Characterization of mitochondria isolated from the freezing-tolerant larvae of the goldenrod gall fly (Eurosta solidaginis): substrate preferences, salt effects, and pH effects on warm- and cold-acclimated animals

1985 ◽  
Vol 63 (2) ◽  
pp. 373-379 ◽  
Author(s):  
James S. Ballantyne ◽  
Kenneth B. Storey
Keyword(s):  
Salt Concentration ◽  
Respiratory Control ◽  
Ph Effects ◽  
Respiratory Control Ratio ◽  
Eurosta Solidaginis ◽  
Optimal Range ◽  
Salt Effects ◽  
Substrate Preferences ◽  
Optimal Ph

The mitochondria of the freezing-tolerant larvae of the goldenrod gall fly (Eurosta solidaginis) have been isolated and characterized. Proline is the preferred substrate of mitochondria from both warm- and cold-acclimated animals based on state 3 rates. Lipid is used as a substrate by warm- and cold-acclimated mitochondria assayed at 20 °C, but not by the mitochondria from cold-acclimated animals assayed at 1 °C. Cold-acclimated mitochondria assayed at 1 °C have a higher and broader optimal range of salt concentration for the oxidation of proline based on the respiratory control ratio (RCR) than those from warm-acclimated animals oxidizing the same substrate at 20 °C. The optimal pH for warm-acclimated mitochondria oxidizing proline at 20 °C is low (6.2) based on the RCR, but rises to pH 7.0 in cold-acclimated animals at 1 °C. It is suggested that the broad optimal salt concentration in the cold-acclimated animals and the very low optimal pH in warm-acclimated animals are adaptations for survival in this freezing-tolerant larva.

scholarly journals Effect of hyperbaric oxygen therapy on liver function during intermittent ischemia

2013 ◽  
Vol 28 (suppl 1) ◽  
pp. 61-65 ◽  
Author(s):  
Leticia Botigeli Baldim ◽  
Ricardo Nejo Jr ◽  
Maria Eliza Jordani Souza ◽  
Maria Cecília Jordani Gomes ◽  
Maria Aparecida Neves Cardoso Picinato ◽  
...  
Keyword(s):  
Liver Function ◽  
Hyperbaric Oxygen ◽  
Mitochondrial Function ◽  
Hyperbaric Oxygen Therapy ◽  
Aspartate Aminotransferase ◽  
Alanine Aminotransferase ◽  
Oxygen Therapy ◽  
Respiratory Control ◽  
Respiratory Control Ratio ◽  
Hepatic Pedicle

PURPOSE: To analyze the effects of hyperbaric oxygen therapy on liver function in rats previously subjected to ischemia and reperfusion. METHODS: A randomly distribution of 23 Wistar rats was conducted into three groups: SHAM, animals subjected to surgical stress without restricting blood flow by clamping the hepatic pedicle, IR, rats underwent hepatic vascular occlusion intermittently for two complete cycles of 15 minutes of ischemia followed by 5 min of reperfusion, IR / HBO, rats underwent hepatic pedicle clamping and thereafter exposed to hyperbaric oxygen pressure of 2 absolute atmospheres for 60 minutes. We evaluated liver function through mitochondrial function, determined by the stages 3 and 4 of respiration, respiratory control ratio (RCR) and mitochondrial permeability transition (Swelling). Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also quantified . We analyzed the results using the Mann-Whitney test and were considered significant all results with p <0.05. RESULTS: There were significant differences between the results of stage 3 in SHAM vs IR group ; of the stage 4 in the groups IR vs SHAM and SHAM vs IR /HBO; of the Respiratory Control Ratio (RCR) in the group IR vs IR / HBO ; of alanine aminotransferase in the groups IR vs SHAM , SHAM vs IR/HBO and IR vs IR / HBO; aspartate aminotransferase in the groups SHAM vs IR and SHAM vs IR / HBO. CONCLUSION: The whole analysis of the mitochondiral function indicators permits us to conclude that the hyperbaric oxygen therapy acted as a protective agent of the mitochondrial function, minimizing the ischemia-reperfusion injury of the hepatic parenchyma.

