Warburg Respirometer Research Articles

Effect of Pre-Culture Conditions on the Sensitivity of Yeasts to the Glucose Effect

In an experiment to determine the effect of pre-culture conditions on the sensitivity of yeasts to the glucose effect, the yeast species Saccharomyces uvarum (carlsbergensis) K19, was used. This species is from the collection of the Industrial Microbiology Laboratory of ENSAIA-INPL, Nancy France. The yeast was initially cultured on industrial wort with constant aeration throughout the culture period in the first instance and without aeration throughout the culture period in the second instance, creating aerobic and anaerobic conditions.The yeasts from the two culture different media were harvested and placed in synthetic media containing known sugar concentrations of glucose and maltose as substrates, and fermentations were carried out at 30°C. Cells were harvested during growth and the specific rate of fermentation (fermentation intensity) measured, using the Warburg respirometer. Irrespective of initial and main culture media used, yeasts from anaerobic preculture media had highly significantly lower (P<0.05) fermentation intensities than those cultivated initially under aerobic conditions. Fermentation intensity on glucose after preculture on glucose is significantly lower (P<0.05) for yeasts grown under anaerobic conditions when compared to those with access to oxygen. Oxygen limitation during preculture growth of the yeasts in either glucose or maltose media depressed fermentation on glucose or maltose thereafter.

Ritmo circadiano da taxa respiratória de Tetragonisca angustula fiebrigi (Schwarz), T. a. angustula (Latreille) e Trigona spinipes (Fabricius) (Hymenoptera, Apidae, Meliponinae)

Foi determinado em operárias isoladas de Tetragonisca angustula fiebrigi (Schwarz, 1938), T. a. angustula (Latreille, 1807) e Trigona spinipes (Fabricius, 1793) o ritmo circadiano das taxas respiratórias médias (VO2) em condições de ciclo normal (dia/claro e noite/escuro), durante a primavera. O consumo de oxigênio foi determinado a 30ºC usando um respirômetro de Warburg. A análise estatística dos resultados revelou interações significativas entre intervalos de tempo e entre as espécies. Foram comparadas as taxas respiratórias usando o teste do Tukey. Um padrão definido de ritmo circadiano metabólico foi observado para ambas as espécies, apresentando um maior consumo de oxigênio durante o dia, com um pico entre 10:00 e 15:00. À noite o consumo diminuiu, alcançando os níveis mínimos entre 2:00 e 3:00. Tetragonisca angustula angustula e T. a. fiebrigi não apresentaram diferenças significativas entre si, mas diferiram de T. spinipes, que apresentou taxas respiratórias maiores.

RELAÇÕES FISIOECOLÓGICAS NO DIPLÓPODO Oxidus gracilis (POLYDESMIDA, STRONGYLOSOMIDADE): O CONSUMO DE OXIGÊNIO EM RELAÇÃO AO TAMANHO, SEXO E CONDIÇÃO ALIMENTAR

O consumo de oxigênio do diplópodo Oxidus gracilis foi determinado em respirômetro de Warburg, a 25 ºC, em 21 machos e 24 fêmeas, com a finalidade de estudar as relações fisioecológicas e metabólicas com o tamanho, sexo e condição&#x0D; alimentar. Expressando o metabolismo ou consumo horário de oxigênio (M) em função da massa corpórea (P) e usando regressões logarítmicas, os resultados da equação alométrica M = a. Pb, foram: M = 2,589. P0,89 para os machos, M = 2,715.P0,78 para as fêmeas e M = 2,6814.P0,86 para ambos os sexos, conjuntamente. Os coeficientes de regressão (índices de b) obtidos indicaram que o metabolismo respiratório de Oxidus gracilis fica num nível intermediário de dependência, entre a massa e a superfície corpórea.&#x0D; Os efeitos da condição alimentar foram avaliados em diplópodos recémalimentados e jejunos de 24, 48, 72 e 96 horas. Ao final do 5º dia (96 h) a massa corpórea teve uma redução de 21,46% e o consumo de oxigênio de 52,37%. Em ambos os casos as reduções foram significativas (P &lt; 0,05). A despeito de que nenhuma morte tenha ocorrido durante o período estudado, concluiu-se que o estresse provocado pelo jejum alimentar produz mudanças mais acentuadas no metabolismo do que na massa corpórea de Oxidus gracilis.

