Acid Phosphatase Activity Research Articles

Dietary Clostridium autoethanogenum protein has dose-dependent influence on the gut microbiota, immunity, inflammation and disease resistance of abalone Haliotis discus hannai

Clostridium autoethanogenum protein (CAP) is an eco-friendly protein source and has great application potential in aquafeeds. The present study aimed to investigate the effects of dietary CAP inclusion on the anti-oxidation, immunity, inflammation, disease resistance and gut microbiota of abalone Haliotis discus hannai after a 110-day feeding trial. Three isonitrogenous and isolipidic diets were formulated by adding 0 % (control), 4.10 % (CAP4.10) and 16.25 % (CAP16.25) of CAP, respectively. A total of 540 abalones with an initial mean body weight of 22.05 ± 0.19 g were randomly distributed in three groups with three replicates per group and 60 abalones per replicate. Results showed that the activities of superoxide dismutase and glutathione peroxidase in the cell-free hemolymph (CFH) were significantly decreased and the content of malondialdehyde in CFH was significantly increased in the CAP16.25 group. The diet with 4.1 % of CAP significantly increased the activities of lysozyme and acid phosphatase in CFH. The expressions of pro-inflammatory genes such as tumor necrosis factor-α (tnf-α), nuclear factor-κb (nf-κb) and toll-like receptor 4 (tlr4) in digestive gland were downregulated, and the expressions of anti-inflammatory genes such as β-defensin and mytimacin 6 in digestive gland were upregulated in the CAP4.10 group. Dietary CAP inclusion significantly decreased the cumulative mortality of abalone after the challenge test with Vibrio parahaemolyticus for 7 days. Dietary CAP inclusion changed the composition of gut microbiota of abalone. Besides, the balance of the ecological interaction network of bacterial genera in the intestine of abalone was enhanced by dietary CAP. The association analysis showed that two bacterial genera Ruegeria and Bacteroides were closely correlated with the inflammatory genes. In conclusion, the 4.10 % of dietary CAP enhanced the immunity and disease resistance as well as inhibited the inflammation of abalone. The 16.25 % of dietary CAP decreased the anti-oxidative capacity of abalone. The structure of the gut microbiota of abalone changed with dietary CAP levels.

Exposure to Fluoxetine induced Gonado-toxicity in female rats: Modulating role of Hybanthus enneaspermus

Several scientific evidence supports the use of Hybanthus enneaspermus leaves in the management of female sexual inadequacies. Additionally, fluoxetine is a reproductive toxicant that induces sexual dysfunction. To determine the modulating role of aqueous extract of Hybanthus enneaspermus leaves on fluoxetine-induced gonado-toxicity, sixty healthy, sexually-responsive female rats (157.21 ± 6.89) were divided into six groups (A–F) comprising of 10 rats each. Group A (control group) were administered distilled water only, Group B-F received orally 15 mg/kg body weight (b.w) of fluoxetine prepared daily for 14 days for the induction of anti-oestrogenicity and subsequently received 0.5ml of distilled water, 20 mg/kg b.w of a reference drug (Tadalafil) and 0.5 mL equivalent to 250, 500 and 1000 mg/kg b.w of the extract respectively, orally, once daily (08:00-08:45h) for 7 days. Fluoxetine reduced serum oestrogen concentrations by 54.79% and significantly reduced (p<0.05) ovarian and uterine total protein, glycogen, cholesterol, the activities of alkaline phosphatase and acid phosphatase. The reductions were by (22.91%, 25.57%, 22.82 %, 15.09 % and 43.17 %) in the ovaries and (21.25 %, 26.9%, 7.20%, 16.82% and 29.85%) in the uteri of the animals respectively. In contrast, these reductions were overturned by the extract towards the control group. The extract at 1000 mg/kg b.w ameliorated the reductions of these oestrogenic indices. Hybanthus enneaspermus attenuated the deleterious effects of fluoxetine on the ovaries and uteri, restored sexual competence and promoted oogenesis. These may further lend backing to its widespread use in handling some sterility/infertility problems in women.

