Reduction of Soluble and Solid Ferric Iron by Acidiphilium SJH

2007 ◽  
Vol 20-21 ◽  
pp. 497-500 ◽  
Author(s):  
Alexandra Vašková ◽  
Daniel Kupka
Keyword(s):  
Iron Reduction ◽  
Consumption Rate ◽  
Ferric Iron ◽  
Oxygen Transfer Rate ◽  
Oxygen Limitation ◽  
Co2 Production ◽  
Anaerobic Conditions ◽  
Terminal Electron Acceptor ◽  
Aerobic Conditions ◽  
Microaerobic Conditions

Facultative Fe(III)-reducing bacterium Acidiphilium SJH was incubated in media with ferric iron under various conditions with respect to oxygen availability for the growing cells. The bacteria oxidized organic substratum to carbon dioxide using oxygen and ferric iron as terminal electron acceptors. Ferric iron reduction was observed in all incubation modes. The distribution of reducing equivalents from the oxidation of organic carbon for the reduction of both O2 and Fe(III) was evaluated from CO2 production rate and O2 consumption rate. In fully aerobic conditions approximately 10 % of CO2 produced was coupled with reduction of Fe(III) as terminal electron acceptor. Under aerobic conditions, the ratio of CO2 produced to O2 consumed remained unaffected in a broad concentration range of dissolved oxygen. In the course of oxygen limitation (microaerobic conditions) the molar CO2 to O2 ratio increased from approx. 1 to 2 and even much more with respect to oxygen transfer rate during incubation. On the other hand no bacterial growth and extremely slow iron reduction was observed in obligatory anaerobic conditions in a reactor purged with either pure or CO2-enriched nitrogen.

scholarly journals Anaerobic Sulfur Metabolism Coupled to Dissimilatory Iron Reduction in the Extremophile Acidithiobacillus ferrooxidans

2013 ◽  
Vol 79 (7) ◽  
pp. 2172-2181 ◽  
Author(s):  
Héctor Osorio ◽  
Stefanie Mangold ◽  
Yann Denis ◽  
Ivan Ñancucheo ◽  
Mario Esparza ◽  
...  
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Iron Reduction ◽  
Ferric Iron ◽  
Sulfur Metabolism ◽  
Anaerobic Growth ◽  
Anaerobic Conditions ◽  
Heterodisulfide Reductase ◽  
Content Type ◽  
Protein Levels

ABSTRACTGene transcription (microarrays) and protein levels (proteomics) were compared in cultures of the acidophilic chemolithotrophAcidithiobacillus ferrooxidansgrown on elemental sulfur as the electron donor under aerobic and anaerobic conditions, using either molecular oxygen or ferric iron as the electron acceptor, respectively. No evidence supporting the role of either tetrathionate hydrolase or arsenic reductase in mediating the transfer of electrons to ferric iron (as suggested by previous studies) was obtained. In addition, no novel ferric iron reductase was identified. However, data suggested that sulfur was disproportionated under anaerobic conditions, forming hydrogen sulfide via sulfur reductase and sulfate via heterodisulfide reductase and ATP sulfurylase. Supporting physiological evidence for H2S production came from the observation that soluble Cu2+included in anaerobically incubated cultures was precipitated (seemingly as CuS). Since H2S reduces ferric iron to ferrous in acidic medium, its production under anaerobic conditions indicates that anaerobic iron reduction is mediated, at least in part, by an indirect mechanism. Evidence was obtained for an alternative model implicating the transfer of electrons from S0to Fe3+via a respiratory chain that includes abc1complex and a cytochromec. Central carbon pathways were upregulated under aerobic conditions, correlating with higher growth rates, while many Calvin-Benson-Bassham cycle components were upregulated during anaerobic growth, probably as a result of more limited access to carbon dioxide. These results are important for understanding the role ofA. ferrooxidansin environmental biogeochemical metal cycling and in industrial bioleaching operations.

Effects of medium composition on cell pigmentation, cytochrome content, and ferric iron reduction in a Pseudomonas sp. isolated from crude oil

1982 ◽  
Vol 28 (8) ◽  
pp. 989-992 ◽  
Author(s):  
C. O. Obuekwe ◽  
D. W. S. Westlake
Keyword(s):  
Iron Reduction ◽  
Direct Relationship ◽  
Ferric Iron ◽  
Synthetic Medium ◽  
Medium Composition ◽  
Terminal Electron Acceptor ◽  
Spectrophotometric Data ◽  
Cytochrome Content ◽  
Orange Color ◽  
Pipeline Corrosion

Cells of a pseudomonad associated with pipeline corrosion grown on a complex medium were orange in color and vigorously reduced ferric iron. The intensity of orange color of cells grown on a synthetic medium and their ability to reduce ferric iron was directly related to the iron content of the medium. Absorption spectrophotometric data show a direct relationship between color of cells, cytochrome content, and ability to reduce ferric iron. Carbon monoxide markedly, but not completely, inhibits the reduction of ferric iron. The data presented indicate that ferric iron can serve as a terminal electron acceptor for cytochrome-associated respiratory processes of this corrosive pseudomonad.

