Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sphaerotilus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2003

Modeling of chlorine effect on floc forming and filamentous micro-organisms of activated sludges.

Chlorination is the most economical, non-specific method to control the excessive growth of filamentous micro-organisms causing bulking in activated sludge systems in the treatment of food industrial wastewaters; it was one of the first methods used to control filamentous bulking and is still widely employed. Considering that chlorination affects both floc-forming and filamentous micro-organisms and leaves undesirable disinfection by-products, it is necessary to define the adequate doses to control bulking, minimizing the effect on floc-forming bacteria. In the present work the effect of biomass concentration and type of micro-organism on chlorine decay kinetics was evaluated; the inactivation of either a filamentous (Sphaerotilus natans) or a floc-forming (Acinetobacter anitratus) micro-organism due to chlorination was also analyzed. For chlorine decay assays, the samples were treated in a batch system with sodium hypochlorite ranging between 9.8 and 56.6 mg Cl(2) (gVSS)(-1). Respirometric assays were used to evaluate the effect of chlorine on micro-organisms respiratory activity; in these cases, sodium hypochlorite doses ranged between 2.5 and 18 mgCl(2) (gVSS)(-1).A model that allowed to predict simultaneously chlorine consumption and respiratory activity decay for both micro-organisms as a function of time was proposed. The model includes three coupled differential equations corresponding to respiratory inhibition, readily organic matter oxidation by chlorine and chlorine decay. The rate of chlorine decay depended on both, type and concentration of the micro-organisms in the system. Chlorine consumption rate due to S. natans was 2-4 times faster than A. anitratus. Using the proposed model initial critical chlorine doses (the lowest initial dose that leads to a total inhibition of the respiratory activity) were calculated for both micro-organisms and values of 11.9 mgCl(2) (gVSS)(-1) for S. natans and 4.5 mgCl(2) (gVSS)(-1) for A. anitratus were obtained. These critical doses indicated that in non flocculated pure cultures, floc-former bacteria A. anitratus was more susceptible to chlorine action than S. natans.

Acinetobacter↗
PubMed2003

A survey of filamentous organisms at the Deer Island treatment plant.

The Deer Island Treatment Plant (DITP) treating both domestic and industrial wastewater, has a peak flow capacity of up to 1270 million gallons per day (MGD) (3342 m3 min(-1). The DITP contains a Pilot Plant, which consists of two identical pure oxygen activated sludge treatment trains, each with a maximum capacity of 1 MGD (2.63 m3 min(-1)) to simulate the maximum flow of the full size facility. This study documents the community of filamentous organisms living in the activatedsludge under various operational conditions in the Pilot Plant. Sixteen types of filamentous organisms were identified. The major filamentous organisms present in the Pilot Plant were Type 1701, Type 0041, Sphaerotilus natans, Microthrix parvicella, and Nocardia sp. Nocardia sp. was quite dominant in the early stages of the experimental period during high ambient temperatures (summer), indicating that temperature is one determining factor in the distribution of Nocardia sp. Thiothrix sp. was very sensitive to the dissolved oxygen (DO) level, with low DO values favoring the growth of the organisms. Microbiological observations made during the start-up and stable operation of the full-scale secondary treatment plant (maximum capacity 780 MGD) are also reported. No dominant filamentous species existed during the start-up period. Type 0803 and Type 1701, indicators of low oxygen level for the applied food to microorganism ratio, confirmed the low DO conditions of activated sludge tanks.

Data Collection↗
PubMed1977

Numerical taxonomy and ecology of petroleum-degrading bacteria.

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae, Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station.

Bacteria↗
PubMed1992

Enzymatic iron oxidation by Leptothrix discophora: identification of an iron-oxidizing protein.

