Peroxidase Enzyme Activity Research Articles

Automatic non-destructive estimation of polyphenol oxidase and peroxidase enzyme activity levels in three bell pepper varieties by Vis/NIR spectroscopy imaging data based on machine learning methods

The browning process of food products if often formed upon cutting and damage during their processing, transport, and storage, amongst other potential sources and reasons. Enzymic browning can be mainly due to polyphenol oxidase (PPO) and peroxidase (POD) enzymes. Visible/near-infrared (Vis/NIR) imaging spectroscopy in the range of 350–1150 nm was used in this study for automatic and non-destructive evaluation of PPO and POD activity levels in three bell pepper varieties (red, yellow, orange; N = 30), with a total of 30 inputs samples in each variety. The spectral data were then modeled by the partial least squares regression (PLSR) throughout the whole spectral range, without using any subset of the most effective wavelength (EW) values. Regression determination coefficient (R2) values for the estimation (prediction) of POD enzyme activity levels were 0.794, 0.772, and 0.726 for red, yellow, and orange bell peppers, respectively, all over the validation set. At the same time, the activity levels of PPO enzyme over bell peppers showed R2 values of 0.901, 0.810, and 0.859, for red, yellow, and orange bell peppers, respectively, all over the validation set. In addition, a combination of support vector machine (SVM) with either genetic algorithms (GA), particle swarm optimization (PSO), ant colony optimization (ACO), or imperialistic competitive algorithms (ICA) hybrid machine learning (ML) techniques were used to select the optimal (discriminant) spectral EW wavelength values, and regression performance was consistently improved, to judge from higher regression fit R2 values. Either 14 or 15 EWs were computed and selected in order of their discriminative power using previously mentioned ML techniques. The hybrid SVM-PSO method resulted the best one in the process of selecting the most effective wavelength values (nm). On the other hand, three regression methods comprising PLSR, multiple least regression (MLR), and neural network (NN), were employed to model the SVM-PSO selected EWs. The ratio of performance to deviation (RPD), the R2 and the root mean square error (RMSE), over the test set, for the non-linear NN regression method exhibited better results as compared to the other two regression methods, being closely followed by PLSR, and therefore NN regression method was selected as the best approach for modeling the most effective spectral wavelength values in this study.

Exploration of resistance level against Black Scurf caused by Rhizoctonia solani in different cultivars of potato

Black Scurf is one of the destructive fungal diseases of potato crops caused by fungus Rhizoctonia solani. Cultural practices and fungicide applications are insufficient in effectively combating the pathogen, while utilizing resistant cultivars has become one of the most economical and effective way to control disease. About ten commercial potato varieties were screened out against the disease by artificially inoculating the plants with R. solani and these potato varieties were grouped based on disease incidence and disease severity. Four varieties (Ronoldo, Rubi, Challenge, and Sadaf) were grouped as resistant, three varieties (SH-5, Sante and Astrex) as moderately susceptible and three varieties (Karoda, Mosica and Simply red) as susceptible with significantly highest disease incidence (P ≤ 0.05). Disease also reduced number and size of tubers, while the disease incidence showed negative (P < 0.001) correlation with chlorophyll and protein contents, and activities of catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) enzymes. It was concluded that a combination of phenotypic and physiological indices could be used to identify black scurf resistance in potatoes.

Cytochrome P450 SmCYP78A7a positively functions in eggplant response to salt stress via forming a positive feedback loop with SmWRKY11

Accumulating salinity in soil critically affected growth, development, and yield in plant. However, the mechanisms of plant against salt stress largely remain unknown. Herein, we identified a gene named SmCYP78A7a, which encoded a cytochrome P450 monooxygenase and belonged to the CYP78A sub-family, and its transcript level was significantly up-regulated by salt stress and down-regulated by dehydration stress. SmCYP78A7a located in the endoplasmic reticulum. Silencing of SmCYP78A7a enhanced susceptibility of eggplant to salt stress, and significantly down-regulated the transcript levels of salt stress defense related genes SmGSTU10 and SmWRKY11 as well as increased hydrogen peroxide (H2O2) content and decreased catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) enzyme activities. In addition, SmCYP78A7a transient expression enhanced eggplant tolerance to salt stress. By chromatin immunoprecipitation PCR (ChIP-PCR), luciferase reporter assay, and electrophoretic mobility shift assay (EMSA), SmWRKY11 activated SmCYP78A7a expression by directly binding to the W-box 6–8 (W-box 6, W-box 7, and W-box 8) within SmCYP78A7a promoter to confer eggplant tolerance to salt stress. In summary, our finds reveal that SmCYP78A7a positively functions in eggplant response to salt stress via forming a positive feedback loop with SmWRKY11, and provide a new insight into regulatory mechanisms of eggplant to salt stress.

