Dynamics Of Enzyme Activity Research Articles

DYNAMICS OF PRETREATED WHEAT STRAW SACCHARIFICATION BY CELLULOSOME OF Trichoderma viride

The main goal of this study was to analyze the potential of Trichoderma viride BEOFB 1210m for cellulase production during solid-state fermentation of wheat straw pretreated with the ligninosome of a well-known white-rot delignificator – Pleurotus pulmonarius HAI 573. After only 7 days of T. viridae BEOFB 1210m cultivation on biologically pretreated wheat straw, this micromycete produced the most active xylanases, which were also the dominant enzymes, with a value of even 3730.10 U L-1. Likewise, maximal but much lower values of exocellulases (155.83 U L-1) and β-glucosidases (59.98 U L-1) were detected after the same period of fermentation. However, much higher activity of endocellulase (2439.55 U L-1) was obtained on the 10th day. The dynamics of enzyme activity was reflected on the level of substrate depolymerization. As much as 30.56% of the cellulose was degraded already on the 7th day, and that percentage did not change significantly until the end of the cultivation period. A significant loss of hemicelluloses was also measured at the beginning of the fermentation process, but it reached a maximum of approximately 50% by the 21st day. The results clearly showed that the selected T. viride strain has very good potential to synthesize highly active cellulases when grown on a cheap and available substrate, which is significant for further large-scale industrial applications.

Dynamics of Enzyme Activities during the Decomposition of Castanopsis carlesii Leaf Litter in the Forest Canopy and Forest Floor in a Mid-Subtropical Area

Enzyme activity plays a pivotal role in leaf litter decomposition, but the variations have not been well addressed in the forest canopy with amounts of leaf litter. Therefore, eight enzymes related to carbon, nitrogen, and phosphorus mineralization were checked during Castanopsis carlesii leaf litter decomposition in the forest canopy and on the forest floor from April 2021 to February 2022. The results displayed that most enzyme activities were lower in the forest canopy compared to the forest floor during litter decomposition, except for acid phosphatase, polyphenol oxidase, and peroxidase activities. Moreover, enzyme stoichiometry and enzyme vector features indicated that the microbes in both habitats were limited by carbon and phosphorus during litter decomposition. Much stronger carbon limitation was detected on the forest floor, while phosphorus limitation was higher in the forest canopy. Phosphorus limitation was weakened, but carbon limitation was strengthened in the forest canopy with leaf litter decomposition. Additionally, the redundancy analysis revealed that air temperature dominated the variations in enzyme activities during litter decomposition in the forest canopy, and litter mass-loss rate in each period explained much more dynamics on the forest floor compared with those in the forest canopy. These results provide new insight into a comprehensive understanding of litter decomposition in subtropical forests.

Динамика ферментативной активности в эндогенных структурах энтеральной среды модельных животных (мини-пигов)

Энтеральная среда выполняет важную роль в поддержании гомеостаза и во взаимодействии организма с внешней средой. Высокомолекулярные соединения, поступающие с пищей, не способные проникнуть через мембрану кишечника во внутреннюю среду организма, должны быть подвергнуты преобразованию до относительно простых молекул, и активное участие в этом процессе принимают ферменты пищеварительных желез. Изучали места локализации и активность ферментов гамма-глутамилтрансферазы и щелочной фосфотазы на уровне энтеральной среды у модельных животных (мини-пигов). Определена активность ферментов в слизистой оболочке, нативном химусе кишечника и его фракциях - плотной эндогенной и растворимой. Активность гамма-глутамилтрансферазы обнаруживается как в слизистой оболочке, так и в химусе всех отделов тонкого кишечника. Наиболее высокая активность гамма-глутамилтрансферазы зафиксирована в растворимой фракции химуса, самая низкая - в плотной эндогенной фракции с аналогичной выраженной динамикой активности по всей длине тонкого кишечника. Самая высокая активность щелочной фсфотазы обнаружена в слизистых наложениях тонкого отдела кишечника. В ходе эвакуации химуса активность фермента в нем снижается. Максимальная активность щелочной фосфотазы зафиксирована в плотной эндогенной фракции химуса тонкого отдела кишечника. The enteral environment plays an important role in maintaining homeostasis as well as in the interaction between the living body and the external environment. High molecular weight compounds that enter with food, and unable to penetrate the intestinal membrane into the internal environment of the body, must be converted to relatively simple molecules. Enzymes of the digestive glands take an active part in this process. We studied the localization sites and the activity of the enzymes gamma-glutamyltransferase and alkaline phosphatase at the level of the enteral environment in model animals (mini-pigs). The activity of enzymes in the mucous membrane, native chyme of the intestine and its fractions, dense endogenous and soluble, were determined. The activity of gamma-glutamyl transferase is found both in the mucous membrane and in the chyme of all parts of the small intestine. The highest activity of gamma-glutamyltransferase was recorded in the soluble fraction of the chyme, the lowest in the dense endogenous fraction with a similar pronounced dynamics of activity along the entire length of the small intestine. The highest activity of alkaline phosphatase was found in mucous overlays of the small intestine. During the evacuation of the chyme, the activity of the enzyme in it decreases. The maximum activity of alkaline phosphatase was recorded in the dense endogenous fraction of the chyme of the small intestine.

