Enzyme Activity Research Articles

Valorization of Strawberry Juice Production Wastewater: Possibilities for Polyphenols Recovery and Plant Biostimulant Production

Fruit juice production is one of the most important branches of the food and beverage industry, considering both the market size and demand. It is also one of the largest generators of industrial wastewater, considering the large consumption of fresh water during fruit processing. Hence, the appropriate treatment strategies are of the utmost importance to minimize the environmental footprint of food industry effluents. This study aimed to investigate the valorization routes for strawberry juice production wastewater (SJPW), both in terms of nutrient recovery and a circular approach to its utilization as a medium for plant biostimulant production. The results show a low antioxidant capacity and low content of polyphenols in SJPW; however, promising results were obtained for the in vitro seed germination and tomato growth promotion when investigating a biostimulant based on Bacillus sp. BioSol021, which was cultivated using SJPW in a lab-scale bioreactor, with root and shoot length improvements of approximately 30% and 25%, respectively, compared to the control samples. The plant growth promotion (PGP) traits indicated the ability of IAA production, in a concentration of 8.55 ± 0.05 mg/L, and the enzymatic activity was evaluated as through the enzymatic activity index (EAI), achieving the following: 2.26 ± 0.04 for cellulolytic activity, 2.49 ± 0.08 for hemicellulolytic activity, 2.91 ± 0.16 for pectinolytic activity, and 1.05 ± 0.00 for proteolytic activity. This study opens a new chapter of possibilities for the development of techno-economically viable circular bioprocess solutions aimed at obtaining value-added microbial products for sustainable agriculture based on the valorization of food industry effluents thus contributing to more sustainable food production at both the agricultural and industrial levels.

Effect of Plant Growth Regulators on Germination and Seedling Growth of Passiflora alata and Passiflora edulis

The yellow (Passiflora edulis) and sweet (Passiflora alata) passion fruit plants hold significant economic importance in tropical fruit cultivation, valued not only for the quality of their fruit but also for their medicinal properties. Conventional propagation through seeds faces challenges due to irregular and slow germination, affecting the time required for seedling formation and the viability and uniformity of plantations. The use of plant growth regulators has been explored as a strategy to overcome these barriers, improving both the rate and uniformity of seed germination. This study aimed to evaluate the influence of seed imbibition with plant growth regulators on the germination and subsequent growth of yellow and sweet passion fruit seedlings. Gibberellic acid (GA3) and GA4+7 combined with 6-benzyladenine (GA4+7+6BA) were applied in five different concentrations (0, 250, 500, 750, and 1000 mg L−1 a.i.). The experiments were conducted in both laboratory and greenhouse conditions, following a completely randomized design with a 2 × 5 factorial scheme. The varieties tested were ‘BRS Mel do Cerrado’ for sweet passion fruit and ‘IAC-275’ for yellow passion fruit. Quantitative parameters, such as germination percentage, germination speed index, fresh and dry biomass of roots and shoots, and enzymatic activity, were assessed. The results indicated that GA3, at higher concentrations, significantly enhanced both germination percentage and speed index in both Passiflora alata and Passiflora edulis when compared to the control. Additionally, seedlings treated with GA3 showed a marked increase in shoot and root biomass, particularly at concentrations of 500 and 750 mg L−1. Enzymatic assays revealed heightened catalase and peroxidase activities in treated seedlings, indicating improved stress tolerance. In contrast, the GA4+7+6BA treatment showed less pronounced effects on seedling growth. Overall, GA3 was more effective in enhancing germination and seedling growth in both species, suggesting its potential application in improving the propagation of passion fruit.

Understanding the fundamental mechanisms and conditions of the tumor-suppressive and oncogenic roles of sirtuins in cancer: A review

Silent information regulators (SIRTs) or sirtuins represent a group of class III nicotinamide adenine dinucleotide–dependent histone deacetylases. In mammals, seven types of sirtuins are distinguished, differing in their target structures, enzymatic activities, and subcellular localization. Histone deacetylation is a form of epigenetic regulation of gene expression that can cause activation or deactivation of selected genetic targets. Activation of sirtuins is part of the response to nutritional and environmental stimuli (starvation, DNA damage, and oxidative stress). Activated sirtuins subsequently stimulate specific transcriptional programs to make mitochondrial oxidative metabolism more efficient in the fight against oxidative stress or regulate proteins responsible for DNA repair after damage. As a result of their multifunctional involvement in cellular metabolism, dysregulation and aberrant expression of sirtuins have been observed in various cancers. Sirtuins play a dual role in carcinogenesis, acting as either oncogenes or tumor suppressors and affecting the proliferation, apoptosis, and survival of cancerous cells.

