scholarly journals Geographical Variability of Bacterial Communities of Cryoconite Holes of Andean Glaciers

2022 ◽  
Author(s):  
Francesca Pittino ◽  
Roberto Ambrosini ◽  
Michael Seeger ◽  
Roberto Sergio Azzoni ◽  
Guglielmina Diolaiuti ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Extreme Environments ◽  
High Elevation ◽  
Mountain Range ◽  
Glacier Surface ◽  
The World ◽  
Water Ph ◽  
Andean Glaciers ◽  
Patagonian Andes

Abstract Cryoconite holes, ponds full of melting water with a sediment on the bottom, are hotspots of biodiversity on glacier surface and host dynamic micro-ecosystems on these extreme environments. They have been extensively investigated in different areas of the world (e.g., Arctic, Antarctic, Alps, and Himalaya), but no study so far has described the bacterial communities of the glaciers in the Andes, the world longest mountain range. In this study, we start filling this gap of knowledge and describe the bacterial communities of Southern Andes in three small (< 2 km2) high elevation (< 4200 m a.s.l.) glaciers of Central Andes (Iver, East Iver and Morado glaciers) and two large (> 85 km2) glaciers in Patagonian Andes (Exploradores and Perito Moreno glaciers) whose ablation tongues reach low altitude (< 300 m a.s.l). Results show that the bacterial communities were generally similar to those observed in the cryoconite holes of other continents. Indeed, the most abundant orders were Burkholderiales, Cytophagales, Sphingobacteriales, Actinomycetales, Pseudomonadales, Rhodospiarillales, Rhizobiales, Sphingomonadales and Bacteroidales. However, the bacterial communities differed between glaciers and both water pH and O2 concentration influenced the bacterial community composition.

scholarly journals Geographical variability of bacterial communities of cryoconite holes of Andean glaciers

2021 ◽  
Author(s):  
Francesca Pittino ◽  
Michael Seeger ◽  
Roberto Azzoni ◽  
Roberto Ambrosini ◽  
Andrea Franzetti
Keyword(s):  
Bacterial Communities ◽  
High Elevation ◽  
Glacier Surface ◽  
Organic Matter Production ◽  
The Andes ◽  
Matter Production ◽  
O2 Concentration ◽  
The World ◽  
Water Ph ◽  
Andean Glaciers

AbstractCryoconite holes, ponds full of melting water with a sediment on the bottom, are hotspot of biodiversity of glacier surface. They host a metabolically active bacterial community that is involved in different dynamics concerning glacier ecosystems. Indeed, they are responsible of organic matter production and with other microorganisms establish a real microecosystem. Cryoconite holes have been described in different areas of the world (e.g., Arctic, Antarctic, Alps, Himalaya), and with this study we will provide the first description of bacterial communities of cryoconite holes of the Andes in South America. We collected samples on three high elevation glaciers of the Andes (Iver, Iver East and Morado glaciers) and two Patagonian glaciers located at sea level (Exploradores glacier and Perito Moreno). Results show that the most abundant orders are Burkholderiales, Cytophagales, Sphingobacteriales, Actinomycetales, Pseudomonadales, Rhodospiarillales, Rhizobiales, Sphingomonadales and Bacteroidales, which have been reported on glaciers of other areas of the world, Bacterial communities change from one glacier to another and both water pH and O2 concentration affect bacterial communities composition.

scholarly journals Pyrosequencing-Based Assessment of Soil pH as a Predictor of Soil Bacterial Community Structure at the Continental Scale

2009 ◽  
Vol 75 (15) ◽  
pp. 5111-5120 ◽  
Author(s):  
Christian L. Lauber ◽  
Micah Hamady ◽  
Rob Knight ◽  
Noah Fierer
Keyword(s):  
Bacterial Community ◽  
Soil Ph ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Spatial Scales ◽  
Bacterial Community Composition ◽  
Phylogenetic Structure ◽  
Soil Bacterial Communities ◽  
Soil Bacterial Community Structure ◽  
Soil Bacterial

