scholarly journals Machine learning aided analyses of thousands of draft genomes reveal plant- and environment-specific features of activated sludge process

2019 ◽  
Author(s):  
Lin Ye ◽  
Ran Mei ◽  
Wen-Tso Liu ◽  
Hongqiang Ren ◽  
Xuxiang Zhang
Keyword(s):  
Machine Learning ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Nutrient Sensing ◽  
Rrna Gene ◽  
Metagenomic Sequencing ◽  
Sequencing Data ◽  
Wastewater Treatment Process ◽  
Novel Approach

AbstractMicroorganisms in activated sludge (AS) play key roles in the wastewater treatment process. However, the ecological behavior of microorganisms in AS and their differences with microorganisms in other environments have mainly been studied using 16S rRNA gene that may not truly represent their in-situ functions. Here, we present 2045 bacterial and archaeal metagenome-assembled genomes (MAGs) recovered from 1.35 Tb of metagenomic sequencing data generated from 114 AS samples of 23 full-scale wastewater treatment plants (WWTPs). The average completeness and contamination of the MAGs are 82.0% and 2.0%, respectively. We find that the AS MAGs have obviously plant-specific features and few proteins are shared by different WWTPs, especially for WWTPs located in geographically distant areas. Despite the differences, specific functional traits (e.g. functions related to aerobic metabolism, nutrient sensing/acquisition, biofilm formation, etc.) of AS MAGs could be identified by a machine learning approach, and based on these traits, AS MAGs could be differentiated from MAGs of other environments with an accuracy of 96.6%. Our work provides valuable genome resources for future investigation of the AS microbiome and also introduces a novel approach to understand the microbial ecology in different ecosystems.

scholarly journals The capacity of wastewater treatment plants drives bacterial community structure and its assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Bacterial Communities ◽  
Wastewater Treatment Plants ◽  
High Capacity ◽  
Operating Conditions ◽  
Rrna Gene

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

scholarly journals Contribution of prokaryotes and eukaryotes to CO2 emissions in the wastewater treatment process

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9325
Author(s):  
Katarzyna Jaromin-Gleń ◽  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Yaroslav Danko ◽  
Grzegorz Łagód ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Greenhouse Effect ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Wastewater Treatment Process ◽  
Eukaryotic Organisms ◽  
Quantitative Contribution

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2 emissions is still unknown. The emission of CO2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.

scholarly journals Metagenomic Profiles of Antibiotic Resistance Genes in Activated Sludge, Dewatered Sludge and Bioaerosols

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1516
Author(s):  
Il Han ◽  
Keunje Yoo
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Illumina Hiseq ◽  
Wastewater Treatment Process ◽  
Dewatered Sludge ◽  
Scientific Attention

Wastewater treatment plants (WWTPs) have been considered hotspots for the development and dissemination of antibiotic resistance in the environment. Although researchers have reported a significant increase in bioaerosols in WWTPs, the associated bacterial taxa, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) remain relatively unknown. In this study, we have investigated the abundance and occurrences of ARGs and MGEs, as well as the bacterial community compositions in activated sludge (AS), dewatered sludge (DS) and bioaerosols (BA) in a WWTP. In total, 153 ARG subtypes belonging to 19 ARG types were identified by the broad scanning of metagenomic profiles obtained using Illumina HiSeq. The results indicated that the total occurrences and abundances of ARGs in AS and DS samples were significantly higher than those in BA samples (p < 0.05). However, some specific ARG types related to sulfonamide, tetracycline, macrolide resistance were present in relatively high abundance in BA samples. Similar to many other full-scale WWTPs, the Proteobacteria (58%) and Bacteroidetes (18%) phyla were dominant in the AS and DS samples, while the Firmicutes (25%) and Actinobacteria (20%) phyla were the most dominant in the BA samples. Although the abundance of genes related to plasmids and integrons in bioaerosols were two to five times less than those in AS and DS samples, different types of MGEs were observed in BA samples. These results suggest that comprehensive analyses of resistomes in BA are required to better understand the emergence of both ARGs and MGEs in the wastewater treatment process due to the significant increase of scientific attention toward bioaerosols effects.

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR

2006 ◽  
Vol 54 (1) ◽  
pp. 39-45 ◽  
Author(s):  
E.L. Carr ◽  
K.L. Eales ◽  
R.J. Seviour
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Mycolic Acid ◽  
Substrate Uptake ◽  
Wastewater Treatment Process ◽  
Pure Cultures ◽  
Gordonia Amarae

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.

scholarly journals Reduction of Arcobacter at Two Conventional Wastewater Treatment Plants in Southern Arizona, USA

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 175 ◽  
Author(s):  
Ghaju Shrestha ◽  
Sherchan ◽  
Kitajima ◽  
Tanaka ◽  
Gerba ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Quantitative Pcr ◽  
Pathogenic Bacteria ◽  
Wastewater Treatment Plants ◽  
The United States ◽  
Rrna Gene ◽  
Metagenomic Sequencing ◽  
Wwtp Effluent