Biochar enhanced soil aggregation and C‐related enzyme activity in post‐mining land on the Loess Plateau, China

AbstractSoil organic carbon in aggregates of different size classes varies greatly in stabilization and resistance, and its mineralization depends highly on enzyme activity within aggregates. However, the dynamics of enzyme activities in response to aggregate turnover remain unclear. In this study, we explored four soil enzymes within different aggregates (>2, 2–0.25, 0.25–0.053, and <0.053 mm) in a biochar‐addition (1%, 3%, and 5%, respectively) experiment in post‐mining land. Soil aggregate size had significant effects on β‐glucosidase (BG) and urease (UR) (p < 0.01), and the enzyme activities were significantly higher in macroaggregates (>0.25 mm) than in microaggregates (<0.25 mm). Biochar addition increased the proportion and stability of macroaggregates. Moreover, BG, UR, and peroxidase activities were significantly stimulated across all aggregate fractions in treatment of 5% addition, increasing by 134.6%, 163.6%, and 35.7%, respectively (p < 0.01), while alkaline phosphatase activity in macroaggregates decreased by 45.8% compared with that in the control. In macroaggregates, higher enzyme activities were closely correlated with the increase of easily oxidized carbon (p < 0.01) due to biochar addition, and the increase in nitrogen content was also beneficial to promote microbial growth and activity. Our study suggests that biochar addition may improve soil structure and nutrient status, which would accelerate the recovery of microbial function in degraded lands.

Динаміка зміни біохімічних показників у щурів під впливом глутамату натрію

The purpose of the study was to determine metabolic parameters (alpha-amylase, alanine aminotransferase and aspartate aminotransferase, gamaglutamyl transpeptidase, glycoproteins and chondroitin sulfates) at the stages of sodium glutamate intake and after withdrawal. Materials and methods. Studies were conducted on 65 white male rats of reproductive age (2.5-3 months); the experimental group received 70 mg/kg of sodium glutamate per live weight for 8 weeks. The control group of animals received a standard diet. Before drug withdrawal, rats were studied every week, after drug withdrawal the studies were performed every two weeks (10, 12, 14, 16 weeks). Results and discussion. The study of the enzyme activity of alpha-amylase showed that this index increased on the average 1.3-fold compared with the control values, and at the end of the period when the rats were fed with sodium glutamate (8 weeks), the index increased by 3.85 times, alanine aminotransferase – by 12.3 times, aspartate aminotransferase – by 1.4 times, gamaglutamyl transpeptidase – by 2.7 times, glycoproteins – by 1.4 times, chondroitin sulfate – by 1.2 times. After transferring the animals to a normal diet, no recovery of the indices was found. According to the studied indicators sodium glutamate has a toxic effect on the liver, pancreas with elements of systemic inflammation. At the stages of discontinuation of monosodium glutamate recovery of most of the studied biochemical markers is not established. Alanine aminotransferase, determined on the 16th day after the abolition of monosodium glutamate, was reduced by 1.33 times compared to the last 8 weeks of admission, gamaglutamyl transpeptidase after 10 weeks was reduced by 1.5 times, after 12 weeks – by 0.4 times, after 14 and 16 weeks, the values corresponded to the control values at 10 week, the alpha-amylase level was reduced by 1.26 times, at 16 weeks – by 2.29 times, but they did not reach the control values. At the end of the study (16 weeks), the level of chondroitin sulfates was increased compared to 8 weeks of feeding animals with glutamate sodium by 1.27 times, and relative to control – by 1.56 times. There was a decrease in glycoprotein content at 16 weeks compared with 8 weeks of observation by 1.3 times, but did not reach the level of intact animals. Conclusion. Thus, the results of serum biochemical studies of rats treated with monosodium glutamate indicated the development of intoxication and its effect on biochemical markers, which were reflected in the dynamics of enzyme activity, inflammation and fibrosis. Most biochemical markers (except gamaglutamyl transpeptidase and aspartate aminotransferase) at the end of the experiment did not reach the level of intact animals, which is apparently due to the chronicity of the pathological process. In rats after discontinuation of monosodium glutamate from 10 to 16 weeks of the experiment, changes in biochemical parameters were observed, which indicated a toxic effect, which was accompanied by the development of subacute inflammatory process. After the transfer of animals to a normal diet, recovery is not established. Sodium glutamate according to the studied parameters has a toxic effect on the liver, pancreas with elements of systemic inflammation