Safety assessment of three common food additives: the reproductive, oxidative and enzymatic perspective

This investigation was designed to evaluate the reproductive toxicity induced by potassium bromate (at doses of 50, 40, 30, 20, and 10 mg/kg), sodium benzoate (at doses of 5, 4, 3, 2, and 1 mg/kg), and caramel IV (at a dose of 200 mg/kg for 1, 2, 3, 4, and 5 weeks) in male albino mice through the assessments of sperm abnormality and sperm count. The concentrations of the three additives tested were chosen purposefully based on the acceptable daily intake of each of the additives by standard organizations. The level of Total Testosterone (TT), Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH), as well as the activities of catalase (CAT), superoxide dismutase (SOD), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), were also measured. The results obtained showed that all three tested food additives led to a statistically significant (p < 0.05) increase in abnormal sperm cells among exposed mice. The sperm abnormalities observed include folded sperm, amorphous heads, distal droplets, absent hooks, improper tail attachments, and looped tails. Furthermore, it was observed that only mice exposed to potassium bromate and caramel exhibited a statistically significant decrease in mean sperm count. Alterations in the levels and activities of TT, ALT, FSH, AST, LH, and ALP were also observed to be concentration-dependent in the exposed mice. The findings suggest that the reproductive toxicity and changes in enzyme activities in the treated mice are dependent on the concentration of potassium bromate and sodium benzoate, as well as the duration of exposure to caramel IV. These indicate that high consumption of foods or beverages containing potassium bromate, sodium benzoate, and caramel IV colourant may induce reproductive abnormalities in the consumers.

An Overview of the Biological Functions and Mechanisms of Action of Medicinal Plants and Seaweeds in the Shrimp Culture.

Diseases are major constraints to developing large-scale aquaculture practices in many countries. For decades, synthetic chemotherapeutic agents have been widely applied both as prophylactics and therapeutics to inhibit and control aquatic disease outbreaks. However, their use has become more restricted due to the negative impacts they have on the environment, the host and humans, as well as their limitations in preventing the emergence of antimicrobial-resistant bacteria. Therefore, there is a growing interest in the use of medicinal plants and seaweeds as potential alternatives to antibiotics and other synthetic chemotherapeutics. Medicinal plants and seaweeds can enhance the immune systems of animals, thereby providing protection against numerous diseases while minimizing the adverse effects associated with synthetic chemotherapeutics. Furthermore, the advantages of medicinal plants and seaweeds, such as their effectiveness, easy availability and ability to be applied on a large scale, make them appealing for use in the aquaculture industry. The main goal of this study was to review the existing knowledge of the effects of medicinal plants and seaweeds, as well as their extracts, on shrimp growth, immune response and disease resistance against bacterial and viral agents. Moreover, this paper discusses the application of seaweeds in shrimp culture. We also conducted a literature review to identify gaps in the research and provide recommendations for further advancement in this field of study. Further studies should focus on evaluating other physiological aspects, such as feed and mineral utilization, enzyme activities and histological examination.

Arbuscular Mycorrhizal Fungi Ameliorate Selenium Stress and Increase Antioxidant Potential of Zea mays in Seleniferous Soil.

