THE EFFECT OF DECOMPOSITION OF VARIOUS CROP PLANTS ON THE METABOLIC ACTIVITY OF THE SOIL MICROFLORA

1962 ◽  
Vol 8 (4) ◽  
pp. 501-509 ◽  
Author(s):  
I. L. Stevenson
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Activity ◽  
Respiratory Activity ◽  
Experimental Period ◽  
Maximum Activity ◽  
Soil Microflora ◽  
Plant Residues ◽  
Rapid Decline ◽  
Decomposition Of Plant Residues

Studies were undertaken to determine the changes in the soil microflora during the decomposition of plant residues. The methods used include the determination of bacterial numbers, dehydrogenase activity, and oxygen uptake with selected substrates (ethanol, amino acids, organic acids). Tests were conducted at varying intervals during a 66-day experimental period. Maximum activity was observed in all supplemented soils during the early stages of decomposition (5–10 days) followed by a rapid decline. During the first 10 days a correlation was found between numbers of microorganisms and the respiratory activity (oxygen uptake) of the soils. Analysis of the data from this period indicated that the increased metabolic activity of the soil was due partially to a preferential stimulation of the organisms and not to the effects of increased numbers alone. Nutritional grouping of bacteria isolated from the flax supplemented soil at 0 and after 6 days of decomposition indicated a shift in the microbial equilibrium, towards a higher proportion of bacteria with relatively simple nutritional requirements.

OXYGEN UPTAKE BY RHIZOBIA IN SOIL

1954 ◽  
Vol 32 (3) ◽  
pp. 380-385 ◽  
Author(s):  
J. F. T. Spencer
Keyword(s):  
Oxygen Uptake ◽  
Incubation Period ◽  
Room Temperature ◽  
Rhizobium Meliloti ◽  
Soil Microflora ◽  
Plant Residues

Plant residues were mixed with moistened soils and the mixtures incubated at room temperature. Samples were taken at intervals of several days, steam sterilized, and used as substrates in the Lees respirometer for measurements of oxygen uptake by Rhizobium meliloti. Rhizobia were active in the soils and their activity was stimulated by addition of ordinary plant residues. It was found that the shorter the incubation period of the soil – plant residues mixture, the greater was the increase in oxygen uptake over that obtained when the soil alone was used as substrate. The Lees respirometer was found to be a convenient apparatus for measurements of oxygen uptake by soil microflora.

scholarly journals CORRELATION OF METABOLIC ACTIVITY OF MICROORGANISMS AND MICROARTHROPODS IN THE PROCESS OF DESTRUCTION OF PLANT RESIDUES

2017 ◽  
Vol 20 (3) ◽  
pp. 197-201
Author(s):  
Y.V. Simonov
Keyword(s):  
Metabolic Activity ◽  
Soil Biota ◽  
Plant Residues ◽  
Biological Degradation ◽  
Decomposition Of Plant Residues

On the basis of instrumental studies the contribution of microorganisms and small arthropods to the metabolism of soil biota in the decomposition of plant residues was estimated numerically. The dependence of metabolism of biological degradation agents on their biomass was shown.

Investigation of biological activity of recultivated iron ore processing wastes of Abagur agglomeration and processing plant, Novokuznetsk

2021 ◽  
Vol 77 (6) ◽  
pp. 711-716
Author(s):  
M. A. Zakharova ◽  
A. S. Vodoleev ◽  
K. I. Domnin ◽  
S. Yu. Klekovkin
Keyword(s):  
Enzymatic Activity ◽  
Higher Plants ◽  
Maximum Activity ◽  
Soil Microflora ◽  
Plant Residues ◽  
Processing Plant ◽  
Vital Activity ◽  
Tailing Dump ◽  
Degrading Bacteria ◽  
Favorable Conditions

The problem of biotransformation of man-caused disturbed lands is of great importance for the restoration of soil fertility. The leading role in this process is played by soil microorganisms. Toxic industrial waste can make negative adjustments to the species composition of soil microflora (can cause mutation of many microorganisms, as well as the death of some of them). Under certain conditions, in the presence of harmful substances, new microorganisms can arise that decompose precisely those substances that cause soil pollution. Consequently, a new microflora appears, capable of carrying out its trophic functions on an inductive basis on industrially contaminated substrates. As a man-caused control, a mineral substrate of the tailing dump of Abagurskaya agglomeration and processing plant JSC, unfavorable for the vital activity of soil microflora, where, due to the absence of plant residues and other carbon-containing components, an extremely low level of intensity of enzymatic hydrolytic processes was used. The introduction of organic matter containing sewage sludge (WWS) into the substrate as a recultivator creates favorable conditions for the formation of a stable vegetation cover. The presence of an organic component in the mineral substrate of the iron-containing tailings waste creates favorable conditions for the vital activity of microflora. Carbon-containing compounds of technozems create a certain pool of microorganisms. The products of their vital activity create the basis for the formation of an organic-mineral substrate, favorable conditions for the growth of higher plants and the creation of a stable phytocenosis. For the induced manifestation of enzymatic activity under these extreme conditions, a considerable time is required for the bacterial forms introduced from the outside to be able to fix their presence. The maximum activity, comparable both after 1 month and after 3 months with the natural control, was noted on the experimental site with the placement of WWS as a soil conditioner. The presence of WWS and intensive accumulation of leaf litter and other plant residues contribute to the favorable development of cellulose-degrading bacteria, among which rod-shaped forms of the genus Clostridium predominate. The quantitative indicators of the enzymatic activity of technozems are close to the natural level and significantly exceed those of technogenic control.

