A survey of filamentous foaming in activated sludge plants in Hong Kong

1994 ◽  
Vol 30 (11) ◽  
pp. 251-254 ◽  
Author(s):  
H. Chua ◽  
K. Y. Le
Keyword(s):  
Fatty Acids ◽  
Hong Kong ◽  
Carbon Source ◽  
Activated Sludge ◽  
Sole Carbon Source ◽  
Sewage Treatment ◽  
Municipal Sewage ◽  
Filamentous Foaming ◽  
Nocardia Amarae

Of five major secondary sewage treatment works surveyed during 1993 in Hong Kong, two had frequent foaming in the activated sludge plants which resulted in unmanageable operational problems. In this study, branched-filamentous Nocardia amarae was identified as the main causative bacteria in foaming sludges. In vitro studies showed that fatty acids that are commonly found in municipal sewage could be utilized by N. amarae as the sole carbon source, and presence of these fatty acids in sewage could stimulate growth.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

Isolation of alcohol oxidase and two other methanol regulatable genes from the yeast Pichia pastoris

1985 ◽  
Vol 5 (5) ◽  
pp. 1111-1121
Author(s):  
S B Ellis ◽  
P F Brust ◽  
P J Koutz ◽  
A F Waters ◽  
M M Harpold ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeasts ◽  
Sequence Analyses ◽  
Yeast Pichia Pastoris ◽  
Oxidation Of Methanol ◽  
Regulated Expression

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.

Treatment of organic chlorine in pulping effluents by activated sludge

1999 ◽  
Vol 40 (1) ◽  
pp. 275-279 ◽  
Author(s):  
G. (Goktayoglu) Demirbas ◽  
C. F. Gokcay ◽  
F. B. Dilek
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Organic Content ◽  
Domestic Sewage ◽  
Municipal Sewage ◽  
Removal Mechanism ◽  
Start Up ◽  
Organic Chlorine ◽  
Aox Removal

A model activated sludge (AS) plant was fed by pulping effluents from a straw and reed processing paper works. The model was initially operated to simulate a dedicated treatment plant by continuously receiving chlorinated effluents from the pulp bleachery. In this simulation cycle the model activated sludge was seeded only once during start-up and did not receive any domestic sewage after that. A carbon source was added in some of the experiments to bring up the organic content. In the second simulation cycle the pulping effluent was co-treated with municipal sewage. In this case the activated sludge unit was being continuously dosed by microorganisms and the organics present in the sewage. A higher organic chlorine (AOX) removal was obtained at shorter SRTs in the co-treatment AS. High AOX removal was achieved at longer SRTs in the dedicated, once-seeded AS. The AOX removal mechanism was mineralization in both cycles.

Thermochemical pretreatment in the anaerobic digestion of waste activated sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 173-179 ◽  
Author(s):  
S. Tanaka ◽  
K. Kamiyama
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Municipal Sewage ◽  
Waste Activated Sludge ◽  
Anaerobic Digesters ◽  
Thermochemical Pretreatment ◽  
Methane Production Rate

Effects of a thermochemical pretreatment on the anaerobic digestion of waste activated sludge (WAS) was investigated by semicontinuously-fed digesters operated at 37¡C. WAS from a return sludge line of a municipal sewage treatment plant was pretreated by autoclaving at 130°C for 5 minutes after adding 0.3g NaOH/g VSS. Solids of WAS were thermochemically solubilized to one half and then 60% or more were in totality solubilized in anaerobic digesters fed with pretreated WAS at 2-8 days of hydraulic retention times (HRT), while only 16-36% were solubilized in digesters fed with raw WAS. The adverse effect of the set temperature (130°C) on the biodegradability of protein was not found. As a result, removal rates of COD in digestion was increased from 38% to 57% at 8 days HRT by the pretreatment. A specific methane production rate in the pretreated process was three times as high as the normal process. The thermochemical pretreatment was found to be very effective to enhance biodegradability as well as solubilization of WAS in anaerobic digestion.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

scholarly journals Glucose metabolism in the extreme thermoacidophilic archaebacterium Sulfolobus solfataricus

1984 ◽  
Vol 224 (2) ◽  
pp. 407-414 ◽  
Author(s):  
M De Rosa ◽  
A Gambacorta ◽  
B Nicolaus ◽  
P Giardina ◽  
E Poerio ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Sulfolobus Solfataricus ◽  
Oxidative Breakdown

Sulfolobus solfataricus is a thermophilic archaebacterium able to grow at 87 degrees C and pH 3.5 on glucose as sole carbon source. The organism metabolizes glucose by two main routes. The first route involves an ATP-dependent phosphorylation to give glucose 6-phosphate, which readily isomerizes to fructose 6-phosphate. In the second route, glucose is converted into gluconate by an NAD+-dependent dehydrogenation; gluconate is then dehydrated to 2-keto-3-deoxygluconate, which, in turn, is cleaved to pyruvate and glyceraldehyde. Each metabolic step has been tested in vitro at 70 degrees C on dialysed homogenates or partially purified fractions; minimal requirements of single enzymes have been evaluated. Identification of the intermediates is based on chromatographic, spectroscopic and/or synthetic evidence and on specific enzymic assays. The oxidative breakdown of glucose to pyruvate occurring in S. solfataricus differs from the Entner-Doudoroff pattern in that there is an absence of any phosphorylation step.

scholarly journals A synthetic medium for the selection of yeasts able to utilize fatty acids as the sole carbon source.

1996 ◽  
Vol 42 (1) ◽  
pp. 87-91 ◽  
Author(s):  
ESTEBAN C. DELL'ANGELICA ◽  
DANIEL MILIKOWSKI ◽  
DANIEL A. SAENZ ◽  
CARLOS A. STELLA ◽  
EUGENIA H. RAMOS ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Synthetic Medium ◽  
Selection Of

scholarly journals In vitro fermentability of prebiotic oligosaccharides by lactobacilli

2012 ◽  
Vol 29 (Special Issue) ◽  
pp. S49-S54 ◽  
Author(s):  
G. Kunová ◽  
V. Rada ◽  
I. Lisová ◽  
Š. Ročková ◽  
E. Vlková
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Growth Curves ◽  
Exponential Phase ◽  
Carbohydrate Source ◽  
Viable Cells ◽  
Lysozyme Concentration ◽  
Pure Substances ◽  
Prebiotic Oligosaccharides

Twelve strains of lactobacilli were tested for their growth and ability to utilise six prebiotics (pure substances and commercially available prebiotics) as a sole carbon source. All strains showed a considerable growth on all prebiotics tested. Inulin was the best carbohydrate source for lactobacilli, followed by lactulose and raffinose. A massive increase of viable cells on commercial prebiotic mixtures (Vivinal, Oligomate 55, and Orafti P95) was also observed. Lysozyme susceptibility was assayed in 13 strains of lactobacilli. Eight out of 13 strains were completely resistant to the lysozyme concentration of 400 µg/ml, in the rest of the strains a slight delay of the exponential phase of the growth curves was observed. Lactobacilli tolerated lysozyme well and were able to utilise all prebiotics.

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