Gluconate Research Articles

Recovery of Cobalt, Nickel, and Lithium from Spent Lithium-Ion Batteries with Gluconic Acid Leaching Process: Kinetics Study

The demand for lithium-ion batteries (LIBs) is driven by environmental concerns and market growth, particularly in the transportation sector. The EU’s push for net-zero emissions and the European Green Deal accentuates the role of battery technologies in sustainable energy supply. Organic acids, like gluconic acid, are explored for the eco-friendly leaching of valuable metals from spent batteries. This study investigates leaching kinetics using gluconic acid (hydrolyzed glucono-1.5-lacton), analyzing factors such as temperature, acid concentration, particle size, and reaction time. Results reveal the temperature’s influence on leaching efficiency for cobalt, nickel, and lithium. The mechanism for Co follows a surface chemical reaction model with an activation energy of 28.2 kJ·mol−1. Nickel, on the contrary, shows a diffusion-controlled regime and an activation energy of 70.1 kJ·mol−1. The reaction of leaching Ni and Co using gluconic acid was determined to be first-order. The process within this environmentally friendly alternative leaching agent shows great potential for sustainable metal recovery.

Rhizobium symbiosis improves amino acid and secondary metabolite biosynthesis of tungsten-stressed soybean (Glycine max).

The industrially important transition metal tungsten (W) shares certain chemical properties with the essential plant micronutrient molybdenum and inhibits the activity of molybdoenzymes such as nitrate reductase, impacting plant growth. Furthermore, tungsten appears to interfere with metabolic processes on a much wider scale and to trigger common heavy metal stress response mechanisms. We have previously found evidence that the tungsten stress response of soybeans (Glycine max) grown with symbiotically associated N2-fixing rhizobia (Bradyrhizobium japonicum) differs from that observed in nitrogen-fertilized soy plants. This study aimed to investigate how association with symbiotic rhizobia affects the primary and secondary metabolite profiles of tungsten-stressed soybean and whether changes in metabolite composition enhance the plant's resilience to tungsten. This comprehensive metabolomic and proteomic study presents further evidence that the tungsten-stress response of soybean plants is shaped by associated rhizobia. Symbiotically grown plants (N fix) were able to significantly increase the synthesis of an array of protective compounds such as phenols, polyamines, gluconic acid, and amino acids such as proline. This resulted in a higher antioxidant capacity, reduced root-to-shoot translocation of tungsten, and, potentially, also enhanced resilience of N fix plants compared to non-symbiotic counterparts (N fed). Taken together, our study revealed a symbiosis-specific metabolic readjustment in tungsten-stressed soybean plants and contributed to a deeper understanding of the mechanisms involved in the rhizobium-induced systemic resistance in response to heavy metals.

Potential of diallyl sulfide from bulbs of Allium parvum to inhibit the growth and biofilm formation in Malassezia furfur MTCC 1374

The bulbs of Allium parvum are used as a flavoring agent in diet and are conventionally assumed to treat skin infections. The current study evaluates the phytochemicals from organic extract of A. parvum and their antifungal activity against biofilm-forming dermatophytic fungi Malassezia furfur MTCC 1374, yeast found in the normal flora of the skin, causes superficial infections, systemic infections like pulmonary infections, fungemia, etc., and implant-associated infection by biofilm formation. Biofilm formation enables the fungi to escape from antifungal agents and renders resistance to antifungal agents. The phytochemical assay for the organic extract of the onion bulb documented that A. parvum contains phenol (58 + 0.1 mg GAE/g), flavonoids (112 + 0.12 mg QE/g), saponins (1.45 + 0.1 mg AE/g), and tannins (4.1 + 0.03 g TA/g). The FT-IR and GC-MS analysis revealed the presence of specific compounds, alkaloids such as glycosides and quinolones, plant flavonoids such as 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-ester, phenolics, saponins such as butanoic acid and gluconic acid, and organic sulfur compounds such as diallyl sulfide, thiopyran tetrahydro-ester, allyl methyl trisulfide, and allyl methyl di sulfide. These compounds inhibited the growth of M. furfur at a minimum inhibitory concentration (MIC) value of 6.25 mg/ml and its biofilm at a minimum biofilm inhibitory concentration (MBIC) value of 12.5 mg/ml. Further studies required to explore the possible mechanism in controlling the biofilm, so, as to recommend as fungal control agent in medical sector.