ABSTRACT Soils harbor enormously diverse bacterial populations, and soil bacterial communities can vary greatly in composition across space. However, our understanding of the specific changes in soil bacterial community structure that occur across larger spatial scales is limited because most previous work has focused on either surveying a relatively small number of soils in detail or analyzing a larger number of soils with techniques that provide little detail about the phylogenetic structure of the bacterial communities. Here we used a bar-coded pyrosequencing technique to characterize bacterial communities in 88 soils from across North and South America, obtaining an average of 1,501 sequences per soil. We found that overall bacterial community composition, as measured by pairwise UniFrac distances, was significantly correlated with differences in soil pH (r = 0.79), largely driven by changes in the relative abundances of Acidobacteria, Actinobacteria, and Bacteroidetes across the range of soil pHs. In addition, soil pH explains a significant portion of the variability associated with observed changes in the phylogenetic structure within each dominant lineage. The overall phylogenetic diversity of the bacterial communities was also correlated with soil pH (R2 = 0.50), with peak diversity in soils with near-neutral pHs. Together, these results suggest that the structure of soil bacterial communities is predictable, to some degree, across larger spatial scales, and the effect of soil pH on bacterial community composition is evident at even relatively coarse levels of taxonomic resolution.

scholarly journals Rhizobacterial communities of five co-occurring desert halophytes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5508 ◽  
Author(s):  
Yan Li ◽  
Yan Kong ◽  
Dexiong Teng ◽  
Xueni Zhang ◽  
Xuemin He ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Plant Species ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Community Diversity ◽  
Species Identity ◽  
Halostachys Caspica ◽  
Lycium Ruthenicum ◽  
Limonium Gmelinii

BackgroundRecently, researches have begun to investigate the microbial communities associated with halophytes. Both rhizobacterial community composition and the environmental drivers of community assembly have been addressed. However, few studies have explored the structure of rhizobacterial communities associated with halophytic plants that are co-occurring in arid, salinized areas.MethodsFive halophytes were selected for study: these co-occurred in saline soils in the Ebinur Lake Nature Reserve, located at the western margin of the Gurbantunggut Desert of Northwestern China. Halophyte-associated bacterial communities were sampled, and the bacterial 16S rDNA V3–V4 region amplified and sequenced using the Illumina Miseq platform. The bacterial community diversity and structure were compared between the rhizosphere and bulk soils, as well as among the rhizosphere samples. The effects of plant species identity and soil properties on the bacterial communities were also analyzed.ResultsSignificant differences were observed between the rhizosphere and bulk soil bacterial communities. Diversity was higher in the rhizosphere than in the bulk soils. Abundant taxonomic groups (from phylum to genus) in the rhizosphere were much more diverse than in bulk soils. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Planctomycetes were the most abundant phyla in the rhizosphere, while Proteobacteria and Firmicutes were common in bulk soils. Overall, the bacterial community composition were not significantly differentiated between the bulk soils of the five plants, but community diversity and structure differed significantly in the rhizosphere. The diversity ofHalostachys caspica,Halocnemum strobilaceumandKalidium foliatumassociated bacterial communities was lower than that ofLimonium gmeliniiandLycium ruthenicumcommunities. Furthermore, the composition of the bacterial communities ofHalostachys caspicaandHalocnemum strobilaceumwas very different from those ofLimonium gmeliniiandLycium ruthenicum. The diversity and community structure were influenced by soil EC, pH and nutrient content (TOC, SOM, TON and AP); of these, the effects of EC on bacterial community composition were less important than those of soil nutrients.DiscussionHalophytic plant species played an important role in shaping associated rhizosphere bacterial communities. When salinity levels were constant, soil nutrients emerged as key factors structuring bacterial communities, while EC played only a minor role. Pairwise differences among the rhizobacterial communities associated with different plant species were not significant, despite some evidence of differentiation. Further studies involving more halophyte species, and individuals per species, are necessary to elucidate plant species identity effects on the rhizosphere for co-occurring halophytes.