Production of &lt;FONT FACE=Symbol&gt;a&lt;/FONT&gt;-amylase in acid cheese whey culture media with automatic pH control

The influence of aeration and automatic pH control on the production of &lt;FONT FACE="Symbol"&gt;a&lt;/FONT&gt;-amylase by a strain of Bacillus subtilis NRRL 3411 from acid cheese whey was studied. Tests were carried out in a rotary shaker and in mechanically stirred fermenters. &lt;FONT FACE="Symbol"&gt;a&lt;/FONT&gt;-amylase was analysed according to DUN’s method. Oxygen absorption rate was determined by Cooper’s method. Cell oxygen demand was determined as oxygen consumption in a Warburg respirometer. The level of dissolved oxygen was measured by means of a galvanic silver-lead electrode. Results suggest the possibility of industrial use of acid cheese whey as a carbon source for &lt;FONT FACE="Symbol"&gt;a&lt;/FONT&gt;-amylase production, since the yield was similar to that produced with lactose. The highest &lt;FONT FACE="Symbol"&gt;a&lt;/FONT&gt;-amylase levels 10,000 DUN/ml units were not attained at higher aeration rates -431 mLO2/L.h-. The indicated value correspond to a 96 h process with automatic pH control at 7.5. These conditions resulted in double concentration of &lt;FONT FACE="Symbol"&gt;a&lt;/FONT&gt;-amylase. The enzyme production was directly related to growth in the form of cell aggregates.

Respiratory Metabolism of Camponotus rufipes Ants: Brood and Adults

The respiratory metabolism of immature forms (eggs, larvae, prepupae and pupae) of Camponotus rufipes (Hymenoptera: Formicidae) was studied at 25°C, using a Warburg respirometer. Mean respiratory rates (μl O2·mg−1 live weight·hr−1) for eggs, first instars, second instars, third instars, fourth instars, prepupae, and pupae were respectively: 2.53, 5.07, 1.23, 0.32, 0.22, 0.19 and 0.13. Adult workers with body mass between 20 and 30 mg had a mean respiratory rate of 0.43. The high respiratory rate in first instars probably reflects, besides the size influence, the metabolic costs of differentiation that occurs in this phase.

Effect of temperature and salinity on respiratory rate and development of early larval stages of Macrobrachium acanthurus (Wiegmann, 1836) (Decapoda, Palaemonidae)

Macrobrachium acanthurus larvae were reared at different salinity and temperature combinations (0, 7, 14, 21, 28 and 35‰S at 15, 20, 25 and 30°C). The survival and respiratory rate were measured for zoea I, II, III and IV. The oxygen consumption rates were measured at 25°C in all tested salinities, using a Warburg respirometer. Larvae reared in fresh water died at stage I in all tested temperatures. The highest survival rates were obtained at 25 and 30°C within a range of 14–21‰S. The metabolic rate-salinity (M-S) curves for all zoeae studied showed lower values either in 14 (zoeae II and III) or 21‰S (zoeae I and IV). However, values were not significantly different for zoeae III and IV, which showed to be more salinity independent.

The influence of nitrapyrin and sodium azide on the growth and respiration of some Rhizobium strains

In vitro addition of different concentrations of nitrification inhibitor nitrapyrin and respiratory inhibitor sodium azide to the growth media of seven Rhizobium strains representing the four Rhizobium species ( R. leguminosarum, R. phaseoli, R. trifolii and R. loti) influenced the growth of these strains within 48 h at 28 °C incubation on a rotary shaker. All doses of nitrapyrin inhibited growth. In contrast, 0.1 mg 1 -1 enhanced the respiration rate of the strains using Warburg's respirometer. The doses 10 and 100 mg 1 -1 were highly toxic and depressed the respiration rates of Rhizobium within 180 minutes. Application of 10 mM NaN 3 enhanced the growth and respiration rates of all the strains. The growth of R. leguminosarum (Lóbab Z and Bükköny 75/4 strains) was stimulated by 20 mM and also R. phaseoli (Bab 5/3 strain) by 30 mM NaN 3. The growth and respiration rates of the tested Rhizobium strains were significantly depressed by 50 mM NaN 3, whereas the respiration rates of the strains Lóbab Z, Bükköny 75/4 and Bab 5/3 at 30 mM NaN 3 were higher than the control. However, 50 mM NaN 3 was significantly high and depressed the respiration rates of Rhizobium strains at P = 0.05.