Zeolitic imidazole framework-derived rich-Zn-Co3O4/N-doped porous carbon with multiple enzyme-like activities for synergistic cancer therapy

Reactive oxygen species (ROS)-centered chemodynamic therapy (CDT) holds significant potential for tumor-specific treatment. However, insufficient endogenous H2O2 and extra glutathione within tumor microenvironment (TME) severely deteriorate the CDT's effectiveness. Herein, rich-Zn-Co3O4/N-doped porous carbon (Zn-Co3O4/NC) was fabricated by two-step pyrolysis, and applied to build high-efficiency nano-platform for synergistic cancer therapy upon combination with glucose oxidase (GOx), labeled Zn-Co3O4/NC-GOx for clarity. Specifically, the multiple enzyme-like activities of the Zn-Co3O4/NC were scrutinously investigated, including peroxidase-like activity to convert H2O2 to O2∙−, catalase-like activity to decompose H2O2 into O2, and oxidase-like activity to transform O2 to O2∙−, which achieved the CDT through the catalytic cascade reaction. Simultaneously, GOx reacted with intracellular glucose to produce gluconic acid and H2O2, realizing starvation therapy. In the acidic TME, the Zn-Co3O4/NC-GOx rapidly caused intracellular Zn2+ pool overload and disrupted cellular homeostasis for ion-intervention therapy. Additionally, the Zn-Co3O4/NC exhibited glutathione peroxidase-like activity, which consumed glutathione in tumor cells and reduced the ROS consumption for ferroptosis. The tumor treatments offer some constructive insights into the nanozyme-mediated catalytic medicine, coupled by avoiding the TME limitations.

Plasma Metabolic Profiling and Multiclass Diagnostic Model Development for Stable Angina Pectoris and Acute Myocardial Infarction.

Coronary heart disease remains a major global health challenge, with a clear need for enhanced early risk assessment. This study aimed to elucidate metabolic signatures across various stages of coronary heart disease and develop an effective multiclass diagnostic model. Using metabolomic approaches, gas chromatography-mass and liquid chromatography-tandem mass spectrometry were used to analyze plasma samples from healthy controls, patients with stable angina pectoris, and those with acute myocardial infarction. Pathway enrichment analysis was conducted on metabolites exhibiting significant differences. The key metabolites were identified using Random Forest and Recursive Feature Elimination strategies to construct a multiclass diagnostic model. The performance of the model was validated through 10-fold cross-validation and evaluated using confusion matrices, receiver operating characteristic curves, and calibration curves. Metabolomics was used to identify 1491 metabolites, with 216, 567, and 295 distinctly present among the healthy controls, patients with stable angina pectoris, and those with acute myocardial infarction, respectively. This implicated pathways such as the glucagon signaling pathway, d-amino acid metabolism, pyruvate metabolism, and amoebiasis across various stages of coronary heart disease. After selection, testosterone isobutyrate, N-acetyl-tryptophan, d-fructose, l-glutamic acid, erythritol, and gluconic acid were identified as core metabolites in the multiclass diagnostic model. Evaluating the diagnostic model demonstrated its high discriminative ability and accuracy. This study revealed metabolic pathway perturbations at different stages of coronary heart disease, and a precise multiclass diagnostic model was established based on these findings. This study provides new insights and tools for the early diagnosis and treatment of coronary heart disease.

