Terms Of Enzyme Activity Research Articles

Safety and efficacy of a feed additive consisting of endo-1,4-β xylanase, endo-1,4-β-glucanase and xyloglucan-specific-endo-β-1,4-glucanase produced by Trichoderma citrinovirideDSM 33578 (Huvezym® neXo) for all Suidae (Huvepharma EOOD).

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Huvezym® neXo 100 G/L, a product containing endo-1,4-β-xylanase, endo-1,4-β-glucanase and xyloglucan-specific-endo-β-1,4-glucanase activities produced by a non-genetically modified strain of Trichoderma citrinoviride (DSM 33578), as a zootechnical additive for all Suidae. The applicant provided information confirming the taxonomic identification of the production strain. The batches used for the characterisation of the final formulations showed compliance with the minimum specifications of the additive in terms of enzyme activities (> 15,000 EPU, > 1000 CU, > 1000 XGU per g) but not for the ratio of the enzymes, which is lower (ca. 7:1:1) than the ones specified (15:1:1). The Panel could not conclude on the representativeness of the test item used in the toxicological and tolerance studies with respect to the final formulations. Therefore, the conclusions are limited to the product with a minimum enzyme activity of 15,000 EPU, 1000 CU, 1000 XGU per g and a xylanase:glucanase:xyloglucanase ratio of 15:1:1. The Panel concluded that the additive is safe for the target species, consumers and the environment. Huvezym® neXo 100 G is not an irritant to the skin and eyes but should be considered a skin sensitiser. Huvezym® neXo 100 L is neither an irritant to the skin and eyes nor a skin sensitiser. Due to the proteinaceous nature of the active substances, the additive is considered a respiratory sensitiser. The additive has the potential to be efficacious in all reproductive Suidae at the minimum proposed use level. Owing to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for Suidae for fattening or reared for reproduction.

In vitro replicative potential of an HIV-1/MO intergroup recombinant virus compared to HIV-1/M and HIV-1/O parental viruses

Genetic recombination is one of the major evolution processes of HIV-1. Despite their great genetic divergence, HIV-1 groups M and O can generate HIV-1/MO intergroup recombinants. The current description of 20 HIV-1/MO unique recombinant forms suggests a possible benefit of the recombination. The aim of this work was to study in vitro the replicative potential of HIV-1/MO recombinant forms. This analysis was based on a simple recombination pattern, [Ogag/pol-Menv], harboring a breakpoint in Vpr. A chimeric infectious molecular clone, pOM-TB-2016 was synthesized from HIV-1/M subtype B and HIV-1/O subgroup T and recombinant viruses were obtained by transfection/co-culture. To compare the replicative potential of these viruses, two markers were monitored in culture supernatants: Reverse Transcriptase (RT) activity and P24 antigen concentration. The results showed a superiority of the group M parental virus compared to group O for both markers. In contrast, for the recombinant virus, RT activity data did not overlap with the concentration of P24 antigen, suggesting a hybrid behavior of the recombinant, in terms of enzyme activity and P24 production. These results highlighted many hypotheses about the impact of recombination on replicative potential and demonstrated again the significant plasticity of HIV genomes and their infinite possibility of evolution.

Molecular Docking, Simulation Against SARS-COV-2, Theoretical Study (DFT) and Superoxide Anion Scavenging by Cyclic Voltammetry of 2-Hydroxyphenyl Imino Naphthalen-2-ol