Fructooligosaccharide Utilization by Salmonellae and Potential Direct-Fed-Microbial Bacteria for Poultry

Experiments were done to characterize potential direct-fed-microbial (DFM) bacteria for poultry and Salmonella spp. with respect to their abilities to metabolize fructooligosaccharide substrates (FOS-50® or pure FOS). Oxygen uptake (QO2) by these bacteria in media containing either glucose, FOS-50®, or FOS was determined with a Warburg respirometer. QO2 values for Salmonella spp. In media containing glucose or FOS-50® were similar(P >0.05); however, QO2 values in medium with FOS were significantly lower (P <0.05).The QO2 values for Enterococcus faecium, Lactococcus lactis, and Pediococcus sp. were considerably lower, reflecting the inability of these bacteria to oxidatively utilize these carbohydrates. The ability of E. faecium, L. lactis, and Pediococcus sp. to ferment glucose, FOS-50®, or FOS was determined by measuring pH changes of the media. All carbohydrate sources were fermented by these bacteria, but at different rates. The lowest pH values (<4.6) were obtained in inoculated media supplemented with glucose. The highest fermentation rate was achieved by Pediococcus sp. (pH< 5.2 at 7h), while L. lactis showed the slowest fermentation rate (pH > 6.4 at 10 h). To test the ability of Pediococcus sp. to hydrolyze FOS substrates, a cell-free extract was spectrophotometrically analyzed for the presence of active enzymes capable of hydrolyzing FOS or sucrose (a component of FOS). Hydrolysis of FOS (release of glucose) but not of sucrose was evident. However, equal activity was found in aqueous FOS without the cell-free extract, which suggests that free glucose was a component of the FOS solution tested.

Modification of oxidizing activity of Thiobacillus ferroxidans by some particulate solids

Different particulate solids such as glass powder, various types of activated carbon and bentonite suspended in Thiobacillus ferrooxidans cultures produce very different effects on the oxidizing activity of the microorganism. The atmospheric oxygen uptake by Thiobacillus ferrooxidans in Warburg respirometer flasks containing 9K medium with ferrous sulfate as energy source and suspended bentonite is 2.8 times that in the absence of solids. The dissolution rate of pure pyrite in 250 cm 3 shake flasks containing 9K medium and bentonite is considerably enhanced over that where the only solid phase is pyrite. Conversely, the oxidizing ability of the microorganism seems to be inhibited by all the activated carbons tested. The effect of ground glass seems to be related to its particle size distribution. Implications for the bioleaching of sulfide ores and coal pyrite are discussed in the light of current knowledge on the adsorption of Thiobacillus ferrooxidans cells on solid surfaces.

Interaction of chalcopyrite and sphalerite with pyrite during leaching by Thiobacillus ferrooxidans and Thiobacillus thiooxidans

