As one of the largest biotechnological applications, activated sludge (AS) systems in wastewater treatment plants (WWTPs) harbor enormous viruses, with 10-1,000-fold higher concentrations than in ...natural environments. However, the compositional variation and host-connections of AS viruses remain poorly explored. Here, we report a catalogue of ~50,000 prokaryotic viruses from six WWTPs, increasing the number of described viral species of AS by 23-fold, and showing the very high viral diversity which is largely unknown (98.4-99.6% of total viral contigs). Most viral genera are represented in more than one AS system with 53 identified across all. Viral infection widely spans 8 archaeal and 58 bacterial phyla, linking viruses with aerobic/anaerobic heterotrophs, and other functional microorganisms controlling nitrogen/phosphorous removal. Notably, Mycobacterium, notorious for causing AS foaming, is associated with 402 viral genera. Our findings expand the current AS virus catalogue and provide reference for the phage treatment to control undesired microorganisms in WWTPs.
Understanding the general rules of microbial interactions is central for advancing microbial ecology. Recent studies show that interaction range, interaction strength, and community context determine ...bacterial interactions and the coexistence and evolution of bacteria. We highlight how these factors could contribute to a general understanding of bacterial interactions.
Bringing together the viewpoints of leading experts in taxonomy, ecology and biogeography of different taxa, this book synthesises discussion surrounding the so-called 'everything is everywhere' ...hypothesis. It addresses the processes that generate spatial patterns of diversity and biogeography in organisms that can potentially be cosmopolitan. The contributors discuss questions such as: are microorganisms (e.g. prokaryotes, protists, algae, yeast and microscopic fungi, plants and animals) really cosmopolitan in their distribution? What are the biological properties that allow such potential distribution? Are there processes that would limit their distribution? Are microorganisms intrinsically different from macroscopic ones? What can microorganisms tell us about the generalities of biogeography? Can they be used for experimental biogeography? Written for graduate students and academic researchers, the book promotes a more complete understanding of the spatial patterns and the general processes in biogeography.
Soil microbiota as game-changers in restoration of degraded lands Coban, Oksana; De Deyn, Gerlinde B; van der Ploeg, Martine
Science (American Association for the Advancement of Science),
2022-Mar-04, 2022-03-04, 20220304, Letnik:
375, Številka:
6584
Journal Article
Recenzirano
Land degradation reduces soil functioning and, consequently, the services that soil provides. Soil hydrological functions are critical to combat soil degradation and promote soil restoration. Soil ...microorganisms affect soil hydrology, but the role of soil microbiota in forming and sustaining soil is not well explored. Case studies indicate the potential of soil microorganisms as game-changers in restoring soil functions. We review the state of the art of microorganism use in land restoration technology, the groups of microorganisms with the greatest potential for soil restoration, knowledge of the effect of microorganisms on soil physical properties, and proposed strategies for the long-term restoration of degraded lands. We also emphasize the need to advance the emerging research field of biophysical landscape interactions to support soil-plant ecosystem restoration practices.
The rhizosphere is of central importance not only for plant nutrition, health and quality but also for microorganism-driven carbon sequestration, ecosystem functioning and nutrient cycling in ...terrestrial ecosystems. A multitude of biotic and abiotic factors are assumed to influence the structural and functional diversity of microbial communities in the rhizosphere. In this review, recent studies on the influence of the two factors, plant species and soil type, on rhizosphere-associated microbial communities are discussed. Root exudates and the response of microorganisms to the latter as well as to root morphology were shown to shape rhizosphere microbial communities. All studies revealed that soil is the main reservoir for rhizosphere microorganisms. Many secrets of microbial life in the rhizosphere were recently uncovered due to the enormous progress in molecular and microscopic tools. Physiological and molecular data on the factors that drive selection processes in the rhizosphere are presented here. Furthermore, implications for agriculture, nature conservation and biotechnology will also be discussed.