The simulation in terms of enzymatic activity and the estimation of the process transfer of electronic active sites of the synthesized compound: 2-hydroxyphenyl imino naphthalen-2-ol (Schiff basis) required the use of valuable calculation programs such as the docking, for which we used the Arguslab program and the Gaussian endowed to the calculation of the functional density theory of the molecule studied. And as the experimental study designed under difficult, costly or sometimes impossible conditions, the docking program simulates the molecular binding of the protein target with the ligand, which can reveal the arrangement of the hydrogen and hydrophobic bonds that link the active sites and the ligand; it is an economical step in terms of time and money that can lead to the selectivity of the product of interest in drug manufacturing. In this context, we are currently focused on the study of the inhibitory effect of this molecule with the enzyme (6lu7) fighting against covid-19, and have compared it to the drug chloroquine. The obtained results show that the calculated Gibbs free energy with protease is -9.215 Kcal/mol, which is almost more inhibiting than chloroquine (-7.2652 Kcal/mol). The DFT method allowed us to estimate that the potentially positive sites easily cede an electron when they are brought into contact with oxidizing species during the reduction reaction. The study of the superoxide anion scavenging activity via this product is performed practically by electrochemical way, the Gibbs standard energy (-16.9022 KJ/mol) explains that the reaction can spontaneously form very stable inactive species with the oxidizing ion.

Curtobacterium caseinilyticum sp. nov., Curtobacterium subtropicum sp. nov. and Curtobacterium citri sp. nov., isolated from citrus phyllosphere.

Three novel Gram-stain-positive, aerobic and rod-shaped bacterial strains, designated RHCKG28T, RHCJP20T and RHCKG23T, were isolated from phyllosphere of healthy citrus leaves collected from Renhua County in Guangdong Province, PR China. 16S rRNA gene sequences comparison and phylogenetic analyses showed that they all belonged to the genus Curtobacterium, among which strain RHCKG28T showed the highest similarity to Curtobacterium herbarum NBRC 103064T (99.3 %), while strains RHCJP20T and RHCKG23T showed 99.2 and 99.0 % similarity to Curtobacterium citreum JCM 1345T, respectively. Phylogenomic analysis showed that the three novel strains were most closely related to C. citreum JCM 1345T and Curtobacterium albidum JCM 1344T. The novel strains could be distinguished from their closely related type strains in terms of enzyme activities, substrate assimilation and fatty acid profiles. In addition, the average nucleotide identity and digital DNA-DNA hybridization values between the novel strains and closely related type strains were 84.4‒89.5 % and 24.5‒34.1 %, respectively, which were below the threshold values for species delimitation. They all took anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 as the major fatty acids, menaquinone 9 (MK-9) as the sole predominant respiratory quinone, and ornithine as the principal cell-wall diamino acid. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol and several unidentified glycolipids. The phenotypic, genotypic and chemotaxonomic data supported that they represent three distinct novel species of the genus Curtobacterium, for which the names Curtobacterium caseinilyticum sp. nov., Curtobacterium subtropicum sp. nov. and Curtobacterium citri sp. nov. are proposed, with RHCKG28T (=GDMCC 1.2667T=JCM 34828T), RHCJP20T (=GDMCC 1.2668T=JCM 34829T) and RHCKG23T (=GDMCC 1.2669T=JCM 34830T) as the type strains, respectively.

Detection of combined frost and drought stress in wheat using hyperspectral and chlorophyll fluorescence imaging

Immediate detection and prediction tools for interactive stresses are essential to avoid yield losses. This study investigated the capability of hyperspectral (HSI) and chlorophyll fluorescence imaging (CFI) to characterize individual and interactive frost (−4 °C) and drought (40% soil moisture content) stress responses at the booting stage of wheat under controlled environmental conditions. HSI full range reflectance (280–2500 nm), CFI, and traditional responses (leaf water content, photosynthesis, and enzymatic activity) were measured from flag leaves. The potentiality of HSI to detect cellular damage in terms of enzymatic activity was explored by developing partial least square regression (PLSR) models, and spectral indices were calculated to characterize the responses to individual and combined stresses. Reflectance in 360, 700, 1400, 1900, and 2460 nm wavebands showed the most important variables in developing PLSR models for enzymes. Superoxide dismutase, peroxidase, and ascorbate peroxidase showed the highest R2c (0.99, 0.95, and 0.98), R2v (0.94, 0.90, 0.93), and the ratio of prediction to deviation (4.04, 3.06, and 3.85). CFI decreased under individual frost and combined frost and drought stresses. Ratio vegetation stress index (RVSI), green difference vegetation index (GDVI), difference vegetation index (DVI), and normalized difference water index (NDWI) were the most important variables and could be used to detect combined frost and drought by determining enzymatic activity and reactive oxygen species (ROS), verified by PLSR models. Spectral indices and enzyme activities showed a strong correlation in determining yield losses. Hence, HSI and CFI techniques successfully detected combined frost and drought stresses for rapid quantification.