Fertilizers and Manures Enhance the Bioavailability of Soil Phosphorus Fractions in Karst Grassland

Phosphorus is one of the major constraints to karst grassland productivity. Understanding the effects of different fertilization practices on soil phosphorus dynamics is essential for enhancing phosphorus bioavailability and rational management of soil phosphorus in karst grasslands. Here, we investigated the effects of fertilizers and manures on soil bioavailability of phosphorus fractions and explored the relationship between soil properties and soil phosphorus fractions. The four fertilizer application designs were as follows: control (CK; no fertilizer or manure); fertilization (F); manure application (M); fertilization and manure application (FM). The results showed that total phosphorus (TP) concentration was elevated by 23%, 1%, and 42% in F, M, and FM treatments, respectively, compared with CK. F and FM treatments enhanced the total inorganic phosphorus (Pi) concentration by 65% and 66%, respectively, while M and FM treatments enhanced the total organo-phosphorus (Po) concentration by 21% and 35%, respectively. FM treatment elevated bioavailable P, active Po, secondary mineral P, primary mineral P, and occluded P by 69%, 39%, 50%, 31%, and 41%, respectively. Fertilizers inhibited soil acid phosphatase activity, whereas alkaline phosphatase did not respond significantly to fertilizer management in low-latitude karst regions. SOM, TN, AP, and MBP are the key factors affecting the bioavailability of phosphorus fractions. The combined application of fertilizer and manure is the most beneficial measure for enhancing soil phosphorus bioavailability. This research helps deepen our understanding of soil phosphorus dynamics in the karst areas and provides a basis for further enhancement of nutrient availability and vegetation productivity of grassland ecosystems.

Results of biochemical and histological studies after restoration of bone defects using cellular technologies in dental patients

Objective of the research was to find out the effectiveness of the use of osteoplastic materials based on the multipotent mesenchymal stromal cells of the adipose tissue during surgical treatment for restoration of bone defects in dental patients. The clinical material included examination of 79 patients who underwent replacement of bone defects of the alveolar processes and/or an alveolar part of the appropriate jaw by means of different osteoplastic materials and their combinations or without their application (the control group). Acid phosphatase activity in the oral fluid of patients was determined by means of the unified “end point” method. Alkaline phosphatase activity in the oral fluid was determined using a set of reagents produced by the company “Filisit-Diagnostika” (Ukraine). Oral fluid mineralization index (MI) of patients was calculated according to the ratio of enzymatic activity of alkaline phosphatase (ALP) to acid phosphatase (AP) according to the formula: MI=ALP/AP. Histological material was taken at the stage of installation of a dental implant. It was established that the use of a composition based on multipotent mesenchymal stromal cells of adipose tissue, platelet-enriched blood plasma and bone tissue substitute containing hydroxyapatite contributes to the improvement of regenerative processes in the bone tissue of the jaws, which is confirmed by a 28.68% decrease in acid phosphatase activity, an increase by 25, 97% of alkaline phosphatase activity in the oral fluid of group B patients and, accordingly, a 77.08% increase in the ratio of alkaline to acid phosphatase. According to the results of histological studies and phase-contrast microscopy, after 6-8 months of observation, in patients of group B, the areas of jaw defects were filled with newly formed bone tissue, identical to native bone, and the resulting trepanobioptas had the structure of cancellous bone with osteoblastic elements forming a chain around osteoid tissue. Having analyzed the results of biochemical and histological studies it was established that application of an osteoplastic composition based on the multipotent mesenchymal stromal cells of the adipose tissue, bone tissue substitute with hydroxyapatite and platelet-rich plasma allows restoration of bone defects of the alveolar processes and an alveolar part of the appropriate jaw in shorter terms. The method is an optimal alternative to traditional osteoplastic materials to be used in modern dental practice and dental implantation.

Comparative study on biochemical responses to imidacloprid and clothianidin in cockroaches (Blattella germanica)

AbstractCockroaches, ubiquitous pests known for significant reproduction and as potential vectors of diseases, are notorious for their adoptability to a variety of insecticides that cause substantial challenges in pest control. The present research evaluated the LC50 concentrations of imidacloprid (0.65 mg/L) and clothianidin (2.5 μg/L) for Blattella germanica using topical and bait methods. The cockroaches were exposed to one‐third concentration of LC50 at a regular interval of 1, 2, 4, 8, 12, 16 and 20 days. During exposure, the activity of P450 monooxygenase increased, whereas the activity of brain acetylcholinesterase decreased. Lactate dehydrogenase, alkaline and acid phosphatase activity were highest on day 4, with a slight recovery on day 20. The elevated activities for superoxide dismutase and catalase, as well as increased lipid peroxidation levels on day 4, followed by a significant recovery in activity on day 20. The glutathione‐S‐transferase activity was elevated while the glutathione content was reduced, and a significant restoration was observed at the end of the experiment. The biochemical mechanisms of the organisms such as P450, esterase enzymes and oxidative systems, are actively involved in the detoxification mechanism. The study elucidated that the insecticide defence mechanism triggers detoxification pathways that encompass the metabolism of endogenous insecticidal compounds, with clothianidin showing greater efficacy and lower detoxification compared with imidacloprid.

