scholarly journals NADPH oxidase of guinea-pig macrophages catalyses the reduction of ubiquinone-1 under anaerobic conditions

1986 ◽  
Vol 237 (2) ◽  
pp. 541-545 ◽  
Author(s):  
M Murakami ◽  
M Nakamura ◽  
S Minakami
Keyword(s):  
Guinea Pig ◽  
Nadph Oxidase ◽  
Resting Cells ◽  
Maximal Velocity ◽  
Superoxide Anions ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Superoxide Formation ◽  
Electron Carriers ◽  
Anaerobic Reduction

The stimulation-specific NADPH-dependent reduction of ubiquinone-1 (Q-1) in guinea-pig macrophages was studied. The activity was due neither to any modified product of the phagocytosis-specific NADPH oxidase nor to non-specific diaphorases of the cells, since the activity was measured in sonicated or detergent-disrupted cells by subtracting the activity in the resting cells from that in cells activated by phorbol 12-myristate 13-acetate. The activity was not mediated by superoxide anions, since strict anaerobic conditions were employed. The anaerobic reduction of Q-1 was NADPH-specific, like superoxide formation under aerobic conditions, and its maximal velocity was also essentially the same as that of superoxide formation. The oxidase does not directly reduce Q-1 under aerobic conditions [Nakamura, Murakami, Umei & Minakami (1985) FEBS Lett. 186, 215-218], and the electron transfer from NADPH to cytochrome c by the oxidase under aerobic conditions was not enhanced by the addition of Q-1. The observations indicate that the phagocytosis-specific NADPH oxidase reduces Q-1 and that oxygen competes with the reduction of Q-1. Q-1 seems to accept electrons not from the intermediary electron carriers of the oxidase but from the terminal oxygen-reducing site of the enzyme.

Mechanisms of Adriamycin-Dependent Oxygen Activation Catalyzed by NADPH-Cytochrome c-(Ferredoxin)-Oxidoreductase

1984 ◽  
Vol 39 (3-4) ◽  
pp. 261-267 ◽  
Author(s):  
Eva Paur ◽  
Richard J. Youngman ◽  
Edmund Lengfelder ◽  
Erich F. Elstner
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Reaction Vessel ◽  
Semiquinone Radical ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Ferredoxin Oxidoreductase ◽  
Nadph Cytochrome ◽  
Superoxide Formation ◽  
Electron Donation

Under aerobic conditions, O2 uptake and production of O2- and H2O2 by isolated NADPH - cytochrome c-(ferredoxin)-oxidoreductase from Euglena gracilis was strongly stimulated by adriamycin. Further stimulation was not observed with 0.1 mᴍ Fe3+-EDTA. Methionine fragmentation (measured as ethylene release), as a reliable indicator for the formation of OH- radical-like oxidants under aerobic conditions (100 μmol O2 in a 10 ml reaction vessel) was strongly stimulated by 0.1 mᴍ Fe3+-EDTA or, in the absence of iron, by partial anaerobiosis (1 μmol O2 per vessel). The highest rate of methionine fragmentation was observed under anaerobic conditions in the presence of both reduced adriamycin and added H2O2. Aerobic methionine fragmentation in the presence of adriamycin and Fe3+-EDTA was inhibited by superoxide dismutase and catalase by more than 90%, while methionine fragmentation under semianaerobiosis in the absence of Fe3+-EDTA was inhibited by superoxide dismutase to only about 50%, while catalase again inhibited by more than 90%. These results indicate that the adriamycin-catalyzed production of a strong oxidant appears to be governed by different mechanisms depending on oxygen availability; namely the production of a Fenton-type oxidant driven by adriamycin-catalyzed superoxide formation and also, the formation of the “crypto-OH- radical” by direct electron donation from the adriamycin semiquinone radical to H2O2 under oxygen limiting conditions

Production and Degradation of Formate by Veillonella dispar ATCC 17745

1986 ◽  
Vol 65 (6) ◽  
pp. 903-905 ◽  
Author(s):  
E. Hoshino ◽  
M. Sato
Keyword(s):  
Strictly Anaerobic ◽  
Resting Cells ◽  
Cell Free Extract ◽  
Anaerobic Conditions ◽  
Pyruvate Formate Lyase ◽  
Aerobic Conditions ◽  
Lyase Activity