Investigation of changes in MDH enzyme activity in epilepsy

Aims: Epilepsy is one of the most common neurological diseases. It is classified into three groups: focal onset, generalized onset and unclassifiable. A seizure type is difficult to determine. The malate dehydrogenase (MDH) enzyme has a critical role in the excitability of the brain, and it has been reported that recurrent seizures are seen when its regulation is disturbed. We investigated the contribution of MDH enzyme levels as a biomarker to seizure classification. Methods: Our study was conducted prospectively by patients who were admitted to the emergency department of our hospital within a six-month period. Included in the study were 65 patients diagnosed with epilepsy, according to the International League Against Epilepsy (ILAE) classification. The patients were divided into two groups according to seizure type: focal onset and generalized onset. They were compared in terms of enzyme activity. Results: The MDH value was 47.56 ± 38.65 in patients with focal-onset epilepsy and 109.76 ± 128.44 in patients with generalized-onset epilepsy. Conclusion: Our results reveal the potential of MDH as a biomarker that can be used in epilepsy. In addition, the statistically significant difference between focal-onset and generalized-onset epilepsy indicates that it can be a usable biomarker in seizure classification

Loaded paraquaton polymeric nanocapsules and evaluation for cardiotoxicity in Wistar rats

ABSTRACT Present work was conducted to prepare and evaluate, loaded paraquat nano-hydrogels using chitosan, sodium polytriphosphate, and xanthan via ionic gelification method. The fabricated L-PQ formulations were analyzed for surface morphology and functional groups using SEM and FTIR, respectively. The stability of the synthesized nanoparticle was, also, analyzed in terms of diameter size, zeta potential, dispersion index, and pH. Furthermore, the cardiotoxicity effects of the synthesized nanogels were investigated on Wistar rats in terms of enzymatic activity, echocardiographic, and histological analysis. The proper stability of the prepared formulation was also confirmed by diameter size, zeta potential, dispersion index, and pH. The efficiency of encapsulation was about 90±3.2% and the release of PQ in the loaded nanogel was about 90±2.3%. A decrease in ST (shortening time) segment by formulated PQ, either in peritoneal or gavage exposure pathway, indicates the effectiveness of the capsule layer against the penetration of toxin into the body.

Monitoring the effects of pH and EC regulated drip fertigation on microbial dynamics of calcareous soil in tomato (Solanum lycopersicum L.) cultivation under greenhouse conditions in a Mediterranean climate

The microbial dynamics of the soil, together with the available nutrient content of the soil, is seen as a very important indicator of soil fertility. In this study, the effects of drip fertigation with different pH and EC applications in the cultivation of tomato under greenhouse conditions on microbial dynamics of calcareous soil were investigated using number of bacteria (heterotrophic aerobic mesophilic) and enzyme activities (urease, alkaline phosphatase, β-glucosidase, dehydrogenase). pH and EC regulated fertigation applications on soil are as follows: a) pH 7.2 EC 2.0 dS m−1 (NA+CF-1), b) pH 7.2 EC 3.5 dS m−1 (NA+CF-2), c) pH 6.5 EC 2.0 dS m−1 (NA+CF-3), d) pH 6.5 EC 3.5 dS m−1 (NA+CF-4), e) pH 5.0 EC 2.0 dS m−1 (NA+CF-5); and f) pH 5.0 EC 3.5 dS m−1 (NA+CF-6). Results indicated significant effects of both pH and EC regulated fertigation on soil in terms of enzyme activities (except urease and dehydrogenase) and the presence of bacteria. The measured parameters showed greater values in the first growth season compared to the second (except urease) and the differences between the treatments in the first growth season were statistically significant. In addition, in both growth season, positive relations occurred between number of soil bacteria and total N, available P, urease and alkaline phosphatase activities. On the other hand, due to increasing salinity (in the second growth season) number of soil bacteria, alkaline phosphatase, β-glucosidase and dehydrogenase activities are negatively affected. It would be ideal to have the pH of the water to be dripped to rhizosphere in the range of 6.5-7.2 and the EC in the level of 2.0 dS m−1 in order to provide more efficient and safer protection of the soil fertility in terms of soil microbial dynamics during the tomato cultivaton in calcareous soils under the Mediterranean climate.