Osteogenic differentiation of periodontal ligament fibroblasts inhibits osteoclast formation

One of the deficits of knowledge on bone remodelling, is to what extent cells that are driven towards osteogenic differentiation can contribute to osteoclast formation. The periodontal ligament fibroblast (PdLFs) is an ideal model to study this, since they play a role in osteogenesis, and can also orchestrate osteoclastogenesis.when co-cultured with a source of osteoclast-precursor such as peripheral blood mononuclear cells (PBMCs). Here, the osteogenic differentiation of PdLFs and the effects of this process on the formation of osteoclasts were investigated. PdLFs were obtained from extracted teeth and exposed to osteogenic medium for 0, 7, 14, or 21 out of 21 days. After this 21-day culturing period, the cells were co-cultured with peripheral blood mononuclear cells (PBMCs) for an additional 21 days to study osteoclast formation. Alkaline phosphatase (ALP) activity, calcium concentration, and gene expression of osteogenic markers were assessed at day 21 to evaluate the different stages of osteogenic differentiation. Alizarin red staining and scanning electron microscopy were used to visualise mineralisation. Tartrate-resistant acid phosphatase (TRAcP) activity, TRAcP staining, multinuclearity, the expression of osteoclastogenesis-related genes, and TNF-α and IL-1β protein levels were assessed to evaluate osteoclastogenesis. The osteogenesis assays revealed that PdLFs became more differentiated as they were exposed to osteogenic medium for a longer period of time. Mineralisation by these osteogenic cells increased with the progression of differentiation. Culturing PdLFs in osteogenic medium before co-culturing them with PMBCs led to a significant decrease in osteoclast formation. qPCR revealed significantly lower DCSTAMP expression in cultures that had been supplemented with osteogenic medium. Protein levels of osteoclastogenesis stimulator TNF-α were also lower in these cultures. The present study shows that the osteogenic differentiation of PdLFs reduces the osteoclastogenic potential of these cells. Immature cells of the osteoblastic lineage may facilitate osteoclastogenesis, whereas mature mineralising cells may suppress the formation of osteoclasts. Therefore, mature and immature osteogenic cells may have different roles in maintaining bone homeostasis.

In vitro and in vivo studies on exogenous polyamines and α-difluoromethylornithine to enhance bone formation and suppress osteoclast differentiation

Exogenous polyamines, including putrescine (PUT), spermidine (SPD), and spermine (SPM), and the irreversible inhibitor of the rate-limiting enzyme ornithine decarboxylase (ODC) of polyamine biosynthesis, α-difluoromethylornithine (DFMO), are implicated as stimulants for bone formation. We demonstrate in this study the osteogenic potential of exogenous polyamines and DFMO in human osteoblasts (hOBs), murine monocyte cell line RAW 264.7, and an ovariectomized rat model. The effect of polyamines and DFMO on hOBs and RAW 264.7 cells was studied by analyzing gene expression, alkaline phosphatase (ALP) activity, tartrate-resistant acid phosphatase (TRAP) activity, and matrix mineralization. Ovariectomized rats were treated with polyamines and DFMO and analyzed by micro computed tomography (micro CT). The mRNA level of the early onset genes of osteogenic differentiation, Runt-related transcription factor 2 (Runx2) and ALP, was significantly elevated in hOBs under osteogenic conditions, while both ALP activity and matrix mineralization were enhanced by exogenous polyamines and DFMO. Under osteoclastogenic conditions, the gene expression of both receptor activator of nuclear factor-κB (RANK) and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) was reduced, and TRAP activity was suppressed by exogenous polyamines and DFMO in RAW 264.7 cells. In an osteoporotic animal model of ovariectomized rats, SPM and DFMO were found to improve bone volume in rat femurs, while trabecular thickness was increased in all treatment groups. Results from this study provide in vitro and in vivo evidence indicating that polyamines and DFMO act as stimulants for bone formation, and their osteogenic effect may be associated with the suppression of osteoclastogenesis.

Dual quenching mechanism study and application for sensitive sensing acid phosphatase activity based on bimetallic Au/Ag nanoclusters with enhanced fluorescence

In this study, we synthesized Ag-doped Au/Ag nanoclusters (GSH-Au/Ag NCs) with enhanced luminescence. We conducted a comprehensive investigation into the mechanism behind KMnO4-induced fluorescence (FL) quenching of these bimetallic nanoclusters and, leveraging this understanding, developed a sensitive fluorescent method for determining acid phosphatase activity (ACP). The fluorescence quenching mechanism was attributed to a combination of the inner filter effect (IFE) and redox reactions. Subsequently, ascorbic acid (AA) was generated from L-ascorbic acid 2-phosphate trisodium salt (AAP), which was selectively hydrolyzed by ACP. The released AA then reduced KMnO4, leading to the inhibition of fluorescence quenching of GSH-Au/Ag NCs by KMnO4. This innovative approach exhibited higher sensitivity, with a lower limit of detection of 0.0085 U/L (S/N = 3) for ACP activity sensing. Our proposed strategy was successfully applied to analyze ACP activity in human serum samples, demonstrating promising potential for the widespread utilization of metal nanoclusters in various applications.

