scholarly journals Bacterial Diversity and Sulfur Cycling in a Mesophilic Sulfide-Rich Spring

2003 ◽  
Vol 69 (9) ◽  
pp. 5609-5621 ◽  
Author(s):  
Mostafa S. Elshahed ◽  
John M. Senko ◽  
Fares Z. Najar ◽  
Stephen M. Kenton ◽  
Bruce A. Roe ◽  
...  

ABSTRACT An artesian sulfide- and sulfur-rich spring in southwestern Oklahoma is shown to sustain an extremely rich and diverse microbial community. Laboratory incubations and autoradiography studies indicated that active sulfur cycling is occurring in the abundant microbial mats at Zodletone spring. Anoxygenic phototrophic bacteria oxidize sulfide to sulfate, which is reduced by sulfate-reducing bacterial populations. The microbial community at Zodletone spring was analyzed by cloning and sequencing 16S rRNA genes. A large fraction (83%) of the microbial mat clones belong to sulfur- and sulfate-reducing lineages within δ-Proteobacteria, purple sulfur γ-Proteobacteria, ε-Proteobacteria, Chloroflexi, and filamentous Cyanobacteria of the order Oscillatoria as well as a novel group within γ-Proteobacteria. The 16S clone library constructed from hydrocarbon-exposed sediments at the source of the spring had a higher diversity than the mat clone library (Shannon-Weiner index of 3.84 compared to 2.95 for the mat), with a higher percentage of clones belonging to nonphototrophic lineages (e.g., Cytophaga, Spirochaetes, Planctomycetes, Firmicutes, and Verrucomicrobiae). Many of these clones were closely related to clones retrieved from hydrocarbon-contaminated environments and anaerobic hydrocarbon-degrading enrichments. In addition, 18 of the source clones did not cluster with any of the previously described microbial divisions. These 18 clones, together with previously published or database-deposited related sequences retrieved from a wide variety of environments, could be clustered into at least four novel candidate divisions. The sulfate-reducing community at Zodletone spring was characterized by cloning and sequencing a 1.9-kb fragment of the dissimilatory sulfite reductase (DSR) gene. DSR clones belonged to the Desulfococcus-Desulfosarcina-Desulfonema group, Desulfobacter group, and Desulfovibrio group as well as to a deeply branched group in the DSR tree with no representatives from cultures. Overall, this work expands the division-level diversity of the bacterial domain and highlights the complexity of microbial communities involved in sulfur cycling in mesophilic microbial mats.

2011 ◽  
Vol 77 (19) ◽  
pp. 6908-6917 ◽  
Author(s):  
Hyung Soo Park ◽  
Indranil Chatterjee ◽  
Xiaoli Dong ◽  
Sheng-Hung Wang ◽  
Christoph W. Sensen ◽  
...  

ABSTRACTPipelines transporting brackish subsurface water, used in the production of bitumen by steam-assisted gravity drainage, are subject to frequent corrosion failures despite the addition of the oxygen scavenger sodium bisulfite (SBS). Pyrosequencing of 16S rRNA genes was used to determine the microbial community composition for planktonic samples of transported water and for sessile samples of pipe-associated solids (PAS) scraped from pipeline cutouts representing corrosion failures. These were obtained from upstream (PAS-616P) and downstream (PAS-821TP and PAS-821LP, collected under rapid-flow and stagnant conditions, respectively) of the SBS injection point. Most transported water samples had a large fraction (1.8% to 97% of pyrosequencing reads) ofPseudomonasnot found in sessile pipe samples. The sessile population of PAS-616P had methanogens (Methanobacteriaceae) as the main (56%) community component, whereasDeltaproteobacteriaof the generaDesulfomicrobiumandDesulfocapsawere not detected. In contrast, PAS-821TP and PAS-821LP had lower fractions (41% and 0.6%) ofMethanobacteriaceaearchaea but increased fractions of sulfate-reducingDesulfomicrobium(18% and 48%) and of bisulfite-disproportionatingDesulfocapsa(35% and 22%) bacteria. Hence, SBS injection strongly changed the sessile microbial community populations. X-ray diffraction analysis of pipeline scale indicated that iron carbonate was present both upstream and downstream, whereas iron sulfide and sulfur were found only downstream of the SBS injection point, suggesting a contribution of the bisulfite-disproportionating and sulfate-reducing bacteria in the scale to iron corrosion. Incubation of iron coupons with pipeline waters indicated iron corrosion coupled to the formation of methane. Hence, both methanogenic and sulfidogenic microbial communities contributed to corrosion of pipelines transporting these brackish waters.