This study aimed to identify the bacterial community in two wastewater treatment plants (WWTPs) and to determine the occurrence and reduction of Arcobacter, along with virulence genes (ciaB and pldA). A total of 48 samples (24 influent and 24 effluent) were collected at two WWTPs in southern Arizona in the United States, monthly from August 2011 to July 2012. Bacterial DNA extract was utilized for 16S rRNA metagenomic sequencing. Quantification of Arcobacter 16S rRNA gene was conducted using a recently developed SYBR Green-based quantitative PCR assay. Among 847 genera identified, 113 (13%) were identified as potentially pathogenic bacteria. Arcobacter 16S rRNA gene was detected in all influent samples and ten (83%) and nine (75%) effluent samples at each plant, respectively. Log reduction ratios of Arcobacter 16S rRNA gene in Plant A and Plant B were 1.7 ± 0.9 (n = 10) and 2.3 ± 1.5 (n = 9), respectively. The ciaB gene was detected by quantitative PCR in eleven (92%) and twelve (100%) of 12 influent samples from Plant A and Plant B, respectively, while the pldA gene was detected in eight (67%) and six (50%) influent samples from Plant A and Plant B, respectively. The prevalence of potentially pathogenic bacteria in WWTP effluent indicated the need for disinfection before discharge into the environment.

The development and use of real-time PCR for the quantification of nitrifiers in activated sludge

2002 ◽  
Vol 46 (1-2) ◽  
pp. 267-272 ◽  
Author(s):  
S.J. Hall ◽  
P. Hugenholtz ◽  
N. Siyambalapitiya ◽  
J. Keller ◽  
L.L. Blackall
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Real Time ◽  
Real Time Pcr ◽  
Wastewater Treatment Plants ◽  
Quantitative Polymerase Chain Reaction ◽  
Analytical Data ◽  
Full Scale ◽  
Rrna Gene ◽  
Dna Templates

Chemical analytical data has long been used to monitor the performance of activated sludge plants even though the process relies on the performance of microorganisms. It is now evident that a rapid and reliable quantitative method is required, to be able to monitor the organisms responsible for nutrient transformation and their activities, allowing avenues for more efficient nutrient removal. The development of real-time or quantitative polymerase chain reaction (PCR) also known as TaqMan® or 5′-nuclease assay has allowed the rapid, quantitative analysis of DNA templates, eliminating some of the variability traditionally associated with other quantitative techniques. In this study analysis of Nitrospira spp., one of the key organisms in nitrite oxidation in wastewater treatment, was used to validate real-time PCR for the their quantification in activated sludge. A probe and primer set, targeting the 16S rRNA gene of Nitrospira spp. was designed according to the constraints of the TaqMan® specifications. Samples used to evaluate the method included DNA from the sludge from full-scale wastewater treatment plants and laboratory scale systems. The reproducibility, quantitative efficiency and specificity were assessed in the evaluation. It was concluded that the method is sensitive and reproducible but has some constraints on the quantitative efficiency. A survey of full-scale systems for Nitrospira spp. was carried out and the results are presented here.

scholarly journals Impact of the Biological Cotreatment of the Kalina Pond Leachate on Laboratory Sequencing Batch Reactor Operation and Activated Sludge Quality

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1539 ◽  
Author(s):  
Justyna Michalska ◽  
Izabela Greń ◽  
Joanna Żur ◽  
Daniel Wasilkowski ◽  
Agnieszka Mrozik
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Landfill Leachate ◽  
Sequencing Batch Reactor ◽  
Wastewater Treatment Plants ◽  
Negative Impact ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Wastewater Treatment Process

Hauling landfill leachate to offsite urban wastewater treatment plants is a way to achieve pollutant removal. However, the implementation of biological methods for the treatment of landfill leachate can be extremely challenging. This study aims to investigate the effect of blending wastewater with 3.5% and 5.5% of the industrial leachate from the Kalina pond (KPL) on the performance of sequencing batch reactor (SBR) and capacity of activated sludge microorganisms. The results showed that the removal efficiency of the chemical oxygen demand declined in the contaminated SBR from 100% to 69% and, subsequently, to 41% after the cotreatment with 3.5% and 5.5% of the pollutant. In parallel, the activities of the dehydrogenases and nonspecific esterases declined by 58% and 39%, and 79% and 81% after 32 days of the exposure of the SBR to 3.5% and 5.5% of the leachate, respectively. Furthermore, the presence of the KPL in the sewage affected the sludge microorganisms through a reduction in their functional capacity as well as a decrease in the percentages of the marker fatty acids for different microbial groups. A multifactorial analysis of the parameters relevant for the wastewater treatment process confirmed unambiguously the negative impact of the leachate on the operation, activity, and structure of the activated sludge.

scholarly journals Activated Sludge Respiration Activity Inhibition Caused by Mobile Toilet Chemicals

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 598 ◽  
Author(s):  
Tomáš Vítěz ◽  
Monika Vítězová ◽  
Markéta Nováčková ◽  
Ivan Kushkevych
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Respiratory Activity ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Respiration Activity ◽  
Wastewater Treatment Process ◽  
The Impact ◽  
Active Substances