An iron-oxidizing factor was identified in the spent culture medium of the iron- and manganese-oxidizing bacterial strain Leptothrix discophora SS-1. It appeared to be a protein, with an apparent molecular weight of approximately 150,000. Its activity could be demonstrated after fractionation of the spent medium by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A spontaneous mutant of L. discophora SS-1 was isolated which excreted neither manganese- nor iron-oxidizing activity, whereas excretion of other proteins seemed to be unaffected. Although the excretion of both metal-oxidizing factors was probably linked, the difference in other properties suggests that manganese and iron oxidation represent two different pathways. With a dot-blot assay, it was established that different bacterial species have different metal-oxidizing capacities. Whereas L. discophora oxidized both iron and manganese, Sphaerotilus natans oxidized only iron and two Pseudomonas spp. oxidized only manganese.

Bacteria↗
PubMed1994

Structure and composition of biological slimes on paper and board machines.

Biological slimes (biofilms) collected from the wet end of paper and board machines were examined by electron microscopy and analyzed for fatty acid composition, neutral sugar composition, and ATP. Electron microscopy revealed minuscule prokaryotic organisms (diameter, 0.2 to 0.4 mum). Larger cells morphologically resembling Sphaerotilus and Leptothrix spp. were found in slimes from machines using recycled fiber or unbleached pulp. The bacteria were embedded in a slimy matrix and often contained reserve materials microscopically resembling poly-beta-hydroxybutyrate and glycogen. Fatty acid analysis of the slimes revealed bacterial signature fatty acids in concentrations equivalent to the presence of 2 x 10 to 2.6 x 10 (average, 7 x 10) bacterial cells (live and dead) per g (dry weight) of slime. The slimes contained several known components of bacterial polysaccharides in addition to glucose, indicating that the slime body consisted of bacterial polysaccharides. The slimes contained uronic acids equivalent to a binding capacity of 12.5 to 50 mumol of divalent cations per g (dry weight) of slime. The uronic acid-containing polysaccharides may be responsible for the accumulation of heavy metals in the slime. Calculation of the ATP contents of the slimes resulted in an estimate of 5 x 10 cells per g (dry weight) of slime when calibrated with pure bacterial cultures isolated from the slimes. From electron micrographs, an estimate ranging from 1 x 10 to 1.5 x 10 (average, 4 x 10) cells per g (dry weight) of slime was obtained.

Journal Article↗
PubMed2003

Diversity and seasonal variability of beta-Proteobacteria in biofilms of polluted rivers: analysis by temperature gradient gel electrophoresis and cloning.

The beta-subgroup of the Proteobacteria has been shown to be important in aquatic habitats and was investigated in depth here by molecular 16S rRNA techniques in biofilms of the Elbe River and its polluted tributary, the Spittelwasser River. The bacterial 16S rRNA genes were cloned from each site, screened for beta-proteobacterial clones and sequenced. River biofilm clones from both rivers grouped into 9 clusters (RBFs). RBFs 1, 2, and 3 fell into the recently described betaI cluster of cosmopolitan freshwater bacteria, where they represented new species related to Rhodoferax, Aquaspirillum, and Hydrogenophaga: RBFs 4 to 7 affiliated with Aquabacterium commune, Ideonella dechloratans, and Sphaerotilus natans, respectively. The two remaining RBFs were uncultivated clusters, one of them being distantly related to Gallionella ferruginea. Seasonal changes in the relative intensity of the beta-proteobacterial 16S rRNA genes of biofilms harvested monthly for 1 year were determined by specific amplification and separation by temperature gradient gel electrophoresis (TGGE). Bands were identified by comparison of clones to community fingerprints by TGGE. Eight of 13 identified bands were shared by both habitats but showed different relative abundance and seasonal variability in the two rivers, probably caused by differences in temperature and pollutants. The data indicate new not-yet-cultivated clusters of river biofilm organisms, some of them probably distributed globally. They confirm the importance of certain known freshwater genera in river biofilms. The high phylogenetic resolution obtained by clone library analysis combined with the high temporal resolution obtained by TGGE suggest that the observed microdiversity in the river biofilm clone libraries might be caused by phylogenetically closely related microbial populations which are adapted to ecological parameters.

Betaproteobacteria↗
PubMed2005

A broad-host-range, generalized transducing phage (SN-T) acquires 16S rRNA genes from different genera of bacteria.

