Linking floc structure and settling properties to activated sludge population dynamics in an SBR

2003 ◽  
Vol 47 (12) ◽  
pp. 9-18 ◽  
Author(s):  
R. Govoreanu ◽  
D. Seghers ◽  
I. Nopens ◽  
B. De Clercq ◽  
H. Saveyn ◽  
...  
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Size Distribution ◽  
Community Dynamics ◽  
16S Rrna Genes ◽  
Volume Index ◽  
Rrna Genes ◽  
Filamentous Bacteria ◽  
Floc Size ◽  
Stable Conditions

Over a period of 227 days properties of activated sludge grown in an aequencing batch reactor (SBR) operated under stable conditions were analyzed. Settling properties (sludge volume index (SVI)) of the activated sludge were compared with on-line measurements of floc size and size distribution obtained by using a laser light scattering technique (Malvern Mastersizer/S, Malvern, UK), and with measurements of microbial community dynamics analyzed by denaturing gradient gel electrophoresis (DGGE) patterns of 16S rRNA genes. In addition, microscopical observations were used to confirm the results. Three distinct stages in the SBR evolution were observed. In the first stage the structural floc properties showed predominant presence of floc-forming bacteria in the activated sludge. A good correlation between floc size, settling properties and microbial community evolution was observed. The second stage showed a good balance between floc-forming and filamentous bacteria, with good settling properties and a highly dynamic community in the SBR. In the third stage, an increase in the filamentous bacteria, which became predominant in the system was observed. Again, a good correlation between settling properties and floc size distribution was obtained and a new dominant species was observed in the DGGE patterns, which can be assumed to be a filamentous organism.

scholarly journals Bioaugmentation of Activated Sludge by an Indigenous 3-Chloroaniline-Degrading Comamonas testosteroni Strain, I2gfp

2000 ◽  
Vol 66 (7) ◽  
pp. 2906-2913 ◽  
Author(s):  
Nico Boon ◽  
Johan Goris ◽  
Paul De Vos ◽  
Willy Verstraete ◽  
Eva M. Top
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Activated Sludge ◽  
Microbial Community Structure ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Dynamic Change ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Adaptation Period ◽  
Comamonas Testosteroni

ABSTRACT A strain identified as Comamonas testosteroni I2 was isolated from activated sludge and found to be able to mineralize 3-chloroaniline (3-CA). During the mineralization, a yellow intermediate accumulated temporarily, due to the distalmeta-cleavage of chlorocatechol. This strain was tested for its ability to clean wastewater containing 3-CA upon inoculation into activated sludge. To monitor its survival, the strain was chromosomally marked with the gfp gene and designated I2gfp. After inoculation into a lab-scale semicontinuous activated-sludge (SCAS) system, the inoculated strain maintained itself in the sludge for at least 45 days and was present in the sludge flocs. After an initial adaptation period of 6 days, complete degradation of 3-CA was obtained during 2 weeks, while no degradation at all occurred in the noninoculated control reactor. Upon further operation of the SCAS system, only 50% 3-CA removal was observed. Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes revealed a dynamic change in the microbial community structure of the activated sludge. The DGGE patterns of the noninoculated and the inoculated reactors evolved after 7 days to different clusters, which suggests an effect of strain inoculation on the microbial community structure. The results indicate that bioaugmentation, even with a strain originating from that ecosystem and able to effectively grow on a selective substrate, is not permanent and will probably require regular resupplementation.

A pilot-scale study on PVA gel beads based integrated fixed film activated sludge (IFAS) plant for municipal wastewater treatment

2015 ◽  
Vol 73 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Nitin Kumar Singh ◽  
Jasdeep Singh ◽  
Aakansha Bhatia ◽  
A. A. Kazmi
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
16S Rrna Genes ◽  
Volume Index ◽  
Rrna Genes ◽  
Gel Beads

