Ultramicrobacteria: Formation of the concept and contribution of ultramicrobacteria to biology

Дуда, В. И.; Suzina, N. E.; Поливцева, В. Н.; Boronin, A. M.

doi:10.1134/s0026261712040054

Cited by 67 publications

(77 citation statements)

References 43 publications

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“…Various reviews and workshops have considered a theoretical lower limit for the size of autonomous cells from a physical and biochemical perspective, taking into account the lists of essential macromolecular components and their sizes, as deduced from comparative genomics (48,49). On the basis of those studies, a minimal viable cell diameter of ϳ250 nm (assuming a spherical cell) and a volume of 0.008 to 0.014 m 3 are thought to be required for life (48).…”

Section: Discussionmentioning

confidence: 99%

Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium “Candidatus Pelagibacter ubique”

Zhao

Schwartz

Pierson

et al. 2017

Appl Environ Microbiol

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SAR11 bacteria are small, heterotrophic, marine alphaproteobacteria found throughout the oceans. They thrive at the low nutrient concentrations typical of open ocean conditions, although the adaptations required for life under those conditions are not well understood. To illuminate this issue, we used cryo-electron tomography to study "Candidatus Pelagibacter ubique" strain HTCC1062, a member of the SAR11 clade. Our results revealed its cellular dimensions and details of its intracellular organization. Frozen-hydrated cells, which were preserved in a life-like state, had an average cell volume (enclosed by the outer membrane) of 0.037 Ϯ 0.011 m 3 . Strikingly, the periplasmic space occupied ϳ20% to 50% of the total cell volume in log-phase cells and ϳ50% to 70% in stationary-phase cells. The nucleoid occupied the convex side of the crescent-shaped cells and the ribosomes predominantly occupied the concave side, at a relatively high concentration of 10,000 to 12,000 ribosomes/m 3 . Outer membrane pore complexes, likely composed of PilQ, were frequently observed in both log-phase and stationary-phase cells. Long filaments, most likely type IV pili, were found on dividing cells. The physical dimensions, intracellular organization, and morphological changes throughout the life cycle of "Ca. Pelagibacter ubique" provide structural insights into the functional adaptions of these oligotrophic ultramicrobacteria to their habitat. IMPORTANCE Bacterioplankton of the SAR11 clade (Pelagibacterales) are of interest because of their global biogeochemical significance and because they appear to have been molded by unusual evolutionary circumstances that favor simplicity and efficiency. They have adapted to an ecosystem in which nutrient concentrations are near the extreme limits at which transport systems can function adequately, and they have evolved streamlined genomes to execute only functions essential for life. However, little is known about the actual size limitations and cellular features of living oligotrophic ultramicrobacteria. In this study, we have used cryo-electron tomography to obtain accurate physical information about the cellular architecture of "Candidatus Pelagibacter ubique," the first cultivated member of the SAR11 clade. These results provide foundational information for answering questions about the cell architecture and functions of these ultrasmall oligotrophic bacteria.

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Section: Discussionmentioning

confidence: 99%

Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium “Candidatus Pelagibacter ubique”

Zhao

Schwartz

Pierson

et al. 2017

Appl Environ Microbiol

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“…Irrespective of the metabolic processes adopted by these subsurface organisms, it has been generally observed that their metabolic activities are very low and growth and cell division rates are unbelievably slow. Duda et al, (2012) reported on a community of ultramicrobacteria of less than 0.1 µm 3 containing 0.58 to 3.2 Mb genomes. They appear as starved, tiny and dwarfed microbes with much lower metabolic rates with average frequency of cell divisions being as low as once in a century or less!…”

Section: The Deep Subterranean Microorganismsmentioning

confidence: 99%

The amazing world of microorganisms

Kulasooriya¹

2019

Ceylon J. Sci.

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Among all living organisms on planet Earth, those that are invisible to the naked eye are the most abundant, most widely distributed and are indispensable for the continuation of life which they themselves originated. This review article has been prepared by going through important historical as well as recent literature on microorganisms with the primary purpose of dissemination of knowledge. It starts with the discovery of microorganisms and takes the reader through the key developments that enabled us to understand the invaluable roles they play in our lives, their possible origin on this planet, their diverse ecosystems and the amazing recent findings of some their existence several kilometers below the Earth's surface. Such subterranean communities appear to possess hitherto little known metabolic systems which are yet to be fully resolved. Moreover, whether these organisms originated in their ultra deep habitats or were transported down from the surface during the early formation of the primitive Earth by processes of subduction is still a matter of speculation. This review article is expected to arouse curiosity to pursue further research studies to unravel more novel information on the diverse activities, ubiquitous distribution and potential utilization of these organisms.

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“…free from viable microbes), the type of microorganisms passing through filters is in some respects not the issue, though of course some microbes represent a greater health risk than others and are potentially a greater problem in filtrates. A survey of the literature, while showing that most cases of filterable bacteria are typically environmental species, reveals that there are also cases of clinically important bacteria passing through filters (see Duda et al 2012). Another interesting facet of the field is that some filterable bacteria have shown themselves to be new or novel species, indicating that fractionation by filtration may be useful in discovering new taxa and harvesting their products (Hahn et al 2004;Nakai et al 2013;Maejima et al 2018).…”

Section: Introductionmentioning

confidence: 99%

“…These bacteria are the true Ultramicrobacteria (UMB), a name first applied by Torella & Morita (1981) and subsequently expanded on and qualified particularly by Schut et al (1997). Following on, Duda et al (2012) have listed the following mandatory criteria for UMB: (1) ultra-small sizes (volume of less than 0.1 μm 3 for most cells in the populations); (2) maintenance of ultra-small cell size regardless of the growth conditions and culture development stage, and (3) small genome size (~3.2 to ~0.58 Mb). Other members of the domain Bacteria that pass ultrafilters but fail to meet one or more of the above criteria can then be referred to as "non-UMB filterable bacteria".…”

Section: Introductionmentioning

confidence: 99%

Diversion and phylogenetic relatedness of filterable bacteria from Norwegian tap and bottled waters

Charnock

Hagen

Nguyen

et al. 2019

Journal of Water and Health

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Numerous articles have documented the existence of filterable bacteria. Where filtration is the chosen method of sterilization for medicinal or media components, these bacteria will by definition render products non-sterile. They may further represent a health hazard to the end user. A wide-range of bacterial genera were found in bottled and tap water filtrates from 0.2 μm filters, including genera housing opportunistic pathogens (e.g. Methylobacterium) and endospore formers (Paenibacillus). Two municipal tap water isolates were only distantly related to named species. One of these grew on agar, and could potentially provide hitherto unharvested useful biological products. The other grew only in water, and failed to produce colonies on media targeting either heterotrophs or autotrophs. The present study is one of very few looking at filterable bacteria in bottled waters intended for human consumption and the first identifying the filterable portion. It extends the range of known habitats of filterable bacteria and provides data on two new or novel species.

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Ultramicrobacteria: Formation of the concept and contribution of ultramicrobacteria to biology

Cited by 67 publications

References 43 publications

Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium “Candidatus Pelagibacter ubique”

Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium “Candidatus Pelagibacter ubique”

The amazing world of microorganisms

Diversion and phylogenetic relatedness of filterable bacteria from Norwegian tap and bottled waters

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