scholarly journals Use of Wyoming Southern Bighorn Mountains Topographic Map Evidence to Test a Recently Proposed Regional Geomorphology Paradigm: USA

2019 ◽  
Vol 11 (3) ◽  
pp. 1
Author(s):  
Eric Clausen
Keyword(s):  
Drainage Basin ◽  
Water Source ◽  
High Elevation ◽  
Mountain Range ◽  
Topographic Map ◽  
The South ◽  
New Paradigm ◽  
River Drainage ◽  
North Fork ◽  
Bighorn Mountains

Detailed topographic maps covering a high elevation Bighorn-Powder River drainage divide segment in the southern Bighorn Mountains are used to test a recently proposed regional geomorphology paradigm. Fundamentally different from the commonly accepted paradigm the new paradigm predicts immense south-oriented continental ice sheet melt water floods once flowed across what is now the entire Missouri River drainage basin, in which the high Bighorn Mountains are located. Such a possibility is incompatible with commonly accepted paradigm expectations and previous investigators have interpreted Bighorn Mountains geomorphic history quite differently. The paradigm test began in the high glaciated Bighorn Mountains core area where numerous passes, or divide crossings, indicate multiple and sometimes closely spaced streams of water once flowed across what is now the Bighorn-Powder River drainage divide. To the south of the glaciated area, but still in a Precambrian bedrock region, the test found the roughly adjacent and parallel south-oriented North Fork Powder River and Canyon Creek headwaters located on opposite sides of the Bighorn-Powder River drainage divide with North Fork Powder River headwaters closely linked to a 300-meter deep pass through which south-oriented water had probably flowed. Shallower divide crossings located further to the south suggest diverging and converging streams of water once flowed not only across the Bighorn-Powder River drainage divide, but also across Powder River and Bighorn River tributary drainage divides. The paradigm test also found published geologic maps and reports showing the presence of possible flood transported and deposited alluvium. While unable to determine the water source, the new paradigm test did find evidence that large south-oriented floods had crossed what was probably a rising Bighorn Mountains mountain range.

scholarly journals Children of Heaven

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Olenka Kawchuk
Keyword(s):  
Low Temperature ◽  
South America ◽  
Geographic Origin ◽  
High Elevation ◽  
Human Sacrifice ◽  
Inca Empire ◽  
Pathological Conditions ◽  
The World ◽  
The Subject ◽  
Ritual Process

Ruling over western South America for nearly 100 years, the Inca Empire was one of many global cultures that practiced human sacrifice, though few other rituals of human sacrifice are as captivating as the Inca child sacrifice of capacocha. Capacocha children were chosen to be representatives of the Inca people in the afterlife. As such, they were afforded an elevated position in society before their death. Following their selection, children would undergo a year-long pilgrimage terminating at a mountain top shrine where they would be killed. As a result of the low temperature and oxygen levels present at such a high elevation, the bodies of capacocha children were protected against decomposition, creating some of the best-preserved natural mummies in the world. These mummies have been the subject of numerous bioarchaeological analyses to determine their age, sex, geographic origin, pathological conditions, diet, and cause of death. Beyond these, however, the mummies present a unique opportunity to study how the capacocha ritual process — including the sudden ascension in status — manifested itself on the children's bodies. This paper aims to review the bioarchaeological data garnered from the mummies in order to reconstruct the experience of a child chosen for capacocha. Results suggest higher variability between children selected for capacocha than was originally outlined by Spanish chroniclers.

scholarly journals Quorum Sensing Regulates the Hydrolytic Enzyme Production and Community Composition of Heterotrophic Bacteria in Coastal Waters

