Variability of type 021N in activated sludge as determined by in situ substrate uptake pattern and in situ hybridization with fluorescent rRNA targeted probes

Abstract

Bulking sludges were investigated in seven industrial or municipal activated sludge treatment plants from Denmark, Germany and Australia. The dominating filaments were all identified as type 021N according to the Eikelboom key. The extent of variability in the filament taxonomy was assessed using fluorescence in situ hybridization (FISH) with rRNA-targeted nucleic acid probes specific for type 021N, Thiothrix and Leucothrix. Not all of the filaments morphologically identified as type 021N hybridized with the 021N probe. In one treatment plant the predominant filament hybridized with the probe for Thiothrix and in one treatment plant the predominant filament did not hybridize with any of these probes. In none of the plants did filaments hybridize with the probe for Leucothrix. A study of the in situ uptake of different organic substrates by the various filaments was also conducted using microautogradiography. The uptake of 6 different organic substrates under aerobic conditions was studied by providing C-14 or H-3 labeled substrates (acetate, glucose, ethanol, glycine, leucine and oleic acid) in incubations of a period of 3 hours. No filaments took up all the tested substrates, and type 021N from the various treatment plants varied in their uptake abilities. The study demonstrated that strain differences with regard to substrate utilization are likely to occur among bacteria within the same genera and designated types which are indistinguishable on the basis of morphological observations alone and by the molecular probes used in this study for identification. Whether there is a clear correlation between type of wastewater and the capability of taking up the various organic substrates for the filaments remains to be elucidated.

Phylogenetic relationships of filamentous sulfur bacteria (Thiothrix spp. and Eikelboom type 021N bacteria) isolated from wastewatertreatment plants and description of Thiothrix eikelboomii sp. nov., Thiothrix unzii sp. nov., Thiothrix fructosivorans sp. nov. and Thiothrix defluvii sp. nov.

“…The aqueous phase was transferred to a fresh microcentrifuge tube and 2 vols ice-cold absolute ethanol (98% v/v) was added. The DNA was precipitated (Blackall, 1994).…”

“…The primers of Edwards et al (1989) were used for DNA sequencing. 16s rDNA sequence data for the Ben strains were obtained by the methods described by Blackall (1994 (Maidak et al, 1994) and GenBank were aligned with the sequences from this study using the GDE sequence editor (Smith et al, 1994). Sequence alignments were corrected manually by comparison with the secondary structure of Dichelobacter nodosus (y-Proteobacteria) 16s rRNA.…”

“…They also produce gliding gonidia, form rosettes and have the ability to deposit intracellular sulfur granules (Larkin & Strohl, 1983;Williams & Unz, 1985a, b;Williams et al, 1987). Thiothrix species are found in a number of habitats, ranging from sulfide-containing natural waters (Brigmon et al, 1994a;Jones et al, 1982;McGlannan & Makemson, 1990) and irrigation systems (Ford & Tucker, 1975) to activated-sludge wastewater-treatment plants, where their presence in large numbers contributes to the problem of filamentous sludge bulking (Brigmon et al, 1994b;Eikelboom, 1975;Tandoi et al, 1994;Wagner et al, 1994;Williams & Unz, 1985a). The involvement of Thiothrix species as causative organisms of filamentous sludge bulking in wastewatertreatment plants has led to studies of their physiology (Richard et al, 1985;Williams & Unz, 1985a, b ;Tandoi et al, 1994), ultrastructure (Brigmon et al, 1994b ;Williams et al, 1987), growth characteristics and interactions with heavy nietals (Shuttleworth & Unz, 1991.…”

“…These have been isolated in pure culture and subjected to phenotypic and genotypic characterization (Lane et nl., 1992;Larkin & Shinabarger, 1983;Odintsova & Dubinina, 1990 ;Dul'tseva & Dubinina, 1994;Polz et al, 1996;Teske et al, 1996). Of these, Thiothrix nivea alone appears in the Approved Lists of Bacterial Names (Skerman et al, 1980).…”

Analysis of Microbial Community Structure in Biological Wastewater Treatment Process of Mixed Wastewater Treatment Facility using Environmental·Ecological Technique

“…생물학적 처리공정에 존재하는 다양한 박테리아들은 하·폐 수의 특성에 따라 다양한 박테리아 군집 (consortium)을 형성 하여 존재한다. 따라서 생물학적 처리공정을 효율적으로 운 전하기 위해서는 처리조 내에 존재하는 다양한 박테리아들 의 활성이나 생체량과 같은 생물학적인 인자들의 변화를 파 악하는 것이 매우 중요하다 [1][2][3][4]. 일반적으로 도시 하수나 산업 폐수를 처리하는 생물학적 처리공정에서는 30종 이상 의 다양한 박테리아들이 존재하며 [1,5], 이들은 유입수의 성 상 및 수온과 같은 외부 환경적 요인의 변화에 따라 군집 패 턴에 많은 변화를 유발하기 때문에 생물학적 처리공정 내에 존재하는 다양한 박테리아 군집들을 관찰·해석하려는 연구 들이 많이 시도되었다 [6][7][8][9].…”