2009 ◽  
Vol 71-73 ◽  
pp. 67-70 ◽  
Author(s):  
Inez J.T. Dinkla ◽  
Mariekie Gericke ◽  
B.K. Geurkink ◽  
Kevin B. Hallberg

Bioleaching test work was performed in continuously operated multi-stage reactor systems at 70°C using a thermophilic culture treating an Aguablanca Ni-Cu concentrate from Spain and a blend of Cu concentrates from Bor, Serbia. The copper in both these concentrates occurs as chalcopyrite and therefore the use of thermophiles was applied, which resulted in copper recoveries of over 95%. Qualitative assessment of the microbial community in the bioreactors was performed by terminal restriction enzyme fragment length polymorphism (T-RFLP) and clone library analysis of the 16S rRNA genes amplified by PCR. T-RFLP analysis revealed that only archaea were present, and that the communities in both the Aguablanca and Bor systems consisted of two different microorganisms. A 16S rRNA gene clone library using DNA from the Aguablanca system was constructed and screened. Again, two archaea were detected in similar relative abundance in the population as found by T-RFLP analyses. The sequences of these two cloned genes revealed that the dominant archaeon (up to 98% of the total archaea detected) was Acidianus brierleyi, and the other was Metallosphaera sedula. Quantitative assessment of the microbial community was performed by Q-PCR and confirmed the dominance of archaea in the system with Acidianus being the dominant strain (98-99% of the total population) and a minor part of the population (1-2%) consisted of Metallosphaera. Additionally, very small amounts of Sulfolobus spp. were detected. This study, along with other recent studies on the diversity of thermoacidophiles involved in the solubilization of copper from chalcopyrite concentrates, revealed that a wider variety of thermoacidophiles are involved in bioprocessing of metal sulfides, and showed that A. brierleyi should be considered an important biomining acidophile.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Benjamin J. Callahan ◽  
Dmitry Grinevich ◽  
Siddhartha Thakur ◽  
Michael A. Balamotis ◽  
Tuval Ben Yehezkel

Abstract Background Out of the many pathogenic bacterial species that are known, only a fraction are readily identifiable directly from a complex microbial community using standard next generation DNA sequencing. Long-read sequencing offers the potential to identify a wider range of species and to differentiate between strains within a species, but attaining sufficient accuracy in complex metagenomes remains a challenge. Methods Here, we describe and analytically validate LoopSeq, a commercially available synthetic long-read (SLR) sequencing technology that generates highly accurate long reads from standard short reads. Results LoopSeq reads are sufficiently long and accurate to identify microbial genes and species directly from complex samples. LoopSeq perfectly recovered the full diversity of 16S rRNA genes from known strains in a synthetic microbial community. Full-length LoopSeq reads had a per-base error rate of 0.005%, which exceeds the accuracy reported for other long-read sequencing technologies. 18S-ITS and genomic sequencing of fungal and bacterial isolates confirmed that LoopSeq sequencing maintains that accuracy for reads up to 6 kb in length. LoopSeq full-length 16S rRNA reads could accurately classify organisms down to the species level in rinsate from retail meat samples, and could differentiate strains within species identified by the CDC as potential foodborne pathogens. Conclusions The order-of-magnitude improvement in length and accuracy over standard Illumina amplicon sequencing achieved with LoopSeq enables accurate species-level and strain identification from complex- to low-biomass microbiome samples. The ability to generate accurate and long microbiome sequencing reads using standard short read sequencers will accelerate the building of quality microbial sequence databases and removes a significant hurdle on the path to precision microbial genomics.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 865
Author(s):  
Lantian Su ◽  
Xinxin Liu ◽  
Guangyao Jin ◽  
Yue Ma ◽  
Haoxin Tan ◽  
...  

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions.


2009 ◽  
Vol 75 (12) ◽  
pp. 4139-4148 ◽  
Author(s):  
James P. Davis ◽  
Noha H. Youssef ◽  
Mostafa S. Elshahed