In the present study, a pilot-scale reactor incorporating polyvinyl alcohol gel beads as biomass carrier and operating in biological activated sludge mode (a combination of moving bed biofilm reactor (MBBR) and activated sludge) was investigated for the treatment of actual municipal wastewater. The results, during a monitoring period of 4 months, showed effective removal of chemical oxygen demand (COD), biological oxygen demand (BOD) and NH3-N at optimum conditions with 91%, ∼92% and ∼90% removal efficiencies, respectively. Sludge volume index (SVI) values of activated sludge varied in the range of 25–72 mL/g, indicating appreciable settling characteristics. Furthermore, soluble COD and BOD in the effluent of the pilot plant were reduced to levels well below discharge limits of the Punjab Pollution Control Board, India. A culture dependent method was used to enrich and isolate abundant heterotrophic bacteria in activated sludge. In addition to this, 16S rRNA genes analysis was performed to identify diverse dominant bacterial species in suspended and attached biomass. Results revealed that Escherichia coli, Pseudomonas sp. and Nitrosomonas communis played a significant role in biomass carrier, while Acinetobactor sp. were dominant in activated sludge of the pilot plant. Identification of ciliated protozoa populations rendered six species of ciliates in the plant, among which Vorticella was the most dominant.

Linking nitrification characteristic and microbial community structures in integrated fixed film activated sludge reactor by high-throughput sequencing

2016 ◽  
Vol 74 (6) ◽  
pp. 1354-1364 ◽  
Author(s):  
Bin Dong ◽  
Jie Tan ◽  
Yang Yang ◽  
Zishan Pang ◽  
Zhongtian Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Ammonia Removal ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Community Structures ◽  
Microbial Community Structures ◽  
Fixed Film

The primary goal of this study is to investigate ammonia removal, abundance of nitrifying bacteria and microbial community structures in a laboratory-scale integrated fixed film activated sludge (IFAS) reactor. The results of Illumina MiSeq sequencing based on 16S rRNA genes showed Proteobacteria and Bacteroidetes were the dominant phyla in both biofilm and suspended sludge samples in the IFAS reactor. The dominant ammonia-oxidizing bacteria (AOB) species was Nitrosomonas and the dominant nitrite-oxidizing bacteria species was Nitrospira. The contribution of biofilm to ammonia removal increased from 4.0 ± 0.9% to 37.0 ± 2% when the temperature decreased from 25 °C to 10 °C. The real-time polymerase chain reaction (PCR) result showed the abundance of AOB in suspended sludge was higher than that in biofilm at the same time. However, nitrification is more dependent on attached growth than on suspended growth in the IFAS reactor at 15 °C and 10 °C and the abundance of AOB in biofilm was also higher than that in suspended sludge. The more robust ammonia removal rate at low temperatures by biofilm contributed to the relatively stable ammonia removal, and biofilm attached on carriers in the IFAS reactor is advantageous for nitrification in low-temperature environment.

scholarly journals Ultra-accurate microbial amplicon sequencing with synthetic long reads

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Benjamin J. Callahan ◽  
Dmitry Grinevich ◽  
Siddhartha Thakur ◽  
Michael A. Balamotis ◽  
Tuval Ben Yehezkel
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Amplicon Sequencing ◽  
Species Level ◽  
Full Length ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Strain Identification ◽  
Long Reads ◽  
Long Read

Abstract Background Out of the many pathogenic bacterial species that are known, only a fraction are readily identifiable directly from a complex microbial community using standard next generation DNA sequencing. Long-read sequencing offers the potential to identify a wider range of species and to differentiate between strains within a species, but attaining sufficient accuracy in complex metagenomes remains a challenge. Methods Here, we describe and analytically validate LoopSeq, a commercially available synthetic long-read (SLR) sequencing technology that generates highly accurate long reads from standard short reads. Results LoopSeq reads are sufficiently long and accurate to identify microbial genes and species directly from complex samples. LoopSeq perfectly recovered the full diversity of 16S rRNA genes from known strains in a synthetic microbial community. Full-length LoopSeq reads had a per-base error rate of 0.005%, which exceeds the accuracy reported for other long-read sequencing technologies. 18S-ITS and genomic sequencing of fungal and bacterial isolates confirmed that LoopSeq sequencing maintains that accuracy for reads up to 6 kb in length. LoopSeq full-length 16S rRNA reads could accurately classify organisms down to the species level in rinsate from retail meat samples, and could differentiate strains within species identified by the CDC as potential foodborne pathogens. Conclusions The order-of-magnitude improvement in length and accuracy over standard Illumina amplicon sequencing achieved with LoopSeq enables accurate species-level and strain identification from complex- to low-biomass microbiome samples. The ability to generate accurate and long microbiome sequencing reads using standard short read sequencers will accelerate the building of quality microbial sequence databases and removes a significant hurdle on the path to precision microbial genomics.

