Microbial community structure of activated sludge during aerobic granulation in an annular gap bioreactor

Williams, Jon C.; Reyes, Francis L. de los

doi:10.2166/wst.2006.381

Cited by 30 publications

(17 citation statements)

References 14 publications

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“…Liu et al (2010b) also used DGGE to compare the microbial communities of co-existing flocs and granules treating wastewater and reported similar results, which led them to speculate that microbial selection between flocs and granules during steady state is not strong. While it has been demonstrated that the microbial community within a single reactor shifts over time as granules are developed (Williams and de los Reyes 2006), our results indicate that the dominant bacterial community composition of granules and flocs, at some 'steady-state' (in this case, after over 2 years) is similar. This highlights the importance of granule physical structure to developing and maintaining higher reaction rates compared to flocs.…”

Section: Potential Granule Contribution To Nitrification and Denitrifcontrasting

confidence: 45%

Structural integrity affects nitrogen removal activity of granules in semi-continuous reactors

et al. 2014

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Granules were observed after more than two years of operation in two semi-continuously fed intermittently aerated reactors treating swine wastewater with aerobic:anoxic cycles of 1:1 h and 1:4 h. Subsequently, the granules and flocs were compared with respect to physical characteristics, activity, and microbial community structure. Granules exhibited higher specific nitrification and denitrification rates than flocs. However, once granule structural integrity was disrupted, the rates decreased to levels similar to those of flocs. Membrane hybridizations using 16S rRNA-targeted probes showed that ammonia oxidizing bacteria populations in flocs and granules were dominated by Nitrosomonas and Nitrosococcus mobilis. Granules provided better conditions for Nitrospira compared to flocs. The diversities of the dominant bacterial populations in granules and flocs were not significantly different. Our findings highlight the importance of structural integrity of granules to their nitrogen removing activity.

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Section: Potential Granule Contribution To Nitrification and Denitrifcontrasting

confidence: 45%

Structural integrity affects nitrogen removal activity of granules in semi-continuous reactors

et al. 2014

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“…Only a small number of published papers have used molecular methods to study fungi in wastewater treatment plant communities, and these have focused on fungi associated with aerobic granules [70,72]. Several of the 18S rRNA sequences recovered from plants A and B were closely related to the fungal sequences reported by Weber et al [70].…”

Section: Discussionmentioning

confidence: 92%

“…Clones A63 (plant A), B34 (plant B), C79 (plant C), D45 (plant D) and E46 (plant E) also clustered with the Cercozoan (infrakingdom Rhizaria). Partial Cercozoa sequences have been recovered from aerobic granules from an SBR treating synthetic wastewater [72]. …”

Section: Non-fungal 18s Rrna Sequences In Treatment Plant Communitiesmentioning

confidence: 99%

“…Our present understanding of the biodiversity of fungi in wastewater treatment plants has come almost exclusively from the application of culture-dependent methods [16,17,21,24,42,50,53,57,70,72]. It has been suggested that the functional importance of fungi in such systems is minor since they are rarely found as dominant organisms in activated sludge systems, except under toxic or highly acidic conditions, and in systems treating nitrogen-deficient wastes or operating at cold temperatures [67], where their growth rates make them competitive with the bacterial populations present [60].…”

Section: Introductionmentioning

confidence: 99%

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Estimating Biodiversity of Fungi in Activated Sludge Communities Using Culture-Independent Methods

Evans

Seviour

2011

Microb Ecol

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Fungal diversity of communities in several activated sludge plants treating different influent wastes was determined by comparative sequence analyses of their 18S rRNA genes. Methods for DNA extraction and choice of primers for PCR amplification were both optimised using denaturing gradient gel electrophoresis profile patterns. Phylogenetic analysis revealed that the levels of fungal biodiversity in some communities, like those treating paper pulp wastes, were low, and most of the fungi detected in all communities examined were novel uncultured representatives of the major fungal subdivisions, in particular, the newly described clade Cryptomycota. The fungal populations in activated sludge revealed by these culture-independent methods were markedly different to those based on culture-dependent data. Members of the genera Penicillium, Cladosporium, Aspergillus and Mucor, which have been commonly identified in mixed liquor, were not identified in any of these plant communities. Non-fungal eukaryotic 18S rRNA genes were also amplified with the primer sets used. This is the first report where culture-independent methods have been applied to flocculated activated sludge biomass samples to estimate fungal community composition and, as expected, the data obtained gave a markedly different view of their population biodiversity compared to that based on culture-dependent methods.

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“…Recently, a new kind of bioreactor was developed for the cultivation of aerobic granules (Williams and de los Reyes 2006). This annular gap bioreactor (also called a Couette-Taylor bioreactor; CTB) provides shear by placing the biomass between two rotating, concentric cylinders.…”

Section: Introductionmentioning

confidence: 99%

Monitoring Microbial Shifts during Activated Sludge Floc and Aerobic Granule Development

Hong¹,

Williams²,

Hsieh³

et al. 2008

proc water environ fed

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Annular gap bioreactors or Couette-Taylor bioreactors (CTB) were used to apply varying shear forces to the biomass in this study. The shear forces in these bioreactors were controlled by adjusting the rotational speeds, allowing the shear to be independent of aeration rates. Both the inner-cylinder rotating CTB (i-CTB) and outer-cylinder rotating CTB (o-CTB) showed decreasing mean floc diameter as the shear increased. Denaturing gradient gel electrophoresis (DGGE) revealed that microbial communities from the activated sludge from both i-CTB and o-CTB were changing over time and indicated the potential contribution of protozoa to the development of aerobic granules.

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Microbial community structure of activated sludge during aerobic granulation in an annular gap bioreactor

Cited by 30 publications

References 14 publications

Structural integrity affects nitrogen removal activity of granules in semi-continuous reactors

Structural integrity affects nitrogen removal activity of granules in semi-continuous reactors

Estimating Biodiversity of Fungi in Activated Sludge Communities Using Culture-Independent Methods

Monitoring Microbial Shifts during Activated Sludge Floc and Aerobic Granule Development

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