scholarly journals Effects of influent composition on biological activity, acclimation time and microbial community profile of activated sludge

2021 ◽  
pp. 44028-44034
Keyword(s):  
Biological Activity ◽  
Microbial Community ◽  
Activated Sludge ◽  
Oxygen Demand ◽  
P Value ◽  
Chemical Compositions ◽  
Significant Difference ◽  
Community Profile ◽  
Microbial Community Profile ◽  
Influent Wastewater

Background: The performance and stability of activated sludge (AS) processes are strongly related to influent wastewater characteristics. Objective: To investigate the influence of different chemical compositions of influent wastewater, in terms of source of carbon, on activated sludge. Methods: Response was measured in oxygen uptake rate (OUR), volatile suspended solids in the mixed liquor (MVLSS), chemical oxygen demand (COD), and microbial community profile, obtained using Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Results: Results showed that the microbial community profile obtained in both reactors is consistent with those reported for full-scale AS bioreactors treating sewage. However, when the source of carbon is less bioavailable (bioreactor 1), there was a statistically significant difference (p-value<0.05, 95% confidence) in the biological activity of the biomass, both in terms of MLVSS growth and OUR in comparison with the reactor with source of carbon more bioavailable (bioreactor 2). This difference also impacted the time required for complete acclimation: it could be considered completed in 15 days in bioreactor 2, whereas in bioreactor 1, acclimation required more than 120 days to be completed, as during this period there was no net biomass growth even though there was high COD removal.

scholarly journals Benchmarking laboratory processes to characterise low-biomass respiratory microbiota

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raiza Hasrat ◽  
Jolanda Kool ◽  
Wouter A. A. de Steenhuijsen Piters ◽  
Mei Ling J. N. Chu ◽  
Sjoerd Kuiling ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Positive Control ◽  
Rrna Gene ◽  
Elution Buffer ◽  
Community Profile ◽  
Microbial Community Profile ◽  
Microbial Dna ◽  
Pcr Conditions

AbstractThe low biomass of respiratory samples makes it difficult to accurately characterise the microbial community composition. PCR conditions and contaminating microbial DNA can alter the biological profile. The objective of this study was to benchmark the currently available laboratory protocols to accurately analyse the microbial community of low biomass samples. To study the effect of PCR conditions on the microbial community profile, we amplified the 16S rRNA gene of respiratory samples using various bacterial loads and different number of PCR cycles. Libraries were purified by gel electrophoresis or AMPure XP and sequenced by V2 or V3 MiSeq reagent kits by Illumina sequencing. The positive control was diluted in different solvents. PCR conditions had no significant influence on the microbial community profile of low biomass samples. Purification methods and MiSeq reagent kits provided nearly similar microbiota profiles (paired Bray–Curtis dissimilarity median: 0.03 and 0.05, respectively). While profiles of positive controls were significantly influenced by the type of dilution solvent, the theoretical profile of the Zymo mock was most accurately analysed when the Zymo mock was diluted in elution buffer (difference compared to the theoretical Zymo mock: 21.6% for elution buffer, 29.2% for Milli-Q, and 79.6% for DNA/RNA shield). Microbiota profiles of DNA blanks formed a distinct cluster compared to low biomass samples, demonstrating that low biomass samples can accurately be distinguished from DNA blanks. In summary, to accurately characterise the microbial community composition we recommend 1. amplification of the obtained microbial DNA with 30 PCR cycles, 2. purifying amplicon pools by two consecutive AMPure XP steps and 3. sequence the pooled amplicons by V3 MiSeq reagent kit. The benchmarked standardized laboratory workflow presented here ensures comparability of results within and between low biomass microbiome studies.

scholarly journals Evaluation of the accuracy of two simple methods for microscopic activated sludge analysis

2018 ◽  
Vol 78 (10) ◽  
pp. 2104-2112
Author(s):  
Mateusz Sobczyk ◽  
Agnieszka Pajdak-Stós ◽  
Edyta Fiałkowska ◽  
Wioleta Kocerba-Soroka ◽  
Joanna Starzycka-Giża ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Microscopic Analysis ◽  
Volume Index ◽  
Sign Test ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Effluent Quality ◽  
Significant Difference

