scholarly journals Microbial community structure and diversity within hypersaline Keke Salt Lake environments

2017 ◽  
Vol 63 (11) ◽  
pp. 895-908 ◽  
Author(s):  
Rui Han ◽  
Xin Zhang ◽  
Jing Liu ◽  
Qifu Long ◽  
Laisheng Chen ◽  
...  

Keke Salt Lake is located in the Qaidamu Basin of China. It is a unique magnesium sulfate-subtype hypersaline lake that exhibits a halite domain ecosystem, yet its microbial diversity has remained unstudied. Here, the microbial community structure and diversity was investigated via high-throughput sequencing of the V3–V5 regions of 16S rRNA genes. A high diversity of operational taxonomic units was detected for Bacteria and Archaea (734 and 747, respectively), comprising 21 phyla, 43 classes, and 201 genera of Bacteria and 4 phyla, 4 classes, and 39 genera of Archaea. Salt-saturated samples were dominated by the bacterial genera Bacillus (51.52%–58.35% relative abundance), Lactococcus (9.52%–10.51%), and Oceanobacillus (8.82%–9.88%) within the Firmicutes phylum (74.81%–80.99%), contrasting with other hypersaline lakes. The dominant Archaea belonged to the Halobacteriaceae family, and in particular, the genera (with an abundance of >10% of communities) Halonotius, Halorubellus, Halapricum, Halorubrum, and Natronomonas. Additionally, we report the presence of Nanohaloarchaeota and Woesearchaeota in Qinghai–Tibet Plateau lakes, which has not been previously documented. Total salinity (especially Mg2+, Cl–, Na+, and K+) mostly correlated with taxonomic distribution across samples. These results expand our understanding of microbial resource utilization within hypersaline lakes and the potential adaptations of dominant microorganisms that allow them to inhabit such environments.

2000 ◽  
Vol 66 (7) ◽  
pp. 2906-2913 ◽  
Author(s):  
Nico Boon ◽  
Johan Goris ◽  
Paul De Vos ◽  
Willy Verstraete ◽  
Eva M. Top

ABSTRACT A strain identified as Comamonas testosteroni I2 was isolated from activated sludge and found to be able to mineralize 3-chloroaniline (3-CA). During the mineralization, a yellow intermediate accumulated temporarily, due to the distalmeta-cleavage of chlorocatechol. This strain was tested for its ability to clean wastewater containing 3-CA upon inoculation into activated sludge. To monitor its survival, the strain was chromosomally marked with the gfp gene and designated I2gfp. After inoculation into a lab-scale semicontinuous activated-sludge (SCAS) system, the inoculated strain maintained itself in the sludge for at least 45 days and was present in the sludge flocs. After an initial adaptation period of 6 days, complete degradation of 3-CA was obtained during 2 weeks, while no degradation at all occurred in the noninoculated control reactor. Upon further operation of the SCAS system, only 50% 3-CA removal was observed. Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes revealed a dynamic change in the microbial community structure of the activated sludge. The DGGE patterns of the noninoculated and the inoculated reactors evolved after 7 days to different clusters, which suggests an effect of strain inoculation on the microbial community structure. The results indicate that bioaugmentation, even with a strain originating from that ecosystem and able to effectively grow on a selective substrate, is not permanent and will probably require regular resupplementation.


mBio ◽  
2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Ashley Shade ◽  
Patricia S. McManus ◽  
Jo Handelsman

ABSTRACTDespite its importance to the host, the flower microbiome is poorly understood. We report a culture-independent, community-level assessment of apple flower microbial diversity and dynamics. We collected flowers from six apple trees at five time points, starting before flowers opened and ending at petal fall. We applied streptomycin to half of the trees when flowers opened. Assessment of microbial diversity using tag pyrosequencing of 16S rRNA genes revealed that the apple flower communities were rich and diverse and dominated by members of TM7 andDeinococcus-Thermus, phyla about which relatively little is known. From thousands of taxa, we identified six successional groups with coherent dynamics whose abundances peaked at different times before and after bud opening. We designated the groups Pioneer, Early, Mid, Late, Climax, and Generalist communities. The successional pattern was attributed to a set of prevalent taxa that were persistent and gradually changing in abundance. These taxa had significant associations with other community members, as demonstrated with a cooccurrence network based on local similarity analysis. We also detected a set of less-abundant, transient taxa that contributed to general tree-to-tree variability but not to the successional pattern. Communities on trees sprayed with streptomycin had slightly lower phylogenetic diversity than those on unsprayed trees but did not differ in structure or succession. Our results suggest that changes in apple flower microbial community structure are predictable over the life of the flower, providing a basis for ecological understanding and disease management.IMPORTANCEFlowering plants (angiosperms) represent a diverse group of an estimated 400,000 species, and their successful cultivation is essential to agriculture. Yet fundamental knowledge of flower-associated microbiotas remains largely unknown. Even less well understood are the changes that flower microbial communities experience through time. Flowers are particularly conducive to comprehensive temporal studies because they are, by nature, ephemeral organs. Here, we present the first culture-independent time series of bacterial and archaeal communities associated with the flowers of apple, an economically important crop. We found unexpected diversity on apple flowers, including a preponderance of taxa affiliated withDeinococcus-Thermusand TM7, phyla that are understudied but thought to be tolerant to an array of environmental stresses. Our results also suggest that changes in microbial community structure on the apple flower may be predictable over the life of the flower, providing the basis for ecological understanding and disease management.


