Enzyme Activity Values Research Articles

Variation in soil enzyme activity with amendments of biochar and polyacrylamide in coal gangue soils

Coal gangue is a prevalent solid waste material, and its utilization presents an urgent challenge. This study investigates the impact of incorporating biochar (BC) and polyacrylamide (PAM) into a composite matrix of coal gangue soil (CGS). We conducted incubation experiments to evaluate the physicochemical properties and enzyme activity of CGS with different ratios of BC (1%, 2%, and 5% designated as B1, B2, and B5) and PAM (0.02%, 0.05%, and 0.10% designated as P2, P5, and P10), compared to a control (CK) with no amendments. The results indicate that (1) the lowest bulk density was observed in the B5P10 treatment. The organic carbon content in B5P10 increased by 57.98% compared to the CK. (2) The activities of α-glucosidase, N-acetyl-glucosidase, and alkaline phosphatase in the B5P10 treatment increased by 112.34%, 110.77%, and 52.40%, respectively. The geometric mean values of enzyme activities showed no significant differences among the treatments B2P5, B2P10, B5P2, B5P5, and B5P10, but these were significantly higher than those in the CK. (3) The parameters of pH, active carbon, field capacity, and available phosphorus were identified as the main factors affecting enzyme activity. CGS incorporating 2% BC and 0.05% PAM is recommended for soil reconstruction in mining regions.

Customized design of host-independent T7 expression system (HITES) for a broad host range.

Efficient methods and universal DNA elements are eagerly required for the expression of proteins and the production of target chemicals in synthetic biology and metabolic engineering. This paper develops a customized-design approach by utilizing the host-independent T7 expression system (HITES), which facilitates the rational design and rapid construction of T7 expression systems. Firstly, the EiL (Upper-limit value of initial enzyme activity) value is discovered to play a pivotal factor in the successful construction of the T7 expression system, different host strains exhibit varying EiL values, and this study presents a method to measure the EiL values. Secondly, E. coli DH5α is chosen as the host strain, and it demonstrates that various strategies to modulate T7 RNA polymerase activity can efficiently construct the HITES T7 expression system in E. coli DH5α under the guidance of EiL. Lastly, the customized-design of HITES enables the efficient expression of sfGFP and D-MIase proteins across 13 host strains, guided by EiL values. This customized-design method of HITES offers a streamlined pathway for T7 system construction across a broad range of hosts and serves as an enabling tool for synthetic biology, metabolic engineering, and enzyme engineering.

Dietary organic acid blend modulates hemato-immunological parameters, digestive and reproductive performances in red tilapia (Oreochromis niloticus × O. mossambicus) broodstock.

This study evaluated the effects of dietary organic acid (OA) blend on hemato-immunological responses, reproduction capacity, gene expression, and histological features of red tilapia (Oreochromis niloticus × O. mossambicus) broodstock. Four diets were formulated, containing 0 (control), 2, 3, and 4g OAs kg-1. The diets were fed to triplicate groups (n = 3) of red tilapia broodstock (75 ± 5.56g( (mean ± standard deviation (SD)) stocked in 10-m3 concrete tanks at a male to female ratio of 1:3, to satiation, twice a day, for 8weeks. At the end of the feeding trial, fish in each tank were collected, counted, and weighed. Blood samples were collected from five fish from each tank and used for the determination of hematological and biochemical parameters. The fish were then dissected to study the reproductive performance and reproduction-related genes. The red blood cells (RBCs), hemoglobin (Hb), packed cell volume (PCV%), mean corpuscular volume (MCV), and lysozyme activity were significantly increased (P < 0.05) with increasing dietary OAs to 4gkg-1. Mean corpuscular hemoglobin (MCH), white blood cells (WBCs), total protein, albumin, and globulin), and digestive enzyme activity values leveled off or slightly decreased (P > 0.05) at OA levels above 3gkg-1. Optimum liver enzyme activity was obtained at 2gkg-1 OA. The reproductive hormones: testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (Prog), organo-somatic index (GSI), reproductive performance, and the expression of reproductive genes (vasa, nanos1a, nanos2, dnd1, pum1, amh, and VTG) exhibited dose-dependent responses (P < 0.05), suggesting that 4g OA kg-1 boosted the optimum reproductive performance. In conclusion, about 2-3g OA kg-1 diet can improve the hemato-biochemical parameters, immune response, antioxidant status, and digestive enzyme activity in red tilapia broodstock, whereas 4gkg-1 could accelerate their reproductive performance through upregulation of reproductive genes.