scholarly journals Habitat Elevation Shapes Microbial Community Composition and Alter the Metabolic Functions in Wild Sable (Martes zibellina) Guts

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 865
Author(s):  
Lantian Su ◽  
Xinxin Liu ◽  
Guangyao Jin ◽  
Yue Ma ◽  
Haoxin Tan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Environmental Factors ◽  
Microbial Communities ◽  
Community Composition ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Functional Genes ◽  
Martes Zibellina ◽  
Clear Cutting ◽  
Metabolic Functions

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions.

scholarly journals Subsoil microbial community responses to air exposure and legume growth depend on soil properties across different depths

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hongmei Yan ◽  
Fan Yang ◽  
Jiamin Gao ◽  
Ziheng Peng ◽  
Weimin Chen
Keyword(s):  
Microbial Community ◽  
Soil Properties ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Soil Profiles ◽  
Air Exposure ◽  
Structure Variation ◽  
Α Diversity ◽  
Different Depths ◽  
Legume Growth

AbstractAnthropogenic disturbance, such as agricultural and architectural activities, can greatly influence belowground soil microbes, and thus soil formation and nutrient cycling. The objective of this study was to investigate microbial community variation in deep soils affected by strong disturbances. In present study, twelve soil samples were collected from different depths (0–300 cm) and placed onto the surface. We investigated the structure variation of the microbial community down through the soil profiles in response to disturbance originated by legume plants (robinia and clover) cultivation vs. plant-free controls. The high-throughput sequencing of 16S rRNA genes showed that microbial α-diversity decreased with depth, and that growing both plants significantly impacted the diversity in the topsoil. The soil profile was clustered into three layers: I (0–40 cm), II (40–120 cm), and III (120–300 cm); with significantly different taxa found among them. Soil properties explained a large amount of the variation (23.5%) in the microbial community, and distinct factors affected microbial assembly in the different layers, e.g., available potassium in layer I, pH and total nitrogen in layer II, pH and organic matter in layer III. The prediction of metabolic functions and oxygen requirements indicated that the number of aerobic bacteria increased with more air exposure, which may further accelerate the transformation of nitrogen, sulfur, carbon, and pesticides in the soil. The diversity of soil microorganisms followed a depth-decay pattern, but became higher following legume growth and air exposure, with notable abundance variation of several important bacterial species, mainly belonging to Nitrospira, Verrucomicrobia, and Planctomycetes, and soil properties occurring across the soil profiles.

scholarly journals Abundance and Microbial Diversity from Surface to Deep Water Layers Over the Rio Grande Rise, South Atlantic

2021 ◽  
Author(s):  
Juliana Correa Neiva Ferreira ◽  
Natascha M. Bergo ◽  
Pedro M. Tura ◽  
Mateus Gustavo Chuqui ◽  
Frederico P. Brandini ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Diversity ◽  
Rio Grande ◽  
South Atlantic ◽  
Water Masses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
List Type ◽  
Tropical Water ◽  
Southwestern Atlantic Ocean

