The Phylogeny, Biodiversity, and Ecology of the in Activated Sludge.

It is now clear that several of the filamentous bacteria in activated sludge wastewater treatment plants globally, are members of the phylum They appear to be more commonly found in treatment plants designed to remove nitrogen (N) and phosphorus (P), most of which operate at long sludge ages and expose the biomass to anaerobic conditions. The seem to play an important beneficial role in providing the filamentous scaffolding around which flocs are formed, to feed on the debris from lysed bacterial cells, to ferment carbohydrates and to degrade other complex polymeric organic compounds to low molecular weight substrates to support their growth and that of other bacterial populations. A few commonly extend beyond the floc surface, while others can align in bundles, which may facilitate interfloc bridging and hence generate a bulking sludge.

Eikelboom filamentous morphotypes 0675 and 0041 embrace members of the Chloroflexi: resolving their phylogeny, and design of fluorescence in situ hybridisation probes for their identification.

Although the phylogeny of many of the filamentous bacteria responsible for bulking in activated sludge plants is now known, and fluorescence in situ hybridisation (FISH) probes have been designed for their in situ identification, there are some noticeable exceptions. This study reports the identification of the Eikelboom morphotypes 0041 and 0675. Because these morphotypes differ only in their filament diameters, they are often considered together in surveys based on microscopic identifications.

Quantification of Chloroflexi Eikelboom morphotype 1851 for prediction and control of bulking events in municipal activated sludge plants in Japan.

The dominant filamentous bacteria associated with bulking incidents in Japanese activated sludge plants with nutrient removal were identified and their quantitative correlations with sludge settleability were assessed, with the aim of controlling bulking incidents by specifically suppressing bacterial growth. Fluorescence in situ hybridization (FISH) analyses using existing oligonucleotide FISH probes indicated that the presence of Eikelboom type 1851 filamentous bacteria belonging to the phylum Chloroflexi is correlated with biomass settleability in the municipal wastewater treatment plants examined. Real-time quantitative PCR (qPCR) assays developed in this study also showed a linear correlation between type 1851 filament members and sludge settleability, with the exception of some winter samples.

The activated sludge bulking filament Eikelboom morphotype 0803 embraces more than one member of the Chloroflexi.

The Eikelboom filamentous morphotype 0803 is commonly found in activated sludge systems globally, where it contributes to sludge bulking events. Earlier reports have suggested that it is a member of both the Proteobacteria and Chloroflexi. This study shows that this filament contributing to a period of poor sludge settleability in an Australian activated sludge plant is a member of the Chloroflexi, but not within the Caldilinea, as reported for this morphotype in Danish plants.

Fluorescence in situ hybridization probes targeting members of the phylum Candidatus Saccharibacteria falsely target Eikelboom type 1851 filaments and other Chloroflexi members.

The FISH probe TM7-305 is thought to target the filamentous Eikelboom morphotype 0041 as a member of the Candidatus ‘Saccharibacteria’ (formerly TM7) phylum. However, with activated sludge samples in both Japan and Australia, this probe hybridized consistently with filamentous bacteria fitting the description of the morphotype 1851, which also responded positively to the CHL1851 FISH probe designed to target Chloroflexi members of this morphotype. 16S rRNA clone libraries from samples containing type 1851 TM7-305-positive filaments yielded Chloroflexi clones with high sequence similarity to Kouleothrix aurantiaca.

In situ profiling of microbial communities in full-scale aerobic sequencing batch reactors treating winery waste in australia.

On-site aerobic sequencing batch reactor (SBR) treatment plants are implemented in many Australian wineries to treat the large volumes of associated wastewater they generate. Yet very little is known about their microbiology. This paper represents the first attempt to analyze the communities of three such systems sampled during both vintage and nonvintage operational periods using molecular methods.

The activated sludge bulking filament Eikelboom morphotype 0914 is a member of the Chloroflexi.

The filamentous bacterium Eikelboom morphotype type 0914 responsible for bulking in activated sludge plants is identified here for the first time as a member of the phylum Chloroflexi subgroup 1. Two FISH probes, CFX67a and CFX67b, targeting the 16S rRNA sequences of this filament morphotype were designed, validated and used successfully for its in situ identification. A survey of plants in eastern Australia with the CFX67a probe showed it targeted only the type 0914 morphotype that was common especially in long sludge age plants designed to remove phosphorus and nitrogen microbiologically, although being in very low abundance in many samples.