2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Olga Mikanová ◽  
Tomáš Šimon ◽  
Jan Kopecký ◽  
Markéta Ságová-Marečková

AbstractThe influence of different fertilization treatments on soil biological characteristics and microbial community structure was investigated. Soil samples were taken from a long-term field experiment which was conducted to explore the effect of eight treatments: control (non-fertilized), NPK (nitrogen, phosphorus and potassium), FYM (farmyard manure), FYM + NPK, CSl + St (cattle slurry + straw), CSl + St + NPK, CSl, CSl + NPK. The highest values of invertase activity were found in treatment fertilized with farmyard manure combined mineral fertilizers, similarly to total N content, activity of urease, and C of microbial biomass. Dehydrogenase activity was lower in all treatments with mineral fertilization. Bacterial and actinobacterial T-RFLP profiles of 16S rRNA genes showed similar patterns in response to eight fertilization treatments. In both, the communities formed distinct groups, which were separated by organic fertilization i.e. cattle slurry and straw amendments along the x axes and by NPK amendments along the y axes using the Sammon’s method of multidimensional scaling. Significant correlations were determined in several situations related to diversity: between invertase and 1/Db (dominance, bacteria), 1/Da (dominance, actinobacteria) and between T-RFLP profiles of actinobacteria, nitrogen and organic carbon content and bacterial E (evenness).


2021 ◽  
Author(s):  
Yanbo Liu ◽  
Mengxiao Sun ◽  
Pei Hou ◽  
Wenya Wang ◽  
Xiangkun Shen ◽  
...  

Abstract In this study, the pit mud used in manufacturing Taorong-type Baijiu was collected from the upper, middle, lower and bottom layers of pits in Henan Yangshao Liquor Co., LTD. Besides, high-throughput sequencing (HTS) technology was adopted to analyze the microbial community structure of the pit mud. In addition, the volatile compounds in the pit mud were subjected to preliminarily qualitative analysis through headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The results of HTS demonstrated that there were 5, 3, 5 and 5 dominant bacterial phyla (including 11, 11, 9 and 8 dominant bacterial genera) and 3, 3, 3 and 3 dominant fungal phyla (including 4, 7, 7 and 5 dominant fungal genera) in the pit mud from F-S (upper), G-Z (middle), H-X (lower) and I-D (bottom), respectively. The qualitative analysis results of volatile compounds demonstrated that a total of 78 kinds of volatile compounds were detected in the pit mud, including 46, 45, 39 and 49 kinds in the pit mud from F-S, G-Z, H-X and I-D, respectively. Ester and acid were the two main components in the pit mud. Meanwhile, the correlation between microorganisms and main volatile compounds in the pit mud was analyzed. Moreover, Lentimicrobium, Syner-01 and Blvii28_wastewater-sludge group were found for the first time in the pit mud used for manufacturing Taorong-type Baijiu. The findings of this study could provide a theoretical foundation for improving the quality of pit mud and the flavor of Taorong-type Baijiu.


2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Ryan A. Blaustein ◽  
Graciela L. Lorca ◽  
Julie L. Meyer ◽  
Claudio F. Gonzalez ◽  
Max Teplitski

ABSTRACTStable associations between plants and microbes are critical to promoting host health and productivity. The objective of this work was to test the hypothesis that restructuring of the core microbiota may be associated with the progression of huanglongbing (HLB), the devastating citrus disease caused byLiberibacter asiaticus,Liberibacter americanus, andLiberibacter africanus. The microbial communities of leaves (n= 94) and roots (n= 79) from citrus trees that varied by HLB symptom severity, cultivar, location, and season/time were characterized with Illumina sequencing of 16S rRNA genes. The taxonomically rich communities contained abundant core members (i.e., detected in at least 95% of the respective leaf or root samples), some overrepresented site-specific members, and a diverse community of low-abundance variable taxa. The composition and diversity of the leaf and root microbiota were strongly associated with HLB symptom severity and location; there was also an association with host cultivar. The relative abundance ofLiberibacterspp. among leaf microbiota positively correlated with HLB symptom severity and negatively correlated with alpha diversity, suggesting that community diversity decreases as symptoms progress. Network analysis of the microbial community time series identified a mutually exclusive relationship betweenLiberibacterspp. and members of theBurkholderiaceae,Micromonosporaceae, andXanthomonadaceae. This work confirmed several previously described plant disease-associated bacteria, as well as identified new potential implications for biological control. Our findings advance the understanding of (i) plant microbiota selection across multiple variables and (ii) changes in (core) community structure that may be a precondition to disease establishment and/or may be associated with symptom progression.IMPORTANCEThis study provides a comprehensive overview of the core microbial community within the microbiomes of plant hosts that vary in extent of disease symptom progression. With 16S Illumina sequencing analyses, we not only confirmed previously described bacterial associations with plant health (e.g., potentially beneficial bacteria) but also identified new associations and potential interactions between certain bacteria and an economically important phytopathogen. The importance of core taxa within broader plant-associated microbial communities is discussed.