The indigenous arbuscular mycorrhizal fungi (AMF) spores were isolated from rhizosphere soil associated with maize plants grown in natural selenium-impacted agricultural soils present in north-eastern region of Punjab, India (32°46' N, 74°46' N), with selenium concentration ranging from 2.1 to 6.1 mg kg-1 dry weight, and their role in plant growth promotion, mitigation of selenium stress and phytochemical and antioxidant potential of host maize plants in natural seleniferous soil were examined. Soils with selenium content between 2 and 200 mg kg-1 and producing plants with 45 mg selenium kg-1 dry weight are considered seleniferous soils. AMF inoculum consisting of indigenous AMF spores multiplied in pot cultures were inoculated to maize seeds at the time of sowing alongside control maize seeds in a total of 12 plots (6 replicates) made in seleniferous agricultural fields and sampled at maturity, i.e. 3 months. Asignificant difference was observed in plant growth parameters between control and AMF-inoculated maize plants. AMF-inoculated plants had 24.0 cm and 101.1 cm higher root and shoot length along with 27.2 g, 119.4 g and 28.1 g higher root, shoot and maize cob biomass in comparison to control plants. Se uptake studies through measurement of the emission spectrum of piazselenol complex by fluorescence spectrometry revealed that AMF inoculation led to 6.3 µg g-1 more selenium accumulation in mycorrhizal maize roots in comparison to control roots but lesser translocation to shoots and seeds, i.e. 17.17 µg g-1 and 19.58 µg g-1 lesser. AMF increased total phenolic content by 13 µg GAE mg-1 and total flavonoid content by 13.4 µg QE mg-1 in inoculated maize plants when compared to control plants. Antioxidant studies revealed that AMF inoculation also led to significant rise in enzyme activities by a difference of 115 and 193 EU g-1 in catalase, 140 and 93 EU g-1 in superoxide dismutase, 15 and 37 EU g-1 in ascorbate peroxidase and 19.8 and 23.6% higher DPPH radical scavenging activities, respectively, in shoots and roots of plants with AMF inoculation. The findingsof this study imply that AMF inoculated to maize plants in seleniferous field boost their plant growth and phytochemical and antioxidant properties, as well as minimize Se bioaccumulation in shoots and seeds of plants inoculated with AMF in comparison to control plants.

Interactive effects of microplastics and cadmium on soil properties, microbial communities and bok choy growth

The simultaneous presence of microplastics (MPs) and cadmium (Cd) in soil environments has raised concerns regarding their potential interactive effects on soil-plant ecosystems. This study explores how polyethylene (PE) at concentrations of 0.5 % (w/w), 1 % (w/w), and 2 % (w/w), and Cd at concentrations of 3 mg kg−1 and 12 mg kg−1, either alone or combined, impact soil physicochemical properties, microbial community structures, and bok choy growth through a 40-day pot experiment. Our findings reveal that the addition of 2 % (w/w) PE significantly increased soil organic carbon (SOC). However, when 2 % PE coexisted with Cd, SOC levels decreased, potentially due to a reduction in enzyme activity (β-1,4-glucosidase). PE increased the proportion of 1–2 mm soil aggregates, while the coexistence of 2 % PE and Cd significantly increased the content of soil aggregates larger than 2 mm. The coexistence of PE and Cd increased available potassium (AK) in the soil by approximately 13 % to 41 %. Regarding bok choy growth, the aboveground biomass under 2 % PE was approximately 210 % of that under 0.5 % PE, possibly because of the enhancement in soil nutrients. The presence of Cd, however, reduced the chlorophyll content of bok choy by approximately 18 % to 34 %. Notably, the coexistence of high PE concentration (2 % w/w) and low Cd concentration (3 mg kg−1) resulted in the highest aboveground biomass among all coexistence treatments. Furthermore, the addition of PE and Cd significantly altered the structure of soil bacterial and fungal communities, with fungi showing a greater response. Bacteria were significantly associated with soil inorganic N content and plant growth. This study provides new insights into the interactions of microplastics and Cd within microbial-soil-plant systems.

Seasonal variation in expression patterns of anti-microbial peptides and activity of anti-oxidant defence enzymes in muga silkworm larvae, Antheraea assamensis Helfer

Seasonal variation in expression patterns of anti-microbial peptides and activity of anti-oxidant defence enzymes in muga silkworm larvae, Antheraea assamensis Helfer

Effects of four-week lasting aerobic treadmill training on hepatic injury biomarkers, oxidative stress parameters, metabolic enzymes activities and histological characteristics in liver tissue of hyperhomocysteinemic rats.

