Effect of sulfadiazine and trimethoprim on activated sludge performance and microbial community dynamics in laboratory-scale membrane bioreactors and sequencing batch reactors at 8°C

2018 ◽  
Vol 35 (1) ◽  
pp. e2708 ◽  
Author(s):  
Antonina Kruglova ◽  
Anna Mikola ◽  
Alejandro Gonzalez-Martinez ◽  
Riku Vahala
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Community Dynamics ◽  
Membrane Bioreactors ◽  
Laboratory Scale ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Microbial Community Dynamics

scholarly journals Seasonal Dynamics of the Activated Sludge Microbiome in Sequencing Batch Reactors, Assessed Using 16S rRNA Transcript Amplicon Sequencing

2020 ◽  
Vol 86 (19) ◽  
Author(s):  
Juliet Johnston ◽  
Sebastian Behrens
Keyword(s):  
Wastewater Treatment ◽  
Microbial Community ◽  
16S Rrna ◽  
Activated Sludge ◽  
Seasonal Dynamics ◽  
Activity Patterns ◽  
Amplicon Sequencing ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Copy Numbers

ABSTRACT Activated sludge is comprised of diverse microorganisms which remediate wastewater. Previous research has characterized activated sludge using 16S rRNA gene amplicon sequencing, which can help to address questions on the relative abundance of microorganisms. In this study, we used 16S rRNA transcript sequencing in order to characterize “active” populations (via protein synthesis potential) and gain a deeper understanding of microbial activity patterns within activated sludge. Seasonal abundances of individual populations in activated sludge change over time, yet a persistent group of core microorganisms remains throughout the year which are traditionally classified on presence or absence without monitoring of their activity or growth. The goal of this study was to further our understanding of how the activated sludge microbiome changes between seasons with respect to population abundance, activity, and growth. Triplicate sequencing batch reactors were sampled at 10-min intervals throughout reaction cycles during all four seasons. We quantified the gene and transcript copy numbers of 16S rRNA amplicons using real-time PCR and sequenced the products to reveal community abundance and activity changes. We identified 108 operational taxonomic units (OTUs) with stable abundance, activity, and growth throughout the year. Nonproliferating OTUs were commonly human health related, while OTUs that showed seasonal abundance changes have previously been identified as being associated with floc formation and bulking. We observed significant differences in 16S rRNA transcript copy numbers, particularly at lower temperatures in winter and spring. The study provides an analysis of the seasonal dynamics of microbial activity variations in activated sludge based on quantifying and sequencing 16S rRNA transcripts. IMPORTANCE Sequencing batch reactors are a common design for wastewater treatment plants, particularly in smaller municipalities, due to their low footprint and ease of operations. However, like for most treatment plants in temperate/continental climates, the microbial community involved in water treatment is highly seasonal and its biological processes can be sensitive to cold temperatures. The seasonality of these microbial communities has been explored primarily in conventional treatment plants and not in sequencing batch reactors. Furthermore, most studies often only address which organisms are present. However, the activated sludge microbial community is very diverse, and it is often hard to discern which organisms are active and which organisms are simply present. In this study, we applied additional sequencing techniques to also address the issues of which organisms are active and which organisms are growing. By addressing these issues, we gained new insights into seasonal microbial populations dynamics and activity patterns affecting wastewater treatment.

scholarly journals Microbial community dynamics during aerobic granulation in a sequencing batch reactor (SBR)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7152
Author(s):  
Fabiola Gómez-Basurto ◽  
Miguel Vital-Jácome ◽  
Elizabeth Selene Gómez-Acata ◽  
Frederic Thalasso ◽  
Marco Luna-Guido ◽  
...  
Keyword(s):  
Microbial Community ◽  
Relative Abundance ◽  
Community Dynamics ◽  
Batch Reactor ◽  
Rrna Gene ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
Reactor Operation ◽  
Granule Formation ◽  
Microbial Community Dynamics

Microorganisms in aerobic granules formed in sequencing batch reactors (SBR) remove contaminants, such as xenobiotics or dyes, from wastewater. The granules, however, are not stable over time, decreasing the removal of the pollutant. A better understanding of the granule formation and the dynamics of the microorganisms involved will help to optimize the removal of contaminants from wastewater in a SBR. Sequencing the 16S rRNA gene and internal transcribed spacer PCR amplicons revealed that during the acclimation phase the relative abundance of Acinetobacter reached 70.8%. At the start of the granulation phase the relative abundance of Agrobacterium reached 35.9% and that of Dipodascus 89.7% during the mature granule phase. Fluffy granules were detected on day 43. The granules with filamentous overgrowth were not stable and they lysed on day 46 resulting in biomass wash-out. It was found that the reactor operation strategy resulted in stable aerobic granules for 46 days. As the reactor operations remained the same from the mature granule phase to the end of the experiment, the disintegration of the granules after day 46 was due to changes in the microbial community structure and not by the reactor operation.

scholarly journals Microbial community similarity and dissimilarity inside and across full-scale activated sludge processes for simultaneous nitrification and denitrification

2020 ◽  
Vol 81 (2) ◽  
pp. 333-344
Author(s):  
Jianfeng Wen ◽  
Mark W. LeChevallier ◽  
Wendong Tao
Keyword(s):  
Microbial Community ◽  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Relative Abundance ◽  
Nitrogen Removal ◽  
Full Scale ◽  
Batch Reactors ◽  
Simultaneous Nitrification And Denitrification ◽  
Sequencing Batch Reactors ◽  
Mixed Liquor

Abstract Simultaneous nitrification and denitrification under low dissolved oxygen conditions is an energy-saving modification of the activated sludge process to achieve efficient nitrogen removal. Geographically distinct full-scale treatment plants are excellent platforms to address the links of microbial community with operating parameters. Mixed liquor samples were collected from a sequencing batch reactor plant, oxidation ditch plant, and step-feed activated sludge plant. Next-Generation Sequencing of the samples showed that the microbial communities were similar at the phylum level among the plants, being dominated by Proteobacteria. Microbial composition of functional groups was similar between the react fill and react phases of the sequencing batch reactors, among four sequencing batch reactors, and among four oxidation ditches. Nitrospira was the only identified genus of autotropic nitrifying bacteria with a relative abundance of 2.2–2.5% in the oxidation ditches and 0.4–0.7% at the other plants. Heterotrophic nitrifying–aerobic denitrifying bacteria were dominated by Dechloromonas with a relative abundance of 0.4–1.0%. Microbial community composition and nitrogen removal mechanisms were related to overall level and local zonation of dissolved oxygen, mixed liquor suspended solids concentration, nitrogen and organic loadings, and solids retention time. Low dissolved oxygen and low organic and nitrogen loadings favored growth of Nitrospira.

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