Seed pretreatment with brassinosteroids stimulates sunflower immunity against parasitic weed (Orobanche cumana) infection.

Broomrape (Orobanche cumana) negatively affects sunflower, causing severe yield losses, and thus, there is a need to control O. cumana infestation. Brassinosteroids (BRs) play key roles in plant growth and provide resilience to weed infection. This study aims to evaluate the mechanisms by which BRs ameliorate O. cumana infection in sunflower (Helianthus annuus). Seeds were pretreated with BRs (1, 10, and 100 nM) and O. cumana inoculation for 4 weeks under soil conditions. O. cumana infection significantly reduced plant growth traits, photosynthesis, endogenous BRs and regulated the plant defence (POX, GST), BRs signalling (BAK1, BSK1 to BSK4) and synthesis (BRI1, BR6OX2) genes. O. cumana also elevated the levels of malondialdehyde (MDA), hydroxyl radical (OH-), hydrogen peroxide (H2O2) and superoxide (O2 •-) in leaves/roots by 77/112, 63/103, 56/97 and 54/89%, as well as caused ultrastructural cellular damages in both leaves and roots. In response, plants activated a few enzymes, superoxide dismutase (SOD), peroxidase (POD) and reduced glutathione but were unable to stimulate the activity of ascorbate peroxidase (APX) and catalase (CAT) enzymes. The addition of BRs (especially at 10 nM) notably recovered the ultrastructural cellular damages, lowered the production of oxidative stress, activated the key enzymatic antioxidants and induced the phenolic and lignin contents. The downregulation in the particular genes by BRs is attributed to the increased resilience of sunflower via a susceptible reaction. In a nutshell, BRs notably enhanced the sunflower resistance to O. cumana infection by escalating the plant immunity responses, inducing systemic acquired resistance, reducing oxidative or cellular damages, and modulating the expression of BR synthesis or signalling genes.

Moisture content and mycorrhizal fungi in maternal environment influence performance and composition of Lallemantia species offspring

The availability of soil water content and nutrition in the maternal plant environment plays pivotal roles in shaping the performance, physio-biochemical properties, and chemical composition of the produced seed. This study aimed to investigate the effects of water and arbuscular mycorrhizal fungi (AMF) of maternal plant environment on performance, physio-biochemical properties, and chemical compositions of Lallemantia species offspring. A split-factorial experiment was performed using a randomized complete block design (RCBD) with three replications. The main plot consisted of three drought stress (30 %, 60 % and 90 % of soil available water depletion). The subplots were the factorial combination of arbuscular mycorrhizal fungi (AMF− and AMF+) and Lallemantia species (L. iberica and L. royleana). The offspring of both Lallemantia species experienced a decrease in seed performance, superoxide dismutase, catalase, ascorbate peroxidase enzyme activities, proline, and chemical composition as well as a rise in hydrogen peroxide and lipid peroxidation due to the limited availability of water in the maternal plant environment. On the other hand, providing adequate nutrition in the maternal plant environment resulted in improved germination index, increased starch, and oil content, as well as higher levels of nitrogen and phosphorus in the offspring of both Lallemantia species. Compared to the offspring of L. royleana, the offspring of L. iberica had a higher number of achenes, seeds, seed weight, larger seed size, greater germination index, and higher levels of starch, oil, nitrogen, phosphorus, potassium, and calcium. In contrast, the offspring of L. royleana exhibited higher longevity, enhanced germination under osmotic and salinity stress, increased proline levels, and higher activities of antioxidant enzymes such as superoxide dismutase, catalase, and ascorbic peroxidase as well as sucrose and total soluble sugar. The study concludes that the best seed performance, antioxidant enzyme activities, and carbohydrate levels were observed in the offspring of both Lallemantia species produced under 60 % soil available water depletion with AMF inoculation in the maternal plant environment. These findings highlight the significant impact of the soil available water depletion and AMF inoculation on the seed performance, physio-biochemical properties, and chemical composition of the offspring, providing valuable insights for optimizing seed production and performance.

