scholarly journals Soil enzyme activity in the dry valley phytocenoses under the influence of Acer negundo L.

2021 ◽  
Vol 31 ◽  
pp. 00029
Author(s):  
Oksana Tsandekova

The activity of hydrolytic enzymes in the soil of dry valley phytocenoses under the influence of ash-leaved maple was investigated. The research objects were selected taking into account the ranking of plantations by crown density. Soil samples were collected depending on the horizontal differentiation of communities in the undercrown and outer zones of phytogenic fields. An increase in the enzyme activity during the period of active tree growth among experimental and control samples was established. Among the enzymes, invertase demonstrated the highest activity, while protease and phosphatase were characterised by medium activity. An increased invertase activity was found in the trees with a high crown density as compared to the trees of other groups. The obtained data can be used as diagnostic indicators of soil condition for monitoring natural ecosystems.

On the grey forest medium-loamy soil of Vladimir Opolye region we have studied the impact of various methods of basic cultivation and fertilizer systems on the activity of redox and hydrolytic enzymes: ure-ase (nitrogen cycle), invertase (carbon cycle), phosphatase (phosphorus cycle), and catalase, involved in the cycle of carbon in the soil. The second humus horizon with capacity of 19-24cm was found at the depth of 20 - 21 cm on the experimental field. We have studied three modes of basic soil cultivation: an-nual shallow flat plowing (6-8 cm), annual deep flat plowing (20-22 cm), and annual moldboard plowing (20-22 cm) with normal and intensive application of fertilizers. The most enzymatically active layer is 0-20 cm. No relevant difference has been found in the level of enzymes activity between variants of basic soil treatment. Activity of enzymes increases with application of fertilizers on the intensive background. In agrogenic soils, soil enzymatic activity is lower on average by 16-22% compared to the soil of the res-ervoir. The biggest negative transformation of activity has been observed at the urease enzyme (up to 50%). With annual moldboard plowing on the intensive backgroung, enzyme activity has been close to the natural level – 98.4%. Catalise and invertase activity in this case were found to be higher (105 and 116% respectively) than that of natural analogues. Activity of enzymes increases with intensive application of fertilizers as compared with normal background. This is particularly evident with 6-8cm deep beardless plowing and 20-22cm deep moldboard plowing. In general, the obtained biochemical indicators charac-terize the highest environmental sustainability of this variation within our research.


2017 ◽  
Vol 63 (6) ◽  
pp. 926-932
Author(s):  
Lyudmila Belskaya ◽  
Viktor Kosenok ◽  
Ж. Массард

So far optimization problems for diagnostics and prognostication aids remained relevant for lung cancer as a leader in the structure of cancers. Objective: a search for regularities of changes in the saliva enzyme activity in patients with nonsmall cell lung cancer. In the case-control study, 505 people took part, divided into 2 groups: primary (lung cancer, n=290) and control (conventionally healthy, n=215). All the participants went through a questionnaire survey, saliva biochemical counts, and a histological verification of their diagnosis. The enzyme activity was measured with spectrophotometry. Between-group differences were measured with the nonparametric test. It was shown that in terms of lung cancer, we observe metabolic changes, described with the decreased de Ritis coefficient (p


1991 ◽  
Vol 116 (2) ◽  
pp. 239-243 ◽  
Author(s):  
H. L. Sehtiya ◽  
J. P. S. Dendsay ◽  
A. K. Dhawan

SUMMARYAcid and neutral invertase activities in the stem of an early (CoJ 64) and a late cultivar (Col 148) of sugarcane were estimated by incubating stem slices in buffered sucrose solution and measuring the production of reducing sugars. High enzyme activity occurred in young tissue but the activity of both enzymes was considerably lower in the mature internodes. Acid and neutral invertase activity was highest in the midinternode position, corresponding to the region of cell expansion.


1985 ◽  
Vol 248 (1) ◽  
pp. E1-E9 ◽  
Author(s):  
J. D. Robishaw ◽  
J. R. Neely

The metabolism of coenzyme A and control of its synthesis are reviewed. Pantothenate kinase is an important rate-controlling enzyme in the synthetic pathway of all tissues studied and appears to catalyze the flux-generating reaction of the pathway in cardiac muscle. This enzyme is strongly inhibited by coenzyme A and all of its acyl esters. The cytosolic concentrations of coenzyme A and acetyl coenzyme A in both liver and heart are high enough to totally inhibit pantothenate kinase under all conditions. Free carnitine, but not acetyl carnitine, deinhibits the coenzyme A-inhibited enzyme. Carnitine alone does not increase enzyme activity. Thus changes in the acetyl carnitine-to-carnitine ratio that occur with nutritional states provides a mechanism for regulation of coenzyme A synthetic rates. Changes in the rate of coenzyme A synthesis in liver and heart occurs with fasting, refeeding, and diabetes and in heart muscle with hypertrophy. The pathway and regulation of coenzyme A degradation are not understood.