Abstract Biological microscopic analysis is a popular method employed in wastewater treatment plants worldwide for evaluating activated sludge condition. However, many operators still have reservations regarding its reliability. In this study, we evaluated and compared two methods of microscopic sludge investigation: the sludge index (SI) and the Eikelboom–van Buijsen method (EB). We investigated 79 activated sludge samples from nine treatment plants located in southern Poland over a 1-year period. For each sample, sludge volume index values were calculated and compared with the results of evaluation made on the basis of microscopic analysis. Additionally, the effluent quality was analysed in 45 of 79 cases, including investigation of suspended solids, biochemical oxygen demand, chemical oxygen demand, total nitrogen and total phosphorous. The sign test and Wilcoxon matched pairs test showed that a significant difference existed between the two investigated methods. General conclusions from both methods do not provide reliable information concerning nitrogen and phosphorus removal. The EB method had a tendency to be more conservative in its general conclusions than the SI method. Both are highly reliable for estimating activated sludge quality and solid separation properties.

Effect of chemical oxygen demand load on the nitrification and microbial communities in activated sludge from an aerobic nitrifying reactor

2020 ◽  
Vol 66 (1) ◽  
pp. 59-70
Author(s):  
Dan Li ◽  
Xihong Liang ◽  
Zhengwei Li ◽  
Yao Jin ◽  
Rongqing Zhou ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Chemical Oxygen Demand ◽  
Microbial Communities ◽  
High Throughput Sequencing ◽  
Oxygen Demand ◽  
Nitrification Rate ◽  
Culture Time ◽  
Degradation Rates ◽  
Significant Difference ◽  
Over Time

In this study, we explored the effect of chemical oxygen demand (COD) load on the nitrification and microbial communities in activated sludge isolated from an aerobic nitrifying tank. The activated sludge was cultured in three different COD groups: L-COD, 200 mg/L; M-COD, 1200 mg/L; H-COD, 4200 mg/L. The results indicated that the COD exerts a negligible effect on the nitrogen removal ability within the first 24 h. However, the nitrification rate decreased with culture time; the ammonium degradation rates were found to be 80.26%, 57.56%, and 43.43% at 72 h in the three COD groups, respectively. These values correspond to decreases of 19.40%, 41.83%, and 51.48%, respectively, in relation to those observed at 24 h. The activated sludge in the different COD groups exhibited similar community compositions after 24 h, as assessed by Illumina high-throughput sequencing, while a significant difference in the relative abundances of some organisms occurred after 48 and 72 h. Proteobacteria was the main phylum, with a relative abundance of >51.45%. The genera Aridibacter, Paracoccus, Nitrospira, and Nitrosomonas were suppressed by COD load over time. This study may contribute to our knowledge about the nitrification ability and microbial communities in activated sludge at different COD load levels.

scholarly journals Obesity Alters the Microbial Community Profile in Korean Adolescents

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0134333 ◽  
Author(s):  
Hae-Jin Hu ◽  
Sin-Gi Park ◽  
Han Byul Jang ◽  
Min-Gyu Choi ◽  
Kyung-Hee Park ◽  
...  
Keyword(s):  
Microbial Community ◽  
Korean Adolescents ◽  
Community Profile ◽  
Microbial Community Profile

scholarly journals Correction: Obesity Alters the Microbial Community Profile in Korean Adolescents

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0138015 ◽  
Author(s):  
Hae-Jin Hu ◽  
Sin-Gi Park ◽  
Han Byul Jang ◽  
Min-Kyu Choi ◽  
Kyung-Hee Park ◽  
...  
Keyword(s):  
Microbial Community ◽  
Korean Adolescents ◽  
Community Profile ◽  
Microbial Community Profile

scholarly journals Effect of different types of olive oil pomace dietary supplementation on the rumen microbial community profile in Comisana ewes

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Federica Mannelli ◽  
Alice Cappucci ◽  
Francesco Pini ◽  
Roberta Pastorelli ◽  
Francesca Decorosi ◽  
...  
Keyword(s):  
Microbial Community ◽  
Olive Oil ◽  
Dietary Supplementation ◽  
Different Types ◽  
Community Profile ◽  
Microbial Community Profile
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