Identification of the Gossypium hirsutum SDG Gene Family and Functional Study of GhSDG59 in Response to Drought Stress.

SET-domain group histone methyltransferases (SDGs) are known to play crucial roles in plant responses to abiotic stress. However, their specific function in cotton's response to drought stress has not been well understood. This study conducted a comprehensive analysis of the SDG gene family in Gossypium hirsutum, identifying a total of 82 SDG genes. An evolutionary analysis revealed that the SDG gene family can be divided into eight subgroups. The expression analysis shows that some GhSDG genes are preferentially expressed in specific tissues, indicating their involvement in cotton growth and development. The transcription level of some GhSDG genes is induced by PEG, with GhSDG59 showing significant upregulation upon polyethylene glycol (PEG) treatment. Quantitative polymerase chain reaction (qPCR) analysis showed that the accumulation of transcripts of the GhSDG59 gene was significantly upregulated under drought stress. Further functional studies using virus-induced gene silencing (VIGS) revealed that silencing GhSDG59 reduced cotton tolerance to drought stress. Under drought conditions, the proline content, superoxide dismutase (SOD) and peroxidase (POD) enzyme activities in the GhSDG59-silenced plants were significantly lower than in the control plants, while the malondialdehyde (MDA) content was significantly higher. Transcriptome sequencing showed that silencing the GhSDG59 gene led to significant changes in the expression levels of 1156 genes. The KEGG enrichment analysis revealed that these differentially expressed genes (DEGs) were mainly enriched in the carbon metabolism and the starch and sucrose metabolism pathways. The functional annotation analysis identified known drought-responsive genes, such as ERF, CIPK, and WRKY, among these DEGs. This indicates that GhSDG59 is involved in the drought-stress response in cotton by affecting the expression of genes related to the carbon metabolism and the starch and sucrose metabolism pathways, as well as known drought-responsive genes. This analysis provides valuable information for the functional genomic study of SDGs and highlights potential beneficial genes for genetic improvement and breeding in cotton.

Nano vitamin E improved the antioxidant capacity of broiler chickens.

Vitamin E (VE) is a potent nutritional antioxidant that is critical in alleviating poultry oxidative stress. However, the hydrophobic nature and limited stability of VE restrict its effective utilization. Nanotechnology offers a promising approach to enhance the bioavailability of lipophilic vitamins. The objective of this experiment was to investigate the effects of different sources and addition levels of VE on the growth performance, antioxidant capacity, VE absorption site, and pharmacokinetics of Arbor Acres (AA) broilers. Three hundred and eighty-four 1-d-old AA chicks were randomly allocated into four groups supplemented with 30 and 75 IU/kg VE as regular or nano. The results showed that dietary VE sources had no significant impact on broiler growth performance. However, chickens fed 30 IU/kg VE had a higher average daily gain at 22 to 42 d and 1 to 42 d, and lower feed conversion ratio at 22 to 42 d than 75 IU/kg VE (P < 0.05). Under normal feeding conditions, broilers fed nano VE (NVE) displayed significantly higher superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) enzyme activities and lower malonic dialdehyde (MDA) concentration (P < 0.05). Similarly, NVE had a higher antioxidant effect in the dexamethasone-constructed oxidative stress model. It was found that nanosizing technology had no significant effect on the absorption of VE in the intestinal tract by examining the concentration of VE in the intestinal tract (P > 0.05). However, compared to broilers perfused with regular VE (RVE), the NVE group displayed notably higher absorption rates at 11.5 and 14.5h (P < 0.05). Additionally, broilers perfused with NVE showed a significant increase in the area under the concentration versus time curve from zero to infinity (AUC0-∞), mean residence time (MRT0-∞), elimination half-life (t1/2z), and peak concentration (Cmax) of VE in plasma (P < 0.05). In summary, nanotechnology provides more effective absorption and persistence of VE in the blood circulation for broilers, which is conducive to the function of VE and further improves the antioxidant performance of broilers.

