scholarly journals The effect of soil sample size, for practical DNA extraction, on soil microbial diversity in different taxonomic ranks

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260121
Author(s):  
Hiroki Morita ◽  
Satoshi Akao

To determine the optimal soil sample size for microbial community structure analysis, DNA extraction, microbial composition analysis, and diversity assessments were performed using soil sample sizes of 0.2, 1, and 5 g. This study focused on the relationship between soil amount and DNA extraction container volume and the alteration in microbial composition at different taxonomic ranks (order, class, and phylum). Horizontal (0.2 and 1 g) and vertical (5 g) shaking were applied during DNA extraction for practical use in a small laboratory. In the case of the 5 g soil sample, DNA extraction efficiency and the value of α-diversity index fluctuated severely, possibly because of vertical shaking. Regarding the 0.2 and 1 g soil samples, the number of taxa, Shannon–Wiener index, and Bray–Curtis dissimilarity were stable and had approximately the same values at each taxonomic rank. However, non-metric multidimensional scaling showed that the microbial compositions of these two sample sizes were different. The higher relative abundance of taxa in the case of the 0.2 g soil sample might indicate that cell wall compositions differentiated the microbial community structures in these two sample sizes due to high shear stress tolerance. The soil sample size and tube volume affected the estimated microbial community structure. A soil sample size of 0.2 g would be preferable to the other sample sizes because of the possible higher shearing force for DNA extraction and lower experimental costs due to smaller amounts of consumables. When the taxonomic rank was changed from order to phylum, some minor taxa identified at the order rank were integrated into major taxa at the phylum rank. The integration affected the value of the β-diversity index; therefore, the microbial community structure analysis, reproducibility of structures, diversity assessment, and detection of minor taxa would be influenced by the taxonomic rank applied.

2020 ◽  
Vol 41 (05) ◽  
pp. 292-299 ◽  
Author(s):  
Jarrad Timothy Hampton-Marcell ◽  
Tifani W. Eshoo ◽  
Marc D. Cook ◽  
Jack A. Gilbert ◽  
Craig A. Horswill ◽  
...  

AbstractExercise can influence gut microbial community structure and diversity; however, the temporal dynamics of this association have rarely been explored. Here we characterized fecal microbiota in response to short term changes in training volume. Fecal samples, body composition, and training logs were collected from Division I NCAA collegiate swimmers during peak training through their in-season taper in 2016 (n=9) and 2017 (n=7), capturing a systematic reduction in training volume near the conclusion of their athletic season. Fecal microbiota were characterized using 16S rRNA V4 amplicon sequencing and multivariate statistical analysis, Spearman rank correlations, and random forest models. Peak training volume, measured as swimming distance, decreased significantly during the study period from 32.6±4.8 km/wk to 11.3±8.1 km/wk (ANOVA, p<0.05); however, body composition showed no significant changes. Coinciding with the decrease in training volume, the microbial community structure showed a significant decrease in overall microbial diversity, a decrease in microbial community structural similarity, and a decrease in the proportion of the bacterial genera Faecalibacterium and Coprococcus. Together these data demonstrate a significant association between short-term changes in training volume and microbial composition and structure in the gut; future research will establish whether these changes are associated with energy balance or nutrient intake.


2020 ◽  
Vol 69 (2) ◽  
pp. 151-164
Author(s):  
XU-JIA WANG ◽  
HONG-MEI ZHU ◽  
ZHI-QIANG REN ◽  
ZHI-GUO HUANG ◽  
CHUN-HUI WEI ◽  
...  

In the traditional fermentation process of strong-aroma Baijiu, a fermentation pit mud (FPM) provides many genera of microorganisms for fermentation. However, the functional microorganisms that have an important effect on the quality of Baijiu and their changes with the age of fermentation pit (FP) are poorly understood. Herein, the Roche 454 pyrosequencing technique and a phospholipid fatty-acid analysis were employed to reveal the structure and diversity of prokaryotic communities in FPM samples that have been aged for 5, 30, and 100 years. The results revealed an increase in total prokaryotic biomass with an FP age; however, Shannon’s diversity index decreased significantly (p < 0.01). These results suggested that a unique microbial community structure evolved with uninterrupted use of the FP. The number of functional microorganisms, which could produce the flavor compounds of strong-aroma Baijiu, increased with the FP age. Among them, Clostridium and Ruminococcaceae are microorganisms that directly produce caproic acid. The increase of their relative abundance in the FPM might have improved the quality of strong-aroma Baijiu. Syntrophomonas, Methanobacterium, and Methanocorpusculum might also be beneficial to caproic acid production. They are not directly involved but provide possible environmental factors for caproic acid production. Overall, our study results indicated that an uninterrupted use of the FP shapes the particular microbial community structure in the FPM. This research provides scientific support for the concept that the aged FP yields a high-quality Baijiu.


2021 ◽  
Vol 36 (1) ◽  
pp. n/a
Author(s):  
Mariia Pavlovska ◽  
Ievgeniia Prekrasna ◽  
Ivan Parnikoza ◽  
Evgen Dykyi

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.


Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Sahra J. Webb ◽  
Tia Rabsatt ◽  
Natalia Erazo ◽  
Jeff S. Bowman

Marine eelgrasses are influential to their surrounding environments through their many ecosystem services, ranging from the provisioning of food and shelter for marine life to serving as a natural defense against pollution and pathogenic bacteria. In the marine waters of San Diego, CA, USA, eelgrass beds comprised of Zostera spp. are an integral part of the coastal ecosystem. To evaluate the impact of eelgrass on bacterial and archaeal community structure we collected water samples in San Diego Bay and sequenced the 16S rRNA gene from paired eelgrass-present and eelgrass-absent sites. To test the hypothesis that microbial community structure is influenced by the presence of eelgrass we applied mixed effects models to these data and to bacterial abundance data derived by flow cytometry. This approach allowed us to identify specific microbial taxa that were differentially present at eelgrass-present and eelgrass-absent sites. Principal coordinate analysis organized the samples by location (inner vs. outer bay) along the first axis, where the first two axes accounted for a 90.8% of the variance in microbial community structure among the samples. Differentially present bacterial taxa included members of the order Rickettsiales, family Flavobacteriaceae, genus Tenacibaculum and members of the order Pseudomonadales. These findings constitute a unique look into the microbial composition of San Diego Bay and examine how eelgrasses contribute to marine ecosystem health, e.g., by supporting specific microbial communities and by filtering and trapping potentially harmful bacteria to the benefit of marine organisms.


2017 ◽  
Vol 6 (4) ◽  
pp. e00453 ◽  
Author(s):  
Sylwia Zielińska ◽  
Piotr Radkowski ◽  
Aleksandra Blendowska ◽  
Agnieszka Ludwig-Gałęzowska ◽  
Joanna M. Łoś ◽  
...  

2014 ◽  
Author(s):  
Catherine A Pfister ◽  
Jack A Gilbert ◽  
Sean M Gibbons

Rocky shore microbial diversity presents an excellent system to test for microbial habitat specificity or generality, enabling us to decipher how common macrobiota shape microbial community structure. At two coastal locations in the northeast Pacific Ocean, we show that microbial composition was significantly different between inert surfaces, the biogenic surfaces that included rocky shore animals and an alga, and the water column plankton. While all sampled entities had a core of common OTUs, rare OTUs drove differences among biotic and abiotic substrates. For the mussel Mytilus californianus, the shell surface harbored greater alpha diversity compared to internal tissues of the gill and siphon. Strikingly, a 7-year experimental removal of this mussel from tidepools did not significantly alter the microbial community structure of microbes associated with inert surfaces when compared with unmanipulated tidepools. However, bacterial taxa associated with nitrate reduction had greater relative abundance with mussels present, suggesting an impact of increased animal-derived nitrogen on a subset of microbial metabolism. Because the presence of mussels did not affect the structure and diversity of the microbial community on adjacent inert substrates, microbes in this rocky shore environment may be predominantly affected through direct physical association with macrobiota.


Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 183 ◽  
Author(s):  
I.-Shuo Huang ◽  
Lee J. Pinnell ◽  
Jeffrey W. Turner ◽  
Hussain Abdulla ◽  
Lauren Boyd ◽  
...  

Aside from two samples collected nearly 50 years ago, little is known about the microbial composition of wind tidal flats in the hypersaline Laguna Madre, Texas. These mats account for ~42% of the lagoon’s area. These microbial communities were sampled at four locations that historically had mats in the Laguna Madre, including Laguna Madre Field Station (LMFS), Nighthawk Bay (NH), and two locations in Kenedy Ranch (KRN and KRS). Amplicon sequencing of 16S genes determined the presence of 51 prokaryotic phyla dominated by Bacteroidota, Chloroflexi, Cyanobacteria, Desulfobacteria, Firmicutes, Halobacteria, and Proteobacteria. The microbial community structure of NH and KR is significantly different to LMFS, in which Bacteroidota and Proteobacteria were most abundant. Twenty-three cyanobacterial taxa were identified via genomic analysis, whereas 45 cyanobacterial taxa were identified using morphological analysis, containing large filamentous forms on the surface, and smaller, motile filamentous and coccoid forms in subsurface mat layers. Sample sites were dominated by species in Oscillatoriaceae (i.e., Lyngbya) and Coleofasciculaceae (i.e., Coleofasciculus). Most cyanobacterial sequences (~35%) could not be assigned to any established taxa at the family/genus level, given the limited knowledge of hypersaline cyanobacteria. A total of 73 cyanobacterial bioactive metabolites were identified using ultra performance liquid chromatography-Orbitrap MS analysis from these commu nities. Laguna Madre seems unique compared to other sabkhas in terms of its microbiology.


2021 ◽  
Author(s):  
Xin ZHANG ◽  
Ge-Er QING ◽  
Ju-Lin GAO ◽  
Xiao-Fang YU ◽  
Shu-Ping HU ◽  
...  

Abstract To systematically analyze the succession of functional microbiota that plays an important role during culture of microbial consortia M44 and its relationship with straw degradation characteristics, we determined the straw degradation ratio and activities of cellulose, hemicellulose, lignin enzyme, and VFA content of M44 in different culture periods. We also used 16S rRNA gene sequencing to analyze the change in microbial community structure in M44 and explore the differences in microbial composition in the original sample. The results showed that at 15 ℃ for 21 days, the straw degradation rate, endoglucanase activity, and filter paper enzyme activity of M44 generally decreased with increasing culture age, reaching their highest values at F1. The activities of xylanase, laccase, and lignin peroxidase, as well as VFA content, were the highest at F5, showing a single-peak curve change with first an increase and then decrease. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes were dominant in the original samples and in different culture stages. At the genus level, Devosia and Bacillus were dominant in the original sample. During subculture, the dominant bacteria in the first generation (F1) were Pseudomonas, Flavobacterium, Brevundimonas, Achromobacter, Chryseobacterium, and Devosia. The dominant genera in the last generation (F11) were Trichococcus, Acinetobacter, Dyssgonomonas, and Rhizobium. In conclusion, we identified changes in microbial community structure occurring in M44 during subculture, as well as similarities and differences in microbial communities from the original sample.


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