Identification of a bio-signature for barley resistance against Pyrenophora teres infection based on physiological, molecular and sensor-based phenotyping

Necrotic and chlorotic symptoms induced during Pyrenophora teres infection in barley leaves indicate a compatible interaction that allows the hemi-biotrophic fungus Pyrenophora teres to colonise the host. However, it is unexplored how this fungus affects the physiological responses of resistant and susceptible cultivars during infection. To assess the degree of resistance in four different cultivars, we quantified visible symptoms and fungal DNA and performed expression analyses of genes involved in plant defence and ROS scavenging. To obtain insight into the interaction between fungus and host, we determined the activity of 19 key enzymes of carbohydrate and antioxidant metabolism. The pathogen impact was also phenotyped non-invasively by sensor-based multireflectance and –fluorescence imaging.Symptoms, regulation of stress-related genes and pathogen DNA content distinguished the cultivar Guld as being resistant. Severity of net blotch symptoms was also strongly correlated with the dynamics of enzyme activities already within the first day of infection. In contrast to the resistant cultivar, the three susceptible cultivars showed a higher reflectance over seven spectral bands and higher fluorescence intensities at specific excitation wavelengths. The combination of semi high-throughput physiological and molecular analyses with non-invasive phenotyping enabled the identification of bio-signatures that discriminates the resistant from susceptible cultivars.

Phenylalanine Ammonia-Lyase Enzyme Activity in the Symbiotic System Glycine max – Bradyrhizobium japonicum by Seed Inoculation Different in Activity and Virulation Strain and Treatment with Fungicides

Phenylalanine ammonia-lyase (PAL) is a key enzyme of the phenylpropanoid pathway and provides precursors for the synthesis of many secondary metabolites, which are necessary for the development and protection of plants from external factors of various natures, in particular plays an important role in the formation and development of their symbiosis with microorganisms. Aim. To study the activity of PAL in soybean plants in the early stages of legume-rhizobial symbiosis under the influence of seed inoculation with Bradyrhizobium japonicum strains with different symbiotic properties on the background of fungicide treatment. Methods. Microbiology (bacterial culture growing, seeds inoculation), physiological (pot experiment), biochemical (determining the PAL enzyme activity). Results. Inoculation of soybean seeds with active virulent rhizobia induces a significant decrease in PAL activity in the roots at the primordial leaf stage and a significant increase in its activity level at the first true leaf stage, compared to inactive symbiosis. At the stage of third true leaf, the activity of PAL increased more significantly in soybean root nodules formed by inactive rhizobia, compared to active symbiosis. However, at the stage of third true leaves, the activity of PAL in soybean root nodules formed by inactive rhizobia increased significantly compared to active symbiosis. The use of fungicides for pre-sowing treatment of soybean seeds induces changes in the level of PAL activity in roots and nodules, which do not affect the overall dynamics of enzyme activity in different effective symbiotic systems Glycine max - Bradyrhizobium japonicum. Conclusions. The activity of PAL in the roots and especially in the root nodules of soybeans in the early stage of plant development in the case of fungicides using and bacterization is primarily due to the action of the inoculation factor, and is determined by the symbiotic properties of rhizobia strains, in particular, their virulence and nitrogen fixation activity.