A Reactive Oxygen Species-Scavenging 'Stealth' Polymer, Poly(thioglycidyl glycerol), Outperforms Poly(ethylene glycol) in Protein Conjugates and Nanocarriers and Enhances Protein Stability to Environmental and Biological Stressors.

This study addresses well-known shortcomings of poly(ethylene glycol) (PEG)-based conjugates. PEGylation is by far the most common method employed to overcome immunogenicity and suboptimal pharmacokinetics of, for example, therapeutic proteins but has significant drawbacks. First, PEG offers no protection from denaturation during lyophilization, storage, or oxidation (e.g., by biological oxidants, reactive oxygen species); second, PEG's inherent immunogenicity, leading to hypersensitivity and accelerated blood clearance (ABC), is a growing concern. We have here developed an 'active-stealth' polymer, poly(thioglycidyl glycerol)(PTGG), which in human plasma is less immunogenic than PEG (35% less complement activation) and features a reactive oxygen species-scavenging and anti-inflammatory action (∼50% less TNF-α in LPS-stimulated macrophages at only 0.1 mg/mL). PTGG was conjugated to proteins via a one-pot process; molar mass- and grafting density-matched PTGG-lysozyme conjugates were superior to their PEG analogues in terms of enzyme activity and stability against freeze-drying or oxidation; the latter is due to sacrificial oxidation of methionine-mimetic PTGG chains. Both in mice and rats, PTGG-ovalbumin displayed circulation half-lives up to twice as long as PEG-ovalbumin, but most importantly─and differently from PEG─without any associated ABC effect seen either in the time dependency of blood concentration, in the liver/splenic accumulation, or in antipolymer IgM/IgG titers. Furthermore, similar pharmacokinetic results were obtained with PTGGylated/PEGylated liposomal nanocarriers. PTGG's 'active-stealth' character therefore makes it a highly promising alternative to PEG for conjugation to biologics or nanocarriers.

Surface display of (R)-carbonyl reductase on Escherichia coli as biocatalyst for recycling biotransformation of 2-hydroxyacetophenone

The purified (R)-Carbonyl reductase (RCR) is widely applied in the synthesis of chiral compounds, but often involves tedious procedures and high production costs of protein separation and purification. A surface immobilization of biocatalyst on cell surface for biotransformation is an option for ease enzyme separation and recycling. In this study, the RCR from Candida parapsilosis was immobilized on the surface of E. coli using the Lpp–OmpA and EhaA anchors, showing that the Lpp–OmpA is better for displaying the target molecules in terms of enzyme activities, product formation, and display efficiency. By deleting the NAD+ degrading enzyme UshA, the whole-cell biocatalytic activity was two-fold higher than that of the original strain. The created biocatalyst can retain about 80% of its catalytic activity after four rounds of recycling, reached the conversion rate of 83.5% within 30 mins with the substrate (R)-PED concentration of 1 mM. This study provides a novel strategy for 2-hydroxy acetophenone synthesis using the surface display of the enzyme on the cell while avoiding enzyme purification and side reactions from the host.