2021 ◽  
Vol 12 ◽  
Author(s):  
Marion Urvoy ◽  
Raphaël Lami ◽  
Catherine Dreanno ◽  
Daniel Delmas ◽  
Stéphane L’Helguen ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Community Composition ◽  
Coastal Waters ◽  
Bacterial Communities ◽  
Heterotrophic Bacteria ◽  
Bacterial Community Composition ◽  
Marine Ecosystem ◽  
Hydrolytic Enzyme ◽  
Enzymatic Activities ◽  
Hydrolytic Activities

Heterotrophic microbial communities play a central role in biogeochemical cycles in the ocean by degrading organic matter through the synthesis of extracellular hydrolytic enzymes. Their hydrolysis rates result from the community’s genomic potential and the differential expression of this genomic potential. Cell-cell communication pathways such as quorum sensing (QS) could impact both aspects and, consequently, structure marine ecosystem functioning. However, the role of QS communications in complex natural assemblages remains largely unknown. In this study, we investigated whether N-acylhomoserine lactones (AHLs), a type of QS signal, could regulate both hydrolytic activities and the bacterial community composition (BCC) of marine planktonic assemblages. To this extent, we carried out two microcosm experiments, adding five different AHLs to bacterial communities sampled in coastal waters (during early and peak bloom) and monitoring their impact on enzymatic activities and diversity over 48 h. Several specific enzymatic activities were impacted during both experiments, as early as 6 h after the AHL amendments. The BCC was also significantly impacted by the treatments after 48 h, and correlated with the expression of the hydrolytic activities, suggesting that changes in hydrolytic intensities may drive changes in BCC. Overall, our results suggest that QS communication could participate in structuring both the function and diversity of marine bacterial communities.

Roof of the World: Tibet, Pamirs

2013 ◽  
Author(s):  
Mike Searle
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Tien Shan ◽  
Palm Tree ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
North West ◽  
Mountain Ranges ◽  
The North ◽  
The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

Amazing Glacier Stuff

Glaciers ◽  
2015 ◽  
Author(s):  
Jorge Daniel Taillant
Keyword(s):  
Climate Change ◽  
Rocky Mountains ◽  
Central Andes ◽  
Mountain Range ◽  
Outburst Floods ◽  
The World ◽  
Industrial Use ◽  
Mitigating Circumstances ◽  
Story Building ◽  
At Home

This chapter is about what glaciers—and particularly what glacial and periglacial melt—mean to people and communities around the world. We often don’t realize that people interact daily with glaciers. Some go to visit and hike on glaciers or to photograph them for their magnificent beauty. Some ski on glaciers. Others extract water from glaciers for personal and industrial use. Others fear glaciers for their potent fury and destruction. People and communities are adapting to climate change and its impacts on glaciers, sometimes without even knowing it. Others are very aware of glacier vulnerability and are taking measures to address the changing cryosphere. They are mitigating circumstances and are adapting to impacts. In this chapter, we share stories and facts about glaciers and periglacial environments, which most people are probably unfamiliar with, and we explain how lives in these environments are changing due to climate change. Few people have heard of glacier tsunamis, but they exist, they’re real, they’re ferocious, and they can kill. Scientists call them glacier lake outburst floods (GLOFs). And as climate change deepens, more and more GLOF phenomena can be expected. Imagine you live at the foot of a mountain range like the Rocky Mountains, the Himalayas, or the Central Andes. On a nice sunny day, you can see the snow-capped mountains in the distance, maybe 20 or 30 km (12–18 mi) out, maybe even more. You are sitting at home when all of a sudden you feel shaking and hear a rumble. People start screaming. You look out the window and see people running frantically and erratically about. Then a woman yells, “The mountain! It’s coming! Run!” Imagine a large glacier the size of a dozen or so city blocks, perched atop a mountain. It’s 180 meters thick (600 ft), which is as tall as a sixty-story building. Below it, time and climate have formed a lake, a glacier lake occupying the same spot where the glacier once rested, pushing rock and earth out and forward as the glacier flowed downhill when it was solidly frozen and healthy.