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 Biofilm Formation by Campylobacter jejuni Is Increased under Aerobic Conditions

2010 ◽  
Vol 76 (7) ◽  
pp. 2122-2128 ◽  
Author(s):  
Mark Reuter ◽  
Arthur Mallett ◽  
Bruce M. Pearson ◽  
Arnoud H. M. van Vliet
Keyword(s):  
Campylobacter Jejuni ◽  
Food Chain ◽  
Biofilm Formation ◽  
Planktonic Cells ◽  
Aerobic Conditions ◽  
Food Borne ◽  
Passive Release ◽  
Bacterial Gastroenteritis ◽  
Microaerobic Conditions ◽  
Developed World

ABSTRACT The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O2) than under microaerobic conditions (5% O2, 10% CO2), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.

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.

Growth and Sporulation Potential of Clostridium perfringens in Aerobic and Vacuum-Packaged Cooked Beef

1994 ◽  
Vol 57 (5) ◽  
pp. 393-398 ◽  
Author(s):  
V. K. JUNEJA ◽  
B. S. MARMER ◽  
A. J. MILLER
Keyword(s):  
Clostridium Perfringens ◽  
Food Poisoning ◽  
Ground Beef ◽  
Viable Count ◽  
Anaerobic Conditions ◽  
Vegetative Cells ◽  
Aerobic Conditions ◽  
C Storage ◽  
Meat Samples ◽  
Aerobic And Anaerobic

Growth of Clostridium perfringens in aerobic-and anaerobic-(vacuum) packaged cooked ground beef was investigated. Autoclaved ground beef was inoculated with ~3.0-log10 CFU/g of C. perfringens, packaged and stored at various temperatures. Vegetative cells and heat-resistant spores were enumerated by plating unheated and heated (75°C for 20 min) meat samples on tryptose-sulfite-cycloserine agar. Clostridium perfringens grew to >7 logs within 12 h at 28, 37 and 42°C under anaerobic atmosphere and at 37 and 42°C under aerobic conditions. At 28°C under aerobic conditions, growth was relatively slow and total viable count increased to >6 logs within 36 h. Similarly, growth at 15°C in air was both slower and less than under vacuum. Regardless of packaging, the organism either declined or did not grow at 4, 8 and 12°C. Spores were not found at <12°C. Spores were detected as early as 8 h at 42°C under anaerobic conditions, but in general, the type of atmosphere had little influence on sporulation at ≥28°C. Temperature abuse (28°C storage) of refrigerated products for 6 h will not permit C. perfringens growth. However, cyclic and static temperature abuse of such products for relatively long periods may lead to high and dangerous numbers of organisms. Reheating such products to an internal temperature of 65°C before consumption would prevent food poisoning since the vegetative cells were killed.

Influence of Glucose on Contractile Activity of Papillary Muscle During and After Anoxia

1956 ◽  
Vol 187 (1) ◽  
pp. 135-138 ◽  
Author(s):  
Martin M. Winbury
Keyword(s):  
Right Ventricle ◽  
Papillary Muscle ◽  
Contractile Activity ◽  
Oxygen Deficiency ◽  
Full Recovery ◽  
Papillary Muscles ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Deficient Medium ◽  
The Right

Papillary muscles from the right ventricle of the cat were subjected to periods of anoxia ranging from 15–60 minutes with and without glucose in the Krebs-Henseleit (bicarbonate) solution. Under aerobic conditions glucose was not required in the medium for the maintenance of contraction strength. Under anaerobic conditions the contraction strength decreased rapidly and after 30 minutes of oxygen deficiency contractile activity ceased. Reintroduction of oxygen after 15 minutes of anoxia resulted in full recovery of contraction strength for both control and glucose deficient muscles. After longer periods of anoxia, aerobic recovery was greater for muscles with glucose present during the anaerobic period. Little aerobic recovery was noted for muscles in glucose deficient medium during the 60 minutes of anoxia.

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