Disruptions in homocysteine (Hcy) metabolism may increase the liver's susceptibility to developing conditions such as alcoholic liver disease, viral hepatitis, hepatocellular carcinoma (HCC), and cirrhosis. The aim of this study was to examine effects of aerobic treadmill training on hepatic injury biomarkers in sera, oxidative stress parameters, the activity of metabolic enzymes, and histological characteristics in the liver tissue of rats with experimentally induced hyperhomocysteinemia. Male Wistar albino rats were divided into four groups (N = 10, per group): C-saline 0.2mL/day sc. 2×/day for 14days + saline 0.5mL ip.1×/day for 28days; H-homocysteine 0.45µmol/g b.w. 2×/day for 14days + saline 0.5mL ip.1×/day for 28days; CPA-saline 0.2mL/day sc. 2×/day for 14days + aerobic treadmill training for 28days; and HPA-homocysteine 0.45µmol/gb.w. 2×/day for 14days + aerobic treadmill training for 28days. The serum albumin concentration was decreased in both physically active (PA) groups compared to sedentary groups. Concentration of malondialdehyde in liver tissue homogenates was lower in both PA groups compared to the H group. The total lactate dehydrogenase and malate dehydrogenase activities were significantly elevated in the HPA group compared to the C and H groups. Activities of aminotransferases in sera samples, and activities of catalase and superoxide dismutase in liver tissue did not significantly differ between groups. No significant histological changes were found in liver tissue in groups. This study demonstrated that aerobic treadmill training can reduce lipid peroxidation in liver tissue under hyperhomocysteinemic conditions, providing a protective effect. However, hyperhomocysteinemia can alter energy metabolism during aerobic exercise, shifting it toward anaerobic pathways and leading to elevated lactate dehydrogenase activity in the liver. Given that conditions like hyperhomocysteinemia are associated with an increased risk of cardiovascular diseases and liver damage, understanding how exercise influences these dynamics could guide therapeutic approaches.

Enhancing physio-biochemical characteristics in okra genotypes through seed priming with biogenic zinc oxide nanoparticles synthesized from halophytic plant extracts

Poor seedling germination and growth can result in large financial losses for farmers, thus, there is an urgent need for sustainable agricultural techniques to enhance seed germination and early growth. As an outcome, sustainable agriculture-which emphasizes the smart and effective utilization of resources-has gained popularity worldwide. At numerous levels, the field of nanotechnology is capable of significant benefit in achieving sustainable agricultural practices. Zinc oxide nanoparticles (ZnO NPs) have been shown to have biostimulatory properties and serve as effective solutions for addressing environmental and biotic stressors. The purpose of this study, investigating Salvadora persica halophytic leaf extract -synthesized zinc oxide nanoparticles (S-ZnONPs) as nano-priming agents to ensure okra seeds germinated under stress-free conditions. From an application perspective, we examined the effect of seed priming with varying concentrations of S-ZnO NPs (0, 20 and 40 ppm) for 18 and 24 h of soaking. Results indicated that the germination rate of hybrid variety improved with 20 ppm at 18 h, increasing by 58.22%, while mean germination time reduced by 24.62%. An enhancement trend was observed in the shoot, root length, shoot and root fresh weight, shoot and root dry weight of hybrid variety at 20ppm with 18 h priming by 34.2, 84.3, 80.2, 47.4, 50.3, and 36.2%, respectively. However, chlorophyll pigments chl a, chl b, and carotenoids was significantly raised in desi variety by 42.4, 79.31, and 142.29% with 20 ppm at 18 h priming. Hydrogen per oxide decreased up to 87.8% with 40 ppm at 24 h in hybrid variety, while, in desi variety H2O2 was reduced 88.3% with 20 ppm at 24 h. Non enzymatic antioxidant activities such as ascorbic acid, was highly increased 130.6% in hybrid at 24 h priming with 20 ppm dose. Flavonoids raised in same variety by 166.1% with 20 ppm at 18 h. Proline content was increased by 144.5% with 40ppm at 18 h. Moreover, Antioxidant enzymes, superoxide dismutase, peroxidase and catalase were significantly increased in both varieties with both levels of S-ZnO NPs and priming time. This cost-effective and environmentally safe technique to produce nanoparticles of different halophytic plants can maximize resource utilization, supporting sustainable agriculture by minimizing adverse environmental effects without compromising efficiency.