A ubiquitous tire rubber additive induced serious eye injury in zebrafish (Danio rerio)

Previous studies have indicated that tire wear particles (TWPs) leachate exposure induced serious eye injury in fish through inhibiting the thyroid peroxidase (TPO) enzyme activity. However, the main TPO inhibitors in the leachate were still unknown. In this study, we identified 2-Mercaptobenzothiazole (MBT) as the potential TPO inhibitor in the TWPs leachate through references search, model prediction based on Danish QSAR and ToxCast database, molecular docking, and in vivo assay. We further explored the toxic mechanism of MBT under environmentally relevant concentrations. The decreased eye size of zebrafish larvae was mainly caused by the decreased lens diameter and cell density in the inner nuclear layer (INL) and outer nuclear layer (ONL) of the retina. Transcriptomics analysis demonstrated that the eye phototransduction function was significantly suppressed by inhibiting the photoreceptor cell proliferation process after MBT exposure. The altered opsin gene expression and decreased opsin protein levels were induced by weakening thyroid hormone signaling after MBT treatment. These results were comparable to those obtained from a known TPO inhibitor, methimazole. This study has identified MBT as the primary TPO inhibitor responsible for inducing eye impairment in zebrafish larvae exposed to TWPs leachate. It is crucial for reducing the toxicity of TWPs leachate in fish.

Efficacy of Using Chemical Inducers and Biological Agents to Control Strawberry Leaf Spot Disease on Chemical Components and Enzyme Activity

Strawberry plants are subjected to many pathogens. Fungal diseases of strawberries are important worldwide and occur in all parts of the plant, including leaves, crowns, and fruits. The results of the bio-agent experiment indicated that Trichoderma harzianum was the most effective in reducing the growth of Alternaria alternata and Botrytis cinerea in vitro, the main causes of leaf spots in strawberry plants. The inhibition zone was observed and mycelium of T. harzianum invaded the colony of the tested pathogens. The importance of the biochemical study of defense reaction in the physiology of disease resistance was accepted. The activity of total, free, and conjugated phenols as well as peroxidase, polyphenol oxidase, and catalase enzyme activities were determined in resistant and susceptible strawberry cultivars. All the total, free, and conjugated phenols increased in resistant cultivars (Fortuna and Winter Star) and decreased in susceptible cultivar (Festival). Oxidative enzymes, like the increased activity of enzymes that appear mince of new polypeptide protein, have become models in the study of plant disease resistance. The higher content of peroxidase, polyphenol oxidase, and catalase enzymes in resistant cultivars, were noticed compared with those in susceptible ones. It was found also that, the chemical inducers increased total phenols in resistant and susceptible cultivars i.e., potassium di-phosphate, ferrous sulphate, and oxalic acid. Inducer resistance also caused an increase of free phenols than the control. However, conjugated phenols accumulated faster after using chemical inducers in the leaves of the resistant cultivars, than the susceptible ones.

The impact of melatonin and glutathione on the physiological characteristics of the hot pepper Capsicum annuum L. grown under cadmium pollution

The experiment was conducted in pots within the plastic house of a nursery located in the Al-Muqdadiya district, situated to the north of Baqubah, the central city of Diyala governorate, which lies 90 km northeast of the capital, Baghdad. This study focused on Capsicum annuum L, specifically the Barbarian F1 class of Indian origin, during the autumn season. The objective of the experiment was to investigate the effects of melatonin and glutathione treatments on the physiological characteristics of Capsicum annuum L grown under conditions polluted with cadmium. The research followed a Randomized Complete Block Design (R.C.B.D.) with three replicates. Three treatments were applied: cadmium, added to the soil at concentrations of 0 and 15 mg.kg soil-1, and melatonin and glutathione, applied to the leaves at concentrations of 0, 50, and 100 mg.L-1. The results revealed a significant decrease in fruit carbohydrate content and catalase enzyme activity when treated with cadmium at a concentration of 15 mg.kg soil-1. However, applying melatonin at concentrations of 50 and 100 mg.L-1 led to a significant increase in fruit carbohydrate and protein content, along with a notable rise in catalase and peroxidase enzyme activities. The concentration of 100 mg.L-1 demonstrated the highest mean values for these features. Moreover, the study demonstrated a significant increase in fruit carbohydrate and protein content, as well as catalase enzyme activity, when plants were treated with glutathione at concentrations of 50 and 100 mg.L-1. The highest mean values for these features were observed when plants were treated with glutathione at a concentration of 100 mg.L 1.