Research on Drying Technology for Pressing Landscaping Waste - A Case Study of Hibiscus Rosa-Sinensis Flowers

With the gradual enhancement of people’s awareness of ecological environment and sustainable development, the concept of green and low-carbon development has received more and more attention. Building a waste recycling system has also become an important task for building a beautiful China. The art of pressed flowers is such an ecological industry for recycling abandoned landscaping plants. Hibiscus rosa-sinensis is a plant widely distributed and loved by the people in China. In order to explore the most suitable drying technology for pressing Hibiscus rosa-sinensis，we study the differences of petal color, anthocyanins content, pH value, enzyme activity, drying status, protecting color, flatness between no-pressed and two different drying methods. Compared with the fresh flowers, the L, a, and C values of dried petal were lower, the pH was higher, and the enzyme activity was lower. But the difference is not significant in anthocyanins content between them. Furthermore, the enzyme activity and pH value of pressed petal with microwave were lower than those with drying plate. On the contrary, the anthocyanins content of pressed petal with microwave was higher than that with drying plate. The final study data shows that microwave pressed flower with 80% microwave power and 60-second drying time, was better for drying Hibiscus rosa-sinensis than drying plate，this method leads to better pressed flower，so as to produce plant products that are more suitable for consumer’s needs

PH dan Suhu Optimum Aktivitas Enzim Amilase Kapang Termofilik dari Hot Spring Sulili

Enzyme activity is greatly influenced by several factors including incubation time, temperature, and pH. This study aimed to determine the optimum pH and temperature of amylase enzyme activity of mold PSA 02 (5) isolated from Sulili hot spring, Pinrang Regency, South Sulawesi, Indonesia. This study was conducted in two stages, the first is determining the optimum pH of amylase enzyme activity where enzyme activity testing carried out at pH 4, 5, 6, 7, and 8. After determination of optimum pH, it continued to determine the optimum temperature of amylase enzyme activity at temperatures of 30, 40, 50, 60, 70, and 80oC. Determination of protein content using the Lowry method and determination of amylase enzyme activity using the Dinitrosalicilyc (DNS) method. The results of this study showed that the optimum pH of amylase enzyme activity is pH 4 with an enzyme activity value of 81.37 U/mL and a specific enzyme activity of 57.61 U/mg, while the optimum temperature of amylase enzyme activity is 50oC with a value of 81.44 U/mL and a specific enzyme activity of 57.74 U/mg. It is interesting to note that the amylase enzyme activity remains high up to a temperature of 80oC with a value of 81.20 U/mL. This study indicates that the amylase enzyme of mold isolate PSA 02 (5) is a thermostable enzyme up to a temperature of 80oC.

Changes in Selected Biochemical Markers of Honey Bees Exposed to Fermented Common Tansy Solution (Tanacetum vulgare L.).