ABSTRACT We used a combination of 16S rRNA gene clone library surveys, quantitative PCR (qPCR) analysis, and fluorescent in situ hybridization to investigate the diversity, abundance, and distribution of members of candidate division SR1 in multiple habitats. Using SR1-specific 16S rRNA gene primers, we identified multiple novel SR1 lineages in four different anaerobic environments: sediments from Zodletone Spring, a sulfide- and sulfur-rich spring in southwestern Oklahoma; inner layers of microbial mats obtained from Sperm Pool, a high-temperature, low-pH pool (55°C, pH 2.5) in Yellowstone National Park; fresh bovine ruminal contents; and anaerobic freshwater pond sediments (Duck Pond) in Norman, Oklahoma. qPCR analysis indicated that SR1 members constitute a small fraction (<0.01%) of the microbial communities in Duck Pond and ruminal samples but constitute a significant fraction (11.6 and 48.7%) of the total number of bacterial 16S rRNA genes in Zodletone Spring and the inner layers of Sperm Pool microbial mat samples, respectively. By using SR1-specific fluorescent probes, filamentous cells were identified as the sole SR1 morphotype in all environments examined, with the exception of Sperm Pool, where a second bacillus morphotype was also identified. Using a full-cycle 16S rRNA approach, we show that each of these two morphotypes corresponds to a specific phylogenetic lineage identified in the Sperm Pool clone library. This work greatly expands the intralineage phylogenetic diversity within candidate division SR1 and provides valuable quantification and visualization tools that could be used for investigating the ecological roles, dynamics, and genomics of this as-yet-uncultured bacterial phylum.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hongmei Yan ◽  
Fan Yang ◽  
Jiamin Gao ◽  
Ziheng Peng ◽  
Weimin Chen

AbstractAnthropogenic disturbance, such as agricultural and architectural activities, can greatly influence belowground soil microbes, and thus soil formation and nutrient cycling. The objective of this study was to investigate microbial community variation in deep soils affected by strong disturbances. In present study, twelve soil samples were collected from different depths (0–300 cm) and placed onto the surface. We investigated the structure variation of the microbial community down through the soil profiles in response to disturbance originated by legume plants (robinia and clover) cultivation vs. plant-free controls. The high-throughput sequencing of 16S rRNA genes showed that microbial α-diversity decreased with depth, and that growing both plants significantly impacted the diversity in the topsoil. The soil profile was clustered into three layers: I (0–40 cm), II (40–120 cm), and III (120–300 cm); with significantly different taxa found among them. Soil properties explained a large amount of the variation (23.5%) in the microbial community, and distinct factors affected microbial assembly in the different layers, e.g., available potassium in layer I, pH and total nitrogen in layer II, pH and organic matter in layer III. The prediction of metabolic functions and oxygen requirements indicated that the number of aerobic bacteria increased with more air exposure, which may further accelerate the transformation of nitrogen, sulfur, carbon, and pesticides in the soil. The diversity of soil microorganisms followed a depth-decay pattern, but became higher following legume growth and air exposure, with notable abundance variation of several important bacterial species, mainly belonging to Nitrospira, Verrucomicrobia, and Planctomycetes, and soil properties occurring across the soil profiles.


2021 ◽  
Author(s):  
Juliana Correa Neiva Ferreira ◽  
Natascha M. Bergo ◽  
Pedro M. Tura ◽  
Mateus Gustavo Chuqui ◽  
Frederico P. Brandini ◽  
...  

AbstractMarine microbes control the flux of matter and energy essential for life in the oceans. Until now, the distribution and diversity of planktonic microorganisms above Fe-Mn crusts has received relatively little attention. Future mining\dredging of these minerals is predicted to affect microbial diversity and functioning in the deep sea. Here, we studied the ecology of planktonic microbes among pelagic environments of an Fe-Mn deposit region, at Rio Grande Rise, Southwestern Atlantic Ocean. We investigated microbial community composition using high-throughput sequencing of 16S rRNA genes and their abundance estimated by flow cytometry. Our results showed that the majority of picoplanktonic was found in epi- and mesopelagic waters, corresponding to the Tropical Water and South Atlantic Central Water. Bacterial and archaeal groups related to phototrophy, heterotrophy and chemosynthesis, such as Synechococcales, Sar11 (Proteobacteria) and Nitrosopumilales (Thaumarchaeota) were the main representatives of the pelagic microbial community. Additionally, we detected abundant assemblages involved in biodegradation of marine organic matter and iron oxidation at deep waters, i.e., Pseudoalteromonas and Alteromonas. No differences were observed in microbial community alpha diversity. However, we detected differences in community structure between water masses, suggesting that changes in an environmental setting (i.e. nutrient availability or circulation) play a significant role in structuring the pelagic zones, also affecting the meso- and bathypelagic microbiome.HighlightsRio Grande Rise pelagic microbiomePicoplankton carbon biomass partitioning through pelagic zonesUnique SAR11 Clade I oligotype in the shallowest Tropical WaterHigher number of shared oligotypes between deepest water massesNitrogen, carbon and sulfur may be important contributors for the pelagic microbiome