The enzyme activity dynamic relationship with the content of structural polypeptides of enterocyte membranes in cattle fetal

The article performs new data on the relationship between the hydrolytic and transport enzyme activity at different poles of the enterocytes plasmolemma of cow's fetal large intestine with the content of individual fractions of polypeptides. An expressive direct dependence of enzyme activity dynamics on the apical and basolateral membranes of enterocytes containing low molecular weight proteins and an inverse relationship with the concentration of proteins with medium and large molecular weights has been proved. It was found that the alkaline activity of the phosphatase and γ-glutamyltransferase on the apical domain of enterocyte plasmolemma is directly related to the proteins content with molecular masses of 9.6–14.2 kD, 21 kD, 22.5 kD, 26 kD, 33 kD, 35 kD, 170–185 kD, and 205 kD (P ≤ 0.05–0.001). Gamma-glutamyltransferase activity is straightly related to protein quantity with molecular weights of 15.5 kDa and 39 kD (P ≤ 0.05). In contrast, alkaline phosphatase and GGT activity have inverse correlations with the content of polypeptides with molecular masses of 46 kD, 63 kD, and 250 kD in the apical membrane of enterocytes (P ≤ 0.01–0.001). The lactase activity in the cattle enterocytes apical membrane during the test period has significant direct correlations only with the amount of the polypeptide of polypeptides with molecular weights of 31 kD, 39 kD, and 100 kD (P ≤ 0.05–0.01) and inverse relationships containing proteins with molecular masses of 46 kD and 120 kD (P ≤ 0.05). A linear dependence of the different ATPase activity of the apical membrane of red blood cells containing proteins with molecular weights of 9.6–14.2 kD, 15.5 kD, 21 kD, 22.5 kD, 33 kD, 35 kD, 39 kD, and 205 kD (P ≤ 0.05–0.001) was observed. Alkaline phosphatase activity in the apical membrane of enterocytes is only directly related to the number of proteins with molecular weights of 17 kD and 24 kD (P ≤ 0.001) in this domain. It inversely depends on the content of proteins with molecular masses of 9.6–14.2 kD and 52 kD (P ≤ 0.001). G-glutamyltransferase activity is inversely related to protein content with molecular weights of 43 kD, 52 kD, 66 kD, 87 kD, and 100 kD and 155 kD (P ≤ 0.001). The Ca2+, Mg2+-ATPase of the basolateral membrane activity of enterocytes is directly related to the protein amount with molecular weights of 26 kD (P ≤ 0.01), Mg2+-ATPase and Mg2+-ATPase with protein content with the molecular value of 100 kD (P ≤ 0.05).

Changes in the structural components of the mucous membrane and plasma proteins of small intestine enterocytes in fetuses of cattle

The interrelationships of morphological changes of the mucosa of the large intestine with the dynamics of enzyme activity at different poles of enterocytes of cattle during the fetal period of ontogenesis are shown and analyzed. The work was performed on Holstein cattle aged two to nine months. The activity of hydrolytic and transport enzymatic systems in the basolateral membrane of cattle enterocytes depends less on the morphometric parameters of the large intestine than in the apical membrane. It is proved that during the fruitful period of ontogenesis there are dynamic transformations of enzyme systems of enterocytes of the large intestine of cattle which are connected with morphological changes of the mucous membrane of the large intestine. The activity of hydrolytic and transport enzymes in different domains of the plasma enterocytes of fetal cattle is interrelated with the morphometric parameters of the colon, in particular. the activity of alkaline phosphatase, γ-glutamyltransferase, Na+, K+-ATPase, Ca2 +, Mg2 +-ATPase and Mg-ATPase in the apical membrane of enterocytes is inversely related to the thickness of the intestinal wall with villi and the mucous membrane of the cavity (P ≤ 0.01–0.001). A significant correlation was found between the activity of alkaline phosphatase, γ-glutamyltransferase, Na+, K+-ATPase, Ca2 +, Mg2 +-ATPase and Mg-ATPase in the apical membrane of enterocytes with villi height (P ≤ 0.05). The activity of hydrolytic and transport enzymatic systems in the basolateral membrane of bovine fetal enterocytes depends to a lesser extent on the morphometric parameters of the large intestine than in the apical membrane. In particular, only the activity of alkaline phosphatase and γ-glutamyltransferase is inversely related to the thickness of the intestinal wall with villi and the mucous membrane of the jejunum with villi (P ≤ 0.01–0.001). The activity of transport enzymes is directly related to the morphometric parameters of the colon (P ≤ 0.01). The activity of these enzymes in the basolateral membrane does not significantly depend on the width of the villi, but is dependent on their height.

