Search results: Found 6

Listing 1 - 6 of 6
Sort by
The microbial nitrogen cycle

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194124 Year: Pages: 174 DOI: 10.3389/978-2-88919-412-4 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:06
License:

Loading...
Export citation

Choose an application

Abstract

Nitrogen is an essential element in biological systems, and one that often limits production in both aquatic and terrestrial systems. Due to its requirement in biological macromolecules, its acquisition and cycling have the potential to structure microbial communities, as well as to control productivity on the ecosystem scale. In addition, its versatile redox chemistry is the basis of complex biogeochemical transformations that control the inventory of fixed nitrogen, both in local environments and over geological time. Although many of the pathways in the microbial nitrogen cycle were described more than a century ago, additional fundamental pathways have been discovered only recently. These findings imply that we still have much to learn about the microbial nitrogen cycle, the organisms responsible for it, and their interactions in natural and human environments. Progress in nitrogen cycle research has been facilitated by recent rapid technological advances, especially in genomics and isotopic approaches. In this Research Topic, we reviewed the leading edge of nitrogen cycle research based on these approaches, as well as by exploring microbial processes in modern ecosystems.

The Microbial Regulation of Global Biogeochemical Cycles

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192977 Year: Pages: 241 DOI: 10.3389/978-2-88919-297-7 Language: English
Publisher: Frontiers Media SA
Subject: Geography --- Microbiology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:07
License:

Loading...
Export citation

Choose an application

Abstract

Global biogeochemical cycles of carbon and nutrients are increasingly affected by human activities. So far, modeling has been central for our understanding of how this will affect ecosystem functioning and the biogeochemical cycling of carbon and nutrients. These models have been forced to adopt a reductive approach built on the flow of carbon and nutrients between pools that are difficult or even impossible to verify with empirical evidence. Furthermore, while some of these models include the response in physiology, ecology and biogeography of primary producers to environmental change, the microbial part of the ecosystem is generally poorly represented or lacking altogether. The principal pool of carbon and nutrients in soil is the organic matter. The turnover of this reservoir is governed by microorganisms that act as catalytic converters of environmental conditions into biogeochemical cycling of carbon and nutrients. The dependency of this conversion activity on individual environmental conditions such as pH, moisture and temperature has been frequently studied. On the contrary, only rarely have the microorganisms involved in carrying out the processes been identified, and one of the biggest challenges for advancing our understanding of biogeochemical processes is to identify the microorganisms carrying out a specific set of metabolic processes and how they partition their carbon and nutrient use. We also need to identify the factors governing these activities and if they result in feedback mechanisms that alter the growth, activity and interaction between primary producers and microorganisms. By determining how different groups of microorganisms respond to individual environmental conditions by allocating carbon and nutrients to production of biomass, CO2 and other products, a mechanistic as well as quantitative understanding of formation and decomposition of organic matter, and the production and consumption of greenhouse gases, can be achieved. In this Research Topic, supported by the Swedish research councils' programme "Biodiversity and Ecosystem Services in a Changing Landscape" (BECC), we intend to promote this alternative framework to address how cycling of carbon and nutrients will be altered in a changing environment from the first-principle mechanisms that drive them – namely the ecology, physiology and biogeography of microorganisms – and on up to emerging global biogeochemical patterns. This novel and unconventional approach has the potential to generate fresh insights that can open up new horizons and stimulate rapid conceptual development in our basic understanding of the regulating factors for global biogeochemical cycles. The vision for the research topic is to facilitate such progress by bringing together leading scientists as proponents of several disciplines. By bridging Microbial Ecology and Biogeochemistry, connecting microbial activities at the micro-scale to carbon fluxes at the ecosystem-scale, and linking above- and belowground ecosystem functioning, we can leap forward from the current understanding of the global biogeochemical cycles.

Roles and mechanisms of parasitism in aquatic microbial communities

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195886 Year: Pages: 153 DOI: 10.3389/978-2-88919-588-6 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
License:

Loading...
Export citation

Choose an application

Abstract

Next Generation Sequencing technologies are increasingly revealing that microbial taxa likely to be parasites or symbionts are probably much more prevalent and diverse than previously thought. Every well studied free-living species has parasites; parasites themselves can be parasitized. As a rule of thumb, there is an estimated 4 parasitic species for any given host, and the better a host is studied the more parasites are known to infect it. Therefore, parasites and other symbionts should represent a very large number of species and may far outnumber those with 'free-living' lifestyles. Paradoxically, free-living hosts, which form the bulk of our knowledge of biology, may be a minority! Microbial parasites typically are characterized by their small size, short generation time, and high rates of reproduction, with simple life cycle occurring generally within a single host. They are diverse and ubiquitous in the environment, comprising viruses, prokaryotes and eukaryotes. This Frontiers Research Topic sought to provide a broad overview but concise, comprehensive, well referenced and up-to-date state of the art for everyone involved with microbial parasites in aquatic microbial ecology.