The more the better – determining the optimal range when performing single-vesicle phenotyping

2021 ◽  
Vol 1 (1) ◽  
pp. 26-33
Author(s):  
María Gómez-Serrano ◽  
Christian Preußer ◽  
Kathrin Stelter ◽  
Elke Pogge von Strandmann
Keyword(s):  
Extracellular Vesicles ◽  
Particle Number ◽  
Experiment Design ◽  
Surface Markers ◽  
Optimal Range ◽  
Design And Optimization ◽  
Highly Sensitive ◽  
Single Vesicle

The characterization of extracellular vesicles (EVs) has evolved rapidly in recent years due to advances in straightforward technologies. Based on these more sensitive methods, it is now possible to describe EV populations in their entirety more precisely. However, these applications require an equivalently delicate experiment design and optimization steps to draw valid conclusions in the end. One of these methods is represented by the highly sensitive nanoflow cytometry (nFCM), by which particles can be analyzed not only on their size (< 40 nm) and concentration but also concerning surface markers. In this work, we addressed some of the potential caveats of this method, especially when characterizing particles with fluorescently labelled antibodies. In particular, we show, when using low particle concentrations, which are inevitably encountered when working with EVs, the characterization of surface markers is prone to significantly varying. We hypothesized that these technical limitations could respond to the stickiness of EVs and should be properly counteracted. As a reference, we strongly recommend performing particle number-based comparisons with at least 109 particles as staining input in nFCM analyses. Moreover, we provided representative particle-number based immunoblotting results, underlying the significance of this parameter as a normalizer in future EV research.

Comparative characterization of digestive proteases in redhead cichlid (Vieja melanurus) and twoband cichlid (Vieja bifasciata) (Percoidei: Cichlidae)

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Carlos Alfonso Frías-Quintana ◽  
Emyr Saul Peña-Marín ◽  
Carlos David Ramírez-Custodio ◽  
Rafael Martínez-García ◽  
Luis Daniel Jiménez-Martínez ◽  
...  
Keyword(s):  
Meat Quality ◽  
Alkaline Proteases ◽  
Optimal Temperature ◽  
Digestive Capacity ◽  
Digestive Proteases ◽  
Ph Values ◽  
Specific Diet ◽  
Specific Inhibitors ◽  
Optimal Ph

ABSTRACT In the Southeast of Mexico, there are many native cichlids with commercial interest such as redhead cichlid (Vieja melanurus) and twoband cichlid (V. bifasciata), which have a great local demand and excellent meat quality. However, it is necessary to implement their culture based on nutrition studies and digestive biochemistry. This study’s objective was to characterize these two cichlids’ digestive proteases (pH, temperature, and inhibitors) through biochemistry techniques. Results showed that V. melanurus and V. bifasciata have a digestive capacity analogous to other omnivore fishes, where the optimal pH values of stomach proteases (4 and 2, respectively) and intestinal proteases (6 and 12, respectively), the optimal temperature of acid (35°C and 55°C, respectively) and alkaline proteases (45°C and 55°C, respectively) are quite similar. Both species presented high thermal and pH stabilities. Inhibition showed that V. melanurus is more sensitive to specific inhibitors for alkaline proteases than V. bifasciata. In conclusion, V. bisfasciata and V. melanurus have different digestive protease patterns. Both species can hydrolyze different protein ingredients to formulate a specific diet. Nevertheless, V. bifasciata is more resistant to the presence of inhibitors, which allow it to include vegetable proteins in its diet.

