scholarly journals Taxonomical and functional diversity of microbial communities in two hot springs of the Baikal rift zone

2021 ◽  
Vol 908 (1) ◽  
pp. 012001
Author(s):  
D D Barkhutova ◽  
S P Buryukhaev ◽  
V B Dambaev ◽  
D D Tsyrenova ◽  
E V Lavrentyeva

Abstract The Baikal Rift Zone hosts many hot springs with a wide range of temperature and physical-chemical conditions, which may harbour different niches for the distribution of microbial communities. We investigated microbial community composition and their functional activity in two alkaline hot springs with a temperature range of 34.4 to 73.6°C. Comparative analysis of the composition of the dominant taxa showed significant differences depending on the collection sites. In the community of high-temperature zones with a water temperature of 55-64°C, a high proportion of thermophilic bacteria Acetothermia (up to 57.9%), Deinococcus-Thermus (up to 50%), and Aquificae (up to 10.8%). Proteobacteria (29-77%) and Firmicutes (15-26%) dominate in the sulphide-free Garga spring (73-75°C). The functional analysis of the microbial community showed that the primary producers are cyanobacteria, anoxygenic phototrophs, and chemolithotrophic bacteria. At the terminal stages of the mineralization of organic matter, sulphate-reducing bacteria are the main destructors in the microbial communities in hot springs. The cyano-bacterial and sulfidogenic microbial communities play an important role in the formation of geochemical barriers and mineral formation.

2017 ◽  
Author(s):  
Svetlana V. Zaitseva ◽  
Elena V. Lavrentieva ◽  
Aryuna A. Radnagurueva ◽  
Olga A. Baturina ◽  
Marsel R. Kabilov ◽  
...  

Alkaline hot springs are unique extreme habitats resemble the early Earth and present a valuable resource for the discovery of procaryotic community diversity and isolation of the novel thermophilic Bacteria and Archaea. One of the model for the possible origin of biochemistry in alkaline hot springs revealed the acetyl-CoA pathway of CO2 fixation might be the most ancient form of carbon metabolism. Recent phylogenetic studies have suggested that the phylum Acetothermia is one of the deep branches of the Bacteria domain. Firstly Acetothermia (Candidate division OP1) was characterized in a culture independent molecular phylogenetic survey based on the 16S rRNA gene of the sulfide-rich hot spring, Obsidian Pool, a 75 to 95oC hot spring. Two nearly complete genomes of Acetothermia were established based on genome-resolved metagenomic analysis and its capability of implementing acetogenesis through the ancient reductive acetyl-CoA pathway by utilizing CO2 and H2 was revealed. Although genomic, proteomic and metagenomic approaches investigate basic metabolism and potentional energy conservation of uncultivated candidate phyla but ecological roles of these bacteria and general patterns of diversity and community structure stay unclear. General hydrochemical and geological characterization of alkaline thermal springs of the Baikal Rift zone with high silica concentrations and a nitrogen dominated gas phase is provided. Previous microbiogical studies based on culture-dependent methods recovered a large number of bacterial strains from thermal springs located in Baikal Rift zone. We combined microbial communities analysis by using high-throughput 16S rRNA gene sequencing, biogeochemical measurements, sediment mineralogy and physicochemical characteristics to investigate ecosystems of alkaline hot springs located in the Baikal Rift zone. Uncultivated bacteria belonging to the phylum Acetothermia, along with members of the phyla Firmicutes and Proteobacteria, were identified as the dominant group in hydrothermal sediments communities in the alkaline hot springs of Baikal Rift zone. In bottom sediments of the Alla hot spring, about 57% of all classified sequences represent this phylum. Geochemistry of fluids and sample type were strongly correlated with microbial community composition. The Acetothermia exhibited the highest relative abundance in sediment microbial community associated with alkaline thermal fluids enriched in Fe, Zn, Ni, Al and Cr.


Author(s):  
Svetlana V. Zaitseva ◽  
Elena V. Lavrentieva ◽  
Aryuna A. Radnagurueva ◽  
Olga A. Baturina ◽  
Marsel R. Kabilov ◽  
...  