Syntrichia caninervis adapt to mercury stress by altering submicrostructure and physiological properties in the Gurbantünggüt Desert

Sewage and industrial waste discharges have been found to have a deleterious effect on plant growth and environmental safety through the accumulation of trace metal mercury (Hg) in soils. Although the effects of Hg on vascular plants have been reported in terms of enzyme activity, oxidative damage and physiology, few studies have been done on non-vascular plants. A simulation experiment including 7 Hg concentrations (0, 10, 20, 30, 40, 50, 75 µM) was conducted to investigate the influence of Hg stress on ultrastructure and physiological properties of biocrust moss Syntrichia. caninervis across 7 consecutive days. The results showed that the lowest lethal concentration of S. caninervis was 30 µM Hg. The mortality rate of the plants increased significantly with Hg concentrations. The ultrastructure did not change significantly at Hg concentration ≤ 20 µM, while exceeding which, cell walls began to separate, nuclei began to blur, and chloroplasts began to expand. The soluble sugars (SS), peroxidase (POD), and superoxide dismutase (SOD) activities increased initially and then decreased with the increase of concentration in the time gradient, with the largest values at 20 µM. The contents of malondialdehyde (MDA) and proline (Pro) increased with the increase of Hg concentration, both reached peak value at 50 µM. However, chlorophyll (Chl) contents continued to decrease along both the concentration and time gradients. Pearson correlation and principal component analysis showed that two principal components (PC1 and PC2) explained 73.9% of the variance in plant adaptation to Hg stress. SOD, POD, Chl, SS, and Pro all responded well to Hg in S. caninervis. Our study showed that Hg stress caused changes in ultrastructure and physiological metabolism of S. caninervis. 20 µM was the maximum concentration of Hg that biocrust moss S. caninervis can tolerate. S. caninervis mainly adopted two adaptation strategies related to exclusion and accumulation to reduce Hg stress.

Characterisation of recombinant GH 3 β-glucosidase from β-glucan producing Levilactobacillus brevis TMW 1.2112

Levilactobacillus (L.) brevis TMW 1.2112 is an isolate from wheat beer that produces O2-substituted (1,3)-β-D-glucan, a capsular exopolysaccharide (EPS) from activated sugar nucleotide precursors by use of a glycosyltransferase. Within the genome sequence of L. brevis TMW 1.2112 enzymes of the glycoside hydrolases families were identified. Glycoside hydrolases (GH) are carbohydrate-active enzymes, able to hydrolyse glycosidic bonds. The enzyme β-glucosidase BglB (AZI09_02170) was heterologous expressed in Escherichia coli BL21. BglB has a monomeric structure of 83.5 kDa and is a member of the glycoside hydrolase family 3 (GH 3) which strongly favoured substrates with β-glycosidic bonds. Km was 0.22 mM for pNP β-D-glucopyranoside demonstrating a high affinity of the recombinant enzyme for the substrate. Enzymes able to degrade the (1,3)-β-D-glucan of L. brevis TMW 1.2112 have not yet been described. However, BglB showed only a low hydrolytic activity towards the EPS, which was measured by means of the D-glucose releases. Besides, characterised GH 3 β-glucosidases from various lactic acid bacteria (LAB) were phylogenetically analysed to identify connections in terms of enzymatic activity and β-glucan formation. This revealed that the family of GH 3 β-glucosidases of LABs comprises most likely exo-active enzymes which are not directly associated with the ability of these LAB to produce EPS.

Study on Baohe Pills Regulating Intestinal Microecology and Treating Diarrhea of High-Fat and High-Protein Diet Mice.