VALUE OF BONE REMODELLING MARKERS IN MANDIBULAR FRACTURE PATIENTS BY GENDER AND BONE MINERAL DENSITY

Numerous studies have shown that fractures of the mandible are the most common injuries of the facial skeleton. The high incidence of such fractures is due to the anatomical and physiological characteristics of the mandible, as well as a variety of local and general causes. Disturbances in the structural-functional properties of bone tissue can occur as a result of internal and external influences and provide a favorable background for the development of fractures in various locations, including the mandible. A large number of regulatory factors of a nervous, humoral and immune nature, the presence of inflammation as an obligatory (first) phase of reparative regeneration after bone damage, dictate the need for an in-depth study of the structuralfunctional state of bone tissue in patients with traumatic injuries of the mandible, through the improvement of diagnostic and therapeutic methods. The aim of the study is to analyze the levels of bone remodeling markers in the oral fluid of patients with traumatic lesions of the mandible according to sex and BMD status compared with those of practically healthy control subjects (without general somatic and dental diseases). Materials and methods. The study is based on the results of laboratory tests on 151 people (main group) with mandibular fractures and 30 people (control group) without general somatic and dental diseases. The study included patients of both sexes aged 18-44 years: 92 (60,93%) male and 59 (39,07%) female patients. The levels of total calcium (Ca) and inorganic phosphorus (P) in the oral fluid were determined by photometric methods using commercial kits from «Filisit-Diagnostics» (Ukraine). The activity of alkaline phosphatase and acid phosphatase in oral fluid was determined by the kinetic method with n-nitrophenol phosphate. Oxyproline excretion was determined in daily urine using the Cobas test system (Roshe Diagnostics, Germany). Statistical processing of the study results was performed using Microsoft Excel and Statistics software packages for the statistical analysis of biomedical research data. Results and discussion. As a result of the studies, it was found that in men with osteoporosis, the levels of P in oral fluid were not significantly different from those in the control group, p>0,05. At the same time, the remaining values of bone remodeling markers in biological fluids were characterized by a pronounced imbalance, namely an increase in Ca content by 92,85%, p<0,01, p1<0,05, Ca/P ratio by 2,8 times, p, p1<0,01, AP activity by 89,48%, p<0,01, p1>0,05, ALP by 56,34%, p<0,05, p1>0,05, and urinary hydroxyproline level by 54,09%, p, p1<0,01, compared with the same data in the control group. In women with osteoporotic mandibular fractures, the values of all the parameters studied were significantly different from those of the control group. Thus, we found an increase in the oral fluid content of Ca – by 102,38%, p, p1<0,05, Ca/P ratio – by 3,5 times, p, p1<0,01, AP activity – by 99,06%, p, p1<0,01, ALP – by 65,15%, p, p1<0,01 against a decrease in the value of P – by 42,31%, p, p1<0,05, compared to the data of the control group. At the same time, in this subgroup of women there was an increase in urinary hydroxyproline by 58,26%, p, p1<0,01, compared to the data in the control group. Conclusions. Thus, analysis of bone remodeling marker levels showed that in patients with mandibular fractures due to destruction of the bone matrix as a result of trauma, there was an increase in osteoresorption activity that depended on the structural-functional state of the patients' bone tissue and was more pronounced in women.

Fungal composition associated with host tree identity mediates nutrient addition effects on wood microbial respiration.

Fungi are key decomposers of deadwood, but the impact of anthropogenic changes in nutrients and temperature on fungal community and its consequences for wood microbial respiration are not well understood. Here, we examined how nitrogen and phosphorus additions (field experiment) and warming (laboratory experiment) together influence fungal composition and microbial respiration from decomposing wood of angiosperms and gymnosperms in a subtropical forest. Nutrient additions significantly increased wood microbial respiration via fungal composition, but effects varied with nutrient types and taxonomic groups. Specifically, phosphorus addition significantly increased wood microbial respiration (65%) through decreased acid phosphatase activity and increased abundance of fast-decaying fungi (e.g., white rot), while nitrogen addition marginally increased it (30%). Phosphorus addition caused a greater increase in microbial respiration in gymnosperms than in angiosperms (83.3% vs. 46.9%), which was associated with an increase in Basidiomycota:Ascomycota operational taxonomic unit abundance in gymnosperms but a decrease in angiosperms. The temperature dependencies of microbial respiration were remarkably constant across nutrient levels, consistent with metabolic scaling theory hypotheses. This is because there was no significant interaction between temperature and wood phosphorus availability or fungal composition, or the interaction among the three factors. Our results highlight the key role of tree identity in regulating nutrient response of wood microbial respiration through controlling fungal composition. Given that the range of angiosperm species may expand under climate warming and forest management, our data suggest that expansion will decrease nutrient effects on forest carbon cycling in forests previously dominated by gymnosperm species.