Genomic analysis has revealed heterogeneity among bacterial 16S rRNA gene sequences within a single species; yet the cause(s) remains uncertain. Generalized transducing bacteriophages have recently gained recognition for their abundance as well as their ability to affect lateral gene transfer and to harbor bacterial 16S rRNA gene sequences. Here, we demonstrate the ability of broad-host-range, generalized transducing phages to acquire 16S rRNA genes and gene sequences. Using PCR and primers specific to conserved regions of the 16S rRNA gene, we have found that generalized transducing phages (D3112, UT1, and SN-T), but not specialized transducing phages (D3), acquired entire bacterial 16S rRNA genes. Furthermore, we show that the broad-host-range, generalized transducing phage SN-T is capable of acquiring the 16S rRNA gene from two different genera: Sphaerotilus natans, the host from which SN-T was originally isolated, and Pseudomonas aeruginosa. In sequential infections, SN-T harbored only 16S rRNA gene sequences of the final host as determined by restriction fragment length polymorphism analysis. The frequency of 16S rRNA gene sequences in SN-T populations was determined to be 1 x 10(-9) transductants/PFU. Our findings further implicate transduction in the horizontal transfer of 16S rRNA genes between different species or genera of bacteria.

Bacteriophages↗
PubMed1977

Numerical taxonomy and ecology of oligotrophic bacteria isolated from the estuarine environment.

Slow-growing bacteria, isolated on nutrient-rich and nutrient-limited media, from Chesapeake Bay water and sediment samples, were examined for 119 biochemical, cultural, morphological, nutritional, and physiological characters. Those bacteria which grow on low nutrient media, termed oligotrophs, a total of 162 strains, were subjected to taxonomic analysis, as a preliminary step in determining their ecological significance. The data for all strains included in the study were examined by computer and the simple matching (S SM) and Jaccard (SJ) coefficients calculated. Clustering was achieved by the unweighted average-linkage method. From sorted similarity matrices and dendrograms, 148 strains, 90% of the total, were recovered in 24 phenetic groups defined at the 80 to 85% similarity level. Only 12 phena could be presumptively identified and these included representatives of Alcaligenes, Corynebacterium, Hyphomicrobium, Hyphomonas polymorpha, Listeria, Nocardia marina, Pedomicrobium, Planococcus citreus, Sphaerotilus, Streptothrix, and Streptomyces. Of the remaining organisms, 10% were unidentified sheathed bacteria. It is concluded that slow-growing bacteria are distributed throughout the estuarine environment and can account for a large proportion of the colonies observed on media after prolonged periods of incubation. The oligotrophic bacteria appear to predominate in areas where the concentration of available nutrients is low and are more characteristic of non-eutrophic aquatic systems.

Actinomycetales↗
PubMed1987

Bacterial flora in bottled uncarbonated mineral drinking water.

A quantitative study of bacterial populations in mineral water was carried out. Samples were stored at 6 and 20 degrees C, and the colony counts were determined on tryptone agar plates incubated at 22 and 37 degrees C. Samples were collected from the spring source in sterile glass flasks and from the bottling factory in conventional plastic and glass containers. In both cases, the initial population (10(1)-10(2) cfu/mL water) increased to 10(5)-10(6) cfu/mL after 3 days storage as determined from plate counts incubated at 22 degrees C. The levels reached by this population were similar to those of samples of mineral water obtained at the market stage. Results from plate counts incubated at 37 degrees C showed that populations in samples collected at the bottling factory reached 10(2)-10(3) cfu/mL. No growth was observed in water collected from spring source. Bacterial multiplication was not stopped even when water was stored at 6 degrees C. Caulobacter was the genus found most frequently in both types of samples, followed by Sphaerotilus-Leptothrix. Acinetobacter calcoaceticus and Pseudomonas fluorescens were frequently found in only two springs, and Pseudomonas putida, Arthrobacter, Aeromonas hydrophilia, and Corynebacterium were isolated less frequently. Janthinobacterium was recovered only once from a single spring. A giant bacterium closely resembling Hyphomicrobium and a budding one similar to Pasteuria were recovered from all samples of a single spring and from some of the commercial samples.