Objective To investigate the effects of Baohe pills on intestinal microorganisms and enzyme activities in mice with a high-fat and high-protein diet. Methods 45 KM male mice were randomly divided into the control group, the high-fat and high-protein diet group, and the Baohe pill intervention group. The mice in the high-fat and high-protein diet group and the Baohe pill intervention group were fed with the self-made high-fat and high-protein diet as the sole food source of the mice, and the mice in the control group were fed with the normal diet. Starting from the 7th day of the feed intervention, mice in the Baohe pill intervention group were given 0.28 g/mL of Baohe pill decoction twice a day at the dose of 6.67 g/(kg·day), each time of 0.35 mL for 6 days. Mice in the control group and the high-fat and high-protein diet group were given the same amount of distilled water by gavage. The general state of mice in each group was observed, and the changes of intestinal microorganisms and intestinal enzyme activities were analyzed by culturable microorganism technology and intestinal functional enzyme detection technology. Results The excrement of mice fed with a high-fat and high-protein diet was relatively thin and wet, and the Baohe pill intervention could not improve the symptoms well. In the high-fat and high-protein diet group, the number of bacteria, Escherichia coli, Lactobacillus, and Bifidobacterium, was significantly lower than that in the control group (P < 0.01). Baohe pills could obviously increase the high-fat, high-protein diet for the number of culturable microorganisms in mice, the total number of bacteria, and the number of Bifidobacteria in the most significant (P < 0.01), but the number of bacteria, Escherichia coli, and the Lactobacillus are still significantly lower than the control group (P < 0.01). In terms of enzyme activity, both contents and mucosa, the Baohe pill could improve the activities of amylase, protease, sucrase, and lactase in high-fat and high-protein diet mice, which were significantly different from the control group (P < 0.05). In terms of microbial activity, the intestinal contents of high-fat and high-protein mice were lower than those of the control group, while the intestinal mucosa was higher than that of the control group, but the difference was not significant (P > 0.05). Baohe pills could improve the intestinal contents and intestinal mucosal microbial activity of mice, and the difference was significant in the high-fat and high-protein diet group (P < 0.05). Discussion. A high-fat and high-protein diet can destroy the physiological balance of the body, which is mainly reflected in the disturbance of intestinal flora and the decrease of some enzyme activities and microbial activity. Baohe pills can restore the number of intestinal flora to a certain extent and improve the activities of various digestive enzymes including protease and amylase.

Yeast-produced fructosamine-3-kinase retains mobility after ex vivo intravitreal injection in human and bovine eyes as determined by Fluorescence Correlation Spectroscopy

Globally, over 2 billion people suffer from vision impairment. Despite complex multifactorial etiology, advanced glycation end products are involved in the pathogenesis of many causative age- and diabetes-related eye diseases. Deglycating enzyme fructosamine-3-kinase (FN3K) was recently proposed as a potential therapeutic, but for further biopharmaceutical development, knowledge on its manufacturability and stability and mobility in the vitreous fluid of the eye is indispensable. We evaluated recombinant production of FN3K in two host systems, and its diffusion behavior in both bovine and human vitreous. Compared to Escherichia coli, intracellular production in Pichia pastoris yielded more and higher purity FN3K. The yeast-produced enzyme was used in a first attempt to use fluorescence correlation spectroscopy to study protein mobility in non-sonicated bovine vitreous, human vitreous, and intact bovine eyes. It was demonstrated that FN3K retained mobility upon intravitreal injection, although a certain delay in diffusion was observed. Alkylation of free cysteines was tolerated both in terms of enzymatic activity and vitreous diffusion. Ex vivo diffusion data gathered and the availability of yeast-produced high purity enzyme now clear the path for in vivo pharmacokinetics studies of FN3K.