2018 ◽  
Author(s):  
wenjuan zhang ◽  
xian xue ◽  
fei peng ◽  
quangang you ◽  
jing pan ◽  
...  

Soil microbial community structure is an effective indicator to reflect changes in soil quality. Little is known about the effect of alpine meadow degradation on the soil bacterial and fungal community. In this study, we used the Illumina MiSeq sequencing method to analyze the microbial community structure of alpine meadow soil in five different degradation levels (i.e., non-degraded (ND), slightly degraded (LD), moderately degraded (MD), severely degraded (SD), and very severely degraded (VD)) in the Qinghai-Tibet Plateau. Proteobacteria, Actinobacteria, and Acidobacteria were the mainly bacterial phyla in meadow soil across all five degradation levels investigated. Basidiomycota was the mainly fungal phylum in ND; however, we found a shift from Basidiomycota to Ascomycota with an increase (severity) in degradation level. The overall proportion of Cortinariaceae exhibited high fungal variability, and reads were highest in ND (62.80%). Heatmaps of bacterial genera and fungal families showed a two-cluster sample division on a genus/family level: (1) an ND and LD group and (2) an SD, VD, and MD group. Redundancy analysis (RDA) showed that 79.7%and 71.3% of the variance in bacterial and fungal composition, respectively, could be explained by soil nutrient conditions (soil organic carbon, total nitrogen, and moisture) and plant properties (below-ground biomass). Our results indicate that meadow degradation affects both plant and soil properties and consequently drives changes in soil microbial community structure.


2021 ◽  
Vol 12 ◽  
Author(s):  
Li Ma ◽  
Geng Wu ◽  
Jian Yang ◽  
Liuqin Huang ◽  
Dorji Phurbu ◽  
...  

Investigating the distribution of hydrogen-producing bacteria (HPB) is of great significance to understanding the source of biological hydrogen production in geothermal environments. Here, we explored the compositions of HPB populations in the sediments of hot springs from the Daggyai, Quzhuomu, Quseyongba, and Moluojiang geothermal zones on the Tibetan Plateau, with the use of Illumina MiSeq high-throughput sequencing of 16S rRNA genes and hydA genes. In the present study, the hydA genes were successfully amplified from the hot springs with a temperature of 46–87°C. The hydA gene phylogenetic analysis showed that the top three phyla of the HPB populations were Bacteroidetes (14.48%), Spirochaetes (14.12%), and Thermotogae (10.45%), while Proteobacteria were absent in the top 10 of the HPB populations, although Proteobacteria were dominant in the 16S rRNA gene sequences. Canonical correspondence analysis results indicate that the HPB community structure in the studied Tibetan hot springs was correlated with various environmental factors, such as temperature, pH, and elevation. The HPB community structure also showed a spatial distribution pattern; samples from the same area showed similar community structures. Furthermore, one HPB isolate affiliated with Firmicutes was obtained and demonstrated the capacity of hydrogen production. These results are important for us to understand the distribution and function of HPB in hot springs.


2014 ◽  
Vol 88 (s1) ◽  
pp. 61-62 ◽  
Author(s):  
Alla BRYANSKAYA ◽  
Alexey ROZANOV ◽  
Tatyana MALUP ◽  
Taisiya ALESHINA ◽  
Elena LAZAREVA ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Danyang Zheng ◽  
Yujiao Sun ◽  
Huijuan Li ◽  
Sidan Lu ◽  
Mingjun Shan ◽  
...  

In recent years, the effect of formaldehyde on microorganisms and body had become a global public health issue. The multistage combination of anaerobic and aerobic process was adopted to treat paraformaldehyde wastewater. Microbial community structure in different reaction stages was analyzed through high-throughput sequencing. Results showed that multistage A-O activated sludge process positively influenced polyformaldehyde wastewater. The removal rates of formaldehyde were basically stable at more than 99% and those of COD were about 89%. Analysis of the microbial diversity index indicated that the microbial diversity of the reactor was high, and the treatment effect was good. Moreover, microbial community had certain similarity in the same system. Microbial communities in different units also showed typical representative characteristics affected by working conditions and influent concentrations. Proteobacteria, Firmicutes, and Bacteroidetes were the dominant fungal genera in the phylum level of community composition. As to family and genus levels, Peptostreptococcaceae was distributed at various stages and the dominant in this system. This bacterium also played an important role in organic matter removal, particularly decomposition of the acidified middle metabolites. In addition, Rhodobacteraceae and Rhodocyclaceae were the formaldehyde-degrading bacteria found in the reactor.


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