Honey bees use pollen and nectar from flowers to produce food. Because they often forage on crops, they are at risk of being exposed to plant protection products (PPPs), both directly and in stored food. Due to the adverse effects of synthetic PPPs on pollinators, biopesticides may be a viable alternative. Common tansy extract is used as one of the natural substitutes for synthetic pesticides. In our study, the effect of fermented common tansy extract on aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (GGTP) activity and the concentration of triglycerides (TGs), total protein (TP), total antioxidant status (TAS), and glucose in honey bee workers' hemolymph was assessed. These biochemical markers give valuable information about the immunity, detoxification, and nutrition of a bee's body. Caged bees were given tansy extract added at various concentrations in sugar syrup for 24 h. Then, they were provided with only sugar syrup. After 7 days of the experiment, hemolymph was collected and analyzed. We observed changes in the activity of AST, ALT, GGTP enzymes and TG, TP, and glucose levels, but not all changes were statistically significant. In terms of AST activity, statistically significant differences were found. All groups tested, including the negative control group, showed reduced enzyme activity values compared to the positive control group. In TG concentration, differences were observed between the groups receiving 2% extract and 1% ethanol. Glucose levels differed between the groups receiving 1% extract and 2% extract and between the positive control group and 1% extract. Bee body proper functioning is affected by changes in enzyme activity, especially those responsible for immunity and detoxification, such as AST, ALT, ALP, and GGTP. Despite the short time of bees' exposure to the agent, the results of study show visible effects. Our results provide a basis for further research on the impact of tansy extract on honey bees.

GST Enzyme Content of Wheat Landraces and Comparison with Modern Varieties

The development of high-yielding modern wheat varieties to feed the growing population has had a negative impact on the production of ancestral and landrace crops. The use of modern varieties, which are very deficient in vitamins, minerals, antioxidants, and flavonoids, has caused people to turn to old varieties due to health problems that arise over time. In this study, which aimed to determine the glutathione S-transferase (GST) enzyme activity of registered varieties and landraces, the differences between the protein values and GST enzyme activity values of wheat were found to be statistically significant. When protein values were analysed among wheat varieties, einkorn wheat had the highest value with 15.53 mg/ml, and KUNDURU-1149 had the second highest value with 13.52 mg/ml. The lowest protein values were found in wheat landraces. Lr-4 had the highest GST enzyme activity with 299.7 mmol/min/mg protein and Lr-10 with 265.3 mmol/min/mg protein. A negative and high correlation was found between wheat protein values and GST enzyme activity, and it was determined that landraces were prominent in terms of GST enzyme activity.

Iskanje in določanje bakterij, ki so sposobne razgraditi celulozo s pomočjo IAA kot potencialnih pospeševalcev rasti rastlin

Strains with both straw degradation and plant growth promotion ability were selected from the cultivated soil in Bac Kan, Vietnam to solve the problems of poor soil microbial diversity status, weak corrosion promotion effect, and poor crop growth caused by fungal rot diseases. Among seventeen bacteria isolated, strain NR1 presented the highest value for cellulase enzyme activity (Hydrolysis index = 24.8 mm), and IAA production (20.15 mg l-1), and was identified as Bacillus amyloliquefaciens Priest et al., 1987. Inoculation with NR1 significantly increased the rot promotion rate of straw under liquid fermentation by 54.71 % compared with the control and increased the root length and average diameter, and SPAD value of maize under soil culture by 18.3 %, 22.0 %, and 5.24 % respectively (p &lt; 0.05). In addition, fertilizing 8 or 9 tons of NR1-degraded compost fertilizer per hectare had the best effect on the growth, development, and productivity of the L14 peanut variety. These results suggest strain NR1 could be used to produce multi-functional humus, accelerate the decomposition of straw in the cultivated soil, and promote crop growth.

Evaluation of Glutathione S-transferases Expression as Biomarkers by Heavy Metals in Geloina expansa from Sepang Besar River, Selangor, Malaysia

Glutathione S-transferases (GSTs) are enzymes involved in phase II of detoxification metabolism and could be used as biomarkers for water pollution. This study aims to determine heavy metal concentrations in the soft tissue of the mangrove clam Geloina expansa, as well as the expression of GSTs in the species. The acid digestion method was used to digest the samples, followed by a standard USEPA 6010B procedure using inductively coupled plasma optical emission spectrometry (ICP-OES) to measure the heavy metal contents in the samples. GST enzyme activity was measured using 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. One-way ANOVA was performed to compare the mean values of heavy metal concentration, protein concentration, enzyme activity, and specific activity. There was a significant difference (p&lt;0.05) for Zn, total protein, and specific activity in G. expansa, but no significant difference in Pb, Cu and enzyme activity. GST enzyme activities were estimated at 0.16 ± 0.01 µmol/min, with a protein content of 1.24 ± 0.04 mg. The specific activity for GST was 0.13 ± 0.01 µmol/min/mg, calculated as the ratio of enzyme activity to the total protein. GST-specific activity positively correlates with Pb concentration in the soft tissue of G. expansa. Detailed studies on the effects of pollution on the expression of GST need to be further investigated for the future use of this species as an efficient biomarker model.