Effect of natural astaxanthin on sperm quality and mitochondrial function of breeder rooster semen cryopreservation

Cryopreservation causes higher reactive oxygen species (ROS) concentrations, leading to oxidative stress and lipid peroxidation damage sperm, and using antioxidants can improve semen quality after freeze-thaw. Natural astaxanthin (ASTA) can be inserted into cell membranes and its antioxidant properties are stronger than other antioxidants. We aimed to investigate the effects of ASTA supplementation in the Beltsville Poultry Semen Extender (BPSE) on post-thaw rooster semen quality and to explore the potential mechanism of rooster semen quality change. The qualifying semen ejaculates collected from 30 adult male Jinghong No.1 laying hen breeder roosters (65wk old) were pooled, divided into four aliquots, and diluted with BPSE having different levels of ASTA (0, 0.5, 1, or 2μg/mL). Treated semen was cryopreserved and kept in liquid nitrogen. The entire experiment was replicated three times independently. Sperm viability, motility, curvilinear velocity, amplitude of lateral head displacement, straightness, plasma membrane integrity, and acrosome integrity were observed highest (P < 0.05) with 1μg/mL ASTA at freeze-thawing. Higher (P < 0.05) antioxidant enzyme (CAT-like, SOD) activities and free radical (·OH, O2.-) scavenging ability, less ROS and malondialdehyde (MDA) concentrations were recorded with the addition of appropriate concentrations of ASTA compared to control. In addition, the levels of mitochondrial membrane potential (MMP), adenosine triphosphate (ATP), and lactate dehydrogenase (LDH) in the 1μg/mL ASTA group improved compared to the control group, and decreased the amount of AIF protein level but increased the Bcl-2 protein level (P < 0:05). Collectively, these results demonstrate that adding ASTA in the BPSE promoted rooster freeze-thaw sperm quality, which may be related to reducing ROS levels, protecting the antioxidant defense system, preventing lipid peroxidation, improving mitochondrial structural and functional integrity, and inhibiting sperm apoptosis.

Manufacturing of the highly active thermophile PETases PHL7 and PHL7mut3 using Escherichia coli

BackgroundThe global plastic waste crisis requires combined recycling strategies. One approach, enzymatic degradation of PET waste into monomers, followed by re-polymerization, offers a circular economy solution. However, challenges remain in producing sufficient amounts of highly active PET-degrading enzymes without costly downstream processes.ResultsUsing the growth-decoupled enGenes eX-press V2 E. coli strain, pH, induction strength and feed rate were varied in a factorial-based optimization approach, to find the best-suited production conditions for the PHL7 enzyme. This led to a 40% increase in activity of the fermentation supernatant. Optimization of the expression construct resulted in a further 4-fold activity gain. Finally, the identified improvements were applied to the production of the more active and temperature stable enzyme variant, PHL7mut3. The unpurified fermentation supernatant of the PHL7mut3 fermentation was able to completely degrade our PET film sample after 16 h of incubation at 70 °C at an enzyme loading of only 0.32 mg enzyme per g of PET.ConclusionsIn this research, we present an optimized process for the extracellular production of thermophile and highly active PETases PHL7 and PHL7mut3, eliminating the need for costly purification steps. These advancements support large-scale enzymatic recycling, contributing to solving the global plastic waste crisis.

TET2 promotes tumor antigen presentation and T cell IFN-γ which is enhanced by vitamin C.