Under strictly anaerobic conditions, the resting cells of V. dispar ATCC 17745 produced formate as well as acetate and propionate from pyruvate or from lactate. Pyruvate formate-lyase activity was found when the activity was assayed under strictly anaerobic conditions. Under aerobic conditions, however, the resting cells did not produce formate from pyruvate or from lactate, though the cells actively metabolized pyruvate or lactate (mainly to acetate). This was ascribed to pyruvate formate-lyase activity being easily lost when the cell-free extract was exposed to the air. A part of the produced formate was further degraded to CO2 by the resting cells.

scholarly journals Superoxide-forming NADPH oxidase preparation of pig polymorphonuclear leucocyte

1982 ◽  
Vol 205 (3) ◽  
pp. 593-601 ◽  
Author(s):  
H Wakeyama ◽  
K Takeshige ◽  
R Takayanagi ◽  
S Minakami
Keyword(s):  
Nadph Oxidase ◽  
Enzyme System ◽  
Polymorphonuclear Leucocyte ◽  
Tween 20 ◽  
Polymorphonuclear Leucocytes ◽  
Resting Cells ◽  
Superoxide Formation ◽  
Km Value ◽  
Nadph Oxidation ◽  
Relationship Of

A phagocytic vesicle fraction with high NADPH-dependent superoxide-forming activity was obtained in large quantity from pig blood polymorphonuclear leucocytes, phagocytosing oil droplets in the presence of cyanide. The activity of the homogenate of the phagocytosing cells was 40 times that of the resting cells, and 70% of the activity in the homogenate was recovered in the phagocytic vesicle fraction. Essentially all of the superoxide-forming activity was extracted by repeated extraction with a mixture containing deoxycholate and Tween 20. The extract had a superoxide-forming activity of 1 mumol/min per mg of protein with NADPH, and one-fifth of this with NADH, Km values being similar to those of the vesicle fraction (40 microM for NADPH and 400 microM for NADH). A stoichiometric relationship of 1:2 for NADPH oxidation and superoxide formation was obtained, in agreement with the reaction NADPH +2O2 leads to NADP+ + 2O2 -. + H+. The activity of the extract was enhanced 2-fold by the addition of FAD, suggesting that the flavin is a component of the enzyme system. The Km value for FAD was 0.077 microM. The activities in both vesicle fraction and extract were labile even on refrigeration, but could be kept for several months at −70 degrees C.

The Reaction of Thiol Compounds with the Vitamin-K Dependent Clotting Factors

1969 ◽  
Vol 21 (03) ◽  
pp. 573-579 ◽  
Author(s):  
P Fantl
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Anaerobic Conditions ◽  
Clotting Factors ◽  
Thiol Compounds ◽  
Aerobic Conditions ◽  
One Stage ◽  
Factor Ii ◽  
Ph Dependent ◽  
The One

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.

Performance of aerobic granular sludge at variable circulation rate in anaerobic–aerobic conditions

2014 ◽  
Vol 69 (11) ◽  
pp. 2252-2257 ◽  
Author(s):  
Hasnida Harun ◽  
Aznah Nor Anuar ◽  
Zaini Ujang ◽  
Noor Hasyimah Rosman ◽  
Inawati Othman
Keyword(s):  
Municipal Wastewater ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Soy Sauce ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Circulation Rate ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Mixed Liquor

Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic–aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: VII. FERMENTATION OF WHEAT BY AEROBACILLUS POLYMYXA UNDER AEROBIC AND ANAEROBIC CONDITIONS

1946 ◽  
Vol 24f (1) ◽  
pp. 1-11 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Carbon Dioxide ◽  
Anaerobic Fermentation ◽  
Anaerobic Conditions ◽  
Mechanical Agitation ◽  
Fermentation Time ◽  
Aerobic Conditions ◽  
Ethanol Formation ◽  
Time Required ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aeration by mechanical agitation of 15% wheat mash fermented by Aerobacillus polymyxa inhibited the formation of 2,3-butanediol and particularly of ethanol. Aeration of similar mashes by passage of finely dispersed air or oxygen at the rate of 333 ml. per minute per litre of mash increased the rate of formation and yield of 2,3-butanediol but inhibited ethanol formation. However, the over-all time required for the completion of fermentation was not shortened from the usual 72 to 96 hr. required for unaerated mashes. There was no evidence of a shift from fermentative to oxidative dissimilation. Under aerobic conditions, the final butanediol–ethanol ratio was approximately 3:1. Anaerobic conditions, as produced by the passage of nitrogen or hydrogen through the mash, increased the rate of formation of both butanediol and ethanol and shortened the fermentation time to about 48 hr. Under these conditions, the butanediol–ethanol ratio was reduced to about 1.3:1.0. Carbon dioxide gave a butanediol–ethanol ratio resembling that of anaerobic fermentation but did not reduce fermentation time.