Contrasting patterns of microbial community and enzyme activity between rhizosphere and bulk soil along an elevation gradient

The distribution patterns of the microbial community and enzyme activity in soil systems along an elevation gradient have attracted considerable attention; however, the differences in microbial diversity and enzyme activity between the rhizosphere and bulk soil and their drivers are still unclear. Here, we used an elevation gradient that covered six elevation levels and ranged from 1308 to 2600 m above sea level. Illumina MiSeq sequencing of the 16S rRNA gene and ITS-1 gene was used to analyze the community of bacteria, total fungi, ectomycorrhizal (EcM) fungi, and saprotrophic fungi in both rhizosphere and bulk soil; in addition, the soil enzyme activity (β-glucosidase, N-acetyl-glucosaminidase, leucine aminopeptidase, and acid phosphatase) was investigated. The results revealed that the elevation significantly affected the diversity of the bacterial, total fungal, EcM, and saprotrophic fungal community, as well as the enzyme activity dynamics. The difference in the microbial diversity and enzyme activity between rhizosphere and bulk soil diminished as the elevation increased, except for the saprotrophic fungal diversity. Similarly, the dominant phyla from the compositions of bacteria, fungi, EcM fungi, and saprotrophic fungi, such as Proteobacteria, Acidobacteria, Actinobacteria, Basidiomycota, and Ascomycota, also changed with elevation and rhizosphere. In addition, the elevation-dependent differences in the microbial community and enzyme activity between the rhizosphere and bulk soil were affected mainly by climatic factors (mean annual temperature and precipitation) and soil properties, such as the bulk density, ammonium nitrogen, and total phosphorus. The effects of the climatic factors were greater than those of the soil properties along the elevation gradient. These results suggest that changes in climatic factors, such as temperature, with elevation may affect the microbial interaction between roots and the soil. The result highlight the importance of the ecological roles of the microbial community in climate change.

C/P stoichiometry of dying rice root defines the spatial distribution and dynamics of enzyme activities in root-detritusphere

As the primary microbial substrate after shoot cutting, the element stoichiometry of root-detritus (dying or dead roots) influences the enzyme activity in root-detritusphere. However, the effect of the C/P ratio of root-detritus on the dynamics and distribution of enzyme activities is little revealed. We hypothesised that P fertilisation would decrease the C/P ratio of root-detritus, therefore affecting the hotspot areas and hot moments of C-acquiring and P-acquiring enzyme activities, as well as their activity ratio (C/P acquisition ratio). Root-detritus of low (59.0) and high (170.8) C/P ratios was produced in P-poor soil with and without P fertilisation, respectively. In situ soil zymography showed that the distribution of C-acquiring enzymes (β-glucosidase and cellobiohydrolase) was more associated with root-detritus than P-acquiring enzymes (acid and alkaline phosphomonoesterase). P fertilisation increased the hotspot areas of C-acquiring enzyme activities over the experiment, without influencing their temporal dynamics. However, its effect on phosphomonoesterase activities depended on the decomposition and delayed the appearance of the highest hotspot areas. P supply met the microbial demand in P-fertilised soil, with high C/P acquisition ratio and constant stoichiometry of microbial biomass C (MBC)/microbial biomass P (MBP). A low C/P acquisition ratio and high MBC/MBP in non-fertilised soil was observed, indicating P limitation for microorganisms. After the 150-day incubation, Olsen P significantly increased in P-fertilised soil (P < 0.05), whereas it decreased in the root-detritusphere of non-fertilised soil. We conclude that the decomposition of root-detritus with a low C/P ratio has potential to improve soil P availability; however, C-P imbalance may increase during the decomposition of root-detritus with a high C/P ratio.

Effects of biochar on the microbial activity and community structure during sewage sludge composting

To explore the contributions of functional bacterial community in composting, we performed medium-scale composting of sewage sludge and sawdust mixtures amended with rice straw biochar at different dosages (5, 10, and 20% of fresh mixture weight) in 400 L bioreactor systems. The dynamics of enzyme activity and bacterial community composition were monitored during the composting. The addition of biochar above 10% inhibited the activity of protease but promoted the activities of cellulase and peroxidase, which also increased the fluctuation of bacterial diversity during the composting. The relationship between the activity of most enzymes and bacterial community was strengthened by the addition of biochar (10% and 20%), which further enhanced the contributions of the functional bacterial communities to composting. Therefore, the study provides evidence for the promoting effects of biochar on the functions of bacterial community.