AbstractMarine microbes control the flux of matter and energy essential for life in the oceans. Until now, the distribution and diversity of planktonic microorganisms above Fe-Mn crusts has received relatively little attention. Future mining\dredging of these minerals is predicted to affect microbial diversity and functioning in the deep sea. Here, we studied the ecology of planktonic microbes among pelagic environments of an Fe-Mn deposit region, at Rio Grande Rise, Southwestern Atlantic Ocean. We investigated microbial community composition using high-throughput sequencing of 16S rRNA genes and their abundance estimated by flow cytometry. Our results showed that the majority of picoplanktonic was found in epi- and mesopelagic waters, corresponding to the Tropical Water and South Atlantic Central Water. Bacterial and archaeal groups related to phototrophy, heterotrophy and chemosynthesis, such as Synechococcales, Sar11 (Proteobacteria) and Nitrosopumilales (Thaumarchaeota) were the main representatives of the pelagic microbial community. Additionally, we detected abundant assemblages involved in biodegradation of marine organic matter and iron oxidation at deep waters, i.e., Pseudoalteromonas and Alteromonas. No differences were observed in microbial community alpha diversity. However, we detected differences in community structure between water masses, suggesting that changes in an environmental setting (i.e. nutrient availability or circulation) play a significant role in structuring the pelagic zones, also affecting the meso- and bathypelagic microbiome.HighlightsRio Grande Rise pelagic microbiomePicoplankton carbon biomass partitioning through pelagic zonesUnique SAR11 Clade I oligotype in the shallowest Tropical WaterHigher number of shared oligotypes between deepest water massesNitrogen, carbon and sulfur may be important contributors for the pelagic microbiome

scholarly journals Coaggregation among Nonflocculating Bacteria Isolated from Activated Sludge

2003 ◽  
Vol 69 (10) ◽  
pp. 6056-6063 ◽  
Author(s):  
Anushree Malik ◽  
Masashi Sakamoto ◽  
Shohei Hanazaki ◽  
Masamitsu Osawa ◽  
Takanori Suzuki ◽  
...  
Keyword(s):  
16S Rrna ◽  
Activated Sludge ◽  
Aggregate Size ◽  
Spectrophotometric Assay ◽  
Full Length ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Acinetobacter Junii ◽  
Acinetobacter Johnsonii

ABSTRACT Thirty-two strains of nonflocculating bacteria isolated from sewage-activated sludge were tested by a spectrophotometric assay for their ability to coaggregate with one other in two-membered systems. Among these strains, eight showed significant (74 to 99%) coaggregation with Acinetobacter johnsonii S35 while only four strains coaggregated, to a lesser extent (43 to 65%), with Acinetobacter junii S33. The extent and pattern of coaggregation as well as the aggregate size showed good correlation with cellular characteristics of the coaggregating partners. These strains were identified by sequencing of full-length 16S rRNA genes. A. johnsonii S35 could coaggregate with strains of several genera, such as Oligotropha carboxidovorans, Microbacterium esteraromaticum, and Xanthomonas spp. The role of Acinetobacter isolates as bridging organisms in multigeneric coaggregates is indicated. This investigation revealed the role of much-neglected nonflocculating bacteria in floc formation in activated sludge.

Prokaryote community dynamics in anaerobic co-digestion of swine manure, rice straw and industrial clay residuals

2016 ◽  
Vol 74 (4) ◽  
pp. 824-835 ◽  
Author(s):  
Janet Jiménez ◽  
Susanne Theuerl ◽  
Ingo Bergmann ◽  
Michael Klocke ◽  
Gilda Guerra ◽  
...  
Keyword(s):  
Rice Straw ◽  
Community Dynamics ◽  
Swine Manure ◽  
Molecular Techniques ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Nutritional Conditions ◽  
Continuously Stirred Tank Reactor ◽  
Positive Effect ◽  
Methanosarcina Species

The aim of this study was to analyze the effect of the addition of rice straw and clay residuals on the prokaryote methane-producing community structure in a semi-continuously stirred tank reactor fed with swine manure. Molecular techniques, including terminal restriction fragment length polymorphism and a comparative nucleotide sequence analyses of the prokaryotic 16S rRNA genes, were performed. The results showed a positive effect of clay addition on methane yield during the co-digestion of swine manure and rice straw. At the digestion of swine manure, the bacterial phylum Firmicutes and the archaeal family Methanosarcinaceae, particularly Methanosarcina species, were predominant. During the co-digestion of swine manure and rice straw the microbial community changed, and with the addition of clay residual, the phylum Bacteroidetes predominated. The new nutritional conditions resulted in a shift in the archaeal family Methanosarcinaceae community as acetoclastic Methanosaeta species became dominant.

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