Changing perspectives in marine nitrogen fixation Zehr, Jonathan P; Capone, Douglas G
Science (American Association for the Advancement of Science),
2020-May-15, 2020-05-15, 20200515, Letnik:
368, Številka:
6492
Journal Article
Recenzirano
Nitrogen fixation, the reduction of atmospheric dinitrogen gas (N
) to ammonia, is critical for biological productivity but is difficult to study in the vast expanse of the global ocean. Decades of ...field studies and the infusion of molecular biological, genomic, isotopic, and geochemical modeling approaches have led to new paradigms and questions. The discovery of previously unknown N
-fixing (diazotrophic) microorganisms and unusual physiological adaptations, combined with diagnostic distributions of nutrients and their isotopes as well as measured and modeled biogeographic patterns, have revolutionized our understanding of marine N
fixation and its role in the global nitrogen cycle. Anthropogenic upper-ocean warming, increased dissolved carbon dioxide, and acidification will affect the distribution and relative importance of specific subgroups of N
fixers in the sea; these changes have implications for foodwebs and biogeochemical cycles.
Microbially-mediated methylation of arsenic (As) plays an important role in the As biogeochemical cycle, particularly in rice paddy soils where methylated As, generated microbially, is translocated ...into rice grains. The presence of the arsenite (As(III)) methyltransferase gene (arsM) in soil microbes has been used as an indication of their capacity for As methylation. Here, we evaluate the ability of seven microorganisms encoding active ArsM enzymes to methylate As. Amongst those, only the aerobic species were efficient methylators. The anaerobic microorganisms presented high resistance to As exposure, presumably through their efficient As(III) efflux, but methylated As poorly. The only exception were methanogens, for which efficient As methylation was seemingly an artifact of membrane disruption. Deletion of an efflux pump gene (acr3) in one of the anaerobes, Clostridium pasteurianum, rendered the strain sensitive to As and capable of more efficiently methylating As. Our results led to the following conclusions: (i) encoding a functional ArsM enzyme does not guarantee that a microorganism will actively drive As methylation in the presence of the metalloid and (ii) there is an inverse relationship between efficient microbial As efflux and its methylation, because the former prevents the intracellular accumulation of As.
Schembri, S. and Zammit, G., 2022. The biodiversity of epilithic microalgal communities colonising a central Mediterranean coastline. Journal of Coastal Research, 38(2), 249–260. Coconut Creek ...(Florida), ISSN 0749-0208. Microbial communities colonise the coastal ecosystem around the Maltese islands. However, such communities are understudied, both in Malta and in the central Mediterranean. This research aims to increase current knowledge about the biodiversity of phototrophic communities growing along a central Mediterranean rocky shoreline and is the first such study to be performed on microorganisms growing in epilithic biofilms and microbial mats along the coastline in the Maltese islands. Samples were obtained using techniques that were noninvasive to the underlying substratum. These were studied by direct observation using light and electron microscopy, by culturing in vitro, by molecular analysis via sequencing of the small subunit ribosomal ribonucleic acid genes and phylogenetic analyses. Microscopic analyses revealed highly diverse communities made of both photosynthetic and heterotrophic organisms. The predominant microorganisms were simple filamentous cyanobacteria including species of Leptolyngbya, Phormidesmis, Nodosilinea, Toxifilum, Phormidium, and Lyngbya, as well as heterocytous Calothrix and Nunduva spp. The coccal cyanobacteria included species of Aphanocapsa and Chroococcus, whereas coccal microalgae belonged to Chlorella, Chlamydomonas, and Coelastrella spp., accompanied by diatoms of Navicula sp. These results include first records of cyanobacterial and microalgal barcodes that were genetically sequenced from a coastline in the central Mediterranean. Germlings of the filamentous macroalga Cladophora were embedded in the rocky substrate that was preconditioned by biofilm growth and ciliated protozoans, micronematodes, and microcrustaceans interacted with the microbial communities. The isolation of new cyanobacterial and microalgal strains from these phototrophic communities highlights the importance of employing a combined multiphasic approach to supplement current knowledge about the biodiversity of microbial communities colonising rocky shores.
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