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 ‘Nitrification kinetics and microbial community dynamics of attached biofilm in wastewater treatment’

2020 ◽  
Vol 81 (5) ◽  
pp. 891-905
Author(s):  
Adam Skoyles ◽  
Subba Rao Chaganti ◽  
Scott O. C. Mundle ◽  
Chris G. Weisener
Keyword(s):  
Microbial Community ◽  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Community Dynamics ◽  
Isotope Analysis ◽  
Ammonia Removal ◽  
Nitrifying Bacteria ◽  
Rrna Gene ◽  
Bench Scale ◽  
Microbial Community Dynamics

Abstract A comparative bench-scale and field site analysis of BioCord was conducted to investigate seasonal microbial community dynamics and its impact on nitrogen removal in wastewater. This was assessed using metabolite (NO3−) stable isotope analysis, high-throughput sequencing of the 16S rRNA gene, and RT-qPCR of key genes in biological treatment representing nitrification, anammox, and denitrification. Bench-scale experiments showed an increase in nitrifiers with increasing ammonia loading resulting in an ammonia removal efficiency up to 98 ± 0.14%. Stable isotope analysis showed that 15ɛ and δ18ONO3 could be used in monitoring the efficiency of the enhanced biological nitrification. In the lagoon field trials, an increase in total nitrogen promoted three principle nitrifying genera (Nitrosomonas, Nitrospira, Candidatus Nitrotoga) and enhanced the expression of denitrification genes (nirK, norB, and nosZ). Further, anaerobic ammonia oxidizers were active within BioCord biofilm. Even at lower temperatures (2–6°C) the nitrifying bacteria remained active on the BioCord.

scholarly journals Ibuprofen Degradation and Associated Bacterial Communities in Hyporheic Zone Sediments

2020 ◽  
Vol 8 (8) ◽  
pp. 1245
Author(s):  
Cyrus Rutere ◽  
Kirsten Knoop ◽  
Malte Posselt ◽  
Adrian Ho ◽  
Marcus A. Horn
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Hyporheic Zone ◽  
Community Dynamics ◽  
Environmental Concern ◽  
Transformation Products ◽  
Pollutant Removal ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Microbial Community Dynamics

Ibuprofen, a non-steroidal anti-inflammatory pain reliever, is among pharmaceutical residues of environmental concern ubiquitously detected in wastewater effluents and receiving rivers. Thus, ibuprofen removal potentials and associated bacteria in the hyporheic zone sediments of an impacted river were investigated. Microbially mediated ibuprofen degradation was determined in oxic sediment microcosms amended with ibuprofen (5, 40, 200, and 400 µM), or ibuprofen and acetate, relative to an un-amended control. Ibuprofen was removed by the original sediment microbial community as well as in ibuprofen-enrichments obtained by re-feeding of ibuprofen. Here, 1-, 2-, 3-hydroxy- and carboxy-ibuprofen were the primary transformation products. Quantitative real-time PCR analysis revealed a significantly higher 16S rRNA abundance in ibuprofen-amended relative to un-amended incubations. Time-resolved microbial community dynamics evaluated by 16S rRNA gene and 16S rRNA analyses revealed many new ibuprofen responsive taxa of the Acidobacteria, Actinobacteria, Bacteroidetes, Gemmatimonadetes, Latescibacteria, and Proteobacteria. Two ibuprofen-degrading strains belonging to the genera Novosphingobium and Pseudomonas were isolated from the ibuprofen-enriched sediments, consuming 400 and 300 µM ibuprofen within three and eight days, respectively. The collective results indicated that the hyporheic zone sediments sustain an efficient biotic (micro-)pollutant degradation potential, and hitherto unknown microbial diversity associated with such (micro)pollutant removal.

scholarly journals Microbial community dynamics based on 16S rRNA gene profiles in a Pacific Northwest estuary and its tributaries

2005 ◽  
Vol 52 (1) ◽  
pp. 115-128 ◽  
Author(s):  
Anne E. Bernhard ◽  
Debbie Colbert ◽  
James McManus ◽  
Katharine G. Field
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Pacific Northwest ◽  
Community Dynamics ◽  
Rrna Gene ◽  
Microbial Community Dynamics ◽  
Gene Profiles

scholarly journals 919. Understanding Intermittent Detection of Multidrug-Resistant Organisms (MDROs) in Rectally Colonized Patients

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S494-S494
Author(s):  
Sarah Sansom ◽  
Michael Y Lin ◽  
Michael Schoeny ◽  
Christine Fukuda ◽  
Christine Bassis ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Community Dynamics ◽  
Limit Of Detection ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Rrna Gene ◽  
Multilevel Regression ◽  
Microbial Community Dynamics ◽  
Culture Positivity ◽  
Phenotypic Methods

Abstract Background MDRO detection in colonized patients may be intermittent for reasons that are incompletely understood. We examined temporal patterns of gut MDRO colonization after initial MDRO detection by rectal swab screening, and determined the relationship of culture positivity to the relative abundance of corresponding MDRO operational taxonomic units (OTUs) identified by 16S rRNA gene sequence analysis. Methods Rectal or fecal swabs were collected daily from MICU patients 1/11/2017-1/11/2018. First MICU admissions with ≥2 swabs and MICU stays ≥3 days were studied. Samples were cultured for vancomycin-resistant enterococci (VRE), carbapenem-resistant Enterobacteriaceae (CRE) and P. aeruginosa (CRPA), and extended-spectrum β-lactamase-producing (ESBL) Enterobacteriaceae by selective media. Resistance mechanisms were confirmed by phenotypic methods and/or PCR. Limit of detection was similar for different MDROs (24-52 CFU/sample). OTU categories corresponding to MDRO species were identified by taxonomy and BLAST. Multilevel regression models estimated the association between MDRO detection and relative abundance of the corresponding OTU. Results 796 unique patients with 3519 swabs were studied. Median (IQR) age was 64 (51-74) years, MICU length of stay was 5 (3-8) days, and number of samples-per-patient was 3 (2-5). Following initial MDRO detection, the probability of subsequent detection varied by MDRO type, and was highest for VRE and lowest for CRPA [Figure 1]. Within each sample, we found a significant association between MDRO detection and relative abundance of the corresponding OTU [Table 1]. In contrast, relative OTU abundance in the first sample with MDRO detection was not predictive of odds of future MDRO detection (p >0.05 for all comparisons). Carriage of >1 MDRO did not affect the odds of MDRO detection in later samples. Figure 1. Probability of Subsequent MDRO Detection after First Positive Varies by MDRO Type Table 1. Higher Mean Corresponding OTU Relative Abundance Within Each Sample is Associated with MDRO Detection Conclusion MDRO culture positivity in rectally colonized patients was correlated with relative abundance of the corresponding OTU in the same sample. Serial detection of different MDRO types was variable, possibly due to distinct microbial community dynamics of different MDRO types. Intermittent failure to detect MDROs could result in misattribution of MDRO acquisition, resulting in inappropriate investigation or intervention. Disclosures All Authors: No reported disclosures

scholarly journals Strengths and Limitations of 16S rRNA Gene Amplicon Sequencing in Revealing Temporal Microbial Community Dynamics

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e93827 ◽  
Author(s):  
Rachel Poretsky ◽  
Luis M. Rodriguez-R ◽  
Chengwei Luo ◽  
Despina Tsementzi ◽  
Konstantinos T. Konstantinidis
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Community Dynamics ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Microbial Community Dynamics
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