The interaction of chalcopyrite and sphalerite with pyrite during leaching by Thiobacillus ferrooxidans and Thiobacillus thiooxidans was studied in shake-flask leaching experiments and in respirometer experiments with resting cells. Two samples of pyrite (Nos. 1 and 2) were used. In shake-flask experiments in the absence of bacteria, the copper and zinc extraction rates increased in the presence of No. 1 pyrite from 1.6 to 10.2 and 13%, respectively, and in the presence of No. 2 pyrite from 1.6 to 3.5 and 5.8%, respectively. Thus the effect of pyrite was greater with sphalerite than with chalcopyrite and the No. 1 pyrite was more effective than the No. 2 pyrite. Thiobacillus ferrooxidans increased the leaching rates of Cu from chalcopyrite (from 1.6 to 11.1%), of Zn from sphalerite (from 1.6 to 36%), and of Fe from pyrite (from 7.3 to 29.9% (No. 1) and from 5.1 to 49.3% (No. 2)), although a period of adaptation was required for sphalerite leaching. Thiobacillus thiooxidans did not leach Cu form chalcopyrite, but increased leaching of Zn from sphalerite (from 1.6 to 8.3%) and some Fe from pyrite (from 7.3 to 9.5% (No. 1) and from 5.1 to 13.1% (No. 2)). In the chalcopyrite–pyrite mixture, Cu leaching was further stimulated by T. ferrooxidans (from 10.2 to 14.5% (No. 1) and from 3.5 to 12.2% (No. 2)) and by T. thiooxidans (from 3.5 to 5.8% (No. 2)). The Zn leaching from the sphalerite–pyrite combination increased further with T. ferrooxidans (from 13.0 to 61.7% (No. 1) and from 5.8 to 65.8% (No. 2)) and T. thiooxidans (from 13.0 to 22.4% (No. 1) and from 5.8 to 14.7% (No. 2)). The Fe solubilization from pyrite was inhibited by the presence of chalcopyrite or sphalerite with or without bacteria. Short-term respirometer studies generally supported the leaching results. Oxygen consumption was faster for chalcopyrite or sphalerite in the presence of pyrite. The effect was stronger for sphalerite, although the rapid pyrite oxidation by T. ferrooxidans was inhibited by the interaction. Chalcopyrite alone was oxidized by T. ferrooxidans but not by T. thiooxidans, while sphalerite alone was oxidized only by the latter. It is concluded that shake-flask leaching and Warburg respirometer experiments complement each other in elucidating the complex processes involved in bacterial metal leaching of sulfide ores. Key words: Thiobacillus, sulfide ores, oxidation, mineral leaching.

Simple combination of biodegradation and carbon adsorption—the mechanism of the biological activated carbon process

This paper focuses on the mechanisms of the biological activated carbon (BAC) process. It is found that the bioregeneration hypothesis of desorption by exoenzymatic reactions is the common basis for some previous mechanisms. But by considering properties of the enzymes involved in the biodegradation pathway of phenols and aromatic hydrocarbons and distribution of exoenzymes in carbon pores, it is suggested that the hypothesis is not valid in most circumstances. A series of tests has been made in which phenol was used as the testing pollutant. The BAC column test was performed to investigate the changes in carbon adsorption capacity during operation. Properties of biological activity in BAC were measured by a Warburg respirometer. A comparative test between the BAC bed reactor and biological aerated filters was also made. All test results were contradictory to the mechanisms based on the bioregeneration hypothesis and supported the authors' suggestion that the mechanism of the BAC process is basically a simple combination of biodegradation and carbon adsorption. It is suggested that some specially designed biological aerated filter (BAF), instead of a BAC bed reactor, may be used in advanced wastewater treatment.

Respiratory Responses in a Brazilian Millipede, Pseudonannolene tricolor, to Declining Oxygen Pressures

Oxygen uptake and the influence of declining oxygen pressures (Po2's) were examined in a Brazilian spirostreptid millipede, Pseudonannolene tricolor. The data were obtained in a Warburg respirometer at 25° C from both male and female animals, sexually inactive, in the intermolt stage, and fasting for 24 h. In a sudden exposure to a decreased Po2 the millipedes regulated respiration down to at least 71 mmHg O₂. From a Po2 of 35 mmHg O₂ downward the animals started to show oxyconformity. When the millipedes were exposed to a stepwise declining Po2 the results indicated only conformation. After exposure to hypoxia, P. tricolor showed a pattern of "underrepayment" on return to normoxia, but larger millipedes accumulated more O₂ debt than smaller ones.

Functional metallomacrocycles and their polymers. 25. Kinetics and mechanism of the biomimetic oxidation of thiol by oxygen catalyzed by homogeneous polycarboxyphthalocyaninato metals