ОЦЕНКА ФЕРМЕНТАТИВНОЙ АКТИВНОСТИ НЕФТЕЗАГРЯЗНЕННОГО ЧЕРНОЗЕМА ПОСЛЕ БИОРЕМЕДИАЦИИ

Introduction. The evaluation of the ecological state of soils in terms of enzymatic activity during the remediation of petroleum hydrocarbons contamination is very informative. The activity of enzymes of the oxidoreductases and hydrolases classes in chernozem is most sensitive to contamination by heavy metals, pesticides, and other types of anthropogenic impact. The informativeness and sensitivity of enzymes during the remediation of petroleum hydrocarbons-contaminated soils have not been adequately studied. Materials and methods. The activity of seven enzymes of oxidoreductases and hydrolases classes of petroleum hydrocarbons-contaminated soils after the application of biochar, sodium humate, nitroammophos and Baikal EM-1 was studied. In 90 days from the moment the ameliorants were introduced into the soil, the enzymatic activity of soils was evaluated by changes in the activity of catalase, dehydrogenases, peroxidases, ferrireductases, invertase, urease, and phosphatases. The integral indicator of soil biological activity (IIBA) and the geometric mean enzymatic activity of soils were evaluated for the classes of oxidoreductases (GMea (ОХ)) and hydrolases (GMea (HD)). Results. During the remediation of petroleum hydrocarbons-contaminated chernozem, the concentration of D0.5 of biochar and Baikal EM-1 has a stimulating effect on the activity of oxidoreductases and hydrolases of the soil, and D2 of nitroammophos and sodium humate – D2. At a dose of D0.5 of nitroammophos and biochar, the maximum stimulation of IIBA was established relative to control and petroleum hydrocarbons contamination. The introduction of nitroammophos stimulated the activity of three out of seven enzymes, and biochar stimulated the activity of five out of seven enzymes regarding petroleum hydrocarbons contamination. The highest efficiency of nitroammophos is largely due to excessive stimulation of the urease activity of ordinary chernozem. The values of the geometric mean enzymatic activity (GMea) of oxidoreductases and hydrolases were stimulated relative to the control at a dose of D0.5 of each ameliorant. The sensitivity series of petroleum hydrocarbons-contaminated chernozem enzymes after the introduction of ameliorants from the most sensitive to the least sensitive is the following: ferrireductases &gt; peroxidases &gt; urease &gt; phosphatase &gt; dehydrogenases &gt; invertase &gt; catalase. According to the degree of restoration of the enzymatic activity of soils, the ameliorants can be arranged in the following order (in % of petroleum hydrocarbons contamination): nitroammophos &gt; biochar &gt; sodium humate &gt; Baikal EM-1. Conclusion. During the remediation of petroleum hydrocarbons-contaminated chernozem, the most stimulating effect on the activity of oxidoreductases and soil hydrolases is exerted by the ameliorant at a concentration of D0.5. For biodiagnostics of the ecological state of petroleum hydrocarbons-contaminated black soils, we recommend using the activity of ferrireductases, peroxidases, urease, and phosphatase.

A Study on Evaluation of Alkaline and Acid Phosphatase Isozymes During Different Developmental Stages of New Breeding Lines and Races of Bombyx mori L

It is interesting to note that different silkworm races reared in laboratory offer an important testing ground for the application of biochemical methods to taxonomic problems. Moreover, there is scarcity of knowledge on enzyme studies in new breeding lines and races of silkworm specially Bombyx mori L. Therefore, we designed the present study with the main goal to evaluate the activities of alkaline and acid phosphatases quantitatively during different developmental stages of new breeding lines and races viz. Kalimpong-A (KA), B18, Pure Mysore (PM), evolved R1 and R2 of Bombyx mori L. Quantitative estimations of in alkaline and acid phosphatases were expressed in terms of enzyme activity. Alkaline and acid phosphatase activities during the different developmental stages of KA, NB18, PM, evolved R1 &amp; R2 races were determined using Sodium-1 naphthahyl phosphate as a substrate following the dye-coupling method. The assay mixture included 2 ml of substrate and 0.2 ml of enzyme extract and incubation was made for 30 minutes at 25°c. The reaction was stopped by adding 2 ml of post coupling solution (5 parts of 4% sodium dodecyl sulphate and 2 parts of 0.2% Fast red TR salt) and colorimetric determination were made at 540 nm. Results illustrated that the activity of phosphatases was found to be different and high activity was found in the larval stage, which is feeding stage followed by pupae.