The Potential Predictive Value of Antioxidant Enzyme Activity on the Recurrence of Colorectal Cancer

The Potential Predictive Value of Antioxidant Enzyme Activity on the Recurrence of Colorectal Cancer

Enhancing the acid stability of the recombinant GH11 xylanase xynA through N-terminal substitution to facilitate its application in apple juice clarification

The utilization of xylanase in juice clarification is contingent upon its stability within acidic environments. We generated a mutant xynA-1 by substituting the N-terminal segment of the recombinant xylanase xynA to investigate the correlation between the N-terminal region of xylanase and its acid stability. The enzymatic activity of xynA-1 was found to be superior under acidic conditions (pH 5.0). It exhibited enhanced acid stability, surpassing the residual enzyme activity values of xynA at pH 4.0 (53.07 %), pH 4.5 (69.8 %), and pH 5.0 (82.4 %), with values of 60.16 %, 77.74 %, and 87.3 %, respectively. Additionally, the catalytic efficiency of xynA was concurrently improved. Through molecular dynamics simulation, we observed that N-terminal shortening induced a reduction in motility across most regions of the protein structure while enhancing its stability, particularly Lys131-Phe146 and Leu176-Gly206. Furthermore, the application of treated xynA-1 in the process of apple juice clarification led to a significant increase in clarity within a short duration of 20 min at 35 °C while ensuring the quality of the apple juice. This study not only enhances the understanding of the N-terminal region of xylanase but also establishes a theoretical basis for augmenting xylanase resources employed in fruit juice clarification.

Pengaruh suhu berbeda terhadap aktifitas enzim kolagenase dari usus ikan cunang (Congresox talabon)

Collagenase enzyme is a type of protease enzyme. The activity of an enzyme is affected by substrate, temperature, inhibitor, and pH. One of the sources of enzymes is the internal organs of fish, namely the gut. This study aims to determine the activity of the collagenase enzyme at different temperatures. The experimental design used was randomized and full non-factorial. The treatments used were different incubation temperatures (50, 55, and 60oC) with three replications. Parameter analysis comprised fish proportion, enzyme activity, and dissolved protein. The results showed that the parts of the yellow pike conger fish were meat (64.25%), bones (19.98%), internal organs (including intestines) (4.50%), and skin (6.30%). Collagenase enzyme activity at temperatures 50, 55, and 60oC was 1.154, 1.702, and 0.667 U/mL, respectively. The dissolved proteins content was 12.89 mg/mL. The optimum temperature of the collagenase enzyme from the fish gut was 55oC with an enzyme activity of 1,702 U/mL. The dissolved protein content of the gut yellow pike conger extract was 12.89 mg/mL Purification of the collagenase enzyme from of the gut yellow pike conger was needed to obtain a higher enzyme activity value.

Produksi Enzim Spesifik Xilanase pada Variasi Suhu Konsorsium Trikultur Bakteri Termofilik