Metabolomics distinguishes different grades of Scrophularia ningpoensis hemsl: Towards a biomarker discovery and quality evaluation

In managing unique complexities associated with Chinese medicinal quality assessment, metabolomics serves as an innovative tool. This study proposes an analytical approach to assess differing qualities of Scrophularia ningpoensis （S. ningpoensis）Hemsl by identifying potential biomarker metabolites and their activity with the corresponding secondary metabolites. The methodology includes four steps; first, a GC-MS based metabolomics exploration of the Scrophularia ningpoensis Hemsl. Second, a multivariate statistical analysis (PCA, PLS-DA, OPLS-DA) for quality assessment and biomarker identification. Third, the application of ROC analysis and pathway analysis based on identified biomarkers. Finally, validation of the associated active ingredients by HPLC. The analysis showed distinct metabolite profiles across varying grades of S. ningpoensis Hemsl, establishing a grading dependency relationship. Select biomarkers (gluconic Acid, d-xylulose, sucrose, etc.) demonstrated robust grading performances. Further, the Pentose Phosphate Pathway, deemed as most influential in grading, was tied to the synthesis of key constituents (iridoids, phenylpropanoids). HPLC validation tests affirm a decreasing trend in harpagoside and cinnamic acid levels between first and third-grade samples. In conclusion, this GC-MS based metabolomics combined HPLC method offers a sound approach to assess and distinguish quality variations in S. ningpoensis Hemsl samples.

Evaluation of the operational conditions of the glucose oxidase and catalase multienzymatic system through enzyme co-immobilization on amino hierarchical porous silica

Hexaric acids have attracted attention lately because they are platform chemicals for synthesizing pharmaceuticals. In particular, gluconic acid is one of the most studied because it is readily available in nature. In this work, operational conditions like temperature and pH were evaluated for the enzymatic production of gluconic acid. For this purpose, glucose oxidase (GOx) and catalase (CAT) were individually immobilized and co-immobilized using amino-silica as support. The catalytic performance of the enzymes both as separate biocatalysts (GOx or CAT) and as an enzymatic complex (GOx-CAT) was assessed in terms of enzymatic activity and stability at temperatures 45 °C and 50 °C and pH 6 to 8. The results show that CAT is a key enzyme for gluconic acid production as it prevents GOx from being inhibited by H2O2. However, CAT was found to be less stable than GOx. Therefore, different GOx to CAT enzymatic ratios were studied, and a ratio of 1–3 was determined to be the best. The highest glucose conversion conditions were 45 °C and pH 7.0 for 24 h. Regarding the biocatalyst reuse, GOx-CAT retained more than 70% of its activity after 6 reaction cycles. These results contribute to further knowledge and application of oxidases for hexaric acid production and shed greater light on the role of the glucose oxidase/catalase pair in better catalytic performance. Both enzymes were immobilized in one pot, which is relevant for their potential use in industry; an enzyme system was obtained in a single step.

Abstract P195: Metabolites Mediate the Association of the MIND Diet With Hypertension and Chronic Kidney Disease