Alkaline hot springs are unique extreme habitats resemble the early Earth and present a valuable resource for the discovery of procaryotic community diversity and isolation of the novel thermophilic Bacteria and Archaea. One of the model for the possible origin of biochemistry in alkaline hot springs revealed the acetyl-CoA pathway of CO2 fixation might be the most ancient form of carbon metabolism. Recent phylogenetic studies have suggested that the phylum Acetothermia is one of the deep branches of the Bacteria domain. Firstly Acetothermia (Candidate division OP1) was characterized in a culture independent molecular phylogenetic survey based on the 16S rRNA gene of the sulfide-rich hot spring, Obsidian Pool, a 75 to 95oC hot spring. Two nearly complete genomes of Acetothermia were established based on genome-resolved metagenomic analysis and its capability of implementing acetogenesis through the ancient reductive acetyl-CoA pathway by utilizing CO2 and H2 was revealed. Although genomic, proteomic and metagenomic approaches investigate basic metabolism and potentional energy conservation of uncultivated candidate phyla but ecological roles of these bacteria and general patterns of diversity and community structure stay unclear. General hydrochemical and geological characterization of alkaline thermal springs of the Baikal Rift zone with high silica concentrations and a nitrogen dominated gas phase is provided. Previous microbiogical studies based on culture-dependent methods recovered a large number of bacterial strains from thermal springs located in Baikal Rift zone. We combined microbial communities analysis by using high-throughput 16S rRNA gene sequencing, biogeochemical measurements, sediment mineralogy and physicochemical characteristics to investigate ecosystems of alkaline hot springs located in the Baikal Rift zone. Uncultivated bacteria belonging to the phylum Acetothermia, along with members of the phyla Firmicutes and Proteobacteria, were identified as the dominant group in hydrothermal sediments communities in the alkaline hot springs of Baikal Rift zone. In bottom sediments of the Alla hot spring, about 57% of all classified sequences represent this phylum. Geochemistry of fluids and sample type were strongly correlated with microbial community composition. The Acetothermia exhibited the highest relative abundance in sediment microbial community associated with alkaline thermal fluids enriched in Fe, Zn, Ni, Al and Cr.


Microbiology ◽  
2018 ◽  
Vol 87 (2) ◽  
pp. 272-281 ◽  
Author(s):  
E. V. Lavrentyeva ◽  
A. A. Radnagurueva ◽  
D. D. Barkhutova ◽  
N. L. Belkova ◽  
S. V. Zaitseva ◽  
...  

Author(s):  
Adam Krieger ◽  
Jiahao Zhang ◽  
Xiaoxia Nina Lin

AbstractEngineering of synthetic microbial communities is emerging as a powerful new paradigm for performing various industrially, medically, and environmentally important processes. To reach the fullest potential, however, this approach requires further development in many aspects, a key one being regulating the community composition. Here we leverage well established mechanisms in ecology which govern the relative abundance of multi-species ecosystems and develop a new tool for programming the composition of synthetic microbial communities. Using a simple model system consisting of two microorganisms Escherichia coli and Pseudomonas putida, which occupy different but partially overlapping thermal niches, we demonstrate that temperature regulation can be used to enable coexistence and program the community composition. We first investigate a constant temperature regime and show that different temperatures lead to different community compositions. Next, we invent a new cycling temperature regime and show that it can dynamically tune the microbial community, achieving a wide range of compositions depending on parameters that are readily manipulatable. Our work provides conclusive proof of concept that temperature regulation is a versatile and powerful tool capable of programming compositions of synthetic microbial communities.


2015 ◽  
Vol 12 (13) ◽  
pp. 10359-10387 ◽  
Author(s):  
W. Y. Dong ◽  
X. Y. Zhang ◽  
X. Y. Liu ◽  
X. L. Fu ◽  
F. S. Chen ◽  
...  

Abstract. Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-Glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the PLFA abundanceespecially in the N2P treatment, the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK. Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. There were also significant relationships between gram-positive (G+) bacteria and all three soil enzymes. These findings indicate that G+ bacteria is the most important microbial community in C, N, and P transformations in Chinese fir plantations, and that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil fertility and microbial activity in this kind of plantation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Scott F. George ◽  
Noah Fierer ◽  
Joseph S. Levy ◽  
Byron Adams

Ice-free soils in the McMurdo Dry Valleys select for taxa able to cope with challenging environmental conditions, including extreme chemical water activity gradients, freeze-thaw cycling, desiccation, and solar radiation regimes. The low biotic complexity of Dry Valley soils makes them well suited to investigate environmental and spatial influences on bacterial community structure. Water tracks are annually wetted habitats in the cold-arid soils of Antarctica that form briefly each summer with moisture sourced from snow melt, ground ice thaw, and atmospheric deposition via deliquescence and vapor flow into brines. Compared to neighboring arid soils, water tracks are highly saline and relatively moist habitats. They represent a considerable area (∼5–10 km2) of the Dry Valley terrestrial ecosystem, an area that is expected to increase with ongoing climate change. The goal of this study was to determine how variation in the environmental conditions of water tracks influences the composition and diversity of microbial communities. We found significant differences in microbial community composition between on- and off-water track samples, and across two distinct locations. Of the tested environmental variables, soil salinity was the best predictor of community composition, with members of the Bacteroidetes phylum being relatively more abundant at higher salinities and the Actinobacteria phylum showing the opposite pattern. There was also a significant, inverse relationship between salinity and bacterial diversity. Our results suggest water track formation significantly alters dry soil microbial communities, likely influencing subsequent ecosystem functioning. We highlight how Dry Valley water tracks could be a useful model system for understanding the potential habitability of transiently wetted environments found on the surface of Mars.


2021 ◽  
Vol 9 (7) ◽  
pp. 1495
Author(s):  
Tim Piel ◽  
Giovanni Sandrini ◽  
Gerard Muyzer ◽  
Corina P. D. Brussaard ◽  
Pieter C. Slot ◽  
...  