Greater influences of nitrogen addition on priming effect in forest subsoil than topsoil regardless of incubation warming

Subsoil (below 20 cm), storing over 50 % of soil organics carbon (SOC) within the 1 m depth, plays a critical role in regulating climate and ecosystem function. However, little was known on the changes in SOC decomposition induced by exogenous C input (i.e., priming effect) across the whole soil profile under nitrogen (N) enrichment and climate warming. We designed an incubation system of soil columns with minor physical disturbance, which allows the manual additions of exogenous C and N and incubation under ambient or elevated temperature. A negative priming effect by glucose was observed in all layers of ambient soil, while the negative priming effect was enhanced by soil depth but inhibited by warming. Nitrogen addition shifted the priming effect from negative to positive under ambient temperature, and decreased the magnitude of negative priming effect under elevated temperature. Nitrogen uplift effect on priming effect was more pronounced in subsoil compared to topsoil, while this effect diminished with rising temperature. Soil microbial activity (e.g., the CO2 production within 3 days) and acid phosphatase activity had important roles in regulating the variations in priming effect across the soil profile. Our results indicated that increase in labile substrate (e.g., exogenous C input) input would not lead to native SOC destabilization in subsoil, N addition shifted the priming effect from negative to positive, increasing the SOC decomposition under ambient temperature, while labile C input together with N addition benefited SOC sequestration by inducing negative priming effects in forest soil under warming climate.

Mineral Components, Organic Matter Quality and Soil Enzymatic Activity under the Influence of Differentiated Farmyard Manure and Nitrogen Fertilisation

Research was carried out on the impact of long-term use of cattle manure (30 t ha−1 FYM) and various doses of N (0, 40, 60 and 120 t ha−1) in the form of ammonium nitrate on the following soil parameters: salinity, hydrolytic acidity, total exchangeable base cations, cation exchange capacity, degree of base saturation of the sorption complex, total organic carbon and total nitrogen content, dissolved organic matter, fractional composition of organic matter and content of bioavailable macroelements: phosphorus, potassium and magnesium in the soil of a multi-year static field experiment. The activities of dehydrogenases, catalase, alkaline and acid phosphatase and proteases were also tested. A significant effect of FYM and N fertilisation on the content of bioavailable macroelements was found. The application of manure at a dose of 30 t ha−1 mitigated the negative effects of the application of N at a dose of 120 kg ha−1. A higher content of total organic carbon (8.42 g kg−1) and humic acid fraction (1761 mg kg−1) and higher values of the CHA/CFA ratio (0.79; parameters that are indicators of soil quality) were found in the soil fertilised with manure compared to the soil without manure added (TOC—7.00 g kg−1; CHAs—1285 mg kg−1; CHAs/CFAs 0.66). The activity of the tested enzymes was also significantly determined by the applied fertilisation. Enzyme activity was highest in the soil to which manure had been applied. Nitrogen fertilisation varied in its impact on the activity of enzymes according to the specifics of each enzyme. The content of humic acids and CHA/CFA values correlated positively with the content of soil minerals and the activity of dehydrogenases, catalase, alkaline and acid phosphatase and GMea and TEI indices. Dehydrogenases and acid phosphatase can be considered enzymes that take part in transforming organic matter towards the formation of FAs.

Soil water content and RubisCO activity control the carbon storage in soil under different land uses in Sanjiang Plain, China