OBSERVATIONS ON THE METABOLIC ACTIVITY OF THE SOIL MICROFLORA

1956 ◽  
Vol 2 (6) ◽  
pp. 611-622 ◽  
Author(s):  
H. Katznelson ◽  
I. L. Stevenson
Keyword(s):  
Organic Matter ◽  
Gas Exchange ◽  
Metabolic Activity ◽  
Respiratory Activity ◽  
Marked Decrease ◽  
Soil Microflora ◽  
Marked Variation ◽  
Lag Period ◽  
Casamino Acids ◽  
Intact Soil

The metabolic activity of the soil microflora has been studied manometrically with intact soil at optimum moisture and in the presence of various substrates. It was found that casamino acids were oxidized rapidly after a preliminary lag period. Oxygen uptake with this substrate showed no marked variation when the moisture level of the soil was between 60 and 80% of its moisture holding capacity. Mixtures of various non-nitrogenous substrates such as hexoses, pentoses, disaccharides, and organic acids yielded variable results. Uptake of oxygen by the soil in the presence of casamino acids was completely inhibited by dinitrophenol and azide. A marked decrease in respiratory activity in the soil was observed also when the reaction was lowered to pH 3.5 and 4.5. Considerable variation in gas exchange was obtained with soils which varied widely in fertility, organic matter, and nitrogen content.

Determination of Caffeine and its Metabolites in Saliva and Urine as a Measure of CYP1A2 Metabolic Activity

2016 ◽  
Vol 12 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Miroslav Turjap ◽  
Ondrej Zendulka ◽  
Zdenek Glatz ◽  
Stanislav Brejcha ◽  
Ales Madr ◽  
...  
Keyword(s):  
Metabolic Activity

Validation of a new method for determination of free fatty acid turnover

1987 ◽  
Vol 252 (3) ◽  
pp. E431-E438 ◽  
Author(s):  
J. M. Miles ◽  
M. G. Ellman ◽  
K. L. McClean ◽  
M. D. Jensen
Keyword(s):  
Steady State ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Clearance Rate ◽  
Experimental Period ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
State Equations ◽  
Tracer Methods

The accuracy of tracer methods for estimating free fatty acid (FFA) rate of appearance (Ra), either under steady-state conditions or under non-steady-state conditions, has not been previously investigated. In the present study, endogenous lipolysis (traced with 14C palmitate) was suppressed in six mongrel dogs with a high-carbohydrate meal 10 h before the experiment, together with infusions of glucose, propranolol, and nicotinic acid during the experimental period. Both steady-state and non-steady-state equations were used to determine oleate Ra ([3H]oleate) before, during, and after a stepwise infusion of an oleic acid emulsion. Palmitate Ra did not change during the experiment. Steady-state equations gave the best estimates of oleate inflow approximately 93% of the known oleate infusion rate overall, while errors in tracer estimates of inflow were obtained when non-steady-state equations were used. The metabolic clearance rate of oleate was inversely related to plasma concentration (P less than 0.01). In conclusion, accurate estimates of FFA inflow were obtained when steady-state equations were used, even under conditions of abrupt and recent changes in Ra. Non-steady-state equations, in contrast, may provide erroneous estimates of inflow. The decrease in metabolic clearance rate during exogenous infusion of oleate suggests that FFA transport may follow second-order kinetics.

A method for measurement of oxygen uptake in neonates

1979 ◽  
Vol 46 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
D. B. Raemer ◽  
D. R. Westenskow ◽  
D. K. Gehmlich ◽  
C. P. Richardson ◽  
W. S. Jordan
Keyword(s):  
Intensive Care ◽  
Oxygen Uptake ◽  
Positive Airway Pressure ◽  
Animal Experiments ◽  
Newborn Infants ◽  
Positive End Expiratory Pressure ◽  
Newborn Intensive Care Unit ◽  
Frequent Use ◽  
Newborn Intensive Care

The frequent use of continuous positive airway pressure and positive end-expiratory pressure in newborn infants with pulmonary disease has prevented the use of conventional methods for measuring oxygen uptake (VO2) in intensive-care units. A feed-back replenishment technique for the determination of the oxygen uptake of these newborn infants has been developed. An instrument utilizing this method has been designed and built permitting continuous VO2 monitoring without interfering in the routine ventilatory therapy of the critically ill infant. Theoretical, bench, and animal experiments using room air as an inspired gas indicate instrument accuracies as a percentage of full scale of 2.4, 2.8, and 7.3, respectively. Preliminary trials on infants demonstrate that the instrument functions satisfactorily in the newborn intensive-care unit.

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