scholarly journals Diversity and Co-Occurrence Patterns of Fungal and Bacterial Communities from Alkaline Sediments and Water of Julong High-Altitude Hot Springs at Tianchi Volcano, Northeast China

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 894
Author(s):  
Xiao Wang ◽  
Lorenzo Pecoraro

The Julong high-altitude volcanic hot springs in northeast China are of undeniable interest for microbiological studies due to their unique, extreme environmental conditions. The objective of this study was to provide a comprehensive analysis of the unexplored fungal and bacterial community composition, structure and networks in sediments and water from the Julong hot springs using a combination of culture-based methods and metabarcoding. A total of 65 fungal and 21 bacterial strains were isolated. Fungal genera Trichoderma and Cladosporium were dominant in sediments, while the most abundant fungi in hot spring water were Aspergillus and Alternaria. Bacterial communities in sediments and water were dominated by the genera Chryseobacterium and Pseudomonas, respectively. Metabarcoding analysis revealed significant differences in the microorganism communities from the two hot springs. Results suggested a strong influence of pH on the analyzed microbial diversity, at least when the environmental conditions became clearly alkaline. Our analyses indicated that mutualistic interactions may play an essential role in shaping stable microbial networks in the studied hot springs. The much more complicated bacterial than fungal networks described in our study may suggest that the more flexible trophic strategies of bacteria are beneficial for their survival and fitness under extreme conditions.

2021 ◽  
Vol 9 (7) ◽  
pp. 1473
Author(s):  
Ani Saghatelyan ◽  
Armine Margaryan ◽  
Hovik Panosyan ◽  
Nils-Kåre Birkeland

The microbial diversity of high-altitude geothermal springs has been recently assessed to explore their biotechnological potential. However, little is known regarding the microbiota of similar ecosystems located on the Armenian Highland. This review summarizes the known information on the microbiota of nine high-altitude mineralized geothermal springs (temperature range 25.8–70 °C and pH range 6.0–7.5) in Armenia and Nagorno-Karabakh. All these geothermal springs are at altitudes ranging from 960–2090 m above sea level and are located on the Alpide (Alpine–Himalayan) orogenic belt, a seismically active region. A mixed-cation mixed-anion composition, with total mineralization of 0.5 mg/L, has been identified for these thermal springs. The taxonomic diversity of hot spring microbiomes has been examined using culture-independent approaches, including denaturing gradient gel electrophoresis (DGGE), 16S rRNA gene library construction, 454 pyrosequencing, and Illumina HiSeq. The bacterial phyla Proteobacteria, Bacteroidetes, Cyanobacteria, and Firmicutes are the predominant life forms in the studied springs. Archaea mainly include the phyla Euryarchaeota, Crenarchaeota, and Thaumarchaeota, and comprise less than 1% of the prokaryotic community. Comparison of microbial diversity in springs from Karvachar with that described for other terrestrial hot springs revealed that Proteobacteria, Bacteroidetes, Actinobacteria, and Deinococcus–Thermus are the common bacterial groups in terrestrial hot springs. Contemporaneously, specific bacterial and archaeal taxa were observed in different springs. Evaluation of the carbon, sulfur, and nitrogen metabolism in these hot spring communities has revealed diversity in terms of metabolic activity. Temperature seems to be an important factor in shaping the microbial communities of these springs. Overall, the diversity and richness of the microbiota are negatively affected by increasing temperature. Other abiotic factors, including pH, mineralization, and geological history, also impact the structure and function of the microbial community. More than 130 bacterial and archaeal strains (Bacillus, Geobacillus, Parageobacillus, Anoxybacillus, Paenibacillus, Brevibacillus Aeribacillus, Ureibacillus, Thermoactinomyces, Sporosarcina, Thermus, Rhodobacter, Thiospirillum, Thiocapsa, Rhodopseudomonas, Methylocaldum, Desulfomicrobium, Desulfovibrio, Treponema, Arcobacter, Nitropspira, and Methanoculleus) have been reported, some of which may be representative of novel species (sharing 91–97% sequence identity with their closest matches in GenBank) and producers of thermozymes and biomolecules with potential biotechnological applications. Whole-genome shotgun sequencing of T. scotoductus K1, as well as of the potentially new Treponema sp. J25 and Anoxybacillus sp. K1, were performed. Most of the phyla identified by 16S rRNA were also identified using metagenomic approaches. Detailed characterization of thermophilic isolates indicate the potential of the studied springs as a source of biotechnologically valuable microbes and biomolecules.