Applying low concentrations of hydrogen peroxide (H2O2) to lakes is an emerging method to mitigate harmful cyanobacterial blooms. While cyanobacteria are very sensitive to H2O2, little is known about the impacts of these H2O2 treatments on other members of the microbial community. In this study, we investigated changes in microbial community composition during two lake treatments with low H2O2 concentrations (target: 2.5 mg L−1) and in two series of controlled lake incubations. The results show that the H2O2 treatments effectively suppressed the dominant cyanobacteria Aphanizomenon klebahnii, Dolichospermum sp. and, to a lesser extent, Planktothrix agardhii. Microbial community analysis revealed that several Proteobacteria (e.g., Alteromonadales, Pseudomonadales, Rhodobacterales) profited from the treatments, whereas some bacterial taxa declined (e.g., Verrucomicrobia). In particular, the taxa known to be resistant to oxidative stress (e.g., Rheinheimera) strongly increased in relative abundance during the first 24 h after H2O2 addition, but subsequently declined again. Alpha and beta diversity showed a temporary decline but recovered within a few days, demonstrating resilience of the microbial community. The predicted functionality of the microbial community revealed a temporary increase of anti-ROS defenses and glycoside hydrolases but otherwise remained stable throughout the treatments. We conclude that the use of low concentrations of H2O2 to suppress cyanobacterial blooms provides a short-term pulse disturbance but is not detrimental to lake microbial communities and their ecosystem functioning.


el–Hayah ◽  
2012 ◽  
Vol 1 (4) ◽  
Author(s):  
Prihastuti Prihastuti

<p>Soils are made up of organic and an organic material. The organic soil component contains all the living creatures in the soil and the dead ones in various stages of decomposition.  Biological activity in soil helps to recycle nutrients, decompose organic matter making nutrient available for plant uptake, stabilize humus, and form soil particles.<br />The extent of the diversity of microbial in soil is seen to be critical to the maintenance of soil health and quality, as a wide range of microbial is involved in important soil functions.  That ecologically managed soils have a greater quantity and diversity of soil microbial. The two main drivers of soil microbial community structure, i.e., plant type and soil type, are thought to exert their function in a complex manner. The fact that in some situations the soil and in others the plant type is the key factor determining soil microbial diversity is related to their complexity of the microbial interactions in soil, including interactions between microbial and soil and microbial and plants. <br />The basic premise of organic soil stewardship is that all plant nutrients are present in the soil by maintaining a biologically active soil environment. The diversity of microbial communities has on ecological function and resilience to disturbances in soil ecosystems. Relationships are often observed between the extent of microbial diversity in soil, soil and plant quality and ecosystem sustainability. Agricultural management can be directed toward maximizing the quality of the soil microbial community in terms of disease suppression, if it is possible to shift soil microbial communities.</p><p>Keywords: structure, microbial, implication, sustainable agriculture<br /><br /></p>


2021 ◽  
Author(s):  
Amandine Erktan ◽  
MD Ekramul Haque ◽  
Jérôme Cortet ◽  
Paul Henning Krogh ◽  
Stefan Scheu

&lt;p&gt;Trophic regulation of microbial communities is receiving growing interest in soil ecology. Most studies investigated the effect of higher trophic levels on microbial communities at the bulk soil level. However, microbes are not equally accessible to consumers. They may be hidden in small pores and thus protected from consumers, suggesting that trophic regulation may depend on the localization of microbes within the soil matrix. As microaggregates (&lt; 250 &amp;#181;m) usually are more stable than macroaggregates (&gt; 250 &amp;#181;m) and embedded in the latter, we posit that they will be less affected by trophic regulations than larger aggregates. We quantified the effect of four contrasting species of collembolans (Ceratophysella denticulata, Protaphorura fimata, Folsomia candida, Sinella curviseta) on the microbial community composition in macro- (250 &amp;#181;m &amp;#8211; 2mm) and microaggregates (50 &amp;#8211; 250 &amp;#181;m). To do so, we re-built consumer-prey systems comprising remaining microbial background (post-autoclaving), fungal prey (Chaetomium globosum), and collembolan species (added as single species or combined). After three months, we quantified microbial community composition using phospholipid fatty acid markers (PLFAs). We found that the microbial communities in macroaggregates were more affected by the addition of collembolans than the communities in microaggregates. In particular, the fungal-to-bacterial (F:B) ratio significantly decreased in soil macroaggregates in the presence of collembolans. In the microaggregates, the F:B ratio remained lower and unaffected by collembolan inoculation. Presumably, fungal hyphae were more abundant in macroaggregates because they offered more habitat space for them, and the collembolans reduced fungal abundance because they consumed them. On the contrary, microaggregates presumably contained microbial communities protected from consumers. In addition, collembolans increased the formation of macroaggregates but did not influence their stability, despite their negative effect on fungal abundance, a well-known stabilizing agent. Overall, we show that trophic interactions between microbial communities and collembolans depend on the aggregate size class considered and, in return, soil macroaggregation is affected by these trophic interactions.&lt;/p&gt;


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