Obesity Is Associated with Oxidative Stress Markers and Antioxidant Enzyme Activity in Mexican Children.

The relationship between metabolic disorders and oxidative stress is still controversial in the child population. The present cross-sectional study aimed to analyze the associations between obesity, cardiometabolic traits, serum level of carbonylated proteins (CPs), malondialdehyde (MDA), and the enzyme activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in children from Mexico City (normal weight: 120; obesity: 81). Obesity resulted in being positively associated with CAT (β = 0.05 ± 0.01, p = 5.0 × 10-3) and GPx (β = 0.13 ± 0.01, p = 3.7 × 10-19) enzyme activity. A significant interaction between obesity and sex was observed in MDA and SOD enzymatic activity (PMDA = 0.03; PSOD = 0.04). The associations between obesity, MDA level, and SOD enzyme activity were only significant in boys (boys: PMDA = 3.0 × 10-3; PSOD = 7.0 × 10-3; girls: p ≥ 0.79). In both children with normal weight and those with obesity, CP levels were positively associated with SOD enzyme activity (PNormal-weight = 2.2 × 10-3; PObesity = 0.03). In conclusion, in Mexican children, obesity is positively associated with CAT and GPx enzyme activity, and its associations with MDA levels and SOD enzyme activity are sex-specific. Therefore, CP level is positively related to SOD enzyme activity independently of body weight.

Exploring the Associations of Inflammatory and Oxidative Stress Biomarkers with Pancreatic Diseases: An Observational and Mendelian Randomisation Study.

Identifying biomarkers linked to pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP) is crucial for early detection, treatment, and prevention. Methods: Association analyses of 10 serological biomarkers involved in cell signalling (IFN-γ, IL-6, IL-8, IL-10), oxidative stress (superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities, total glutathione (GSH), malondialdehyde (MDA) levels), and intestinal permeability proteins (zonulin, I-FABP2) were conducted across PDAC (n = 12), CP (n = 21) and control subjects (n = 23). A Mendelian randomisation (MR) approach was used to assess causality of the identified significant associations in two large genetic cohorts (FinnGen and UK Biobank). Results: Observational results showed a downregulation of SOD and GPx antioxidant enzyme activities in PDAC and CP patients, respectively, and higher MDA levels in CP patients. Logistic regression models revealed significant associations between CP and SOD activity (OR = 0.21, 95% CI [0.05, 0.89], per SD), GPx activity (OR = 0.28, 95% CI [0.10, 0.79], per SD), and MDA levels (OR = 2.05, 95% CI [1.36, 3.08], per SD). MR analyses, however, did not support causality. Conclusions: These findings would not support oxidative stress-related biomarkers as potential targets for pancreatic diseases prevention. Yet, further research is encouraged to assess their viability as non-invasive tools for early diagnosis, particularly in pre-diagnostic CP populations.

