scholarly journals Influence of deterministic and stochastic processes on microbial community assembly during aerobic granulation

2018 ◽  
Author(s):  
Raquel Liébana ◽  
Oskar Modin ◽  
Frank Persson ◽  
Enikö Szabó ◽  
Malte Hermansson ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Community Assembly ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Community Members ◽  
Treatment Performance ◽  
Biofilm Process ◽  
Microbial Community Assembly

ABSTRACTAerobic granular sludge is an energy efficient and compact biofilm process for wastewater treatment which has received much attention during the last decades and is now being implemented in full-scale. However, the factors involved in microbial community assembly during formation of granules are poorly understood and little is known about the reproducibility in treatment performance and community structure. Here we show that both deterministic and stochastic factors exert a dynamic influence during microbial community assembly into granular sludge. During granulation, the microbial communities in three replicate sequencing batch reactors followed similar successional trajectories of the most abundant taxa and showed similar dynamics in diversity. Deterministic factors dominated the assembly of the most abundant community members as the microbial community transitioned from floccular to granular form. Stochastic factors mostly affected rare members of the communities and caused the microbial community structure to diverge in one of the reactors; however, this did not have an impact on the treatment performance. This demonstrates that the reactor function and the dynamics of the most abundant community members are in fact reproducible during the formation of aerobic granules.

scholarly journals Emergent Simplicity in Microbial Community Assembly

2017 ◽  
Author(s):  
Joshua E. Goldford ◽  
Nanxi Lu ◽  
Djordje Bajic ◽  
Sylvie Estrela ◽  
Mikhail Tikhonov ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Community Assembly ◽  
Competitive Exclusion ◽  
Ex Situ ◽  
Coarse Grained ◽  
Natural Environments ◽  
Complex Dynamic ◽  
Microbial Community Assembly ◽  
Consumer Resource

AbstractMicrobes assemble into complex, dynamic, and species-rich communities that play critical roles in human health and in the environment. The complexity of natural environments and the large number of niches present in most habitats are often invoked to explain the maintenance of microbial diversity in the presence of competitive exclusion. Here we show that soil and plant-associated microbiota, cultivated ex situ in minimal synthetic environments with a single supplied source of carbon, universally re-assemble into large and dynamically stable communities with strikingly predictable coarse-grained taxonomic and functional compositions. We find that generic, non-specific metabolic cross-feeding leads to the assembly of dense facilitation networks that enable the coexistence of multiple competitors for the supplied carbon source. The inclusion of universal and non-specific cross-feeding in ecological consumer-resource models is sufficient to explain our observations, and predicts a simple determinism in community structure, a property reflected in our experiments.

scholarly journals Deterministic processes dominate soil microbial community assembly in subalpine coniferous forests on the Loess Plateau

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6746 ◽  
Author(s):  
Pengyu Zhao ◽  
Jiabing Bao ◽  
Xue Wang ◽  
Yi Liu ◽  
Cui Li ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Community Assembly ◽  
Soil Microbial Community ◽  
Coniferous Forests ◽  
The Loess Plateau ◽  
Soil Microbial ◽  
Deterministic Processes ◽  
Microbial Community Assembly

Microbial community assembly is influenced by a continuum (actually the trade-off) between deterministic and stochastic processes. An understanding of this ecological continuum is of great significance for drawing inferences about the effects of community assembly processes on microbial community structure and function. Here, we investigated the driving forces of soil microbial community assembly in three different environmental contexts located on subalpine coniferous forests of the Loess Plateau in Shanxi, China. The variation in null deviations and phylogenetic analysis showed that a continuum existed between deterministic and stochastic processes in shaping the microbial community structure, but deterministic processes prevailed. By integrating the results of redundancy analysis (RDA), multiple regression tree (MRT) analysis and correlation analysis, we found that soil organic carbon (SOC) was the main driver of the community structure and diversity patterns. In addition, we also found that SOC had a great influence on the community assembly processes. In conclusion, our results show that deterministic processes always dominated assembly processes in shaping bacterial community structure along the three habitat contexts.

scholarly journals Effect of Elevated Salt Concentrations on the Aerobic Granular Sludge Process: Linking Microbial Activity with Microbial Community Structure