The oxidation of 2-mercaptoethanol (RSH) catalyzed by (polycarboxyphthalocyaninato) metal acid (M-papc, M=Fe(III), Co(II), Ni(II), Cu(II), pa=−(COOH) 2 , −(COOH) 4 , −(COOH) 8 ) in the presence of molecular oxygen has been studied in aqueous homogeneous solution at pH 7.0 and at 25 o C. The catalytic effects of M-papc have been determined the oxygen consumption in the reaction mixture with a Warburg respirometer. The central metal ions and the number of carboxylate ions on M-papc affected the catalytic activities for the aerobic oxidation of RSH. (Octacarboxyphthalocyaninato) iron (III) and -cobalt (II) are remarkably effective catalysts. (Dicarboxyphthalocyaninato) metals and Ni(II) ― as well as Cu(II) ― phthalocyanine derivatives are less effective catalysts. The kinetics of the aerobic oxidation catalyzed by (octacarboxyphthalocyaninato) iron (III) and -cobalt (II) have been characterized in terms of a bisubstrate Michaelis-Menten rate law (k 5 =600-800 min −1 , at pH 7.0, 25 o C

Antitumor property of the active principle of Jawaharene

The active principle of Jawaharene (JF 1), a mixture of fatty acids, was studied for antitumor properties against Ehrlich Ascites Carcinoma (EAC) and Sarcoma-180 (S-180). Using a Warburg respirometer, respiratory O 2-uptake by EAC and S-180 cells was completely inhibited by JF 1 at the dose of 100 μg ml −1. The in vitro cytotoxicity assay revealed that 100% of JF 1-treated tumor cells were killed within 60 min incubation. In vivo, EAC and S-180 ascites tumor development was completely inhibited by JF 1 at the dose of 5 mg mouse −1 day −1 × 8.

Application of Warburg respirometer data in appraising wastewater treatment processes

Abstract Biological data are usually plotted against time. The shape of the various curves made it difficult to interprete the data specifically. Evaluation of Warburg data was made both on a time basis and for measured components and plotted against one another to ascertain significant relationships between them. The data when checked through Chemical Oxygen Demand (COD) and Oxygen uptake balanced within experimental error. The synthesis reaction was not considered normal as theoretically expected. The O2 uptake/soluble COD and Volatile Suspended Solids (VSS)/ total COD were found to be 0.23/0.77 and 1/0.82 respectively.

Microcomputer-based system for data acquisition and analysis of oxygen uptake studies.

The use of a Warburg Respirometer to study oxidation reactions is tedious and time-consuming. A microcomputer-based oxygen uptake device that is more sensitive than a Warburg Respirometer is described. The device consists of stainless steel or Teflon reaction vessels coupled to ultrasensitive pressure transducers. A high speed analog to digital convertor is used to poll the transducers. The direct memory access (DMA) controller of an IBM XT is used to poll the convertor and store the data in memory. Software used to program the DMA controller and IBM XT is described. The reproducibility and utility of the device is demonstrated with a brief study of lipid oxidation.

Salinity effects on the neuroendocrine control of respiratory metabolism in Macrobrachium olfersii (wiegmann) (crustacea, palaemonidae)

1. 1. The effects of supra-oesophageal ganglion (SEG) extracts on the metabolic response of M. olfersii during salinity adaptation were examined. 2. 2. SEG extracts prepared from animals exposed to salinity (0, 7, 14, 21 and 28‰) for 1, 3 and 6hr were injected in animals kept in fresh water. The metabolic rate of injected animals were measured in a Warburg respirometer after 1 and 3 hr. 3. 3. The SEG extracts from animals exposed to low and high salinities for 1 and 3 hr caused an increase in the metabolic rate and did not have any effect when animals were exposed to mid-range salinities. 4. 4. The SEG extracts from animals exposed to salinities from 7 to 21‰ for 6hr did not cause a significant variation in the metabolic rate of injected animals, but a marked decrease was observed when animals were exposed to 28‰ S. 5. 5. The results suggest a neuroendocrine control of the respiratory metabolism related to osmoregulatory responses in M. olfersii, exerted by two antagonist factors synthetized in the SEG.