Ensuring high quality drinking water sources is important task nowadays. To reach this task, knowledge about the impact of different chemicals on aerobic wastewater treatment is mandatory. A mixture of different chemicals reaches wastewater treatment plant every day. With the growing discharge volume of mobile toilet chemicals, active substances in these products in the past years have been recorded. The respiratory activity of activated sludge was determined to show how mobile toilet chemicals and their active substances may affect the biological wastewater treatment process. The results show negative effect of formaldehyde and bronopol on respiratory activity of activated sludge. The wastewater treatment plants influent composition and size also play important roles. Results shows that activated sludge microorganisms at a wastewater treatment plant in industrial urban area may be adapted to the higher pollutants concentration. When mobile toilet tanks are directly discharged at smaller wastewater treatment plant, an activated sludge process can be affected. For treating mobile toilet wastewater, bacterial degraders can be used. During our respiratory activity experiments, potential degraders were searched. Ralstonia sp. prevails in all samples and it is therefore a potential mobile toilet chemicals degrader.

Revealing microbial community structures in large- and small-scale activated sludge systems by barcoded pyrosequencing of 16S rRNA gene

2012 ◽  
Vol 66 (10) ◽  
pp. 2155-2161 ◽  
Author(s):  
Purnika Damindi Ranasinghe ◽  
Hiroyasu Satoh ◽  
Mamoru Oshiki ◽  
Kenshiro Oshima ◽  
Wataru Suda ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Microbial Community ◽  
16S Rrna ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Rrna Gene ◽  
Community Structures ◽  
Microbial Community Structures ◽  
Insight Into

The diversity of bacterial groups in activated sludge from large- and small-scale wastewater treatment plants was explored by barcoded pyrosequencing of 16S rRNA gene. Activated sludge samples (three small and 17 large scale) were collected from 12 wastewater treatment plants to clarify precise taxonomy and relative abundances. DNA was extracted, and amplified by 4 base barcoded 27f/519r primer set. The 454 Titanium (Roche) pyrosequences were obtained and analyses performed by Quantitative Insight Into Microbial Ecology (QIIME) with around 100,000 reads. Sequence statistics were computed, while constructing a phylogenetic tree and heatmap. Computed results explained total microbial diversity at phylum and class level and resolution was further extended to Operational Taxonomic Unit (OTU) based taxonomic assignment for investigating community distribution based on individual sample. Composition of sequence reads were compared and microbial community structures for large- and small-scale treatment plants were identified as major phyla (Proteobacteria and Bacteroidetes) and classes (Betaproteobacteria and Bacteroidetes). Also, family level breakdowns were explained and differences in family Nitrospiraceae and phylum Actinobacteria found at their species level were also illustrated. Thus, the pyrosequencing method provides high resolution insight into microbial community structures in activated sludge that might have been unnoticed with conventional approaches.

scholarly journals MiDAS 4: A global catalogue of full-length 16S rRNA gene sequences and taxonomy for studies of bacterial communities in wastewater treatment plants

2021 ◽  
Author(s):  
Morten Simonsen Dueholm ◽  
Marta Nierychlo ◽  
Kasper Skytte Andersen ◽  
Vibeke Rudkjoebing Joergensen ◽  
Simon Knutsson ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Species Level ◽  
Full Length ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences

Biological wastewater treatment and an increased focus on resource recovery is fundamental for environmental protection, human health, and sustainable development. Microbial communities are responsible for these processes, but our knowledge of their diversity and function is still poor, partly due to the lack of good reference databases and comprehensive global studies. Here, we sequenced more than 5 million high-quality, full-length 16S rRNA gene sequences from 740 wastewater treatment plants (WWTPs) across the world and used the sequences to construct MiDAS 4, a full-length amplicon sequence variant resolved 16S rRNA gene reference database with a comprehensive taxonomy from the domain to species-level for all references. Using a study-independent amplicon dataset from the Global Water Microbiome Consortium project (269 WWTPs), we showed that the MiDAS 4 database provides much better coverage for bacteria in WWTPs worldwide compared to commonly applied universal references databases, and greatly improved the rate of genus and species-level classification. Hence, MiDAS 4 provides a unifying taxonomy for the majority of prokaryotic diversity in WWTPs globally, which can be used for linking microbial identities with their functions across studies. Taking advantage of MiDAS 4, we carried out an amplicon-based, global-scale microbial community profiling of activated sludge plants using two common sets of primers targeting the V1-V3 and V4 region of the 16S rRNA gene. We found that the V1-V3 primers were generally best suited for this ecosystem, and revealed how environmental conditions and biogeography shape the activated sludge microbiota. We also identified process-critical taxa (core and conditionally rare or abundant taxa), encompassing 966 genera and 1530 species. These represented approximately 80% and 50% of the accumulated read abundance, respectively, and represent targets for further investigations. Finally, we showed that for well-studied functional guilds, such as nitrifiers or polyphosphate accumulating organisms, the same genera were prevalent worldwide, with only a few abundant species in each genus.

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