Microbial community analysis with a high PHA storage capacity

Activated sludge was submitted to aerobic dynamic substrate feeding for the production of biodegradable plastics. Two sequencing batch reactors were operated with acetate or propionate as sole carbon substrates. With acetate a homopolymer of polyhydroxybutyrate (PHB) was obtained and with propionate a copolymer of hydroxybutyrate and hydroxyvalerate P(HB/HV) was produced. Three main morphotypes were identified in both sludges: two belong to the Alphaproteobacteria class and the third to the Betaproteobacteria class. Bacilli belonging to Betaproteobacteria were shown by FISH analysis, applied in combination with Nile Blue post-staining, to be the main responsible for PHAs storage. The latter were affiliated to Azoarcus genus within Betaproteobacteria.

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The effect of anoxic selectors on sludge bulking

Water Science & Technology ◽

10.2166/wst.2004.0384 ◽

2004 ◽

Vol 50 (6) ◽

pp. 261-268 ◽

Cited By ~ 5

Author(s):

M.V. Tampus ◽

A.M.P. Martins ◽

M.C.M. van Loosdrecht

Keyword(s):

Storage Capacity ◽

Volume Index ◽

Feeding Pattern ◽

Batch Reactors ◽

Substrate Uptake ◽

Sequencing Batch Reactors ◽

Floc Structure ◽

Substrate Feeding ◽

Substrate Uptake Rate ◽

Sludge Settleability

The effect of the substrate feeding pattern on sludge settleability in denitrifying systems was investigated. The feeding pattern was simulated in two sequencing batch reactors (SBR). SBR1 simulates a system with a limiting substrate (acetate) and a non-limiting electron acceptor (nitrate), while SBR2 simulates the opposite condition. Sludge volume index (SVI) was the main observed parameter. The stoichiometry, substrate uptake rate, storage capacity as well as sludge morphology and mixed culture population dynamics were also determined. Results show that independent of the feeding pattern, the settleability of the sludge remained good (SVI ≈ 50 mL/g) and stable. Neither the concentration of the acetate nor of the nitrate offered any limitations on sludge settleability, assuring that a good bio-P activity is present in nitrate limiting systems. Filamentous bacteria belonging to the TM group were usually present, although in low numbers. Despite the diffused, irregularly shaped and open floc structure, good settleability was observed. The results obtained were in line with the hypothesis on diffusion based selection.

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Biodegradation of oil sands process affected water in sequencing batch reactors and microbial community analysis by high-throughput pyrosequencing

International Biodeterioration & Biodegradation ◽

10.1016/j.ibiod.2014.04.020 ◽

2014 ◽

Vol 92 ◽

pp. 79-85 ◽

Cited By ~ 18

Author(s):

Jeongdong Choi ◽

Yang Liu

Keyword(s):

Microbial Community ◽

High Throughput ◽

Oil Sands ◽

Community Analysis ◽

Microbial Community Analysis ◽

Batch Reactors ◽

Sequencing Batch Reactors

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Efficient and integrated start-up strategy for partial nitrification to nitrite treating low C/N domestic wastewater

Water Science & Technology ◽

10.2166/wst.2009.619 ◽

2009 ◽

Vol 60 (12) ◽

pp. 3243-3251 ◽

Cited By ~ 11

Author(s):

Jianhua Guo ◽

Shuying Wang ◽

Huijun Huang ◽

Yongzhen Peng ◽

Shijian Ge ◽

...

Keyword(s):

Domestic Wastewater ◽

Kinetic Mechanism ◽

Partial Nitrification ◽

Nitrifying Bacteria ◽

Nitrite Accumulation ◽

Fish Analysis ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

Start Up ◽

Operation Results

Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.

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Polyhydroxyalkanoates production by activated sludge in a SBR using acetate and propionate as carbon sources

Water Science & Technology ◽

10.2166/wst.2004.0641 ◽

2004 ◽

Vol 50 (10) ◽

pp. 189-194 ◽

Cited By ~ 11

Author(s):

P.C. Lemos ◽

L.S. Serafim ◽

M.A.M. Reis

Keyword(s):