Soil carbon storage plays a crucial role in mitigating the climate warming and is significantly impacted by the land use pattern. To better understand soil carbon stability and the underlying microbial mechanism, based on qPCR, ELISA, and fluorescence techniques, the effects of land use changes on soil microbial abundance, enzyme activity, and soil carbon storage were investigated in the complex ecosystems of cropland, forestland, and wetland along three typical river (Wolvlan river, Bielahong river, Wusuli river) basin in Sanjiang Plain, China. We hypothesised that croplands soil carbon storage is lower than forestlands and wetlands, which is regulated by soil water content, microbe and enzyme activity. Results showed that topsoil TC in wetlands (85.54 mg·g−1) was higher than those in croplands (33.46 mg·g−1) and forestlands (46.13 mg·g−1). Topsoil water content increased 73.90 % and 71.64 % in wetlands than in farmland and forestlands, respectively. Additionally, reclamation diminished topsoil carbon storage. In croplands, soil dissolved organic carbon, microbial biomass carbon, microbial biomass nitrogen, available nitrogen, bacterial abundance, and soil enzymes (i.e., RubisCO, β-glucosidase, cellobiohydrolase, 1,4-N-acetylglucosaminidase and acid phosphatase) activities were substantially lower than those in wetlands. Structural equation modeling showed that soil carbon storage was positively related to soil water content and RubisCO activity but negatively related to soil bacterial abundance. Soil water content had the largest standardised total positive effect coefficient and indirectly influenced soil carbon storage by affecting RubisCO activity. Soil depth had a greater effect on SMC, hydrolase and site had a greater effect on bacteria and fungi abundance. The results highlight that the alteration of carbon fixing enzyme activity by soil water content is a crucial mechanism for soil carbon sequestration in response to land-use change. Management strategies that conserve natural wetlands, increase soil water content and minimize land disturbance would be effective in maintaining soil carbon stocks.

One-pot hydrothermal synthesis of silicon, nitrogen co-doped carbon dots for enhancing enzyme activity of acid phosphatase (ACP) to dopamine and for cell imaging

Developing water-soluble nanomaterials with high photoluminescence emission and high yield for biological analysis and imaging is urgently needed. Herein, water-soluble blue emitting silicon and nitrogen co-doped carbon dots (abbreviated as Si-CDs) of a high photoluminescence quantum yield of 80 % were effectively prepared with high yield rate (59.1 %) via one-step hydrothermal treatment of N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO) and trans-aconitic acid. Furthermore, the Si-CDs demonstrate environmental robustness, photo-stability and biocompatibility. Given the importance of the potentially abnormal levels of acid phosphatase (ACP) in cancer diagnosis, developing a reliable and sensitive ACP measurement method is of significance for clinical research. The Si-CDs unexpectedly promote the catalytic oxidation of ACP on dopamine (DA) to polydopamine under acidic conditions through the produced reactive oxygen species (ROS). Correspondingly, a fluorescence response strategy using Si-CDs as the dual functions of probes and promoting enzyme activity of ACP on catalyzing DA was constructed to sensitively determine ACP. The quantitative analysis of ACP displayed a linear range of 0.1–60 U/L with a detection limit of 0.056 U/L. The accurate detection of ACP was successfully achieved in human serum through recovery tests. As a satisfactory fluorescent probe, Si-CDs were successfully applied to fluorescent imaging of A549 cells in cytoplasmic with long-term and safe staining. The Si-CDs have the dual properties of outstanding fluorescent probes and auxiliary oxidase activity, indicating their great potential in multifunctional applications.

The Effects of Acute Ammonia Nitrogen Stress on Antioxidant Ability, Phosphatases, and Related Gene Expression in the Kidney of Juvenile Yellowfin Tuna (Thunnus albacares)

This study investigated the effects of acute ammonia nitrogen (NH3-N) exposure on kidney antioxidant ability and phosphatases and related gene expression in juvenile yellowfin tuna (Thunnus albacares). The 180 juvenile yellowfin tuna (260.39 ± 55.99 g, 22.33 ± 2.28 cm) were exposed to ammonia for 6, 24, and 36 h using natural seawater (0 mg/L) as a control and NH3-N at 5 and 10 mg/L. The lipid peroxidation byproduct malondialdehyde (MDA) and the levels of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), alkaline phosphatase (AKP), and acid phosphatase (ACP), were measured using the colorimetric method in the trunk kidney to determine changes in antioxidant ability and phosphatase activity of juvenile yellowfin tuna exposed to NH3-N. Results indicated that, at 36 h, MDA, SOD, CAT, and GSH-PX levels rose in the 5 mg/L group versus the control. In the 10 mg/L group, MDA and SOD, CAT, and GSH-PX activities significantly increased after 24 and 36 h exposure compared to the control. Phosphatases play a pivotal role in the immune system. AKP activity significantly increased at 6 h, and ACP activity markedly rose at 36 h in the 5 mg/L group versus the control. Real-time fluorescence quantitative PCR was applied to detect alterations in the antioxidant genes SOD2, CAT, and glutathione peroxidase 1b (GPX1b) and immune cytokines-related genes Interleukin 10 (IL-10) and Interleukin 6 receptor (IL-6r) expression in the head kidney in juvenile tuna. Relative to the control, antioxidant gene expression in the 5 mg/L group significantly rose at 6 and 36 h, and in the 10 mg/L group, SOD2 and GPX1b were significantly elevated at 36 h. Compared to the control group, IL-10 expression in the 5 mg/L group significantly increased at 6 h, whereas IL-6r expression decreased. In the 10 mg/L group, both IL-10 and IL-6r levels were observed to be lower. Low ammonia nitrogen concentrations boost antioxidant defenses, phosphatase activities, and gene expression levels, whereas higher levels may induce suppressive effects. In yellowfin tuna juvenile farming, NH3-N concentration significantly affects the health of the juveniles. When the NH3-N concentration is between 5–10 mg/L, the stress duration should be limited to 24 h; if the concentration is below 5 mg/L, the stress duration can be extended to 36 h.