Heavy metals and arsenic phytoremediation potential of invasive alien wetland plants Phragmites karka and Arundo donax: Water-Energy-Food (W-E-F) Nexus linked sustainability implications

Heavy metals and arsenic (As) are hazardous to the environment and human health. In concert with the problem of metallic contaminants, certain macrophytes in wetlands are harmful invasive alien plants (IAP). Nevertheless, there exists a knowledge gap, that whether all IAP are nuisance or possess certain beneficial role as bioresource in environmental amelioration. Present study conducted microcosm experiments to investigate the heavy metals and As phytoremediation potential of IAP (Phragmites karka (Retz.) Trin. ex Steud. and Arundo donax L.). The results revealed the significant but differential heavy metals remediation (31.0 to 73.3%; p ≤ 0.01) and anti-oxidative defence potential (in terms of enzymatic activity) of IAP. Highest translocation factor (TF-0.89) was noted in case of P. karaka for Zn. Rhizofiltration (TF < 1) was observed as main phytoremediation mechanism. In the present experimental design, P. karka was noted as better phytoremediation tool than A. donax. In future studies, phytoremediation potential of these IAP can be tested at field scale, in conjunction with ‘Water-energy food (W-E-F) nexus’ and ‘biorefinery’ co-benefits.

Fabrication and Characterization of Zinc Oxide Nanowire Based Two‐electrode Capacitive Biosensors on Flexible Substrates for Estimating Glucose Content in a Sample

AbstractThe present work deals with fabrication and characterization of the zinc oxide (ZnO) nanowire based novel two‐electrode capacitive biosensors on flexible Polyethylene terephthalate (PET) substrates for accurate estimation of glucose by analyzing the fundamental dielectric nature of the relevant sample. The morphology and crystalline quality of grown nanowires are analyzed by using field‐emission scanning electron microscope (FESEM) and X‐ray diffractometer (XRD), respectively. Current and capacitance values of the device have been studied for ten different glucose concentrations relevant to the physiological standards. The analytical performance of the devices in terms of enzyme activity, reliability and flexibility has also been evaluated.

The Role of Water Activity in Terms of Enzyme Activity and Enantioselectivity during Enzymatic Esterification in Non-conventional Media

During enzymatic esterification in non-conventional media, the activity and enantioselectivity of the enzyme is significantly influenced by the water content of the reaction medium, which continuously changes as water is produced during the esterification. To provide constant reaction parameters, water activity should be kept constant. The commonly used salt hydrate pairs may be difficult to apply and often hinder enzyme activity. During the enantioselective esterification of racemic 2-bromopropionic acid in various solvents (organic solvents, ionic liquids), it was proven that the conditions related to the optimal water content required for kinetic examinations can be provided without using any salt or salt hydrate pairs. This conclusion is based on the realization that the optimal water activity can be set by first determining the initial water content that is necessary to achieve the maximum reaction rate in the given solvent.

Change in root-associated fungal communities affects soil enzymatic activities during Pinus massoniana forest development in subtropical China

Root-associated fungal communities play a key role in plant productivity and soil processes in forest ecosystems. However, how diversity and composition of root-associated fungi change with forest development and their linkage with soil enzyme activities remain largely unknown. We characterized the root-associated fungal communities, plant and soil properties, and extracellular enzyme activities along a chronosequence spanning young (15 years old) to over-mature (63 years old) Pinus massoniana forest development stages. Our results showed that P. massoniana roots harbored diverse root-associated fungal communities and they varied with forest development. Near-mature (36 years old) forest stands had the lowest alpha-diversity but higher relative abundances of ericoid mycorrhizal and activities of enzymes involved in C, N and P acquisition. The relative abundances of ectomycorrhizal fungi and endophyte were higher in middle-age (24 years old) and mature stands (45 years old), whereas the relative abundance of ericoid mycorrhizal fungi was highest in the near-mature stand. Soil pH, soil C:P and N:P ratios were important factors shaping the diversity and composition of root-associated fungal communities. Structural equation modeling indicated that changes in the community composition, but not richness of root-associated fungi, had significant correlations with soil enzymatic C:N and N:P stoichiometry. In conclusion, this study suggests that different stand development stages exhibit distinct diversity and composition of root-associated fungal communities, which affecting soil functions in terms of enzymatic activity.