Xylanase is an extracellular enzyme that is capable of hydrolyzing xylan (hemicellulose) into xylose and xylo-oligosaccharides. Xylanase can be produced by microbes through a fermentation process, the microbes used are thermophilic bacteria. Thermophilic bacteria are microorganisms that are capable of producing thermostable enzymes through fermentation. The bacteria used are MSS11, MS 16 and MS 18. These thermophilic bacteria can live at temperatures above 45°C-80°C. To determine specific enzyme activity, enzyme and protein activity values were tested using a 540 nm (enzyme) and 750 nm (protein) septovotometer. The method used in this research is descriptive in triplicate. The research was carried out at the Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Padang State University on December 23 2023. Beechwood medium which had been mixed with MSS 11, MS 16, and MS 18 bacteria was then incubated at temperatures of 55℃, 65℃ and 75℃ so that specific enzyme activity was obtained. Of these three temperatures, the optimum specific enzyme activity of xylanase is 65℃, where the specific enzyme value obtained at 65℃ is 3.31 U/mg. Meanwhile, at low temperatures, namely at 55℃, the enzymatic reaction is slow, namely it has an enzyme activity value of 1.02 U/mg. Finally, at a temperature of 75, there was a decrease in specific enzyme activity, where the specific enzyme activity value was 3.12 U/mg.

ULTRASOUND-ENZYME ASSISTED EXTRACTION OF POLYPHENOL AND AMYLASE ENZYME FROM VIETNAMESE RAMIE LEAVES: PREDICTIVE MODELING DEVELOPMENT AND OPTIMIZATION STUDY

Ramie leaves are rich in antioxidant polyphenols and amylase enzyme, which could be a good source for food applications. This study investigated the impact of combined ultrasound-enzyme treatment (U-EAT), including ultrasound intensity (10-30%), content of Viscozyme L. enzyme addition (0.5-1%) and extraction time (5-15 min) on polyphenol recovery, antioxidant activity, and amylase activity. The result revealed that U-EAT could enhance the efficiency of extraction, with a significantly higher yield of bioactive compounds and antioxidant capacity, and amylase enzyme activity compared to an untreated sample. Multiple regression analysis was applied to predict the efficacy of extraction through the values of total phenolic content, antioxidant activity and enzyme activity. The established models shown high accuracy in predicting the effect of the extracted conditions on the yield of the extraction of antioxidant and enzyme amylase. It was found that the maximum yield of extraction could be obtained when the operation conditions were ultrasound intensity of 26.5%, enzyme concentration of 0.87% and extraction time of 10.88 min. Under these optimal conditions, the highest values were found (TPC of 99.047 mgGAE/100 g, antioxidant activity of 65.02% and amylase activity of 45.36 U/mL). In summary, the findings indicate that the utilization of ultrasound combined with the enzymatic extraction process of polyphenol and amylase enzyme from ramie leaves holds potential for enhancing both the extraction yield and bioactivity of the extract. Further study should be concerned with the process of producing food ingredients or products from this extract.

Exploring the relationship between oxidative stress status and inflammatory markers during primary Sjögren's syndrome: A new approach for patient monitoring.

Primary Sjögren's syndrome (pSS) is a chronic inflammatory disease primarily affects exocrine glands dysfunction. Oxidative stress (OS) is a phenomenon occurring as a result of an imbalance between the generation of free radicals and antioxidant defense system. Hence, we aimed to establish the status of OS and inflammatory response according to the pSS disease activity index. In this context, we investigated malondialdehyde (MDA), and antioxidant enzymes during pSS. The possible association between MDA and nitric oxide (NO) levels and between MDA and some pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-33). The study has been conducted on 53 pSS patients. The antioxidant enzymes, represented by glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), were estimated by a colorimetric activity kit. Whereas, MDA value was assessed by measuring thiobarbituric acid reactive substances. Moreover, pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-33) and NO were respectively quantified by enzyme-linked immunosorbent assays (ELISA) and the modified Griess. Interestingly, we report a notable reduction in our pSS patients' antioxidant enzyme activity, while NO, MDA and proinflammatory cytokines values were significantly increased. pSS patients with higher disease activity had much stronger increases in NO and MDA levels. No significant difference was assessed in CRP level. Additionally, substantial significant correlations between plasmatic NO and MDA levels and between MDA, NO and IL-1β, IL-6, TNF-α cytokines were reported. However, no significant association was found between NO, MDA and IL-33 concentrations. Collectively, our data showed altered oxidant-antioxidant balance in pSS patients. MDA, NO, IL-1β, IL-6, TNF-α seem to be good indicators in monitoring disease activity. Oxidative stress was closely related to inflammation in pSS. Exploiting this relationship might provide valuable indicators in the follow-up and prognosis of pSS with a potential therapeutic value.