2019 ◽  
Author(s):  
Eric M. Lynch ◽  
Justin M. Kollman

Many enzymes assemble into defined oligomers, providing a mechanism for cooperatively regulating enzyme activity. Recent studies in tissues, cells, and in vitro have described a mode of regulation in which enzyme activity is modulated by polymerization into large-scale filaments1–5. Enzyme polymerization is often driven by binding to substrates, products, or allosteric regulators, and tunes enzyme activity by locking the enzyme in high or low activity states1–5. Here, we describe a unique, ultrasensitive form of polymerization-based regulation employed by human CTP synthase 2 (CTPS2). High-resolution cryoEM structures of active and inhibited CTPS2 filaments reveal the molecular basis of this regulation. Rather than selectively stabilizing a single conformational state, CTPS2 filaments dynamically switch between active and inactive filament forms in response to changes in substrate and product levels. Linking the conformational state of many CTPS2 subunits in a filament results in highly cooperative regulation, greatly exceeding the limits of cooperativity for the CTPS2 tetramer alone. The structures also reveal a link between conformational state and control of ammonia channeling between the enzyme’s two active sites. This filament-based mechanism of enhanced cooperativity demonstrates how the widespread phenomenon of enzyme polymerization can be adapted to achieve different regulatory outcomes.


1985 ◽  
Vol 248 (4) ◽  
pp. F487-F491
Author(s):  
L. C. Garg ◽  
N. Narang ◽  
C. S. Wingo

We determined the effect of dexamethasone on Na-K-ATPase activity in six nephron segments of the adrenalectomized rabbit. Treatment consisted of 1.4 micrograms dexamethasone X 100 g body wt-1 X day-1 for 7 days prior to the study of the nephron segments. Enzyme activity was determined in individual nephron segments by a microfluorometric assay. There was 40-50% less activity of Na-K-ATPase in the S1 portion of the proximal convoluted tubule (PCT, S1), the medullary thick ascending limb (MTAL), and the distal convoluted tubule (DCT) of adrenalectomized rabbits compared with that of control (sham-operated) animals. There was no significant difference in the enzyme activity in proximal straight tubules (PST, S2 and S3) and cortical thick ascending limb (CTAL) of adrenalectomized and control animals. Dexamethasone treatment produced a dexamethasone concentration of 5 +/- 0.8 nM in the plasma and increased Na-K-ATPase activity in PCT (S1), MTAL, and DCT of the adrenalectomized animals to the control levels without significantly affecting the enzyme activity in the PST (S2, S3) or CTAL. The concentration of dexamethasone in the plasma was such that the hormone should bind mainly to dexamethasone receptors (Kd = 5 nM) and very little to aldosterone receptors (Kd greater than 60 nM). Thus, glucocorticoids probably stimulate Na-K-ATPase in PCT, MTAL, and DCT through glucocorticoid (Type II) receptors and not through mineralocorticoid (Type I) receptors.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 335-343 ◽  
Author(s):  
Rajeev Goel ◽  
Takashi Mino ◽  
Hiroyasu Satoh ◽  
Tomonori Matsuo

Enzymatic hydrolysis under different electron acceptor conditions in nutrient removal activated sludge treatment processes is a weak link in the Activated Sludge Model no. 2 (Henze et al., 1995). An experimental study was undertaken to gain insight into the hydrolysis process with specific focus on hydrolysis kinetics and rates under different electron acceptor conditions. Two pure cultures, Bacillus amyloliquefaciens (Gram positive) and Pseudomonas saccharophila (Gram negative) were chosen for the study. In addition, activated sludge grown in an anaerobic-aerobic system was tested for enzymatic activity using starch as the model substrate. The hydrolytic enzymes were found to be released into the bulk in pure cultures whereas the enzyme activity was found to be mainly associated with the cell surfaces in activated sludge. Further, it was observed that the development of the hydrolytic enzyme system in Bacillus amyloliquefaciens and P. saccharophila is strongly suppressed under anoxic and anaerobic conditions. However, the effect of anaerobic and aerobic incubation on hydrolytic enzyme activity in activated sludge was found to be small. Starch hydrolysis kinetic data from batch experiments with activated sludge followed substrate saturation kinetics that were linear with biomass concentration. Finally, the similar hydrolytic enzyme activities observed under anaerobic and aerobic phases of a sequencing batch reactor are explained by considering the aspects of enzyme location and enzyme system development under aerobic and anaerobic phases. It is proposed that the floc bound enzymes are recycled in a single sludge system so that an equilibrium exists between enzyme loss and synthesis at steady state.