Microbial responses to environmental changes

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197231 Year: Pages: 261 DOI: 10.3389/978-2-88919-723-1 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2016-04-07 11:22:02
License:

Loading...
Export citation

Choose an application

Abstract

Advances in next generation sequencing technologies, omics, and bioinformatics are revealing a tremendous and unsuspected diversity of microbes, both at a compositional and functional level. Moreover, the expansion of ecological concepts into microbial ecology has greatly advanced our comprehension of the role microbes play in the functioning of ecosystems across a wide range of biomes. Super-imposed on this new information about microbes, their functions and how they are organized, environmental gradients are changing rapidly, largely driven by direct and indirect human activities. In the context of global change, understanding the mechanisms that shape microbial communities is pivotal to predict microbial responses to novel selective forces and their implications at the local as well as global scale. One of the main features of microbial communities is their ability to react to changes in the environment. Thus, many studies have reported changes in the performance and composition of communities along environmental gradients. However, the mechanisms underlying these responses remain unclear. It is assumed that the response of microbes to changes in the environment is mediated by a complex combination of shifts in the physiological properties, single-cell activities, or composition of communities: it may occur by means of physiological adjustments of the taxa present in a community or selecting towards more tolerant/better adapted phylotypes. Knowing whether certain factors trigger one, many, or all mechanisms would greatly increase confidence in predictions of future microbial composition and processes. This Research Topic brings together studies that applied the latest molecular techniques for studying microbial composition and functioning and integrated ecological, biogeochemical and/or modeling approaches to provide a comprehensive and mechanistic perspective of the responses of micro-organisms to environmental changes. This Research Topic presents new findings on environmental parameters influencing microbial communities, the type and magnitude of response and differences in the response among microbial groups, and which collectively deepen our current understanding and knowledge of the underlying mechanisms of microbial structural and functional responses to environmental changes and gradients in both aquatic and terrestrial ecosystems. The body of work has, furthermore, identified many challenges and questions that yet remain to be addressed and new perspectives to follow up on.

Molecular Ecology and Genetic Diversity of the Roseobacter Clade

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889455386 Year: Pages: 138 DOI: 10.3389/978-2-88945-538-6 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Microbiology
Added to DOAB on : 2019-01-23 14:53:42
License:

Loading...
Export citation

Choose an application

Abstract

Marine bacteria and archaea are key players in the biogeochemical cycling of nitrogen, carbon, and other elements. One important lineage of marine bacteria is the Roseobacter group. Members of this clade are the most abundant bacteria in marine ecosystems constituting up to 25% of the marine bacterioplankton. They have been detected in various marine habitats from coastal regions to deep-sea sediments and from polar regions to tropical latitudes. These bacteria are physiologically and genetically very versatile. Utilization of several organic and inorganic compounds, sulfur oxidation, aerobic anoxygenic photosynthesis, carbon monoxide oxidation, DMSP demethylation, and production of secondary metabolites are some of the important functional traits found in this clade. Moreover, several isolates are available allowing in-depth analysis of physiological and genetic characteristics. Although the Roseobacter group has been intensively studied in recent years, our understanding of its ecological contributions and the evolutionary processes shaping the genomes of this clade is still rather limited.

Microbial Role in the Carbon Cycle in Tropical Inland Aquatic Ecosystems

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451272 Year: Pages: 144 DOI: 10.3389/978-2-88945-127-2 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
License:

Loading...
Export citation

Choose an application

Abstract

Aquatic microorganisms are tidily related to the carbon cycle in aquatic systems, especially in respect to its accumulation and emission to atmosphere. In one hand, the autotrophs are responsible for the carbon input to the ecosystems and trophic chain. On the other hand, the heterotrophs traditionally play a role in the carbon mineralization and, since microbial loop theory, may play a role to carbon flow through the organisms. However, it is not yet clear how the heterotrophs contribute to carbon retention and emission especially from tropical aquatic ecosystems. Most of the studies evaluating the role of microbes to carbon cycle in inland waters were performed in high latitudes and only a few studies in the tropical area. In the prospective of global changes where the warm tropical lakes and rivers become even warmer, it is important to understand how microorganisms behave and interact with carbon cycle in the Earth region with highest temperature and light availability. This research topic documented microbial responses to natural latitudinal gradients, spatial within and between ecosystems gradients, temporal approaches and temperature and nutrient manipulations in the water and in the sediment.

Listing 1 - 6 of 6
Sort by
Narrow your search

Publisher

Frontiers Media SA (6)


License

CC by (6)


Language

english (6)


Year
From To Submit

2018 (1)

2017 (1)

2016 (1)

2015 (2)

2014 (1)