歯肉ミトコンドリアの呼吸調節に関する研究

Many authors have studied the gingival respiration with slice and homogenate to measure the respiration in Warburg respirometer flask. However, no study on the ability to respiratory control of gingiva has been reported. The author prepared the several mitochondrial fractions from gingiva and measured the mitochondrial respiration to obtain the fractions with ability to respiratory control. The gingiva was excised from dogs during anesthesia and minced in cold. The minced gingiva was homogenized with Polytron for 0.5 min., 1 min., 1.5 min., 2 min., 5 min. and 10 min. separately. And then, the nucleus, mitochondrial and supernatant fractions were prepared by differential centrifugation method. On the other hand, the minced gingiva was treated with 0.04%, 0.2%, 1% and 5% collagenase respectively and homogenized with Polytron for 1 min.. Then, the nucleus, mitochondrial and supernatant fractions were prepared by centrifugation. Relative specific activity of the succinate dehydrogenase was measured on each fraction. Furthermore, the respiration of the mitochondrial preparation was measured by using the oxygen electrode. Results are : 1. In the mitochondrial fractions treated with Polytron for 0.5 min. to 10 min., the highest relative specific activity of the succinate dehydrogenase was observed in the treatment for 2 min.. 2. The highest activity was present in the mitochondrial fraction treated with 1% collagenase in the course of digestions with 0.04%, 0.2%, 1% and 5% collagenase. 3. The respiratory control was observed in the mitochondrial preparations treated with 1% and 5% collagenase when the endogenous, succinate-stimulated and ADP-stimulated respirations were measured. 4. The mitochondrial preparation treated with 1% collagenase had the highest ADP/O ratio and respiratory control rate in the present study.

Evaluation of carbamate toxicity: Acute toxicity in a culture of Paramecium multimicronucleatum upon exposure to aldicarb, carbaryl, and mexacarbate as measured by Warburg respirometry and acute plate assay

The present study was undertaken to explore the acute toxicity of three carbamate pesticides, aldicarb, carbaryl, and mexacarbate, on a population of Paramecium multimicronucleatum. The toxicity was evaluated by the Warburg respirometer and the static acute plate assay. Aldicarb, carbaryl, and mexacarbate were shown to significantly inhibit cumulative oxygen uptake at 24 hr in the paramecium culture at 160, 120, and 100 ppm, respectively. Aldicarb, carbaryl, and mexacarbate concentrations of 60, 20, and 10 ppm demonstrated no inhibition of cumulative oxygen uptake when compared to a paramecium control at 24 hr. Pesticide concentrations intermediate to the high and low concentrations demonstrated varying degrees of inhibition. Static plate assay data for aldicarb demonstrated LC 50 values of 93, 104, 122, and 145 ppm at 24, 17, 13, and 9 hr, while carbaryl demonstrated LC 50 values of 28, 34, 46, 65, and 105 ppm at 24, 17, 13, 9, and 7 hr, respectively. Mexacarbate LC 50 values were 19, 25, 35, 57, and 83 ppm at 24, 17, 13, 9, and 7 hr. Oxygen uptake values compared favorably with the static assay data. Scanning electron micrographs demonstrated several morphologic changes in paramecium with increased pesticide concentration and exposure time including ciliary abnormalities and disruption of surface structure.

Functional metal‐porphyrazine derivatives and their polymers. VIII. Catalase‐like activity of Fe(III)‐ and Co(II)‐2,9,16,23‐tetracarboxyphthalocyanine supported on poly(2‐vinylpyridine‐CO‐styrene)

AbstractThe decomposition reaction of hydrogen peroxide by Fe(III)‐ and Co(III)‐2,9,16,23‐tetracarboxyphthalocyanine supported on poly(2‐vinylpyridine‐CO‐styrene) and the quaternized one, was studied at pH 7.0 in aqueous media. The kinetics of this reaction was also investigated at pH 7.0 by measuring the initial velocity V0 of the increasing concentration of O2 with a Warburg respirometer. The reaction proceeded according to the catalaselike mechanism. Fe(III)‐2,9,16,23‐tetracarboxyphthalocyanine supported on poly(2‐vinylpyridine‐CO‐styrene) was a remarkably effective catalyst for a H2O2 decomposition reaction. The coordination sphere around the Fe(III)‐phthalocyanine ring was characterized by electronic and ESR spectroscopy. Fe(III)‐phthalocyanine supported on the copolymer dispersed in water was the five‐coordinated, high‐spin type. A typical competitive inhibition in respect of H2O2 by CN‐ was observed. ESR spectrum of this system showed the low spin iron(III) in the octahedral ligand field. The polymer coils hindered undesirable dimerization of metal‐phthalocyanine molecules by the shielding effect.