2011 ◽  
Vol 77 (22) ◽  
pp. 7942-7953 ◽  
Author(s):  
J. P. Bassin ◽  
M. Pronk ◽  
G. Muyzer ◽  
R. Kleerebezem ◽  
M. Dezotti ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Phosphorus Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Granular Sludge ◽  
Phosphate Removal ◽  
Aerobic Granular Sludge ◽  
Nitrogen And Phosphorus ◽  
Content Type

ABSTRACTThe long- and short-term effects of salt on biological nitrogen and phosphorus removal processes were studied in an aerobic granular sludge reactor. The microbial community structure was investigated by PCR-denaturing gradient gel electrophoresis (DGGE) on 16S rRNA andamoAgenes. PCR products obtained from genomic DNA and from rRNA after reverse transcription were compared to determine the presence of bacteria as well as the metabolically active fraction of bacteria. Fluorescencein situhybridization (FISH) was used to validate the PCR-based results and to quantify the dominant bacterial populations. The results demonstrated that ammonium removal efficiency was not affected by salt concentrations up to 33 g/liter NaCl. Conversely, a high accumulation of nitrite was observed above 22 g/liter NaCl, which coincided with the disappearance ofNitrospirasp. Phosphorus removal was severely affected by gradual salt increase. No P release or uptake was observed at steady-state operation at 33 g/liter NaCl, exactly when the polyphosphate-accumulating organisms (PAOs), “CandidatusAccumulibacter phosphatis” bacteria, were no longer detected by PCR-DGGE or FISH. Batch experiments confirmed that P removal still could occur at 30 g/liter NaCl, but the long exposure of the biomass to this salinity level was detrimental for PAOs, which were outcompeted by glycogen-accumulating organisms (GAOs) in the bioreactor. GAOs became the dominant microorganisms at increasing salt concentrations, especially at 33 g/liter NaCl. In the comparative analysis of the diversity (DNA-derived pattern) and the activity (cDNA-derived pattern) of the microbial population, the highly metabolically active microorganisms were observed to be those related to ammonia (Nitrosomonassp.) and phosphate removal (“CandidatusAccumulibacter”).

Pollutants degradation performance and microbial community structure of aerobic granular sludge systems using inoculums adapted at mild and low temperature

Chemosphere ◽  
2018 ◽  
Vol 204 ◽  
pp. 431-441 ◽  
Author(s):  
Barbara Muñoz-Palazon ◽  
Chiara Pesciaroli ◽  
Alejandro Rodriguez-Sanchez ◽  
Jesús Gonzalez-Lopez ◽  
Alejandro Gonzalez-Martinez
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Low Temperature ◽  
Microbial Community Structure ◽  
Granular Sludge ◽  
Aerobic Granular Sludge

Performance and microbial community structure of a polar Arctic Circle aerobic granular sludge system operating at low temperature

2018 ◽  
Vol 256 ◽  
pp. 22-29 ◽  
Author(s):  
Alejandro Gonzalez-Martinez ◽  
Barbara Muñoz-Palazon ◽  
Paula Maza-Márquez ◽  
Alejandro Rodriguez-Sanchez ◽  
Jesus Gonzalez-Lopez ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Low Temperature ◽  
Microbial Community Structure ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Arctic Circle ◽  
System Operating

scholarly journals Stochastic Community Assembly: Does It Matter in Microbial Ecology?

2017 ◽  
Vol 81 (4) ◽  
Author(s):  
Jizhong Zhou ◽  
Daliang Ning
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Ecology ◽  
Community Assembly ◽  
Community Diversity ◽  
Ecological Processes ◽  
Experimental Approaches ◽  
Deterministic Processes ◽  
Deterministic Components ◽  
Microbial Community Assembly

SUMMARY Understanding the mechanisms controlling community diversity, functions, succession, and biogeography is a central, but poorly understood, topic in ecology, particularly in microbial ecology. Although stochastic processes are believed to play nonnegligible roles in shaping community structure, their importance relative to deterministic processes is hotly debated. The importance of ecological stochasticity in shaping microbial community structure is far less appreciated. Some of the main reasons for such heavy debates are the difficulty in defining stochasticity and the diverse methods used for delineating stochasticity. Here, we provide a critical review and synthesis of data from the most recent studies on stochastic community assembly in microbial ecology. We then describe both stochastic and deterministic components embedded in various ecological processes, including selection, dispersal, diversification, and drift. We also describe different approaches for inferring stochasticity from observational diversity patterns and highlight experimental approaches for delineating ecological stochasticity in microbial communities. In addition, we highlight research challenges, gaps, and future directions for microbial community assembly research.

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