The utilization of Trichoderma viride in Optimising Xylanase Production from Coffee Cherry Processing Waste

The use of enzymes in Indonesia is increasing rapidly and is used in various industries, especially FCMG. One of the enzymes that is widely used is xylanase, which is an extracellular enzyme that can hydrolyze xylan into xylose and xylo-oligosaccharides. This research aims to determine the optimum conditions for the xylanase production process from coffee cherry processing waste (CCPW) using Trichoderma viride through solid fermentation. The research method used was experimental using central composite design (CCD) in Design Expert 13.0 software. The treatment designs used were fermentation times of 24 hours, 48 ​​hours, and 72 hours; and substrate concentrations of 25%, 50%, and 75%. The experimental response analysis design was enzyme activity, protein content, and specific activity. The results of the research show that the optimum conditions for xylanase production are at a substrate concentration of 75% and a fermentation time of 24 hours with a desirability value of 0.742, which produces an enzyme activity value of 36.388 U/mL and a dissolved protein content of 0.494 mg/mL with a specific activity of 73.660. U/mg. The verification results show conformity with the formula predicted by the Design Expert 13.0 software, namely enzyme activity of 36,292 U/mL and protein content of 0.488 mg/mL with a specific activity of 74,369 U/mg

Effect of deforestation on soil organic carbon fate and pool, a case study in Mazandaran, Iran

Deforestation and agricultural operations greatly impact soil organic carbon (SOC) and its fractions. In order to decrease carbon dioxide emissions, prevent threats to ecosystem stability, and apply efficient land use planning for sustainable soil management, it is essential to have a deep understanding of variations in soil organic carbon pools and their fractions. Soil samples were collected from six land uses of the undisturbed forest, pasture, orchard, and agricultural lands (cultivated with Oat, Maize, and three-carbon plants including wheat and soybean, which are indicated by the plant names of Oat, Maize + C3, and Maize + C3 (R) (R = rotationally)) with three replications at 0–30, 30–60, and 60–100 cm depths. The objective of this study was to evaluate the effect of land use on SOC, active carbon (AC), passive carbon (PC), dissolved organic carbon (DOC) content and pools, its fractions, carbon management index (CMI), soil respiration (SR), soil microbial biomass carbon (MBC), invertase (INV), and cellulase (CEL) enzymes activities in Dasht-e Naz region of northern Iran. Results illustrated that the different forms of organic carbon and enzyme activities were sensitive to land use change. The highest values of SOC (167.197, 39.179, 33.211 Mg ha−1), AC (24.596, 1.955, 1.637 Mg ha−1), and PC (142.6, 37.224, 31.575 Mg ha−1) pools were observed in the pasture land at all three depths. the highest value of DOC was seen in the pasture land at 0–30 and 60–100 depths and in the orchard at 30–60 cm depth. The values of SR (1.001 mg CO2 g dry soil−1 week−1), MBC (1367.7 µg organic carbon g soil−1), and CEL enzyme activity (648.04 µg glucose g dry soil−1 24 h−1) in the undisturbed forest were significantly greater relative to other land uses in 0–30 cm depth, along with significantly higher INV enzyme activity in the pasture and the orchard lands. The largest amount of SOC in 2–4.75 and 0.053–0.25 mm aggregates in all depths was related to the pasture and Maize + C3 land use, respectively. The concept of physical protection confirms the importance of aggregation in the stabilization processes of soil organic carbon, as a physical shield against microorganism attacks. The results of CMI demonstrated that the carbon storage capacity decreased due to the agricultural and orchard lands establishment in the region. Also, the change of land use towards pasture land increased the amount of organic carbon, preventing soil degradation.