The Mediterranean-DASH diet intervention for neurodegenerative delay (MIND), is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. The Mediterranean and DASH diets are associated with decreased risk of cardiometabolic disease; however, less is known regarding the association of the MIND diet with cardiometabolic disease. The objectives of this analysis were (1) to determine if the MIND diet is associated with prevalent hypertension and chronic kidney disease (CKD) and (2) to identify metabolites associated with the MIND diet and if these metabolites mediate the association of the MIND diet with hypertension and CKD. In the REasons for Geographic and Racial Disparities in Stroke (REGARDS) cohort, we examined the association of the MIND diet with prevalent hypertension and CKD. Fully adjusted models included age, sex, race, calories, alcohol, smoking, education, exercise, income, region, BMI, lipidemia, history of coronary artery disease, and diabetes. In the REGARDS stroke case-cohort sub-study, 357 metabolites were measured in baseline plasma. Weighted linear regression models were used to test the association between MIND diet score and metabolites adjusting for age, sex, race, calories, alcohol, and smoking. Weighted logistic regression models were used to test the association between MIND-metabolites and hypertension and CKD adjusting for age, race, sex, BMI, alcohol, and smoking. Mediation analysis was conducted to examine metabolites mediating the association between MIND diet and hypertension and CKD. Sensitivity analyses were conducted in the cohort random controls. A higher MIND diet score was associated with lower odds of hypertension (odds ratio [OR] 0.97, 95% CI 0.96-0.99; p=0.01) and CKD (OR 0.88, 95% CI 0.86-0.91; p<0.0001). Fifty-one metabolites were associated with the MIND diet (MIND-metabolites). Three MIND-metabolites were associated with greater odds of hypertension; however, these associations were attenuated in the fully adjusted models. Twelve MIND-metabolites were associated with greater odds of CKD. Mediation analyses indicated dimethylguanidino valeric acid (DMGV), guanosine, and C7 carnitine to mediate the association between MIND diet and hypertension. DMGV, guanosine, gluconic acid, S-Adenosyl-L-homocysteine, C7 carnitine, and 5 triacylglycerols mediated the association between MIND diet and CKD. Higher adherence to the MIND diet is associated with a lower likelihood of hypertension and CKD. MIND diet-related metabolites were found to be associated with hypertension and CKD and may provide insight to metabolic pathways linking diet and disease.

Glucose-Responsive hydrogel optimizing Fenton reaction to eradicate multidrug-resistant bacteria for infected diabetic wound healing

The treatment of infected diabetic wounds faces severe challenges due to vascular deficiencies induced by a hyperglycemia microenvironment and the extensive proliferation of drug-resistant bacteria. In this work, we developed a glucose-responsive hydrogel dressing system (CGH) with dual properties that effectively treat methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds in rats and enhance wound healing. The hydrogel is synthesized using copper nanoclusters (CuNCs) cross-linked with oxidized hyaluronic acid (HA-ALD) in situ and decorated with glucose oxidase (GOx). GOx enzymatically degrades excess glucose at the wound site, generating gluconic acid and H2O2, and optimizes the limiting factors of the Fenton reaction. Decreasing pH weakens the interaction between CuNCs and HA-ALD, resulting in the release of CuNCs that catalyze the production of reactive oxygen species (ROS) by degradation of H2O2 through the Fenton reaction. This process can eradicate drug-resistant bacteria. In addition, CuNCs endowed hydrogels with excellent conductivity, thus enabling the promotion of blood vessel formation by electrical stimulation (ES), thereby facilitating tissue repair around the wound area. In conclusion, the developed novel multifunctional wound healing system can conform to irregular wound shapes, reduce glucose levels within the wound, establish a sustained sterile environment, and promote blood vessel formation through electrical stimulation, thus emerging as a highly promising and comprehensive option for effectively treating complex diabetic wounds.

Exploring the untapped practices in bacterial-fungal mixed-based cultures for acidic treatment of metal-enriched printed circuit board waste

This study explores the extraction of metals from spent mobile phone printed circuit boards (SMPhPCBs) to address environmental and resource depletion concerns. The challenges in metal recovery from SMPhPCBs arise due to their complex composition and high metal content. While previous research has primarily focused on using bio-cyanide, bio-sulfate, and bio-ferric compounds from acidophilic bacteria, the potential of bio-oxalic acid for SMPhPCBs treatment and the alteration of their complex structure has not yet been explored. Additionally, this study suggests evaluating the untapped potential of Aspergillus niger in oxalic acid production through mixed cultures with bacteria, marking a pioneering approach. A unique culture of Bacillus megaterium and A. niger was created, inducing bio-stress by bacterial metabolites, including gluconic acid (2683 mg/l) and live/dead bacterial cells in a medium with glucose deficiency. Results demonstrated reducing sugar consumption and oxalic acid over-production in mixed cultures compared to pure cultures, ranging from 1350 to 4951 mg/l at an initial glucose concentration (IGC) of 10 g/l and 4276 to 7460 mg/l at IGC 20 g/l. This over-production is attributed to proposed fungal signaling mechanisms to bacteria. Metal extraction using organic acids and siderophores at 10 g/l pulp density, 24 h, and 60 °C yielded Mn (100 %), Pt (100 %), Pd (70.7 %), Fe (50.8 %), Co (48.3 %), Al (21.8 %), among others. The final valuable residue containing copper, gold, and silver holds potential for future recycling. The study concludes with XRD and FTIR analyses to assess the bioleaching effect on the bio-leached powder.