2021 ◽  
Vol 9 (3) ◽  
pp. 652
Author(s):  
Shigeru Kawai ◽  
Joval N. Martinez ◽  
Mads Lichtenberg ◽  
Erik Trampe ◽  
Michael Kühl ◽  
...  

Chloroflexus aggregans is a metabolically versatile, thermophilic, anoxygenic phototrophic member of the phylum Chloroflexota (formerly Chloroflexi), which can grow photoheterotrophically, photoautotrophically, chemoheterotrophically, and chemoautotrophically. In hot spring-associated microbial mats, C. aggregans co-exists with oxygenic cyanobacteria under dynamic micro-environmental conditions. To elucidate the predominant growth modes of C. aggregans, relative transcription levels of energy metabolism- and CO2 fixation-related genes were studied in Nakabusa Hot Springs microbial mats over a diel cycle and correlated with microscale in situ measurements of O2 and light. Metatranscriptomic analyses indicated two periods with different modes of energy metabolism of C. aggregans: (1) phototrophy around midday and (2) chemotrophy in the early morning hours. During midday, C. aggregans mainly employed photoheterotrophy when the microbial mats were hyperoxic (400–800 µmol L−1 O2). In the early morning hours, relative transcription peaks of genes encoding uptake hydrogenase, key enzymes for carbon fixation, respiratory complexes as well as enzymes for TCA cycle and acetate uptake suggest an aerobic chemomixotrophic lifestyle. This is the first in situ study of the versatile energy metabolism of C. aggregans based on gene transcription patterns. The results provide novel insights into the metabolic flexibility of these filamentous anoxygenic phototrophs that thrive under dynamic environmental conditions.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1526
Author(s):  
Xiaoqin Yang ◽  
Yang Wang ◽  
Luying Sun ◽  
Xiaoning Qi ◽  
Fengbin Song ◽  
...  

Conservative agricultural practices have been adopted to improve soil quality and maintain crop productivity. An efficient intercropping of maize with mushroom has been developed in Northeast China. The objective of this study was to evaluate and compare the effects of planting patterns on the diversity and structure of the soil bacterial communities at a 0–20 cm depth in the black soil zone of Northeast China. The experiment consisted of monoculture of maize and mushroom, and intercropping in a split-plot arrangement. The characteristics of soil microbial communities were performed by 16S rRNA gene amplicom sequencing. The results showed that intercropping increased soil bacterial richness and diversity compared with maize monoculture. The relative abundances of Acidobacteria, Chloroflexi, Saccharibacteria and Planctomycetes were significantly higher, whereas Proteobacteria and Firmicutes were lower in intercropping than maize monoculture. Redundancy analysis suggested that pH, NO3−-N and NH4+-N contents had a notable effect on the structure of the bacterial communities. Moreover, intercropping significantly increased the relative abundance of carbohydrate metabolism pathway functional groups. Overall, these findings demonstrated that intercropping of maize with mushroom strongly impacts the physical and chemical properties of soil as well as the diversity and structure of the soil bacterial communities, suggesting this is a sustainable agricultural management practice in Northeast China.


2006 ◽  
Vol 72 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Silke Langenheder ◽  
Eva S. Lindström ◽  
Lars J. Tranvik

ABSTRACT The aim of this study was to compare two major hypotheses concerning the formation of bacterial community composition (BCC) at the local scale, i.e., whether BCC is determined by the prevailing local environmental conditions or by “metacommunity processes.” A batch culture experiment where bacteria from eight distinctly different aquatic habitats were regrown under identical conditions was performed to test to what extent similar communities develop under similar selective pressure. Differently composed communities emerged from different inoculum communities, as determined by terminal restriction fragment length polymorphism analysis of the 16S rRNA gene. There was no indication that similarity increased between communities upon growth under identical conditions compared to that for growth at the ambient sampling sites. This suggests that the history and distribution of taxa within the source communities were stronger regulating factors of BCC than the environmental conditions. Moreover, differently composed communities were different with regard to specific functions, such as enzyme activities, but maintained similar broad-scale functions, such as biomass production and respiration.