Dynamics of protection antioxidant system of representatives of Amelanchier Medik. genus during ontogenesis under Steppe Pridniprov’e conditions

Antioxidant reaction in leaves of the representatives of Amelanchier Medik. genus introduced in Steppe Pridniprov’e during vegetative period is studied. Activity of bensidin-peroxidase (BPOD), guaiacol-peroxidase (GPOD) and catalase (CAT) in leaves of four kinds Amelanchier Medik is analysed. Specific features of dynamics of enzymes activity in leaves of representatives of Amelanchier Medik. genus are defined according to phases of seasonal development and in reply to action of hydrothermal stress. On the basis of the received results the wide range of interspecific variability of enzymes activity in leaves of Amelanchier kinds, introduced in new conditions of existance is shown. The studied kinds were characterised by high activity ВРОD in all vegetative season. The greatest activity in leaves of all kinds was shown in a phase of secondary growth, in the most adverse hydrothermal mode that testified to passage of adaptive processes in plants. It is established, that unlike A. ovalis in which leaves level of activity BPOD was equal enough, other kinds in process of ontogenesis have shown sharper differences in activity of enzyme. The difference was essential, especially at A. canadensis in which leaves in May and June sharp falling of activity in 4,0 and 2,9 times accordingly in comparison with April was noticed, and in July and August – sharp increase that testified to a stressful condition of plants. The opposite tendency is found out in dynamics of activity GPOD i CAT. In the beginning phases of active growth (April) at all kinds the highest activity of enzymes, but, since May and till the end of the supervision period was observed, activity sharply went down at all kinds Amelanchier. Essential activation GPOD in a phase of active growth can be connected with processes of lignification to an greater degree, rather than with protection against oxidative stress. Thus in leaves of A. ovalis and A. canadensis higher activity gvaiacol-peroxidase, than at A. spicata and A. florida was observed. Small increase of activity was observed in June and to an greater measure in three kinds: A. ovalis, A. florida і A. spicata. In leaves of A. canadensis activity increase was marked in August in comparison with the period from May till July. The analysis of dynamics of catalase activity in leaves of representatives Amelanchier Medik. has shown similitude as well as at gvaiacol-peroxidase: the highest level was observed in April, and further there was an essential recession of enzyme activity. Dynamics of catalase activity during vegetation has appeared the most similar at kinds of A. ovalis and A. canadensis. In leaves of A. florida unlike last kinds the small peak of activity in July was marked, and in August activity again went down on 21,8 % in comparison with July. A. spicata has shown essential increase of activity САТ in August in comparison with July in 6,4 times. Thus, found out different directions of activity changes of oxidoreductases specify in participation antioxidant systems in realisation of different ways of adaptation of kinds-introducents of Amelanchier Medik. genus in ontogenesis process in the conditions of Pridneprov’e Steppe. Variability of enzymes activity level in leaves of Amelanchier Medik. in the course of vegetation means the adaptation to conditions of environment and as a whole displays adaptive ability of the investigated kinds at the expense of high antioxidant potential to counteract development of oxidative stress at action adverse of abiotic factors.

Impact of secondary forest fallow period on soil microbial biomass carbon and enzyme activity dynamics under shifting cultivation in North Eastern Hill region, India

Length of the secondary forest fallow period has often played an important role in affecting the soil fertility status for first year cultivation of crops in shifting cultivation system. However, information regarding the soils after the first year cultivation is limited. The objective of the study was to assess the effect of different shifting cultivation fallow period on the dynamics of soil health status during the first and second year. Results suggest that increase in the fallow period significantly (p<0.05) decreased the bulk density (BD), while increasing the soil organic carbon (SOC), soil nutrients, MBC and enzyme activities. While the SOC decreases between 6.1 and 31.3% due to cultivation compared to the soil condition before burning during the first year, MBC decreases between 33.61 and 60.9%. The SOC was recovered at the end of second year, while the MBC increases sharply during the second year. Enzyme activities in general decreased after burning and increased gradually during the second year. PCA results indicated that length of fallow period >10year maintains one cluster where fallow period including 10 and below maintains another cluster during the first and second year. Results therefore suggest that MBC, MBC:SOC and soil enzyme activities played as an indicator of soil health and maintaining secondary forest fallow period >10years was better in conserving soil health for first and second year under shifting cultivation.