Changes in Nutrient Content and Physicochemical Properties of Cavendish Bananas var. Pei Chiao during Ripening

Banana is a typical tropical fruit that is widely cultivated in tropical and subtropical regions, and consumed daily because of its superior nutritional profile. This study aimed to investigate the changes in bananas’ physicochemical properties and nutritional composition from ripening stages 1 to 9. The analysis included color (peel and flesh), texture, total starch content, resistant starch content, free sugar content, minerals (calcium, magnesium, potassium, sodium, iron, phosphorus), and vitamin content. At the same time, the browning enzyme activities of polyphenol oxidase (PPO), peroxidase, oxalic acid, and tannin were also measured. In this study, the banana peel gradually changed from dark green to light green to yellow during the ripening process, eventually appearing with many black spots, while the pulp color changed from white to light yellow and decreased in brightness. The pulp became softer with a prolonged ripening period, which was inconsistent with the time point of peel color change (ripening period 4–5). However, total starch content decreased from 74% to 31%, resistant starch originally at 32% gradually decreased to 5%, and free sugar content gradually increased with increasing ripening period. Vitamin C content and PPO activity decreased significantly during the ripening period, while other vitamins and minerals did not change significantly. In contrast, oxalic acid, tannin content, and peroxidase activity were negatively correlated with the ripening period. Therefore, this study reveals the changes in the nutrient content of bananas at different ripening stages, which may provide helpful information for researchers and producers to identify suitable raw materials for producing stable and high-nutrition-value banana-related foods during the peak raw material abundance seasons while reducing business risk.

Evaluating mechanism of banana pseudo-stem retting using seawater: A cost-effective surface pre-treatment approach

Retting has been employed to extract natural fibers from agricultural wastes as a biological and cost-effective approach for centuries. With its global abundance, banana pseudo-stem is a promising agro-waste for lignocellulosic fiber extraction. In this study, fibers were extracted from the pseudo-stems after being pre-treated under four conditions using seawater at room temperature for up to 35 d Bacterial isolation from the fresh seawater sample and screening for ligninolytic ability were conducted. Bacterial load as well as laccase and manganese peroxidase enzyme activity profile assay during the retting duration were analyzed. Fourier transform infrared (FT-IR) and X-day diffraction (XRD) analyses were also examined for both pre-treated and untreated extracted fibers. The results shows that six out of the eight bacterial isolates had the ability to degrade lignin. The treatments (Raw stem + Raw seawater) and (Autoclaved stem + Raw seawater) recorded the highest viable bacterial load of 9.24 × 102 and 4.46 × 102 CFU, respectively, on the 14th day of the retting process. Additionally, the highest laccase and manganese peroxidase enzymes activity was recorded for (Raw stem + Raw seawater) and (Autoclaved stem + Raw seawater) treatments in the second to the third week. The FT-IR spectra of the pre-treated fibers revealed relative reductions in peaks attributed to polysaccharides and other amorphous substances for all retting conditions. The XRD diffractogram revealed that the crystallinity index (CI) of pre-treated fibers increased in all seawater retting treatment conditions. However, the CI for fibers pre-treated under enzymatic conditions were enhanced even after five weeks. Sequence analysis for selected bacterial isolates showed homology to sequences of Bacillus velezensis, Shewanella sp. L8–5, and Citrobacter amalonaticus and Bacillus subtilis j8 strain. From these findings, it was suggested that physical, biological, and chemical actions were collectively involved in the seawater retting process of banana pseudo-stems.

Harnessing the potential of a novel lignin-degrading Streptomyces sp. MS-S2 from wood-feeding termite for malachite green decolorization and detoxification

Lignin and synthetic dyes share complex structural similarities and relevant management difficulties, which should be effectively addressed towards environmental sustainability. Under this scope, the quest for oxidative enzyme-producing microorganisms with a view to efficiently valorizing organic pollutants is of utmost importance. The intestinal bacteria of wood-feeding termites represent a unique source of valuable enzymes. The decolorization efficiency of five different dyes, including malachite green (MG), methyl violet, anihiline blue, reactive red, and reactive blue, after 12 h of degradation by the MS-S2 bacterial strain was recorded to be 98.2, 17.5, 8.7, 4.6, and 3.28%, respectively. Several physico-chemical parameters were then optimized to accelerate MG degradation, including pH, temperature, glucose, and yeast extract concentration. Streptomyces sp. strain MS-S2 completely decolorized MG (50 mg/L) within 2 h under optimized conditions when the cultivation medium was amended with 5 g/L glucose and 0.08 g/L yeast extract at pH 8 and incubated at 28 °C. After MG degradation, the enzyme activities of manganese peroxidase (4.605 U/L) and laccase (45.185 U/L) were estimated. To comprehend the degradation process of MG by the MS-S2 strain, UV-Vis spectroscopy, Fourier transform infrared (FTIR), and gas chromatography-mass spectrometry (GC-MS) analyses were carried out to ascertain the possible degradation mechanism. The metabolites identified, such as 2,6-Bis (tert-butyl) phenol and [4-(dimethylamino) phenyl] phenyl, suggest that MG was broken down into less toxic compounds for further degradation. MS-S2 exhibited outstanding characteristics that could make it suitable for the bioremediation of MG dye in an industrial setting.