Immune evasion by tumors is promoted by low T cell infiltration, ineffective T cell activity directed against the tumor and reduced tumor antigen presentation. The TET2 DNA dioxygenase gene is frequently mutated in hematopoietic malignancies and loss of TET enzymatic activity is found in a variety of solid tumors. We showed previously that vitamin C (VC), a co-factor of TET2, enhances tumor-associated T cell recruitment and checkpoint inhibitor therapy responses in a TET2-dependent manner. Using single-cell RNA sequencing (scRNA-seq) analysis performed on B16-OVA melanoma tumors, we have shown here that an additional function for TET2 in tumors is to promote expression of certain antigen presentation machinery genes, which is potently enhanced by VC. Consistently, VC promoted antigen presentation in cell-based and tumor assays in a TET2-dependent manner. Quantifying intercellular signaling from the scRNA-seq dataset showed that T cell-derived IFNγ-induced signaling within the tumor and tumor microenvironment requires tumor-associated TET2 expression which is enhanced by VC treatment. Analysis of patient tumor samples indicated that TET activity directly correlates with antigen-presentation gene expression and with patient outcomes. Our results demonstrate the importance of tumor-associated TET2 activity as a critical mediator of tumor immunity which is augmented by high-dose VC therapy.

Microplastics impair extracellular enzymatic activities and organic matter cycling in oligotrophic sandy marine sediments

Microplastics (MPs) are ubiquitous and constantly accumulating in the marine environment, especially sediments. Yet, it is not well clarified if and how their carbon backbone could interact with surrounding sediments, eventually impairing key benthic processes. We assessed the effects of a ‘pulse’ contamination event of MPs on sedimentary organic matter (OM) quantity, quality and extracellular enzymatic activities (EEAs), which are well established descriptors of benthic ecosystem functioning. Marine sediments were exposed for 30 days to environmentally relevant concentrations (~0.2 % in weight) of naturally weathered particles (size range 70–210 μm) of polyurethane, polyethylene, and a mixture of the most common polymers that are documented to accumulate in marine sediments. Despite the low concentration, contaminated sediments showed significantly different composition of OM, showing a decrease in lipid content and increase in protein. Moreover, we document a significant decrease (over 25 %) in quantity of biopolymeric C already after 15 days of exposure, compared to controls. Contaminated sediments showed lower C degradation rates (up to −40 %) and altered EEAs, with alkaline phosphatase being ~50 % enhanced and aminopeptidase being reduced over 35 % compared to control treatments. Overall, the effects generated by the mixture of polymers were smaller than those exerted by the same amount of a single polymer. Our results provide insights on how that MPs can significantly alter marine sedimentary biogeochemistry through altered benthic processes, that could cumulatively impair whole benthic trophic webs by enhancing the accumulation and possible longer-term storage of recalcitrant organic C in the seabed.

O-GlcNAcylation of ATP-citrate lyase couples glucose supply to lipogenesis for rapid tumor cell proliferation

Elevated lipid synthesis is one of the best-characterized metabolic alterations in cancer and crucial for membrane expansion. As a key rate-limiting enzyme in de novo fatty acid synthesis, ATP-citrate lyase (ACLY) is frequently up-regulated in tumors and regulated by posttranslational modifications (PTMs). Despite emerging evidence showing O-GlcNAcylation on ACLY, its biological function still remains unknown. Here, we observed a significant upregulation of ACLY O-GlcNAcylation in various types of human tumor cells and tissues and identified S979 as a major O-GlcNAcylation site. Importantly, S979 O-GlcNAcylation is required for substrate CoA binding and crucial for ACLY enzymatic activity. Moreover, it is sensitive to glucose fluctuation and decisive for fatty acid synthesis as well as tumor cell proliferation. In response to EGF stimulation, both S979 O-GlcNAcylation and previously characterized S455 phosphorylation played indispensable role in the regulation of ACLY activity and cell proliferation; however, they functioned independently from each other. In vivo, streptozocin treatment- and EGFR overexpression-induced growth of xenograft tumors was mitigated once S979 was mutated. Collectively, this work helps comprehend how cells interrogate the nutrient enrichment for proliferation and suggests that although mammalian cell proliferation is controlled by mitogen signaling, the ancient nutrition-sensing mechanism is conserved and still efficacious in the cells of multicellular organisms.