Short-term effects of plant litter on the dynamics, amount, and stoichiometry of soil enzyme activity in agroecosystems

Addition of plant litter can affect soil enzyme activity at three scales: dynamics, amount, and stoichiometry. In this study, we examined the dependence of soil enzyme activity at all three scales on litter quality. Soils of similar texture were collected from conventional and organic farming systems, the Center for Environmental Farming Systems, Goldsboro, North Carolina, USA. Soil samples were then amended with senescent pine needles, grass materials, and soybean residues of C:N ratio 139, 50, and 9, respectively, at 2 mg C g−1 soil, and the activities of soil β-glucosidase, exoglucanase, β-glucosaminidase, and phenol oxidase were measured over the course of 90-d incubation. Relationships between the dynamics of enzyme activity and litter quality appeared to be enzyme specific. Time patterns of soil β-glucosidase and β-glucosaminidase activity were independent of litter quality, with rapid increase in enzyme activity and reaching a peak several weeks after litter addition. In contrast, time patterns of polymer-degrading enzymes (exoglucanase and phenol oxidase) were dependent on litter quality. Exoglucanase activity showed a concave function with time following the addition of soybean residues or grass materials, but increased slightly following the addition of pine needles. Cumulative activities of soil enzymes were upregulated following litter addition and could be qualitatively assessed by litter C:N ratio. The activity of β-glucosaminidase was negatively related to litter C:N ratio, being greatest in soybean residues-amended soil. Litter of a low C:N ratio was generally better than litter of a high C:N ratio for increasing soil cellulase activity and vice versa for phenol oxidase. However, the stoichiometry of soil enzyme activity was decoupled with litter C:N ratio. Soybean residues and pine needles at opposite ends of the litter C:N range were more similar in the ratio of C- to N-acquiring enzyme activity. We also examined pH effects on the expression of added enzymes. Soil enzyme activities were enhanced as soil pH increased from 6 to 8. pH-associated changes in enzyme activity were generally smaller as compared to changes caused by other factors during the 42-d incubation. Our results suggest that litter effects on the dynamics, amount, and stoichiometry of soil enzyme activity were independent of soil pH. Litter C:N was a good indicator for the total amount, but not for the dynamics or stoichiometry of soil enzyme activity.

Consecutive Biochar Application Alters Soil Enzyme Activities in the Winter Wheat–Growing Season

Soil enzymes catalyze key biochemical processes in organic matter decomposition and nutrients cycles and are regarded as indicators of soil quality. In this study, we investigated the impact of 4 consecutive years of biochar (corncob; 360°C) amendment on dynamics of enzyme activities (i.e., invertase, urease, catalase, and alkaline phosphatase) during the winter wheat (Triticum aestivum L.) growing period in Northern China. The experiment consisted of four treatments: control (CK), biochar rate at 4.5 t · ha · y (B4.5), biochar rate at 9.0 t · ha· y (B9.0), and crop straw return (SR). Four times throughout the wheat growth period (i.e., 5 Nov. 2010; 26 Mar. 2011; 25 Apr. 2011; 5 Jun. 2011), we determined the enzyme activities down to the 30-cm depth of the soil profile (i.e., 0–5, 5–10, 10–20, and 20–30 cm). Results showed that there were considerable fluctuations in enzyme activities across the observed period and depths. All enzyme activities decreased significantly in deeper soil horizons. High biochar amendment rates (B9.0) lead to the peak activities of invertase, urease, and phosphatase occurring in the 0- to 5-cm layer on 25 Apr. 2011 samples. The greatest catalase activity under B9.0 was found on 26 Mar. 2011 samples. In addition, the effect by B4.5 and SR on enzyme activities was variable and limited. These data support the conclusion that consecutive application of biochar for 4 years increased enzyme activities, which potentially influence soil nutrients dynamics under field condition, although the effects were dependent on sampling depth and time.

METHOD OF MEASUREMENT OF NITRATE REDUCTASE ACTIVITY IN FIELD CONDITIONS

For the last three decades the interest in biomonitoring and ecological studies has been rapidly growing. Therefore, it was necessary develop of new methods of analysis for biochemical parameters which allow to quantify biological response of investigated organisms for environmental factors. The main goal of this paper demonstrates optimal conditions for enzyme kinetics analysis conducted in the field in situ. Nitrate reductase activity is typically assayed in vivo by measuring nitrite production in tissue which has been vacuum infiltrated with buffered nitrate solution. For this study a nitrate reductase assay was adapted from a number of studies with own modifications of authors. Leaves of examined plants were collected from the investigated plots and immediately placed into test tubes with buffer solution (potassium phosphate dibasic containing 0.6% propanol-1) and evacuated in 0.33 atm. for 10 minutes. Then, known amount of potassium nitrate was added, and the solution sample was analyzed in order to obtain a background level of nitrite. The foliage samples were incubated for 2 hours at 20 °C in darkness. Following this procedure, they were given the most optimal conditions for reaction stability. After incubation the amount of synthesized nitrite was determined colorimetrically using sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride, measured at 540 nm. The foliage samples were oven-dried to obtain dry mass. The level of nitrate reductase activity was calculated as the amount of nitrite produced in nmol per gram of dry mass of foliage tissue per hour. The result obtained during the research demonstrate the changes of nitrate reductase dynamics according to change of incubation parameters. Dynamics of enzyme activity with changes of solution pH and incubation temperature was presented. Installation for conducting infiltration process and construction of in cubation chamber is also described in this paper.