Enzyme Activity Stoichiometry Suggests That Fertilization, Especially Nitrogen Fertilization, Alleviates Nutrient Limitation of Soil Microorganisms in Moso Bamboo Forests

Rational application of N fertilizer is essential for maintaining the long-term productivity of Moso bamboo forests. Microbial activity is a crucial indicator of soil quality. Changes in soil nutrient resources due to N addition can lead to microbial nutrient limitations, thereby impeding the maintenance of soil quality. Currently, there is limited research on the effects of N application on microbial nutrient limitations in Moso bamboo forest soils. To examine the changes in extracellular enzyme activity and microbial nutrient limitations in Moso bamboo forest soils following N application, we conducted an N application experiment in northern Guizhou. The findings revealed that the N3 treatment (726 kg·N·hm−2·yr−1) significantly reduced β-glucosidase (BG) activity by 27.61% compared to the control group (no fertilization). The N1 (242 kg·N·hm−2·yr−1), N2 (484 kg·N·hm−2·yr−1), and N3 treatments notably increased the activities of leucine aminopeptidase (LAP) and N-acetyl-β-D-glucosidase (NAG) by 11.45% to 15.79%. Acid phosphatase (ACP) activity remained unaffected by fertilization. N application treatments significantly decreased the C:Ne and C:Pe ratios, while the N:Pe ratio was less influenced by N fertilizer application. Scatter plots and vector characteristics of enzyme activity stoichiometry suggested that microorganisms in the study area were limited by C and N, and N fertilizer application reduced the vector length and increased the vector angle, indicating that N application alleviated the C and N limitation of microorganisms in Moso bamboo forests. Redundancy Analysis (RDA) demonstrated that microbial biomass phosphorus (MBP) was the most critical factor affecting extracellular enzyme activity and stoichiometry. Furthermore, Random Forest Regression analysis identified MBP and the N:Pm ratio as the most significant factors influencing microbial C and N limitation, respectively. The study demonstrated that N application modulates the microbial nutrient acquisition strategy by altering soil nutrient resources in Moso bamboo forests. Formulating fertilizer application strategies based on microbial nutrient requirements is more beneficial for maintaining soil quality and sustainably managing Moso bamboo forests. Additionally, our study offers a theoretical reference for understanding carbon cycling in bamboo forest ecosystems in the context of substantial N inputs.

Immune protection of grass carp by oral vaccination with recombinant Bacillus methylotrophicus expressing the heterologous tolC gene

In the field of aquaculture, the enhancement of animal health and disease prevention is progressively being tackled using alternatives to antibiotics, including vaccines and probiotics. This study was designed to evaluate the potential of a recombinant Bacillus methylotrophicus, engineered to express the outer membrane channel protein TolC of Aeromonas hydrophila AH3 and the green fluorescent protein GFP, as an oral vaccine. Initially, the genes encoding tolC and GFP were cloned into a prokaryotic expression system, and anti-TolC mouse antiserum was generated. Subsequently, the tolC gene was subcloned into a modified pMDGFP plasmid, which was transformed into B. methylotrophicus WM-1 for protein expression. The recombinant B. methylotrophicus BmT was then administered to grass carp via co-feeding, and its efficacy as an oral vaccine was assessed. Our findings demonstrated successful expression of the 55 kDa TolC and 28 kDa GFP proteins, and the preparation of polyclonal antibodies with high specificity. The BmT exhibited stable expression of the GFP-TolC fusion protein and excellent genetic stability. Following oral immunization, significant elevations were observed in serum-specific IgM levels and the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), and lysozyme (LZM) in grass carp. Concurrently, significant upregulation of immune-related genes, including IFN-I, IL-10, IL-1β, TNF-α, and IgT, was noted in the intestines, head kidney, and spleen of the grass carp. Colonization tests further revealed that the BmT persisted in the gut of immunized fish even after a fasting period of 7 days. Notably, oral administration of BmT enhanced the survival rate of grass carp following A. hydrophila infection. These results suggest that the oral BmT vaccine developed in this study holds promise for future applications in aquaculture.