Alda-1 attenuation of binge alcohol-caused atrial arrhythmias through a novel mechanism of suppressed c-Jun N-terminal Kinase-2 activity

Holiday Heart Syndrome (HHS) is caused by excessive binge alcohol consumption, and atrial fibrillation (AF) is the most common arrhythmia among HHS patients. AF is associated with substantial morbidity and mortality, making its prevention and treatment of high clinical interest. This study defines the anti-AF action of Alda-1 (an established cardioprotective agent) and the underlying mechanisms of the action in our well-characterized HHS and cellular models. We found that Alda-1 effectively eliminated binge alcohol-evoked Ca2+ triggered activities (Ca2+ waves, prolonged Ca2+ transient diastolic decay) and arrhythmia inducibility in intact mouse atria. We then demonstrated that alcohol impaired human RyR2 channels (isolated from organ donors' hearts). The functional role of alcohol-caused RyR2 channel dysfunction in Ca2+ triggered arrhythmic activities was evidenced in a unique transgenic mouse model with a loss-of-function mutation (RyR2E4872Q+/−). Alda-1 is known to activate aldehyde dehydrogenase 2 (ALDH2), a key enzyme in alcohol detoxification. However, we found an increased level of ALDH2 and a preserved normal balance of pro- vs anti-apoptotic signaling in binge alcohol exposed hearts and H9c2 differentiated myocytes, which suggests that the link of alcohol-ALDH2-apoptosis is unlikely to be a key factor leading to binge alcohol-evoked arrhythmogenicity. We have previously reported that binge alcohol-activated stress response kinase JNK2 causatively drives Ca2+-triggered atrial arrhythmogenicity. Here, we found that JNK2-specific inhibition in either isolated human RyR2 channels or intact mouse atria abolished alcohol-evoked RyR2 channel dysfunction and Ca2+ triggered arrhythmic activities, suggesting a strong alcohol-JNK2-RyR2 interaction in atrial arrhythmogenicity. Furthermore, we revealed, for the first time, that Alda-1 suppresses JNK2 (but not JNK1) enzyme activity independently of ALDH2, which in turn alleviates binge alcohol-evoked Ca2+ triggered atrial arrhythmogenesis. Our findings provide novel mechanistic insights into the anti-arrhythmic action of Alda-1 and suggest that Alda-1 represents a potential preventative agent for AF management for HHS patients.

Calcium oxide nanoparticles ameliorate cadmium toxicity in alfalfa seedlings by depriving its bioaccumulation, enhancing photosystem II functionality and antioxidant gene expression

Cadmium (Cd) is a highly toxic and carcinogenic pollutant that poses significant risks to living organisms and the environment, as it is absorbed by the plant roots and accumulates in different parts of crop during its production. A promising sustainable strategy to counteract these threats to use calcium oxide nanoparticles (CaO-NPs) as soil supplements in fodder crops. This approach has shown notable morpho-physiological and biochemical improvements under metal toxicity conditions. However, the specific mechanisms driving Cd tolerance, particularly at physio-biochemical level and antioxidant related genes expression in fodder crops including alfalfa remain unexplored. CaO-NPs supplementation can trigger various signaling pathways that lead to enhance the photosynthetic pigments formation, stomatal conductance, CO2 assimilation rate and quantum yield of photosystem II. In this study, we evaluated various doses of CaO-NPs (0, 25, 50, and 100 mg kg−1) for their efficacy in reducing Cd bioavailability and toxicity in alfalfa plants. Our results demonstrated that Ca2+ and Cd2+, which share the same ionic radius, compete for ion transport through channels. The small size and high availability of CaO-NPs facilitate their rapid translocation within plant tissues, reducing metal uptake by 61 % in shoots and 30 % in roots. Notably, application of CaO-NPs at 100 mg kg−1 significantly increased shoot length (44 %) and root lengths (35 %) as compared to Cd-treated control plants. The highest dose of CaO-NPs also improved photosynthetic efficiency and gas exchange attributes including (gs, Tr, Pn and Ci) by 66 %, 27 %, 33 % and Ci 21 %, respectively, compared with the Cd treated control. Moreover, CaO-NPs (at 100 mg kg−1) alleviated metal-induced oxidative stress by boosting antioxidant enzyme activity like SOD (25 %) POD (42 %), CAT (72 %) and APX (87 %) and diminishing reactive oxygen species (ROS) production when compared with sole Cd treatment. Scanning and transmission electron microscopy revealed that CaO-NPs positively impacted stomatal conductance and mitigated Cd toxicity in leaf ultrastructure. Additionally, the highest dose of CaO-NPs markedly upregulated the expression of antioxidant-related genes, MsCu/Zn SOD, MtPOD, MtCAT, and MtAPX in roots and shoots by 0.67 and 1.03 fold-change (FC), 0.61 and 0.53 FC, 0.54 and 0.88 FC, and 0.46 and 0.66 FC, respectively. In conclusion, CaO-NPs demonstrate significant potential for environmentally friendly mitigation of Cd stress in alfalfa by reducing its uptake, thereby supporting sustainable agriculture.

