Filamentous micro-organisms observed in industrial activated sludge plants

Abstract

As part of the EU-sponsored MACOBS (Monitoring and Control of Bulking Sludge through Molecular Probe Assays) project, the size and the composition of the filamentous population in 73 industrial activated sludge plants, were investigated. The inventory included plants in Denmark, Germany, Italy and The Netherlands. Large filamentous populations were present in about 60% of the plants, which means that bulking of activated sludge, which is no longer a serious problem in modern domestic nutrient removal plants, still occurs frequently in industrial treatment plants. The filamentous micro-organisms present were identified/described by "traditional" methods, based on their morphological features and several staining techniques, and by the application of molecular probes (FISH: Fluorescent In Situ Hybridisation). Nine species specific probes were available when the project started, nine new probes have been developed during the project. Fifty nine different filamentous species were observed in the samples, including ca. 40 species that have not been described so far. The unknown species are denoted as Type Ind-1, 2, 3, etc. Probes are now available for the identification of about 17 species. Further research aimed at developing additional probes will be necessary in order to establish which species distinguished provisionally are identical, viz. morphotypes of the same filamentous organism.

Filamentous Bacterium Eikelboom Type 0092 in Activated Sludge Plants in Australia Is a Member of the Phylum Chloroflexi

“…Several different filament morphotypes have been described from systems treating domestic and industrial wastes (17,18) but, in the absence of pure cultures, many of these have never been characterized sufficiently to resolve their taxonomy or provide them with valid names. Hence, they are often still referred to as numerical types persisting from the study of Eikelboom (18).…”

The Problem of Wastewater in Shale Gas Exploitation The Influence of Fracturing Flowback Water on Activated Sludge at a Wastewater Treatment Plant

“…The evaluation of activated sludge parameters was performed according to the procedures described by Eikelboom and Fijałkowska [15][16]. The qualitative species composition of activated sludge was assessed from microscopic observations (magnification 10x, 20x, and 40x) of slides treated with a vital stain.…”

Development and evaluation of a TaqMan duplex real-time PCR quantification method for reliable enumeration of Candidatus Microthrix

“…The filamentous bacteria present in WWTP were morphologically identified and the filament characteristics were determined using the Eikelboom's classification system (Table 1) (Eikelboom and Geurkink, 2000;Eikelboom and van Buijsen, 1983). Referring to morphological and color characteristics of the filaments (Jenkins et al, 2004), the Gram staining and Neisser staining were respectively performed as described by Adamse (1970) and Gurr (1965).…”

“…More than 30 different filament morphotypes have been described in activated sludge systems treating primarily municipal wastewater (Eikelboom, 1975(Eikelboom, , 2000 and many more are encountered in industrial treatment plant communities (Eikelboom, 2006;Eikelboom and Geurkink, 2002). Several global surveys have shown that Candidatus Microthrix parvicella (hereinafter referred to as M. parvicella) is most frequently responsible for the problems of solid-liquid separation in bulking and foaming (Jenkins et al, 2004;Martins et al, 2004;Wanner, 1994).…”