Carbon Sources ◽

Dry Weight ◽

Operating Conditions ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

Cell Content ◽

A Value ◽

Substrate Feeding ◽

Commercial Applications ◽

Processing Properties

In this work, sludge was submitted to aerobic dynamic substrate feeding. Two sequencing batch reactors were operated, with acetate or propionate as carbon substrates. When acetate was used the system only produced a homopolymer of polyhydroxybutyrate (PHB). In order to maximize the PHB production, tests with different concentrations of acetate and ammonia were preformed. The best results (67.2% of PHB by cell dry weight) were obtained for 0.7 Nmmol/l of ammonia and 180 Cmmol/l of acetate. The PHB cell content was further improved by pupulse addition of substrate, three times 60 Cmmol/l of acetate, reaching a value of 78.5%. Propionate can be used as a precursor for hydroxyvalerate. In conjunction with other substrates, it allows for the formation of copolymers, which present better processing properties on commercial applications. Tests with different concentrations of propionate and ammonia were performed. Under the operating conditions used, the maximum PHA accumulated inside cells was 34.8%, with 30 Cmmol/l of propionate and no ammonia.

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Microbial community analysis involved in the aerobic/extended-idle process performing biological phosphorus removal

Water Science & Technology ◽

10.2166/wst.2012.578 ◽

2013 ◽

Vol 67 (3) ◽

pp. 485-493 ◽

Cited By ~ 5

Author(s):

Tian-jing Zeng ◽

Guo-jing Yang ◽

Dong-bo Wang ◽

Xiao-ming Li ◽

Wei Zheng ◽

...

Keyword(s):

Phosphorus Removal ◽

Community Analysis ◽

Microbial Community Analysis ◽

Fish Analysis ◽

Biological Phosphorus Removal ◽

Acclimation Period ◽

Polyphosphate Accumulating Organisms ◽

Biological Phosphorus ◽

Total Bacteria

Recently, it has been found that biological phosphorus removal can be achieved in an aerobic/extended-idle (AEI) process using both glucose and acetate as the sole substrate. However, the microbial consortiums involved in glucose-fed and acetate-fed systems have not yet been characterized. Thus the aims of this paper were to investigate the diversities and dynamics of bacterial communities during the acclimation period, and to quantify polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in the systems. The phylogenetic analysis showed that the microbial communities were mainly composed of phylum Proteobacteria, Bacteroidetes, Chlorobi and another six kinds of unclassified bacteria. Fluorescence in-situ hybridization (FISH) analysis revealed that PAOs and GAOs accounted for 43 ± 7 and 16 ± 3% of all bacteria in the glucose-fed system, and 19 ± 4 and 35 ± 5% of total bacteria in the acetate-fed system, respectively. The results showed that the conventional PAOs could thrive in the AEI process, and a defined anaerobic zone was not necessarily required for putative PAOs growth.

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Biological ammonia removal from anaerobically pre-treated landfill leachate in sequencing batch reactors (SBR)

Water Science & Technology ◽

10.2166/wst.2001.0151 ◽

2001 ◽

Vol 43 (3) ◽

pp. 307-314 ◽

Cited By ~ 22

Author(s):

G. Yalmaz ◽

I. Öztürk

Keyword(s):

Carbon Source ◽

Landfill Leachate ◽

Cycle Time ◽

Biomass Concentration ◽

Ammonia Removal ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

The Third ◽

External Carbon Source ◽

The Difference

The aim of the study was to investigate both the use of the SBR technology in biological ammonia removal from landfill leachate, and the suitability of raw landfill leachate as external carbon source in denitrification step. The SBR was fed with diluted leachate for the first 42 days and then the effluent of UASBR was used as the feed. The SBR was operated intermittently with a cycle time of 24 hours. The effluent NH4+-N values of less than 5 mg NH4+-N L-1 was consistently observed for the initial NH4+-N levels of as high as 1000 mg NH4+-N L-1. The nitrification rates for the first, second and third stages were found as 5.7, 46.8 and 102.8 mg NH4+-N L-1 h-1, respectively. The difference of the nitrification rates in the 2nd and 3rd stages originated from increasing adaptation of the sludge as well as increasing biomass concentration (10.5 mg NH4+-N g-1VSS h-1). No significant accumulation of NO2--N has been observed during the study and NO2--N/NOx--N ratios measured in the 1st aerobic phase and the SBR effluent were less than 7%. The denitrification rates for the second (raw leachate as carbon source) and the third (Ca(CH3COO)2 as carbon source) stages were determined as 45.7 mg NOx--N L-1 h-1 (or 9.85 mg NOx--N g-1VSS h-1) and 125.7 mg NOx--N L-1 h-1 (or 12.88 mg NOx--N g-1VSS h1), respectively.