Effects of sperm concentration on the quality of cryopreserved sperm in Yangtze sturgeon (Acipenser dabryanus)

The Yangtze sturgeon (Acipenser dabryanus) is extinct in the wild; however, artificial propagation in captivity under fully controlled conditions has been successful. Sperm cryopreservation is an effective method for germplasm conservation and aquaculture. Sperm concentration affects the quality of cryopreserved spermatozoa. Thus, in this study, we optimized the concentration (0.25 × 109, 0.5 × 109, 1.0 × 109, and 2.0 × 109 spermatozoa [spz]/mL) for Yangtze sturgeon sperm cryopreservation in a 0.5 mL plastic straw. The greatest value for the kinetic parameters was achieved when sperm were cryopreserved at 0.5 × 109 spz/mL. In comparison to other concentrations, there was a notable increase in both acrosomal and plasma membrane integrity when sperm was cryopreserved at a concentration of 0.5 × 109 spz/mL. No significant difference of superoxide dismutase and glutathione peroxidase enzyme activity was present in post-thaw sperm, except in sperm cryopreserved at a concentration of 2.0 × 109 spz/mL. Catalase activity was significantly higher in post-thaw sperm at a concentration of 0.5 × 109 spz/mL than at other concentrations. Excluding sperm cryopreserved at 2.0 × 109 spz/mL, the fertilization rate of cryopreserved sperm was not significantly different among the different concentrations. This concentration optimization improves cryopreserved sperm quality and standardizes sperm cryopreservation procedures for the Yangtze sturgeon. These findings are especially beneficial for the establishment of a sperm cryobank.

Effects of hypothermia–hypoxia pulping, high hydrostatic pressure processing, and repeat freeze–thaw cycles on the quality of raw kiwifruit puree

AbstractThis study evaluated the effects of the whole process of non‐thermal processing (hypothermia–hypoxia pulping and high hydrostatic pressure (HHP) pasteurization), different freezing methods, and repeat freeze–thaw cycles on physicochemical and nutritional quality of kiwifruit puree. Results showed that hypothermia–hypoxia treatment can retain the vitamin C, total phenol content, and antioxidant capacity of the puree better. Different pasteurization treatments can effectively kill microorganisms and improve the total phenol content and antioxidant capacity of the raw puree. Compared with thermal treatment, HHP can better retain the color, viscosity, and aroma components of the raw puree. The freezing methods have little impact on the quality of the raw puree, but peroxidase enzyme activity after quick freezing was significantly higher than that of slow freezing. Different freeze–thaw treatments had adverse effects on the quality of kiwifruit, and the damage of 25°C thawing conditions was more serious than that of 4°C thawing conditions. This research would provide new ideas for the production and storage of high‐quality kiwifruit puree and potential technical support for kiwifruit puree commercial production.Practical ApplicationsThe results of this study showed that non‐thermal processing can maintain the quality of kiwifruit puree better than traditional thermal processing, which provides a new idea for the production of high‐quality kiwifruit puree. In addition, this study suggests that temperature fluctuations should be minimized during storage to better maintain kiwifruit quality. This will provide potential technical support for the commercialization of kiwifruit puree.

