In situ detection of cell surface hydrophobicity of probe-defined bacteria in activated sludge

The surface hydrophobicity of different types of bacteria in activated sludge were investigated under in situ conditions by following the adhesion of fluorescent microspheres with defined surface properties to bacterial surfaces (the MAC-method). This technique was combined with identification of the bacteria with fluorescence in situ hybridization with rRNA-targeted oligonucleotides (FISH) and could thus be used for characterization of surface properties of probe-defined bacteria directly in a complex system without prior enrichment or isolation. This MAC-FISH technique could be used for single bacteria as well as filamentous bacteria. In the investigated activated sludge from an industrial wastewater treatment plant, two types of filamentous bacteria dominated. One morphotype consistently attracted only very few hydrophobic microspheres, indicating that the thin sheath of exopolymers around the cells had a hydrophilic surface. Use of a hierarchical set of gene probes revealed that these filaments were sulphide oxidising Thiothrix spp. The other predominating filamentous morphotype had a thick, very hydrophobic exopolymeric sheath. This filamentous bacterium was found to belong to the alpha-Proteobacteria. The relevance of the significant differences in surface hydrophobicity for the two morphotypes in respect to substrate uptake and floc formation is discussed.

Download Full-text

Influence of oxygen limitation on the cell surface properties of bacteria from activated sludge

Water Science & Technology ◽

10.2166/wst.1998.0663 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 349-352 ◽

Cited By ~ 5

Author(s):

R. Palmgren ◽

F. Jorand ◽

P. H. Nielsen ◽

J. C. Block

Keyword(s):

Cell Surface ◽

Activated Sludge ◽

Surface Properties ◽

Cell Surface Hydrophobicity ◽

Surface Hydrophobicity ◽

Growth Conditions ◽

Oxygen Limitation ◽

Cell Surface Properties ◽

Number Of Factors ◽

Math Test

Cell surface hydrophobicity is believed to be important to flocculation in activated sludge and biofilm systems. Optimization of these processes includes changes in the growth conditions of the bacteria. A number of factors influence cell surface hydrophobicity. The influence of oxygen on the cell surface hydrophobicity of 4 bacteria isolated from activated sludge was tested. The bacteria were grown in batch cultures with and without oxygen limitation. It was found that oxygen limitation generally caused a lowering of the cell surface hydrophobicity. The study also showed that there are many difficulties in measuring cell surface hydrophobicity since other cell surface properties, such as surface charge, influence the measurement methods. The MATH test was employed to establish how assay conditions influenced the results.

Download Full-text

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

Water Science & Technology ◽

10.2166/wst.1998.0685 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 423-430 ◽

Cited By ~ 16

Author(s):

P. H. Nielsen ◽

K. Andreasen ◽

M. Wagner ◽

L. L. Blackall ◽

H. Lemmer ◽

...

Keyword(s):

In Situ Hybridization ◽

Activated Sludge ◽

Treatment Plant ◽

Strain Differences ◽

Molecular Probes ◽

Clear Correlation ◽

Substrate Uptake ◽

Organic Substrates ◽

Uptake Pattern

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.

Download Full-text

Efficiency of Biological Phosphorus Removal by Filamentous Bacteria

Chemistry-Didactics-Ecology-Metrology ◽

10.1515/cdem-2016-0010 ◽

2016 ◽

Vol 21 (1-2) ◽

pp. 117-123 ◽

Cited By ~ 1

Author(s):

Alicja Machnicka ◽

Klaudiusz Grübel

Keyword(s):

Activated Sludge ◽

Phosphorus Removal ◽

Water Environment ◽

Treatment Plant ◽

Chemical Precipitation ◽

Heterogeneous Structure ◽

Filamentous Bacteria ◽

Biological Phosphorus Removal ◽

High Concentration ◽

Sludge Flocs

AbstractPhosphorus removal in wastewater treatment plant is carried out by chemical precipitation, advanced biological treatment or a combination of both. One of the biggest problems with high concentration of phosphorus in water environment is eutrophication. Activated sludge flocs have a heterogeneous structure, which consist of a variety of microorganisms. Filamentous bacteria are normally present in the activated sludge and have ability to assimilation of phosphorus. In this study phosphorus accumulation by isolated filamentous bacteria from activated sludge foam was present.

