganism in the KB1 community. Overall these results provided sequence and transcription information about possible biomarkers for reductive dechlorination by KB1 and can be used for more effective design and monitoring of bioremediation technologies.
The Impact Of Microorganisms On Consumption Of Atmospheric Trace Gases
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Author : Steffen Kolb
language : en
Publisher: Frontiers Media SA
Release Date : 2017-11-29
The Impact Of Microorganisms On Consumption Of Atmospheric Trace Gases written by Steffen Kolb and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-11-29 with Electronic book categories.
Gases with a mixing ratio of less than one percent in the lower atmosphere (i.e. the troposphere) are considered as trace gases. Numerous of these trace gases originate from biological processes in marine and terrestrial ecosystems. These gases are of relevance for the climate as they contribute to global warming or to the troposphere’s chemical reactive system that builds the ozone layer or they impact on the stability of aerosols, greenhouse, and pollutant gases. These reactive trace gases include methane, a multitude of volatile organic compounds of biogenic origin (bVOCs) and inorganic gases such as nitrogen oxides or ozone. The regulatory function of microorganisms for trace gas cycling has been intensively studied for the greenhouse gases nitrous oxide and methane, but is less well understood for microorganisms that metabolize molecular hydrogen, carbon monoxide, or bVOCs. The studies compiled this Research Topic reflect this very well. While a number of articles focus on nitrous oxide and methane or carbon monoxide oxidation, only a few articles address conversion processes of further bVOCs. The Research Topic is complemented by three review articles about the consumption of methane and monoterpenes, as well as the role of the phyllosphere as a particular habitat for trace gas-consuming microorganisms, and point out future research directions in the field. The presented scientific work illustrates that the field of microbial regulation of trace glas fluxes is still in its infancy when one broadens the view on gases beyond methane and nitrous oxide. However, there is a societal need to better predict global dynamics of trace gases that impact on the functionality and warming of the troposphere. Upcoming modelling approaches will need further information on process rates, features and distribution of the driving microorganisms to fullfill this demanding task.
Size Limits Of Very Small Microorganisms
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Author : National Research Council
language : en
Publisher: National Academies Press
Release Date : 1999-09-13
Size Limits Of Very Small Microorganisms written by National Research Council and has been published by National Academies Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999-09-13 with Science categories.
How small can a free-living organism be? On the surface, this question is straightforward-in principle, the smallest cells can be identified and measured. But understanding what factors determine this lower limit, and addressing the host of other questions that follow on from this knowledge, require a fundamental understanding of the chemistry and ecology of cellular life. The recent report of evidence for life in a martian meteorite and the prospect of searching for biological signatures in intelligently chosen samples from Mars and elsewhere bring a new immediacy to such questions. How do we recognize the morphological or chemical remnants of life in rocks deposited 4 billion years ago on another planet? Are the empirical limits on cell size identified by observation on Earth applicable to life wherever it may occur, or is minimum size a function of the particular chemistry of an individual planetary surface? These questions formed the focus of a workshop on the size limits of very small organisms, organized by the Steering .Group for the Workshop on Size Limits of Very Small Microorganisms and held on October 22 and 23, 1998. Eighteen invited panelists, representing fields ranging from cell biology and molecular genetics to paleontology and mineralogy, joined with an almost equal number of other participants in a wide-ranging exploration of minimum cell size and the challenge of interpreting micro- and nano-scale features of sedimentary rocks found on Earth or elsewhere in the solar system. This document contains the proceedings of that workshop. It includes position papers presented by the individual panelists, arranged by panel, along with a summary, for each of the four sessions, of extensive roundtable discussions that involved the panelists as well as other workshop participants.