scholarly journals The composition of endolithic communities in gypcrete is determined by the specific microhabitat architecture

2020 ◽  
Author(s):  
María Cristina Casero ◽  
Victoria Meslier ◽  
Jocelyne DiRuggiero ◽  
Antonio Quesada ◽  
Carmen Ascaso ◽  
...  

Abstract. Endolithic microhabitats have been described as the last refuge for life in arid and hyper-arid deserts where life has to deal with harsh environmental conditions. A number of rock substrates from the hyper-arid Atacama Desert, colonized by endolithic microbial communities, such as halite, gypsum crusts, gypcrete, calcite, granite and ignimbrite, have been characterized and compared using different approaches. In this work, three different endolithic microhabitats are described, each one with a particular origin and architecture, found within a lithic substrate known as gypcrete. Gypcrete, an evaporitic rock mainly composed of gypsum (CaSO4 ⋅ 2H2O) and collected in the Cordón de Lila area of the desert (Preandean Atacama Desert), was found to harbour cryptoendolithic (within pore spaces in the rock), chasmoendolithic (within cracks and fissures) and hypoendolithic (within microcave-like pores in rock-bottom layer) microhabitats. A combination of microscopy investigations strategies and high-throughput sequencing approaches were used to characterize the endolithic communities at the microscale in these microhabitats within the same piece of lithic substrate. Microscopy techniques revealed differences in the architecture of the endolithic microhabitats and in the distribution of the microorganisms within those microhabitats. Cyanobacteria and Proteobacteria were dominant in the endolithic communities, of which the hypoendolithic community was the least diverse and hosted unique taxa. These results show, for the first time, that the differences in the architecture of a microhabitat, even within the same piece of lithic substrate, might be an essential factor in shaping the diversity and composition of endolithic microbial communities.

2021 ◽  
Vol 18 (3) ◽  
pp. 993-1007
Author(s):  
María Cristina Casero ◽  
Victoria Meslier ◽  
Jocelyne DiRuggiero ◽  
Antonio Quesada ◽  
Carmen Ascaso ◽  
...  

Abstract. Endolithic microhabitats have been described as the last refuge for life in arid and hyper-arid deserts where life has to deal with harsh environmental conditions. A number of rock substrates from the hyper-arid Atacama Desert, colonized by endolithic microbial communities such as halite, gypsum crusts, gypcrete, calcite, granite and ignimbrite, have been characterized and compared using different approaches. In this work, three different endolithic microhabitats are described, each one with a particular origin and architecture, found within a lithic substrate known as gypcrete. Gypcrete, an evaporitic rock mainly composed of gypsum (CaSO4 ⋅ 2H2O) and collected in the Cordón de Lila area of the desert (Preandean Atacama Desert), was found to harbour cryptoendolithic (within pore spaces in the rock), chasmoendolithic (within cracks and fissures) and hypoendolithic (within microcave-like pores in the bottom layer of rock) microhabitats. A combination of microscopy investigation and high-throughput sequencing approaches were used to characterize the endolithic communities and their habitats at the microscale within the same piece of gypcrete. Microscopy techniques revealed differences in the architecture of the endolithic microhabitats and the distribution of the microorganisms within those microhabitats. Cyanobacteria and Proteobacteria were dominant in the endolithic communities, of which the hypoendolithic community was the least diverse and hosted unique taxa, as a result of less access to sun radiation. These results show, for the first time, that the differences in the architecture of a microhabitat, even within the same piece of a lithic substrate, play an essential role in shaping the diversity and composition of endolithic microbial communities.


Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 241-252
Author(s):  
Dyah Asri Handayani Taroepratjeka ◽  
Tsuyoshi Imai ◽  
Prapaipid Chairattanamanokorn ◽  
Alissara Reungsang

Extreme halophiles offer the advantage to save on the costs of sterilization and water for biohydrogen production from lignocellulosic waste after the pretreatment process with their ability to withstand extreme salt concentrations. This study identifies the dominant hydrogen-producing genera and species among the acclimatized, extremely halotolerant microbial communities taken from two salt-damaged soil locations in Khon Kaen and one location from the salt evaporation pond in Samut Sakhon, Thailand. The microbial communities’ V3–V4 regions of 16srRNA were analyzed using high-throughput amplicon sequencing. A total of 345 operational taxonomic units were obtained and the high-throughput sequencing confirmed that Firmicutes was the dominant phyla of the three communities. Halanaerobium fermentans and Halanaerobacter lacunarum were the dominant hydrogen-producing species of the communities. Spatial proximity was not found to be a determining factor for similarities between these extremely halophilic microbial communities. Through the study of the microbial communities, strategies can be developed to increase biohydrogen molar yield.


Author(s):  
Jane Oja ◽  
Sakeenah Adenan ◽  
Abdel-Fattah Talaat ◽  
Juha Alatalo

A broad diversity of microorganisms can be found in soil, where they are essential for nutrient cycling and energy transfer. Recent high-throughput sequencing methods have greatly advanced our knowledge about how soil, climate and vegetation variables structure the composition of microbial communities in many world regions. However, we are lacking information from several regions in the world, e.g. Middle-East. We have collected soil from 19 different habitat types for studying the diversity and composition of soil microbial communities (both fungi and bacteria) in Qatar and determining which edaphic parameters exert the strongest influences on these communities. Preliminary results indicate that in overall bacteria are more abundant in soil than fungi and few sites have notably higher abundance of these microbes. In addition, we have detected some soil patameters, which tend to have reduced the overall fungal abundance and enhanced the presence of arbuscular mycorrhizal fungi and N-fixing bacteria. More detailed information on the diversity and composition of soil microbial communities is expected from the high-throughput sequenced data.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0254971
Author(s):  
Federico Rossi ◽  
Alessandro Crnjar ◽  
Federico Comitani ◽  
Rodrigo Feliciano ◽  
Leonie Jahn ◽  
...  