2003 ◽  
Vol 40 (11) ◽  
pp. 1531-1548 ◽  
Author(s):  
Bruce W Fouke ◽  
George T Bonheyo ◽  
Beth Sanzenbacher ◽  
Jorge Frias-Lopez

A culture-independent molecular survey indicates that the composition of bacterial communities is distinctly partitioned between travertine depositional facies in the surface drainage system of Spring AT-1 at Angel Terrace, Mammoth Hot Springs, Yellowstone National Park. PCR (polymerase chain reaction) amplification and sequencing of 16S rRNA genes with universally conserved bacterial primers has identified over 553 unique partial and 104 complete gene sequences (derived from more than 14 000 clones), affiliated with 221 unique species that represent 21 bacterial divisions. These sequences exhibited < 12% similarity in bacterial community composition between each of the travertine depositional facies. This implies that relatively little downstream bacterial transport and colonization took place despite the rapid and continuous flow of spring water from the high-temperature to low-temperature facies. These results suggest that travertine depositional facies, which are independently determined by the physical and chemical conditions of the hot spring drainage system, effectively predict bacterial community composition as well as the morphology and chemistry of travertine precipitation.


2021 ◽  
Vol 12 (1S) ◽  
pp. 31-39
Author(s):  
Nur Dinie Zailan ◽  
Nurul Asma Hasliza Zulkifly ◽  
Afnani Alwi ◽  
Siti Noor Syuhada Muhammad Amin ◽  
Nadiawati Alias

Efficient strategies for phytase production gained increasing importance as more applications require high amounts of phytase for the market. Four phytase-producing bacterial strains isolated from Malaysia’s hot springs were used in this study to determine the effect of nitrogen sources on phytase production. All of the strains were screened out by applying halozone method which shows all of the strains were definitely positive phytase producer. Phytase Screening Medium (PSM) with soybean extract as substrate was used as a cultivation medium. Optimised condition with 1.0 % (w/v) of glucose (as carbon source), pH 5.5 and 37°C temperature was applied. Yeast extract and peptone were used to identify optimum nitrogen source in maximum phytase production. Quantitative analysis observed were optical density, colony forming unit, pH values and phytase activity to identify the effect of nitrogen source in phytase production. The finding was bacterial strain L3 as the best producer in producing maximum phytase (0.2162 U/mL) with optimised condition using yeast extract as nitrogen source. Findings in this study proved that yeast extract act as the optimum nitrogen source which contribute to maximum phytase production as supported by previous studies. This study can provide an efficient strategy to produce maximum phytase as few studies stated that phytase is an application tool in functional food production that consists of myo-inositol phosphates that is believed to have important pharmacological effects.


2020 ◽  
Vol 11 (1S) ◽  
Author(s):  
Anis Adilah Mustafa ◽  
Nurul Asma Hasliza Zulkifly ◽  
Afnani Alwi@Ali ◽  
Tajul Afif Abdullah ◽  
Nadiawati Alias

The main purpose of this research was to find the best growth curve for bacterial growth and the optimum temperature for the production of phytase from different potential phytase producing bacterial strains. A total of four strains used were originally isolated from hot springs in Malaysia, which were in Labis, Johor (L3), Dusun Tua, Selangor (RT), Ulu Legong, Kedah (A) and Ranau, Sabah (B9). Nutrient Agar (NA) and modified Phytase Screening Medium (PSM) liquid media were used for the culture enrichment while optimisation was carried out through batch culture method using a shake-flask scale. Strains growth and enzyme activity were quantitatively measured at different temperatures at (30°C and 37°C) values. Enzyme activity was determined according to the reaction of the phytase with its substrate (sodium phytate) and expressed in units of phytase activity (U/ mL). As for the overall, strain L3 (from Labis, Johor) exhibit promising rate of Pi released in the media at 30°C and 37°C, with optimum phytase activity values of 0.2047 U/mL and 0.2195 U/mL, respectively. The pH of the cultures was also measured, where it shows that strains grown in cultures at 37°C produced a higher phytase activity and resulting a lower reading of pH compared when grown at 30°C. All around, L3 strains has the lowest value of pH when cultured at 30°C and 37°C, with the pH value of 3.62 and 2.37, respectively.  From the result obtained, the lower pH indicates the process of phytic acid degradation take place by the phytase in producing inorganic phosphate (Pi) due to the accumulation of organic acid. Since these bacterial strains were originally taken from Hot Springs, further analysis of temperature optimization using 55°C and even 60°C should be carried out. In the future, biochemical research and molecular identification may also be carried out to identify molecular identity in the strains.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 280
Author(s):  
Xiao Wang ◽  
Lorenzo Pecoraro