Photophysical Characterization of a Benzo-Fused Analogue of Brooker’s Merocyanine: Solvent Polarity and pH Effects

2012 ◽  
Vol 116 (51) ◽  
pp. 12470-12475 ◽  
Author(s):  
Edward Adjaye-Mensah ◽  
Walter G. Gonzalez ◽  
Jaroslava Miksovska ◽  
James N. Wilson
Keyword(s):  
Solvent Polarity ◽  
Ph Effects ◽  
Brooker’S Merocyanine

Synthesis and Characterization of BaCe0.8Y0.2O2.9 Nanopowder by Sol-Gel Auto-Ignited Method

2007 ◽  
Vol 280-283 ◽  
pp. 661-664 ◽  
Author(s):  
Jing Tao Ma ◽  
Xu Ping Lin ◽  
Bao Qing Zhang ◽  
Jiu Lin Wang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Ph Value ◽  
Sol Gel ◽  
Ceramic Powder ◽  
Solid Oxide ◽  
Synthesis And Characterization ◽  
Nanocrystalline Ceramic ◽  
Optimal Ph ◽  
Nitrate Solutions

A sol-gel auto-ignited synthesis, which is a hybrid of sol-gel and auto-ignited techniques, was applied to preparation of homogeneous and stoichiometric BaCe0.8Y0.2O2.9 nanocrystalline ceramic powder as solid electrolyte used in solid oxide fuel cells at 1000°C. Optimal pH value for the mixed citrate-nitrate solutions was determined by calculation. The DTA-TG and XRD were used to investigate the thermal decomposition of the gel precursor. The structure and phase present of the nanocrystalline BaCe0.8Y0.2O2.9 powders were characterized by XRD, BET and SEM techniques.

Evaluation of coffee pulp as substrate for polygalacturonase production in solid state fermentation

2020 ◽  
pp. 117
Author(s):  
Rosa Amarilis Rodríguez Frómeta ◽  
José Laencina Sánchez ◽  
José María Ros García
Keyword(s):  
Cell Wall ◽  
Solid State ◽  
Solid State Fermentation ◽  
Reducing Sugars ◽  
Growth Substrate ◽  
Optimal Temperature ◽  
Coffee Pulp ◽  
Polygalacturonase Production ◽  
Optimal Ph

The purpose of this research is to evaluate the coffee pulp, a by-product of coffee processing, as substrate for polygalacturonase production by solid state fermentation. In addition, it is a way to take advantage of the coffee pulp. Characterization of the coffee pulp revealed a high content of nutrients for fungi growth, such as reducing sugars (5.4% of dry pulp), proteins (9.4% of dry pulp), pectins (20.5% of dry pulp), which are inducers of pectic hydrolases production and source of carbon after degradation, and caffeine (1.4% of dry pulp), among others. The characterization of the cell-wall of coffee pulp revealed, after polysaccharides fractionation, the content in cell-wall pectins (25.5%), hemicelluloses (11.5%) and cellulosic residue (44%). A strain of Aspergillus niger, called van Thiegem, has been selected as a good producer of polygalacturonases (60 U/ml) using the coffee pulp as the growth substrate. During fermentation, reducing sugars, caffeine and phenolic compounds were consumed till almost exhaustion. A partial characterization of the polygalacturonase using high methoxyl pectin as substrate indicates an optimal pH of 4.0 and 45oC as optimal temperature, which are good values for the use of the enzyme in vegetable processing, including coffee processing.

Cloning, Expression and Characterization of a Monooxygenase P450BM3 from Bacillus megaterium ALA2

2012 ◽  
Vol 518-523 ◽  
pp. 5533-5538
Author(s):  
Ting Wang ◽  
Liang Liang Wang ◽  
Xun Li
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Linoleic Acid ◽  
Bacillus Megaterium ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
Nadph Oxidation ◽  
First Time ◽  
Optimal Ph

Cytochrome P450 monooxygenases are enzymes which are capable of oxidising saturated and unsaturated substrates. P450BM3 from Bacillus megaterium is one of this family. For the first time, the cyp gene for coding P450BM3 from B. megaterium ALA2 has been cloned and expressed in Escherichia coli. The recombinant enzyme is 120 kDa, containing 1049 aa. The highest activity of purified enzyme is 14.8 U/mg towards palmitic acid by monitoring the NADPH oxidation. The optimal pH and temperature were 9.0 and 40°C. The enzyme has higher activity towards linoleic acid, and 2-Methyl-7-octadecene can also be catalyzed which is a precursor of displar.

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