METABOLISM OF RAM TESTICULAR SPERMATOZOA IN THE PRESENCE OF TESTOSTERONE AND RELATED STEROIDS

1970 ◽  
Vol 65 (3) ◽  
pp. 565-576 ◽  
Author(s):  
J. K. Voglmayr ◽  
R. N. Murdoch ◽  
I. G. White
Keyword(s):  
Aerobic Glycolysis ◽  
Rete Testis ◽  
Glycolytic Metabolism ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Testicular Spermatozoa ◽  
Almost All ◽  
Oxidation Of Glucose

ABSTRACT The effects of testosterone* and related steroids on the oxidative and glycolytic metabolism of freshly collected ram testicular spermatozoa and of spermatozoa stored under air in rete testis fluid for 3 days at 3°C have been studied. When freshly collected testicular spermatozoa were incubated with glucose under aerobic conditions only a small proportion of the utilized glucose could be accounted for as lactate. The addition of a number of steroids, including testosterone, androstanedione, 5β-androstanedione, androsterone, epiandrosterone and 5β-androsterone, greatly increased aerobic glycolysis, the oxidation of the substrate and the proportion of the utilized substrate converted to lactic acid. After 3 days storage at 3°C, testicular spermatozoa respired at a greater rate than spermatozoa freshly collected from the testes. Although the stimulating effect of steroids on aerobic glycolysis increased after storage, they depressed rather than stimulated the oxidation of glucose by stored testicular spermatozoa. With the exception of androstanedione, which slightly stimulated glycolysis, storage of testicular spermatozoa for 3 days in the presence of steroids did not significantly influence their subsequent metabolism when washed free of the steroids. Both freshly collected and stored ram testicular spermatozoa displayed a marked Pasteur effect, and utilized more glucose and produced more lactate under anaerobic than under aerobic conditions. In the absence of oxygen the steroids did not stimulate glycolysis to any extent. However, epiandrosterone depressed the glycolysis of freshly collected spermatozoa under anaerobic conditions and after storage, 5β-androsterone had a similar effect. Androstanedione, 5β-androstanedione, epiandrosterone and 5β-androsterone were the most effective steroids in altering the metabolism of testicular spermatozoa and, under almost all conditions of incubation, depressed the synthesis of amino acids from glucose. The results suggest that the effects of testosterone and related steroids in vitro may depend on the age of the spermatozoa after their release from the Sertoli cells; the steroid effects may have important consequences in vivo in relation to sperm maturation.

scholarly journals Biotransformation of 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-Hexaazaisowurtzitane (CL-20) by Denitrifying Pseudomonas sp. Strain FA1

2003 ◽  
Vol 69 (9) ◽  
pp. 5216-5221 ◽  
Author(s):  
Bharat Bhushan ◽  
Louise Paquet ◽  
Jim C. Spain ◽  
Jalal Hawari
Keyword(s):  
Nitrous Oxide ◽  
Enzyme Preparation ◽  
Electron Transfer Reaction ◽  
Garden Soil ◽  
Resting Cells ◽  
Anaerobic Conditions ◽  
Intact Cells ◽  
Cell Biomass ◽  
Membrane Enzyme ◽  
Enzyme Catalyzed Reactions