Download Full-text

Time-series genome-centric analysis unveils bacterial response to operational disturbance in activated sludge

10.1101/565770 ◽

2019 ◽

Cited By ~ 1

Author(s):

María Victoria Pérez ◽

Leandro D. Guerrero ◽

Esteban Orellana ◽

Eva L. Figuerola ◽

Leonardo Erijman

Keyword(s):

Growth Rate ◽

Time Series ◽

Wastewater Treatment ◽

Activated Sludge ◽

Microbial Communities ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Operating Conditions ◽

The Face

ABSTRACTUnderstanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of three years, including a period of nine month of disturbance, characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons and thein situgrowth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the ribosomal RNA (rrn) operon. Despite only moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, as the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions.IMPORTANCEIn this work we investigated the response of microbial communities to disturbances in a full-scale activated sludge wastewater treatment plant over a time-scale that included periods of stability and disturbance. We performed a genome-wide analysis, which allowed us the direct estimation of specific cellular traits, including the rRNA operon copy number and the in situ growth rate of bacteria. This work builds upon recent efforts to incorporate growth efficiency for the understanding of the physiological and ecological processes shaping microbial communities in nature. We found evidence that would suggest that activated sludge could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. This paper provides relevant insights into wastewater treatment process, and may also reveal a key role for growth traits in the adaptive response of bacteria to unsteady environmental conditions.

Download Full-text

Application of oligonucleotide probes for the detection of Thiothrix spp. in activated sludge plants treating paper and board mill wastes

Water Science & Technology ◽

10.2166/wst.2002.0534 ◽

2002 ◽

Vol 46 (1-2) ◽

pp. 559-564 ◽

Cited By ~ 8

Author(s):

S.B. Kim ◽

M. Goodfellow ◽

J. Kelly ◽

G.S. Saddler ◽

A.C. Ward

Keyword(s):

Activated Sludge ◽

Bacterial Population ◽

Oligonucleotide Probe ◽

In Situ Hybridisation ◽

Filamentous Bacteria ◽

Phylogenetic Groups ◽

Investigation Period ◽

Mixed Populations ◽

Conventional Microscopy

Filamentous bacteria belonging to the genus Thiothrix were detected in activated sludge samples using the fluorescent in situ hybridisation (FISH) technique. A 16S rRNA-targeted oligonucleotide probe was developed for the detection of members of the T. fructosivorans group, and the performance of probe TNI for the detection of Thiothrix nivea group was enhanced by using an unlabeled competitor. A set of 5 probes covering all phylogenetic groups of Thiothrix were used to examine samples taken from selected activated sludge plants treating paper and board mill wastes. Members of the T. eikelboomii group formed the predominant filamentous bacterial population in plants experiencing poor sludge settleability, whereas members of the T. nivea group were commonly found but not dominantly in the remaining plants. Members of the T. fructosivorans group were not detected at any significant level in any of the samples. The distribution of the main Thiothrix types remained unchanged throughout the investigation period. It was evident that mixed populations of Thiothrix spp. were present in all activated sludge samples investigated, the observed differences were in the relative abundance of the various groups. These findings were supported by the results obtained using conventional microscopy.

Download Full-text

Phylogenetic Analysis of and Oligonucleotide Probe Development for Eikelboom Type 021N Filamentous Bacteria Isolated from Bulking Activated Sludge

Applied and Environmental Microbiology ◽

10.1128/aem.66.11.5043-5052.2000 ◽

2000 ◽

Vol 66 (11) ◽

pp. 5043-5052 ◽

Cited By ~ 85

Author(s):

Takahiro Kanagawa ◽

Yoichi Kamagata ◽

Shinobu Aruga ◽

Tetsuro Kohno ◽

Matthias Horn ◽

...

Keyword(s):

Activated Sludge ◽

Oligonucleotide Probe ◽

Sequence Similarity ◽

Rdna Sequence ◽

Filamentous Bacteria ◽

16S Rdna Sequence ◽

Monophyletic Cluster ◽

16S Ribosomal Dna ◽

In Situ Detection

ABSTRACT Fifteen filamentous strains, morphologically classified as Eikelboom type 021N bacteria, were isolated from bulking activated sludges. Based on comparative 16S ribosomal DNA (rDNA) sequence analysis, all strains form a monophyletic cluster together with all recognized Thiothrix species (88.3 to 98.7% 16S rDNA sequence similarity) within the gamma-subclass ofProteobacteria. The investigated Eikelboom type 021N isolates were subdivided into three distinct groups (I to III) demonstrating a previously unrecognized genetic diversity hidden behind the uniform morphology of the filaments. For in situ detection of these bacteria, 16S rRNA-targeted oligonucleotide probes specific for the entire Eikelboom type 021N-Thiothrix cluster and the Eikelboom type 021N groups I, II, and III, respectively, were designed, evaluated, and successfully applied in activated sludge.

Download Full-text

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR

Water Science & Technology ◽

10.2166/wst.2006.369 ◽

2006 ◽

Vol 54 (1) ◽

pp. 39-45 ◽

Cited By ~ 16

Author(s):

E.L. Carr ◽

K.L. Eales ◽

R.J. Seviour

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plants ◽

Carbon Sources ◽

Mycolic Acid ◽

Substrate Uptake ◽

Wastewater Treatment Process ◽

Pure Cultures ◽

Gordonia Amarae

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.

Download Full-text