Tree ring features are affected by environmental factors and therefore are the basis for dendrochronological studies to reconstruct past environmental conditions. Oak wood often provides the data for these studies because of the durability of oak heartwood and hence the availability of samples spanning long time periods of the distant past. Wood formation is regulated in part by epigenetic mechanisms such as DNA methylation. Studies of the methylation state of DNA preserved in oak heartwood thus could identify epigenetic tree ring features informing on past environmental conditions. In this study, we aimed to establish protocols for the extraction of DNA, the high-throughput sequencing of whole-genome DNA libraries (WGS) and the profiling of DNA methylation by whole-genome bisulfite sequencing (WGBS) for oak (Quercus robur) heartwood drill cores taken from the trunks of living standing trees spanning the AD 1776-2014 time period. Heartwood contains little DNA, and large amounts of phenolic compounds known to hinder the preparation of high-throughput sequencing libraries. Whole-genome and DNA methylome library preparation and sequencing consistently failed for oak heartwood samples more than 100 and 50 years of age, respectively. DNA fragmentation increased with sample age and was exacerbated by the additional bisulfite treatment step during methylome library preparation. Relative coverage of the non-repetitive portion of the oak genome was sparse. These results suggest that quantitative methylome studies of oak hardwood will likely be limited to relatively recent samples and will require a high sequencing depth to achieve sufficient genome coverage.


Viruses ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 385 ◽  
Author(s):  
Asimina Katsiani ◽  
Varvara Maliogka ◽  
Nikolaos Katis ◽  
Laurence Svanella-Dumas ◽  
Antonio Olmos ◽  
...  

Little cherry virus 1 (LChV1, Velarivirus, Closteroviridae) is a widespread pathogen of sweet or sour cherry and other Prunus species, which exhibits high genetic diversity and lacks a putative efficient transmission vector. Thus far, four distinct phylogenetic clusters of LChV1 have been described, including isolates from different Prunus species. The recent application of high throughput sequencing (HTS) technologies in fruit tree virology has facilitated the acquisition of new viral genomes and the study of virus diversity. In the present work, several new LChV1 isolates from different countries were fully sequenced using different HTS approaches. Our results reveal the presence of further genetic diversity within the LChV1 species. Interestingly, mixed infections of the same sweet cherry tree with different LChV1 variants were identified for the first time. Taken together, the high intra-host and intra-species diversities of LChV1 might affect its pathogenicity and have clear implications for its accurate diagnostics.


2014 ◽  
Vol 44 ◽  
pp. 136-141 ◽  
Author(s):  
Alejandro Aldrete-Tapia ◽  
Meyli C. Escobar-Ramírez ◽  
Mark L. Tamplin ◽  
Montserrat Hernández-Iturriaga

2017 ◽  
Vol 92 (1) ◽  
Author(s):  
Xiaojuan Liu ◽  
Jing Jin ◽  
Ping Qiu ◽  
Fangluan Gao ◽  
Wenzhong Lin ◽  
...  

ABSTRACTMost segmented negative-sense RNA viruses employ a process termed cap snatching, during which they snatch capped RNA leaders from host cellular mRNAs and use the snatched leaders as primers for transcription, leading to the synthesis of viral mRNAs with 5′ heterogeneous sequences (HSs). With traditional methods, only a few HSs can be determined, and identification of their donors is difficult. Here, the mRNA 5′ ends ofRice stripe tenuivirus(RSV) andRice grassy stunt tenuivirus(RGSV) and those of their host rice were determined by high-throughput sequencing. Millions of tenuiviral HSs were obtained, and a large number of them mapped to the 5′ ends of corresponding host cellular mRNAs. Repeats of the dinucleotide AC, which are complementary to the U1G2of the tenuiviral template 3′-U1G2U3G4UUUCG, were found to be prevalent at the 3′ termini of tenuiviral HSs. Most of these ACs did not match host cellular mRNAs, supporting the idea that tenuiviruses use the prime-and-realign mechanism during cap snatching. We previously reported a greater tendency of RSV than RGSV to use the prime-and-realign mechanism in transcription with leaders cap snatched from a coinfecting reovirus. Besides confirming this observation in natural tenuiviral infections, the data here additionally reveal that RSV has a greater tendency to use this mechanism in transcribing genomic than in transcribing antigenomic templates. The data also suggest that tenuiviruses cap snatch host cellular mRNAs from translation- and photosynthesis-related genes, and capped RNA leaders snatched by tenuiviruses base pair with U1/U3or G2/G4of viral templates. These results provide unprecedented insights into the cap-snatching process of tenuiviruses.IMPORTANCEMany segmented negative-sense RNA viruses (segmented NSVs) are medically or agriculturally important pathogens. The cap-snatching process is a promising target for the development of antiviral strategies against this group of viruses. However, many details of this process remain poorly characterized. Tenuiviruses constitute a genus of agriculturally important segmented NSVs, several members of which are major viral pathogens of rice. Here, we for the first time adopted a high-throughput sequencing strategy to determine the 5′ heterogeneous sequences (HSs) of tenuiviruses and mapped them to host cellular mRNAs. Besides providing deep insights into the cap snatching of tenuiviruses, the data obtained provide clear evidence to support several previously proposed models regarding cap snatching. Curiously and importantly, the data here reveal that not only different tenuiviruses but also the same tenuivirus synthesizing different mRNAs use the prime-and-realign mechanism with different tendencies during their cap snatching.


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