Effects of humic acid water-soluble fertilizer on growth and physiological characteristics of Bupleurum chinense seedlings

The effects of humic acid water-soluble fertilizer on the growth and physiological characteristics of Bupleurum chinense seedlings(Zhongchai No.1) were studied by using a single factor experiment design. When the seedling age was 60 days, the humic acid water-soluble fertilizer was diluted 1 200 times(T1), 1 500 times(T2), 1 800 times(T3), and 2 100 times(T4) for seedling treatment, respectively, and water was used as the control(CK). The effects of different treatments on growth indexes, biomass accumulation, root activity, antioxidant enzyme activity, membrane lipid peroxidation, and photosynthetic characteristics of B. chinense seedlings were analyzed after 30 days. The results showed that compared with CK, stem height, leaf number, root diameter, and root length of the B. chinense seedlings under T3 treatment were significantly increased by 36.82%, 37.03%, 42.78%, and 22.38%, respectively. Root fresh weight, leaf fresh weight, root dry weight, and leaf dry weight under T3 treatment were significantly increased by 90.36%, 98.68%, 123.84%, and 104.38%, respectively. In addition, humic acid water-soluble fertilizer also enhanced TTC reducing activity of the root of B. chinense seedlings, inhibited malonaldehyde(MDA) content, increased superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) enzyme activities, improved chlorophyll content, and enhanced P_n, G_s, T_r, and other photosynthetic parameters. In conclusion, the application of humic acid water-soluble fertilizer diluted 1 800 times can significantly promote the growth of B. chinense seedlings, enhance root vitality, improve seedling stress resistance, and enhance photosynthesis. The results of this study can provide a theoretical basis for fertilization of B. chinense seedlings.

Nano Silver and melatonin effectively delay the senescence of cut carnation flowers under simulated vibrational stress

ABSTRACT Carnation (Dianthus caryophyllus L.) holds great significance as a cut flower, and its vase life plays a crucial role in determining its quality and market appeal. However, the extended transportation distances from the production location to consumer markets can have an unfavourable impact on the vase life and overall quality of cut flowers. The first experiment demonstrated that exposing cut carnation flowers to simulated vibrational stress (SVS) led to a decline in vase life and overall quality. Notably, the application of Nano Silver (NS; 25 and 50 μM) and melatonin (MT; 100 and 200 μM) into the holding solution proved effective in counteracting these negative effects, and extended the vase life by promoting cut flower water relations. In the second experiment, the optimal concentrations of NS and MT into the holding solution (25 and 100 μM, respectively) effectively reduced chlorophyll degradation, electrolyte leakage, and lipid peroxidation by enhancing the activity of catalase and peroxidase enzymes. As a result, it appears that the application of NS and MT in the holding solution has successfully prolonged vase life by both improving water balance and boosting antioxidant activity, while mitigating the negative effects of SVS.

Evaluation of different probiotics on growth, body composition, antioxidant capacity, and histoarchitecture of Mugil capito

We investigated the dietary effects of the single application of Saccharomyces cerevisiae, Lactobacillus bulgaricus, and their combination on growth, proximate composition of whole fish body, antioxidant defense, and histoarchitecture of hapa-reared Mugil capito. Healthy fish (Fish weighed = 10.30 ± 0.10 g at first) were randomly allocated into 4 equal groups, each with three replicates. These groups were designed as follows: (1) a group fed a basal diet without probiotics (control), (2) a group fed a diet containing S. cerevisiae (4 g/kg diet), (3) a group fed a diet containing L. bulgaricus (2 g/kg diet), and (4) the last group fed a diet containing a combination of both, all for a duration of 60 days. Probiotic-treated groups showed significantly better growth and nutrition utilization than the control group. Significant differences were observed in the crude fat and crude protein contents among the groups, with the combination group exhibiting the highest levels. However, there were no significant variations in ash content across all groups. The highest hepatic antioxidant capacity (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activities) was observed in the combination group. Thiobarbituric acid reactive substance (TBARS) concentrations were decreased significantly in all probiotic groups, suggesting improved oxidative stress resilience in these groups. The histomorphological analysis of the hepatopancreatic tissues revealed well-arranged parenchyma, increased glycogen storage, and melanomacrophage centers in probiotic-treated groups, particularly the combined probiotics group. Furthermore, the probiotic supplementation improved the histoarchitecture of the intestinal villi compared to the control group. To put it briefly, combined dietary administration of these probiotics improved growth, body composition, antioxidant defenses, and hepatic and intestinal health in hapa-reared M. capito, highlighting their promising role in promoting welfare and productivity.