1968 ◽  
Vol 16 (4) ◽  
pp. 249-262 ◽  
Author(s):  
ZOLTAN POSALAKI ◽  
DEZSÖ SZABÓ ◽  
ERNÖ BÁCSI ◽  
ISTVÁN ÖKRÖS

The localization of lipids and the activities of nonspecific esterase, aryl sulfatase and acid phosphatase were studied in different stages of spermatogenesis in rats. In addition, the distribution of acid phosphatase activity was demonstrated electron histochemically. The spermatogenetic cycle was divided into two phases—corresponding to the first and the last four stages of Roosen-Runge-Giesel (RG) classification. Spermatids in the first phase contained abundant endoplasmic reticulum with rosette formation and well developed Golgi apparatus with numerous vesicles. They displayed high activity of hydrolytic enzymes but contained no appreciable amount of lipids. The Sertoli cells contained large lipid granules but showed minimal enzyme activity. During the second phase reduction of the cytoplasm of spermatids with fragmentation of the endoplasmic reticulum and Golgi lamellae, accumulation of lipids, aggregation of ribonucleo-protein particles, formation of residual bodies and marked decrease of enzyme activity were seen. The Sertoli cells contained large mitochondria, well developed endoplasmic reticulum and numerous dense bodies and revealed high activities of hydrolytic enzymes and rapid depletion of lipids. These ultrastructural and histochemical findings suggested an interaction between the Sertoli cells and the developing spermatids which probably contributed to the regulation of spermatogenesis.


2018 ◽  
Vol 3 ◽  
pp. 30-39
Author(s):  
Sobia Baby Jamro ◽  
Naheed Akhtar Talpur ◽  
Mukesh Kumar Sootahar ◽  
Zial Ul Hassan Shah ◽  
Mahendar Kumar Sootahar ◽  
...  

A field experiment was conducted during summer 2016 to screen out sunflower (Helianthus annuusL.) genotypes for their potassium (K) use efficiency ratio. Eight sunflower genotypes were tested; Samsung 20, Mehran 2, Ho-1, Melabour, Samsung 30, Valugur, Chinika and Sputnik in randomised complete block design (RCBD) with the two treatments comprised of potassium at (50 and 0 kg K ha-1) along with source (SOP) recommended dose fertilizer respectively. The results revealed that the treated and control plots (50 and 0 kg K ha-1) produced different values for of seeds (1763.1 and 1588.5 head-1), shoot dry weight (23.0 and 19.11 g), head diameter (17.45 and 15.72 cm), seed yields (2065.8 and 1918.7 kg ha-1), seed K % (0.60 and 0.30%) and diagnostic tissue % (3.54 and 2.65%) respectively. The considerable increase was found in seeds head-1(10.99%), shoot dry weight (20.35%), head diameter (11.01%), seed yields (11.31%) seed K % (100%), and leaf K % (33.58%). Among genotypes, Ho-1 was highly efficient to utilize added K fertilizer more seed (2039.7 head-1), shoot dry weight (25.86 g), plant height (188.66 cm), head diameter (20.20 cm), seed yields (2409.5 kg hat-1). Moreover seed K % and leaf K % was also high in variety Ho_1 (0.65% and (5.05%) respectively. Among all the sunflower tested genotypes Ho-1 showed significant response applied K but the variety Ho-1 and genotype Chinika were more efficient in utilization of K.


2021 ◽  
Vol 42 (4(SI)) ◽  
pp. 1195-1200
Author(s):  
S. Thirukkumar ◽  
◽  
G. Hemalatha ◽  
S. Vellaikumar ◽  
M. Murugan ◽  
...  

Aim: This research aimed to optimize suitable hydrolytic enzymes for maximizing cottonseed milk extracts for high cottonseed milk yield, protein content and low gossypol level. Methodology: Known amount of cottonseed was soaked for 90 min at 32°C and blended (cottonseed:water@1:6). Different aliquots of the blended cottonseed slurry were treated with 1% of enzymes viz., protease, cellulase and α-amylase enzyme at pH 7.0 followed by incubation at 40 and 52°C for 2.30 hr for the extraction of cottonseed milk. The enzyme activity of extracted milk was subsequently inactivated by pasteurization (90°C, 5 min). Further analysis of physico-chemical characteristics was also carried. The control sample included milk extraction from non-enzyme treated cottonseed milk extract (30±2°C). Results: Among different treatments, cottonseed milk extraction using protease enzyme at 40°C incubation showed the highest milk yield (86.71%) with the lowest sedimentation (3.72%). Further incubation 40°C and 52°C showed the highest protein content of 2.10 and 2.27 g 100 ml-1 and gossypol reduction of 40.36 and 35.22%, respectively, in the cottonseed milk extract. Meanwhile, cellulase and α-amylase enzymes treated samples at both incubation temperatures showed poor physico-chemical characteristics as compared to control. Interpretation: Protease enzyme seems to be the most suitable for optimum or higher extraction of cottonseed milk.


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