PHYSIOLOGY OF WOOD-ROTTING BASIDIOMYCETES: IV. RESPIRATION OF NON-PROLIFERATING CELLS OF POLYPORUS PALUSTRIS

1962 ◽  
Vol 8 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Harvey R. Newcomb ◽  
Marshall W. Jennison

For manometric studies of respiration, small, whole mycelial pellets of Polyporus palustris grown in submerged (shake) culture were much superior to fragmented mycelium. The rates of endogenous and of exogenous respiration were dependent, in part, upon age of culture, and were maximal at pH 5.5. The endogenous respiration was high but could be reduced by starvation (aeration in a non-nutrient medium), permitting measurement of exogenous respiration upon the addition of oxidizable substrate. Of the carbohydrates studied, xylose, glucose, galactose, and sucrose were the most stimulative to aerobic respiration; rhamnose, melezitose, and lactose either were not oxidized or showed only slight stimulation. The alcohols methanol, ethanol, glycerol, and propylene glycol were readily utilized; inositol was oxidized to a lesser degree. The sugar alcohols mannitol, sorbitol, and adonitol were mildly stimulative; the effect of dulcitol was dependent upon its concentration. The fatty acids acetate and caprylate were much more readily utilized than butyrate. Salts of other acids— oxalate, pyruvate, lactate, and fumarate—were oxidized to about the same extent as butyrate. Non-proliferating cells of P. palustris had a definite anaerobic metabolism and fermented glucose with production of carbon dioxide and small amounts of acid(s). In air, oxidative assimilation of glucose was high (79–91%); endogenous respiration apparently was not suppressed during assimilation.

2006 ◽  
Vol 52 (4) ◽  
pp. 317-327 ◽  
Author(s):  
Yongqiang Chen ◽  
Isamu Suzuki

Oxidation of endogenous substrate(s) of Acidithiobacillus ferrooxidans with O2 or Fe3+ as electron acceptor was studied in the presence of uncouplers and electron transport inhibitors. Endogenous substrate was oxidized with a respiratory quotient (CO2 produced/O2 consumed) of 1.0, indicating its carbohydrate nature. The oxidation was inhibited by complex I inhibitors (rotenone, amytal, and piericidin A) only partially, but piericidin A inhibited the oxidation with Fe3+ nearly completely. The oxidation was stimulated by uncouplers, and the stimulated activity was more sensitive to inhibition by complex I inhibitors. HQNO (2-heptyl-4-hydroxyquinoline N-oxide) also stimulated the oxidation, and the stimulated respiration was more sensitive to KCN inhibition than uncoupler stimulated respiration. Fructose, among 20 sugars and sugar alcohols including glucose and mannose, was oxidized with a CO2/O2 ratio of 1.0 by the organism. Iron chelators in general stimulated endogenous respiration, but some of them reduced Fe3+ chemically, introducing complications. The results are discussed in view of a branched electron transport system of the organism and its possible control.Key words: Acidithiobacillus ferrooxidans, endogenous respiration, uncouplers, electron transport.


1957 ◽  
Vol 35 (1) ◽  
pp. 15-23 ◽  
Author(s):  
J. F. Scaife ◽  
B. B. Migicovsky

The in vitro effect of alloxan and insulin on the synthesis of cholesterol and fatty acids from 1-C14-sodium acetate by rat liver homogenates has been examined. Alloxan caused a reduction in the incorporation of acetate into cholesterol, fatty acids, and C14O2, but an increase in the oxygen consumption and carbon dioxide production. The addition of insulin to homogenates caused a reduction in cholesterol synthesis but an increase in fatty acid synthesis both for normal and diabetic animals. Homogenates from thyrotoxic rats exhibited a marked reduction in cholesterol synthesis when compared with normal animals. C14O2 production by homogenates from starved rats was appreciably lower than for those from normal animals. With this exception no appreciable difference was found in the oxygen uptake, carbon dioxide, or C14O2 production in homogenates from normal, starved, thyroxine-treated, or diabetic animals. Synthesized cholesterol was found to be located principally in the particulate matter of the homogenates after they had been incubated with 1-C14-sodium acetate. Homogenates from starved rats showed no greater tendency to degrade preformed cholesterol during incubation than did those from normal rats.