Seed Priming with Biosynthesized Zinc Oxide Nanoparticles for Enhancing Seed Germination and Vigour through Promoting Antioxidant and Hydrolytic Enzyme Activity in Green gram (Vigna radiata)

Seed Priming with Biosynthesized Zinc Oxide Nanoparticles for Enhancing Seed Germination and Vigour through Promoting Antioxidant and Hydrolytic Enzyme Activity in Green gram (Vigna radiata)

Engineering Bacterial Chitinases for Industrial Application: From Protein Engineering to Bacterial Strains Mutation! A Comprehensive Review of Physical, Molecular, and Computational Approaches.

Bacterial chitinases are integral in breaking down chitin, the natural polymer in crustacean and insect exoskeletons. Their increasing utilization across various sectors such as agriculture, waste management, biotechnology, food processing, and pharmaceutical industries highlights their significance as biocatalysts. The current review investigates various scientific strategies to maximize the efficiency and production of bacterial chitinases for industrial use. Our goal is to optimize the heterologous production process using physical, molecular, and computational tools. Physical methods focus on isolating, purifying, and characterizing chitinases from various sources to ensure optimal conditions for maximum enzyme activity. Molecular techniques involve gene cloning, site-directed mutation, and CRISPR-Cas9 gene editing as an approach for creating chitinases with improved catalytic activity, substrate specificity, and stability. Computational approaches use molecular modeling, docking, and simulation techniques to accurately predict enzyme-substrate interactions and enhance chitinase variants' design. Integrating multidisciplinary strategies enables the development of highly efficient chitinases tailored for specific industrial applications. This review summarizes current knowledge and advances in chitinase engineering to serve as an indispensable guideline for researchers and industrialists seeking to optimize chitinase production for various uses.

Ecological adaptations of amphibians to environmental changes along an altitudinal gradient (Case Study: Bufo gargarizans) from phenotypic and genetic perspectives

BackgroundOrganisms have evolved a range of phenotypic and genetic adaptations to live in different environments along an altitudinal gradient. Herein, we studied the widely distributed Chinese toad, Bufo gargarizans, as a model and used an integrated phenotype-genotype approach to assess adaptations to different altitudinal environments.ResultsComparison of populations from four altitudes (50 m, 1200 m, 2300 m, and 3400 m) showed more effective defenses among high-altitude toads. These included thickened epidermis, more epidermal capillaries and granular glands, greater gland size in skin, and higher antioxidant enzyme activities in plasma. High-altitude toads also showed increased erythrocytes and hematocrit and elevated hemoglobin concentration, potentially improving oxygen delivery. Elevated altitude led to a metabolic shift from aerobic to anaerobic metabolism, and high-altitude populations favored carbohydrates over fatty acids to fuel for energy metabolism. Differentially expressed genes were associated with adaptive phenotypic changes. For instance, expression of genes associated with fatty acid metabolism showed greater suppression at high altitude (3400 m), consistent with decreased flux of β-hydroxybutyric acid and lower free fatty acids levels. Moreover, down-regulation of genes involved in carbon metabolism processes at high altitude (3400 m) were coincident with reduced TCA cycle flux. These results suggest that high-altitude toads adopt a metabolic suppression strategy for survival under harsh environmental conditions. Moreover, the hypoxia-inducible factor signaling cascade was activated at high altitude.ConclusionsCollectively, these results advance our comprehension of adaptation to high-altitude environments by revealing physiological and genetic mechanisms at work in Chinese toads living along altitudinal gradients.