Author(s):  
Richard Kevorkian ◽  
Sean Callahan ◽  
Rachel Winstead ◽  
Karen G. Lloyd

AbstractUncultured members of the Methanomicrobia called ANME-1 perform the anaerobic oxidation of methane (AOM) through a process that uses much of the methanogenic pathway. It is unknown whether ANME-1 obligately perform AOM, or whether some of them can perform methanogenesis when methanogenesis is exergonic. Most marine sediments lack advective transport of methane, so AOM occurs in the sulfate methane transition zone (SMTZ) where sulfate-reducing bacteria consume hydrogen produced by fermenters, making hydrogenotrophic methanogenesis exergonic in the reverse direction. When sulfate is depleted deeper in the sediments, hydrogen accumulates making hydrogenotrophic methanogenesis exergonic, and methane accumulates in the methane zone (MZ). In White Oak River estuarine sediments, we found that ANME-1 comprised 99.5% of 16S rRNA genes from amplicons and 100% of 16S rRNA genes from metagenomes of the Methanomicrobia in the SMTZ and 99.9% and 98.3%, respectively, in the MZ. Each of the 16 ANME-1 OTUs (97% similarity) had peaks in the SMTZ that coincided with peaks of putative sulfate-reducing bacteria Desulfatiglans sp. and SEEP-SRB1. In the MZ, ANME-1, but no putative sulfate-reducing bacteria or cultured methanogens, increased with depth. Using publicly available data, we found that ANME-1 was the only group expressing methanogenic genes during both net AOM and net methanogenesis in an enrichment. The commonly-held belief that ANME-1 perform AOM is based on the fact that they dominate natural settings and enrichments where net AOM is measured. We found that ANME-1 also dominate natural settings and enrichment where net methanogenesis is measured, so we conclude that ANME-1 perform methane production. Alternating between AOM and methanogenesis, either in a single ANME-1 cell or between different subclades with similar 16S rRNA sequences of ANME-1, may confer a competitive advantage, explaining the predominance of low-energy adapted ANME-1 in methanogenic sediments worldwide.Abstract ImportanceLife may operate differently at very low energy levels. Natural populations of microbes that make methane survive on some of the lowest energy yields of all life. From all available data, we infer that these microbes alternate between methane production and oxidation, depending on which process is energy-yielding in the environment. This means that much of the methane produced naturally in marine sediments occurs through an organism that is also capable of destroying it under different circumstances.


2009 ◽  
Vol 75 (20) ◽  
pp. 6471-6477 ◽  
Author(s):  
Ondrej Uhlik ◽  
Katerina Jecna ◽  
Martina Mackova ◽  
Cestmir Vlcek ◽  
Miluse Hroudova ◽  
...  

ABSTRACT DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [13C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase α subunits (BphA) from bacteria that incorporated [13C]into DNA in 3-day incubations of the soils with [13C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl.


2004 ◽  
Vol 70 (11) ◽  
pp. 6767-6775 ◽  
Author(s):  
He-Long Jiang ◽  
Joo-Hwa Tay ◽  
Abdul Majid Maszenan ◽  
Stephen Tiong-Lee Tay

ABSTRACT Aerobic granules are self-immobilized aggregates of microorganisms and represent a relatively new form of cell immobilization developed for biological wastewater treatment. In this study, both culture-based and culture-independent techniques were used to investigate the bacterial diversity and function in aerobic phenol- degrading granules cultivated in a sequencing batch reactor. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes demonstrated a major shift in the microbial community as the seed sludge developed into granules. Culture isolation and DGGE assays confirmed the dominance of β-Proteobacteria and high-G+C gram-positive bacteria in the phenol-degrading aerobic granules. Of the 10 phenol-degrading bacterial strains isolated from the granules, strains PG-01, PG-02, and PG-08 possessed 16S rRNA gene sequences that matched the partial sequences of dominant bands in the DGGE fingerprint belonging to the aerobic granules. The numerical dominance of strain PG-01 was confirmed by isolation, DGGE, and in situ hybridization with a strain-specific probe, and key physiological traits possessed by PG-01 that allowed it to outcompete and dominate other microorganisms within the granules were then identified. This strain could be regarded as a functionally dominant strain and may have contributed significantly to phenol degradation in the granules. On the other hand, strain PG-08 had low specific growth rate and low phenol degradation ability but showed a high propensity to autoaggregate. By analyzing the roles played by these two isolates within the aerobic granules, a functional model of the microbial community within the aerobic granules was proposed. This model has important implications for rationalizing the engineering of ecological systems.


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