2014 ◽  
Vol 3 (4) ◽  
pp. 119 ◽  
Author(s):  
Raffaele Romano ◽  
Nadia Manzo ◽  
Immacolata Montefusco ◽  
Annalisa Romano ◽  
Antonello Santini

<p>In this study the use of liquid carbon dioxide, CO<sub>2</sub>, for extraction of oil from olive paste (<em>Peranzana cultivar</em>)<strong> </strong>were examined and extracted oil was compared with oils obtained by centrifugation, pressure and use of chemical solvent.</p> <p>It is well known that the use of CO<sub>2</sub> has many advantages: miscibility with a wide range of molecules, food safety, non-flammability, absence of residues in the extract, possibility of total solvent recovery and no production of olive mill waste water that are highly polluting for the environment and require expansive disposal.</p> <p>Samples were subjected to the following analyses: determination of Free Fatty Acids (FFA), Peroxides Value (PV), Spectrophotometric Indices, Fatty Acids Composition (FA), determination of biophenols content and determination of Volatile Organic Compounds (VOCs). All samples showed FFA, PV and ?K values within the limits established by law for extra-virgin olive oil. The use of CO<sub>2</sub> did not catalyze hydrolysis, oxidation and condensation of double bonds. Centrifuged oils and oils extracted with carbon dioxide presented the lowest PV and FFA values. Extraction with liquid carbon dioxide contributed to an increasing of phenolic content with a value of 270.5 mg/kg, a value twice that of the oils extracted with centrifugation (135.3 mg/kg) or pressure methods (173.2 mg/kg). Oil extracted with liquid carbon dioxide showed the greatest amount of t-2-octenal and t-2-heptenal, giving herbaceous and pungent notes. Moreover the presence of aromatic compounds such as limonene, generally absent in olive oils, was only detected in the sample extracted with liquid carbon dioxide.</p>


1994 ◽  
Vol 42 (2-3) ◽  
pp. 396-402 ◽  
Author(s):  
I. -C. Kong ◽  
J. S. Hubbard ◽  
W. J. Jones

2018 ◽  
pp. 91-97
Author(s):  
Artyom Dmitrievich Ivakhnov ◽  
Kristina Sergeevna Sadkova ◽  
Alina Sergeyevna Sobashnikova ◽  
Tat'yana Eduardovna Skrebets ◽  
Mikhail Vladislavovich Bogdanov

Comparative researches of ways of oil extraction from the fulfilled fruits of cloudberries (Rubus chamaemorus) with application of hexane and supercritical carbon dioxide as solvents are executed. Optimization is performed and optimum conditions of supercritical fluid extraction of oil are defined with use of central composite design of 2nd order. Pressure of carbon dioxide of 350 atm, temperature 85 °C, duration of extraction of 80 min are the optimum conditions of carrying out of the process. The yield of oil is 9.0%. Quality key indicators of the received oil were defined. The difference between the oil received by the SKF-CO2 method and the oil received by hexane extraction consists in improvement of organoleptic properties, the raised share of the combined fatty acids at decrease of a share of the free acids and high content of unsaturated fatty acids. It is shown that supercritical carbon dioxide can be an alternative to the hydrocarbons which are traditionally used for these purposes.


1929 ◽  
Vol 13 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Robert Emerson

1. The respiration of Amoeba proteus was measured. 10 c. mm. of cells were found to use about 1.6 mm.3 of oxygen per hour at 20°C. The respiratory quotient was found to be nearly unity. 2. No anaerobic metabolism was found for Amoeba. 3. The respiration of Blepharisma was found to be from 3 to 7 mm.3 oxygen per hour for 10 mm.3 cells. The respiratory quotient was about 1. 4. Blepharisma was shown to have a definite anaerobic metabolism. 80 mm.3 cells caused the evolution of 12.5 mm.3 carbon dioxide per hour at 20°C. in the presence of bicarbonate.


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