High-altitude volcanoes, typical examples of extreme environments, are considered of particular interest in biology as a possible source of novel and exclusive microorganisms. We analyzed the crater soil microbial diversity of Tianchi Volcano, northeast China, by combining molecular and morphological analyses of culturable microbes, and metabarcoding based on Illumina sequencing, in order to increase our understanding of high-altitude volcanic microbial community structure. One-hundred and seventeen fungal strains belonging to 51 species and 31 genera of Ascomycota, Basidiomycota and Mucoromycota were isolated. Penicillium, Trichoderma, Cladosporium, Didymella, Alternaria and Fusarium dominated the culturable fungal community. A considerable number of isolated microbes, including filamentous fungi, such as Aureobasidium pullulans and Epicoccum nigrum, yeasts (Leucosporidium creatinivorum), and bacteria (Chryseobacterium lactis and Rhodococcus spp.), typical of high-altitude, cold, and geothermal extreme environments, provided new insights in the ecological characterization of the investigated environment, and may represent a precious source for the isolation of new bioactive compounds. A total of 1254 fungal and 2988 bacterial operational taxonomic units were generated from metabarcoding. Data analyses suggested that the fungal community could be more sensitive to environmental and geographical change compared to the bacterial community, whose network was characterized by more complicated and closer associations.


2022 ◽  
Author(s):  
Juanita C. Rodríguez-Rodríguez ◽  
Yves Bergeron ◽  
Steven W. Kembel ◽  
Nicole J. Fenton

The composition of ecologically important moss-associated bacterial communities seems to be mainly driven by host species, but may also be shaped by environmental conditions related with tree-canopy dominance. The moss phyllosphere has been studied in coniferous forests while broadleaf forests remain understudied. To determine if host species or environmental conditions defined by tree-canopy dominance drives the bacterial diversity in the moss phyllosphere, we used 16S rRNA gene amplicon sequencing to quantify changes in bacterial communities as a function of host species (Pleurozium schreberi and Ptilium crista-castrensis) and forest type (coniferous black spruce versus deciduous broadleaf trembling aspen) in eastern Canada. Forest type, not host species, was the main factor affecting moss phyllosphere bacterial community composition, though the interaction of both variables was significant. Bacterial α-diversity was highest in spruce forests, while there was greater turnover (β-diversity) and higher γ-diversity in aspen forests. Unexpectedly, Cyanobacteria were much more relatively abundant in aspen than in spruce forests, with the bacterial family Nostocaceae (Cyanobacteria) differing the most between both forest types. Our results suggest that the increasing change in dominance from coniferous to broadleaf trees due to natural and anthropic disturbances is likely to affect the composition of moss-associated bacteria in boreal forests.


2021 ◽  
Author(s):  
Jeffrey M Dick ◽  
Delong Meng

Thermodynamics predicts a positive correlation between environmental redox potential and oxidation state of molecules; if found for microbial communities it would imply a new kind of deterministic eco-evolutionary process. This study examines evidence for local- and global-scale correlations between oxidation-reduction potential (ORP or Eh) in environmental samples and carbon oxidation state (ZC) of estimated bacterial and archaeal community proteomes. Seventy-nine public datasets for seven environment types (river & seawater, lake & pond, alkaline spring, hot spring, groundwater, sediment, and soil) were analyzed. Taxonomic abundances inferred from high-throughput 16S rRNA gene sequences were combined with NCBI Reference Sequence (RefSeq) proteomes to estimate the amino acid compositions and chemical formulas (CcHhNnOoSs) of community proteomes, which yield ZC. Alkaline hot springs have the lowest ZC for both bacterial and archaeal domains of any environment. Positive global correlations between redox potential and ZC are found for bacterial communities in lake & pond, groundwater, and soil environments, but not archaeal communities, suggesting a broad ecological signal of chemical shaping in Bacteria.


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