Bacteria↗
PubMedDate not supplied

Production of polyhydroxyalkanoate during treatment of low-phosphorus-content wastewater.

To evaluate whether poly-beta-hydroxyalkanoate (PHA) production and wastewater treatment could be combined in a single biological process, a bench-scale sequencing batch reactor was operated with sequential anaerobic and aerobic stages and removal of excess sludge at different stages of treatment. The reactor treated synthetic wastewater with a high organic and low nutrient content, simulating industrial wastewater. Chemical oxygen demand removal efficiency was more than 90% in all cases. Poly-beta-hydroxyalkanoate accumulation was significant, although it did not appear to be induced by oxygen limitations during the anaerobic stage. Sphaerotilus natans was apparently the dominant PHA-accumulating organism at the end of each reactor run and corresponded to a PHA accumulation of 16 to 20% of the total dry cell mass. Before S. natans dominated the reactors, PHA accumulation was approximately 17% when biomass was removed at the end of the aerobic stage and 6.6% when sludge removal also occurred during the anaerobic stage.

Bacteria, Aerobic↗
PubMed2002

First results from a screening of filamentous organisms present in Buenos Aires's activated sludge plants.

Activated sludge samples from municipal and industry plants were evaluated with the aim to recognise the mainly filamentous bacteria found. The routine tests recommended were performed: Gram, Neisser, PHB-Nilo blue epifluorescence reaction and S. The morphologic characteristics were determined. Correlation between environmental conditions and abundance of dominant bacteria were made. All plants were completely mixed configurations with anoxic reactor for denitrification ahead of main aerobic reactor. Also all systems were working at low F/M values or high sludge age (> ten days) and in some cases with low oxygen concentration. The dominant species were Type 021 N, Thiothrix I, Sphaerotilus natans, Microthrix parvicella, Nocardia sp, Type 1701, Type 1863, Type 0041 and Type 0092.

Actinobacteria↗
PubMed1990

[Microbiological profile in water-supply conduits from a clogged well].

This article presents the results of an investigation involving bacterioflora in a water well clogged for the presence of biomass. The water well, placed in a zone near Rome, showed some problems about the water quality and about the extraction of water. The examination of the interior of the pipes showed the presence of biomass. The biomass was examined microscopically and bacteriological analyses were carried out on it. Heterotrophic bacteria were enumerated with three different media by direct count, Pseudomonas sp., yeasts and fungi also by spread plate method. The anaerobic Sulphate Reducing Bacteria were investigated by "Most Probable Number" technique. The results of the analyses showed the presence of protozoa and algae. Moreover high quantity of bacterial flora as heterotrophic bacteria and Pseudomonas sp. were revealed. Sulphate Reducing Bacteria were enumerated in low quantities. Sphaerotilus natans, Actinomyces and Rhodotorula were identified. The clogging problems arose from the presence of filamentous microorganisms as Sphaeroilus natans and Actinomyces sp. When microorganisms of this kind are present in aquifers they can multiply massively if the conditions are favorable.

Animals↗
PubMedDate not supplied

[Isolation and properties of BstBSI restriction endonuclease from the thermophilic soil bacteria Bacillus stearothermophilus BS].

A new restriction endonuclease BstBSI was isolated and purified from the thermophilic soil bacterium Bacillus stearothermophilus BS by the blue sepharose and hydroxyapatite chromatographies. The enzyme is an isoschizomer of SnaI from Sphaerotilus natans C. It recognizes the hexanucleotide GTATAC and cleaves DNA in the center of the sequence. The maximal catalytic activity of the endonuclease is registered in 50 mM tris-HCl (pH 9.0) buffer with the high ionic strength (100 mM NaCl) in the presence of 10 mM MgCl2 at 45 degrees C. Glucosylated DNA of the phage T4 is not cleaved by the enzyme.

Chromatography, Gel↗