POMIAR AKTYWNOŚCI REDUKTAZY AZOTANOWEJ W WARUNKACH TERENOWYCH – METODYKA

During recent three decades interest for biomonitoring and ecological studies was rapidly growing. Therefore was necessary develop of new methods of analysis biochemical parameters whose allow quantify biological response of investigated organisms for environmen- tal factors. The main goal of this paper demonstrates optimal conditions for enzyme kinetics analysis conducted in the field in situ. Nitrate reductase activity is typically assayed in vivo by measuring nitrite production in tis- sue which has been vacuum infiltrated with buffered nitrate solution. For this study a nitrate reductase assay was adapted from a number of studies with own modifications of authors. Leaves of examined plants were collected on investigated plots and immediately placed into test tubes with buffer solution (potassium phosphate dibasic containing 0.6% propanol-1) and evacuated in 0.33 atm. for 10 minutes. Then known amount of potassium nitrate was added, and the solution sample was analyzed in order to obtain a background level of nitrite. The foliage samples were incubated for 2 hours at 20 °C in darkness. Follow this procedure have given the most optimal conditions for reaction stability. After incubation the amount of synthesized nitrite was determined colorimetrically using sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride, measured at 540 nm. The foliage samples were oven-dried to obtain their dry mass. Level of nitrate reductase activity was calculated as the amount of nitrite produced in nmol per gram of dry mass of foliage tissue per hour. The result obtained during these research demonstrate the changes of nitrate reductase dynamics according to change of incubation parameters. Dynamics of enzyme activity with changes of solution pH and incubation temperature was presented. Installation for conducting infiltration process and construction of incubation cham - ber is also described in this paper.

Effects of Biochar Amendment on the Dynamics of Enzyme Activities from a Paddy Soil Polluted by Heavy Metals

Reducing heavy metals mobility and improve the soil physical-chemical property in order to reduce plant uptake would be an urgent demand for safe rice production in China. A field experiment was conducted for the research of biochar (BC) amendment on the dynamics of soil enzyme activities in a contaminated paddy soil after 2 years. BC was applied in 2009 before rice transplantation at rates of 0, 10, 20, 40 t ha-1, and three undisturbed soil cores of 0 to 15 cm depth were sampled from each plot for physicochemical analysis and enzymatic monitoring. Compared to the control, the soil pH and SOC were significantly increased by 2–5 % and 16–51 % after BC amendment. The activities of cellulase, urine enzyme, neutral phosphatase and sucrase were also found to increase by 117.4–178.3 %, 31.1–37.6 %, 29.7–193.8 % and 36.5–328.6 %, respectively. Furthermore, there were positive correlation of soil enzyme activities with soil pH and SOC content. Data in this research indicated that BC amendment may be potential in improvement of soil properties to some extent to achieve the agricultural use. Introduction

Федеральное государственное бюджетное учреждение «Ивановский научно-исследовательский институт материнства и детства им. В.Н. Городкова» Министерства здравоохранения и социального развития Российской Федерации

С целью разработки новых методов диагностики и контроля эффективности лечения ишемической нефропатии у новорожденных, находящихся в отделении реанимации и интенсивной терапии, провели исследование активности щелочной фосфатазы, γ-глутамилтрансферазы, лактатдегидрогеназы, β-глюкуронидазы и холинэстеразы в моче, используя кинетический и фотометрический методы и реактивы фирмы DiaSys (Германия).В результате показаны различный спектр ферментурии, свидетельствующий об уровне повреждения нефрона при нефропатии разной степени тяжести, выраженность и динамика активности ферментов в моче у новорожденных с ишемической нефропатией различной тяжести в неонатальном периоде и на первом году жизни; разработаны новые объективные критерии для диагностики и оценки эффективности лечения ишемической нефропатии. Кроме того, определены границы диапазона референтных значений активности ферментов нефротелия в моче у здоровых детей в неонатальном периоде и обосновано применение метода мягкого вибромассажа в сочетании с моделированием невесомости для лечения ишемической нефропатии у новорожденных.