Environmentally responsive changes in mucus indicators and microbiota of Chinese sturgeon Acipensersinensis

The impact of environmental factors on the health of the endangered Chinese sturgeon (Acipenser sinensis) and the potential hazards associated with sample collection for health monitoring pose urgent need to its conservation. In this study, Chinese sturgeons were selected from indoor and outdoor environments to evaluate metabolic and tissue damage indicators, along with a non-specific immune enzyme in fish mucus. Additionally, the microbiota of both water bodies and fish mucus were determined using 16S rRNA high-throughput sequencing. The correlation between the indicators and the microbiota was investigated, along with the measurement of multiple environmental factors. The results revealed significantly higher levels of two metabolic indicators, total protein (TP) and cortisol (COR) in indoor fish mucus compared to outdoor fish mucus (p < 0.05). The activities of acid phosphatase (ACP), alkaline phosphatase (ALP), creatine kinase (CK), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were significantly higher in indoor fish, serving as indicators of tissue damage (p < 0.05). The activity of lysozyme (LZM) was significantly lower in indoor fish (p < 0.01). Biomarker analysis at the phylum and genus levels in outdoor samples revealed that microorganisms were primarily related to the catabolism of organic nutrients. In indoor environments, microorganisms displayed a broader spectrum of functions, including ecological niche establishment, host colonization, potential pathogenicity, and antagonism of pathogens. KEGG functional enrichment corroborated these findings. Dissolved oxygen (DO), electrical conductivity (EC), ammonia nitrogen (NH3–N), turbidity (TU), and chemical oxygen demand (COD) exerted effects on outdoor microbiota. Temperature (TEMP), nitrate (NO3−), total phosphorus (TP), and total nitrogen (TN) influenced indoor microbiota. Changes in mucus indicators, microbial structure, and function in both environments were highly correlated with these factors. Our study provides novel insights into the health impacts of different environments on Chinese sturgeon using a non-invasive method.

Interactive effect of rhizobacterium Bacillus sp. strain MRD-17 and macro-nutrients on the amelioration of drought stress in mustard (Brassica juncea L.)

ABSTRACT Drought is a major abiotic stress in mustard. In the present investigation, the interactive effects of rhizobacterium Bacillus sp. MRD-17 and nutrients nitrogen, phosphorus, and potassium (N, P, K), 100% and 50% of the recommended dose of fertiliser (RDF) on shoot-root growth and nutrient uptake by mustard under well-watered (−0.33 bar) and water deficit (−8 bar) conditions were determined. Drought stress for 30 days, reduced root growth, but rhizobacterial inoculation under drought and nutrient stress improved root viability (73%, and 39%, respectively) and architecture, nitrate reductase (20% and 12%, respectively) and glutamine synthetase activity (21% and 14%, respectively), shoot nitrogen, phosphorus, and potassium and seed K content. The protective effects of Bacillus sp. MRD-17 to mustard under drought stress was also accompanied by decreased acid phosphatase activity. However, rhizobacterial and macro-nutrient interactions had no impact on seed N and P content on drought and nutrient-stressed plants. Therefore, in terms of plant growth and nutrient uptake, the efficiency of Bacillus sp. MRD-17 was dependent on the soil nutrient status. Furthermore, rhizobacterial application might facilitate a higher uptake of water and nutrients by the plant from the soil and thus sustain crop productivity under water and nutrient stress scenarios.

Effect of repeated semen ejaculation on sperm quality and selected biochemical markers of canine semen

The aim of this study was to evaluate the quality parameters and selected biochemical markers of canine semen sampled at 24-h intervals over a period of 5 days, preceded by 6 months of sexual abstinence. Full ejaculates were obtained from 6 dogs. Ejaculate volume and total sperm counts in the ejaculate decreased gradually on successive sampling days. The percentage of total motile spermatozoa (TMOT), percentage of progressively motile spermatozoa (PMOT), sperm plasma membrane integrity (SPMI), and sperm mitochondrial membrane potential (MMP) increased on successive days of sampling. In addition, ATP content increased in spermatozoa. Total protein content (TPC) and the activity of aspartate aminotransferase (AAT), alkaline phosphatase (AP), and acid phosphatase (AcP) decreased in seminal plasma. Repeated ejaculation over a period of 5 days induced changes in the qualitative and quantitative parameters of canine semen. A decrease in the values of some biochemical markers of semen, secreted by the epididymis and the prostate gland, could point to disturbances in the secretory activity of these organs. Canine semen sampled after prolonged sexual abstinence is generally characterized by less desirable quality parameters, and this observation should be taken into consideration when semen is collected for artificial insemination or preservation. Semen quality can be significantly improved by repeating the sampling procedure after 24 hours. One the other hand, repeated sampling on successive days can significantly decrease total sperm counts in the ejaculate. As a result, a sufficient number of semen doses for artificial insemination may not be obtained from a single ejaculate.