scholarly journals Endophytic bacterial communities of oilseed rape associate with genotype-specific resistance against Verticillium longisporum

2019 ◽  
Vol 96 (1) ◽  
Author(s):  
Stefanie P Glaeser ◽  
Iulian Gabur ◽  
Hossein Haghighi ◽  
Jens-Ole Bartz ◽  
Peter Kämpfer ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Relative Abundance ◽  
Bacterial Communities ◽  
Quantitative Resistance ◽  
Bacterial Community Composition ◽  
Phylogenetic Group ◽  
Rrna Gene ◽  
Host Genotype ◽  
Brassica Napus L ◽  
Verticillium Longisporum

ABSTRACT Associations of endophytic bacterial community composition of oilseed rape (Brassica napus L.) with quantitative resistance against the soil-borne fungal pathogen Verticillium longisporum was assessed by 16S rRNA gene amplicon sequencing in roots and hypocotyls of four plant lines with contrasting genetic composition in regard to quantitative resistance reactions. The plant compartment was found to be the dominating driving factor for the specificity of bacterial communities in healthy plants. Furthermore, V. longisporum infection triggered a stabilization of phylogenetic group abundance in replicated samples suggesting a host genotype-specific selection. Genotype-specific associations with bacterial phylogenetic group abundance were identified by comparison of plant genotype groups (resistant versus susceptible) and treatment groups (healthy versus V. longisporum-infected) allowing dissection into constitutive and induced directional association patterns. Relative abundance of Flavobacteria, Pseudomonas, Rhizobium and Cellvibrio was associated with resistance/susceptibility. Relative abundance of Flavobacteria and Cellvibrio was increased in resistant genotypes according to their known ecological functions. In contrast, a higher relative abundance of Pseudomonas and Rhizobium, which are known to harbor many species with antagonistic properties to fungal pathogens, was found to be associated with susceptibility, indicating that these groups do not play a major role in genetically controlled resistance of oilseed rape against V. longisporum.

scholarly journals Significant Differences in the Gut Bacterial Communities of Hooded Crane (Grus monacha) in Different Seasons at a Stopover Site on the Flyway

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 701 ◽  
Author(s):  
Fengling Zhang ◽  
Xingjia Xiang ◽  
Yuanqiu Dong ◽  
Shaofei Yan ◽  
Yunwei Song ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Bacterial Community Composition ◽  
Stopover Site ◽  
Intestinal Bacterial Community ◽  
Hooded Crane ◽  
Grus Monacha

Intestinal bacterial communities form an integral component of the organism. Many factors influence gut bacterial community composition and diversity, including diet, environment and seasonality. During seasonal migration, birds use many habitats and food resources, which may influence their intestinal bacterial community structure. Hooded crane (Grus monacha) is a migrant waterbird that traverses long distances and occupies varied habitats. In this study, we investigated the diversity and differences in intestinal bacterial communities of hooded cranes over the migratory seasons. Fecal samples from hooded cranes were collected at a stopover site in two seasons (spring and fall) in Lindian, China, and at a wintering ground in Shengjin Lake, China. We analyzed bacterial communities from the fecal samples using high throughput sequencing (Illumina Mi-seq). Firmicutes, Proteobacteria, Tenericutes, Cyanobacteria, and Actinobacteria were the dominant phyla across all samples. The intestinal bacterial alpha-diversity of hooded cranes in winter was significantly higher than in fall and spring. The bacterial community composition significantly differed across the three seasons (ANOSIM, P = 0.001), suggesting that seasonal fluctuations may regulate the gut bacterial community composition of migratory birds. This study provides baseline information on the seasonal dynamics of intestinal bacterial community structure in migratory hooded cranes.

Sign in / Sign up

Export Citation Format

Share Document