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Microbial community analysis during continuous fermentation of thermally hydrolysed waste activated sludge

Water Science & Technology ◽

10.2166/wst.2011.705 ◽

2012 ◽

Vol 65 (1) ◽

pp. 7-14 ◽

Cited By ~ 6

Author(s):

D. G. Cirne ◽

P. Bond ◽

S. Pratt ◽

P. Lant ◽

D. J. Batstone

Keyword(s):

Activated Sludge ◽

Continuous Fermentation ◽

Community Analysis ◽

Microbial Community Analysis ◽

Waste Activated Sludge ◽

Rrna Gene ◽

Fish Analysis ◽

Taxonomic Groups ◽

Bacterial Groups

Acidogenic fermentation of thermally hydrolysed waste activated sludge was carried out at laboratory scale in two reactors operated under different hydraulic retention times (HRT). Process performance was assessed in terms of volatile fatty acid (VFA) composition and yield. The diversity of the microbial population was investigated by constructing a 16S rRNA gene library and subsequent phylogenetic analysis of clones. Fluorescence in situ hybridization (FISH) was used to assess the relative abundance of different bacterial groups. Bacteroidetes and Firmicutes were the dominant taxonomic groups representing 93% of the total sequences obtained in the reactor with 4 d HRT. A similar VFA yield (0.4–0.5 g VFACOD g SCOD−1) was obtained for the HRTs tested (1–4 d), indicating that extended retention times were not useful. Within Firmicutes, Clostridia was the major group detected in the clone sequences. These had close affiliation to Sporanaerobacter acetigenes, suggesting organisms of this group were important for hydrolysis of the protein fraction of the substrate. However, FISH analysis failed to detect the major portion of the bacteria, and this is most likely due to the lack of appropriate probes. This work emphasizes the diversity of fermentative communities, and indicates that more work is needed to identify and detect the important members.

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Microbial community analysis in the gills of abalones suggested possible dominance of epsilonproteobacterium in Haliotis gigantea

PeerJ ◽

10.7717/peerj.9326 ◽

2020 ◽

Vol 8 ◽

pp. e9326

Author(s):

Yukino Mizutani ◽

Tetsushi Mori ◽

Taeko Miyazaki ◽

Satoshi Fukuzaki ◽

Reiji Tanaka

Keyword(s):

Nested Pcr ◽

Gill Tissue ◽

Community Analysis ◽

Microbial Community Analysis ◽

Rrna Gene ◽

Fish Analysis ◽

Specific Primers ◽

Abalone Species ◽

Chemosynthetic Bacteria

Gills are important organs for aquatic invertebrates because they harbor chemosynthetic bacteria, which fix inorganic carbon and/or nitrogen and provide their hosts with organic compounds. Nevertheless, in contrast to the intensive researches related to the gut microbiota, much is still needed to further understand the microbiota within the gills of invertebrates. Using abalones as a model, we investigated the community structure of microbes associated with the gills of these invertebrates using next-generation sequencing. Molecular identification of representative bacterial sequences was performed using cloning, nested PCR and fluorescence in situ hybridization (FISH) analysis with specific primers or probes. We examined three abalone species, namely Haliotis gigantea, H. discus and H. diversicolor using seawater and stones as controls. Microbiome analysis suggested that the gills of all three abalones had the unclassified Spirochaetaceae (one OTU, 15.7 ± 0.04%) and Mycoplasma sp. (one OTU, 9.1 ± 0.03%) as the core microbes. In most libraries from the gills of H. gigantea, however, a previously unknown epsilonproteobacterium species (one OTU) was considered as the dominant bacterium, which accounted for 62.2% of the relative abundance. The epsilonproteobacterium was only detected in the gills of H. diversicolor at 0.2% and not in H. discus suggesting that it may be unique to H. gigantea. Phylogenetic analysis performed using a near full-length 16S rRNA gene placed the uncultured epsilonproteobacterium species at the root of the family Helicobacteraceae. Interestingly, the uncultured epsilonproteobacterium was commonly detected from gill tissue rather than from the gut and foot tissues using a nested PCR assay with uncultured epsilonproteobacterium-specific primers. FISH analysis with the uncultured epsilonproteobacterium-specific probe revealed that probe-reactive cells in H. gigantea had a coccus-like morphology and formed microcolonies on gill tissue. This is the first report to show that epsilonproteobacterium has the potential to be a dominant species in the gills of the coastal gastropod, H. gigantea.

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