Research on Drying Technology for Pressing Landscaping Waste - A case studay of Hibiscus rosa-sinensis flowers

With the gradual enhancement of people's awareness of ecological environment and sustainable development, the concept of green and low-carbon development has received more and more attention. Building a waste recycling system has also become an important task for building a beautiful China. The art of pressed flowers is such an ecological industry for recycling abandoned landscaping plants. Hibiscus rosa- sinensis is a plant widely distributed and loved by the people in China. In order to explore the most suitable drying technology for pressing Hibiscus rosa-sinensis, we study the differences of petal color, anthocyanins content, pH value, enzyme activity, drying status, protecting color, flatness between no-pressed and two different drying methods. Compared with the fresh flowers, the L, a, and C values of dried petal were lower, the pH was higher, and the enzyme activity was lower. But the difference is not significant in anthocyanins content between them. Furthermore, the enzyme activity and pH value of pressed petal with microwave were lower than those with drying plate. On the contrary, the anthocyanins content of pressed petal with microwave was higher than that with drying plate. The final study data shows that microwave pressed flower with 80% microwave power and 60-second drying time, was better for drying Hibiscus rosa-sinensis than drying plate, this method leads to better pressed flower, so as to produce plant products that are more suitable for consumers' needs.

Silicon nutrition improves the quality and yield of rice under dry cultivation.

Dry cultivation of rice is a water-saving, emission reduction and labor-saving rice farming method. However, the development of rice under dry cultivation is hampered by the limitations of dry cultivation on rice yield and rice quality. We hypothesized that additional silicon (Si) would be a measure to address these limitations or challenges. In the present study, we set up field trials with three treatments: flooded cultivation (W), dry cultivation (D) and dry cultivation plus Si. Yield and quality were reduced under D treatment compared to W treatment. The addition of Si promoted root development, increased plant height and leaf area, increased photosynthetic enzyme activity, net photosynthetic rate and SPAD values, and increased biomass under dry crop conditions. Under the drought conditions, silica up-regulated the expression of AGPSI, SBEI, SBEIIb, SSI and SSII-1 genes and the activities of ADP-glucose pyrophosphorylase (AGPase), soluble starch synthetase (SSS) and starch branching enzyme (SBE) enzymes, which reduced protein, amylose, chalkiness percentage and chalkiness degree, increased brown rice rate, milled rice rate and head milled rice rate, and also improved rice quality. In addition, the increase of AGPase, SSS and SBE enzyme activities promoted the filling rate and the number of spikes was guaranteed, whereas the yield was improved by promoting the seed setting rate and 1000-grain weight. The results of the present study indicate that adding appropriate amounts of Si fertilizer can improve the yield and quality of rice under dry cultivation by regulating source supply capacity and grain starch synthesis. © 2023 Society of Chemical Industry.

Lipase and esterase activity in soils from ancient burial vessels

The activity of lipolytic enzymes was assessed using the microplate method using heteromolecular exchange in soils from the bottom of burial vessels, followed by cluster analysis. Groups with a contrasting ratio of lipases C12 - C18 and esterases C4 - C8 were identified in a sample that included 57 burial pots aged two to three thousand years. The total lipolytic activity of soil samples from dishes with the presumptive initial presence of fat-containing food products was above 6% of the maximum value within the sample. Inhibition of esterases in the presence of high concentrations of fatty acids is reflected in the extremely low relative values of esterase activity of the soil microbial community against the background of maximum activity levels of C18 and C12 lipases in two groups of pots. In three groups, esterase activity was observed against the background of high relative activity of C16 lipases, average relative activity of C18 lipases and extremely low activity of true lipases. In the group of pots with high total lipolytic activity (with the exception of certain extreme values of this indicator), the proportion of true lipase activity was 1.7-1.8 times higher compared to the proportion of esterase activity. The grouping of burial vessels by the ratio of lipase and esterase activity reflects the characteristics of the funeral food, while the absolute values of enzyme activity among selected vessels with the highest total lipolytic activity are grouped according to the type of burial.