ABSTRACT The microbial and enzymatic degradation of a new energetic compound, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), is not well understood. Fundamental knowledge about the mechanism of microbial degradation of CL-20 is essential to allow the prediction of its fate in the environment. In the present study, a CL-20-degrading denitrifying strain capable of utilizing CL-20 as the sole nitrogen source, Pseudomonas sp. strain FA1, was isolated from a garden soil. Studies with intact cells showed that aerobic conditions were required for bacterial growth and that anaerobic conditions enhanced CL-20 biotransformation. An enzyme(s) involved in the initial biotransformation of CL-20 was shown to be membrane associated and NADH dependent, and its expression was up-regulated about 2.2-fold in CL-20-induced cells. The rates of CL-20 biotransformation by the resting cells and the membrane-enzyme preparation were 3.2 ± 0.1 nmol h−1 mg of cell biomass−1 and 11.5 ± 0.4 nmol h−1 mg of protein−1, respectively, under anaerobic conditions. In the membrane-enzyme-catalyzed reactions, 2.3 nitrite ions (NO2 −), 1.5 molecules of nitrous oxide (N2O), and 1.7 molecules of formic acid (HCOOH) were produced per reacted CL-20 molecule. The membrane-enzyme preparation reduced nitrite to nitrous oxide under anaerobic conditions. A comparative study of native enzymes, deflavoenzymes, and a reconstituted enzyme(s) and their subsequent inhibition by diphenyliodonium revealed that biotransformation of CL-20 is catalyzed by a membrane-associated flavoenzyme. The latter catalyzed an oxygen-sensitive one-electron transfer reaction that caused initial N denitration of CL-20.

Phosphorus retention capacity of iron-ore and blast furnace slag in subsurface flow constructed wetlands

2001 ◽  
Vol 44 (11-12) ◽  
pp. 69-75 ◽  
Author(s):  
B. Grüneberg ◽  
J. Kern
Keyword(s):  
Blast Furnace ◽  
Constructed Wetlands ◽  
Blast Furnace Slag ◽  
Iron Ore ◽  
Subsurface Flow ◽  
Phosphorus Retention ◽  
Anaerobic Conditions ◽  
Retention Capacity ◽  
Aerobic Conditions ◽  
Furnace Slag

The suitability of iron-ore and blast furnace slag for subsurface flow (SSF) constructed wetlands was studied over a period of four months. Dairy farm wastewater (TP 45 mg l-1) was percolated through buckets planted with reed (volume 9.1 l; hydraulic load 15 l m-2d-1). One group of buckets was kept under aerobic conditions and the other group under anaerobic conditions, monitored by continuous redox potential measurements. Even at high mass loading rates of 0.65 g P m-1d-1 the slag provided 98% removal efficiency and showed no decrease in performance with time. However, phosphorus fractionation data indicate that the high phosphorus retention capacity under aerobic conditions is to a great extent attributable to unstable sorption onto calcium compounds (NH4Cl-P). Phosphorus sorption of both the slag (200 μg P g-1) and the iron-ore (140 μg P g-1) was promoted by predominantly anaerobic conditions due to continuous formation of amorphous ferrous hydroxides. None of the substrates had adverse affects on reed growth.

scholarly journals Chromate Reduction by a Pseudomonad Isolated from a Site Contaminated with Chromated Copper Arsenate

2001 ◽  
Vol 67 (3) ◽  
pp. 1076-1084 ◽  
Author(s):  
Jeff McLean ◽  
Terry J. Beveridge
Keyword(s):  
Reductase Activity ◽  
Wood Preservation ◽  
Chromate Reduction ◽  
Anaerobic Conditions ◽  
Toxic Heavy Metal ◽  
Metal Metal ◽  
A Site ◽  
Anaerobic Reduction ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACT A pseudomonad (CRB5) isolated from a decommissioned wood preservation site reduced toxic chromate [Cr(VI)] to an insoluble Cr(III) precipitate under aerobic and anaerobic conditions. CRB5 tolerated up to 520 mg of Cr(VI) liter−1 and reduced chromate in the presence of copper and arsenate. Under anaerobic conditions it also reduced Co(III) and U(VI), partially internalizing each metal. Metal precipitates were also found on the surface of the outer membrane and (sometimes) on a capsule. The results showed that chromate reduction by CRB5 was mediated by a soluble enzyme that was largely contained in the cytoplasm but also found outside of the cells. The crude reductase activity in the soluble fraction showed aKm of 23 mg liter−1 (437 μM) and a V max of 0.98 mg of Cr h−1 mg of protein−1 (317 nmol min−1 mg of protein−1). Minor membrane-associated Cr(VI) reduction under anaerobiosis may account for anaerobic reduction of chromate under nongrowth conditions with an organic electron donor present. Chromate reduction under both aerobic and anaerobic conditions may be a detoxification strategy for the bacterium which could be exploited to bioremediate chromate-contaminated or other toxic heavy metal-contaminated environments.

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