Cation-mediated acid-base pairs for mild oxidative cleavage of lignocellulosic β-1,4-glycosidic bonds

Solar-driven lignocellulosic biomass photoreforming holds significant promise for the production of value-added chemicals and fuels. The cleavage of the β-1,4-glycosidic bond is crucial for the effective conversion of lignocellulosic biomass. Polymeric carbon nitride (PCN) with acid-base pairs (M-C sites) is developed through heteroatomic carbon incorporation and cation insertion. It can be used for the gentle oxidation of cellobiose to monosaccharides, bypassing the formation of organic acids such as gluconic acid and glucaric acid. A series of different alkaline/alkaline-earth cation for regulation of acid-base pairs exhibited a negative correlation between β-1,4-glycosidic bond cleavage and cation radii. In particular, the introduction of short-radius cations (such as Li) into PCN enabled the formation of acid-base (M-C) pairs characterized by strong acidity. It also enhanced electron delocalization around M-C sites, potentially promoting the generation of reactive radicals in the reaction. Electron paramagnetic resonance analysis confirmed the presence of •OH radicals. The mild oxidative species, are the primary reactive radicals responsible for β-1,4-glycosidic bond cleavage in cellobiose. This study provides insightful evidence for the rational regulation of acid-base sites in facilitating β-1,4-glycosidic bond cleavage. It sheds light on the oxidative cleavage mechanisms integral to lignocellulosic biomass photoreforming, offering insights for advancing sustainable biomass conversion technologies.

Metabolomics profiling for diagnosis of acute renal failure after cardiopulmonary bypass.

Acute renal failure (ARF) is one of the most serious complications of cardiopulmonary bypass (CPB) surgery. Serum creatinine level is a key compound examined to understand whether renal function is normal. However, its level may vary based on age, gender, race, muscle mass, nutrition, and drugs taken by an individual. In addition, it may not be detected without a 50% reduction in renal function and may lead to delays in treatment. New markers are needed for early diagnosis of ARF. They were determined for early diagnosis of ARF after CPB. Metabolic differences in plasma samples of individuals who developed and did not develop ARF after cardiopulmonary bypass were determined. This study was the first to perform an untargeted metabolomics analysis for early diagnosis of ARF after CPB surgery. Plasma samples were taken from 105 patients (9 ARF patients) at five time points to identify the time at which a more accurate ARF diagnosis can be made. A total of 687 samples, including quality control samples, were analyzed. Two hundred twenty-six metabolites were identified using retention index libraries. Based on the statistical evaluations, tryptophan, threonine, and methionine were found in lower concentrations in patients with ARF compared to the control group at all time points. Whereas gluconic acid, hypoxanthine, and lactic acid showed a decreasing trend over time, longitudinal analysis showed that cysteine, hippuric acid, and uric acid levels increased over time in the ARF group. These metabolites are candidate biomarkers for early diagnosis of ARF as well as biomarkers for tracking the recovery of ARF patients.

Improved Immune Response for Colorectal Cancer Therapy Triggered by Multifunctional Nanocomposites with Self-Amplifying Antitumor Ferroptosis.

Ferroptosis, as a type of regulated cell death, can trigger the release of damage-associated molecular patterns from cancer cells and lead to the enhancement of immune recognition. Fenton reaction-mediated chemodynamic therapy could initiate ferroptosis by generating lipid peroxides, but its efficiency would be greatly restricted by the insufficient H2O2 and antioxidant system within the tumor. Herein, this work reports the successful preparation of H2O2 self-supplied and glutathione (GSH)-depletion therapeutic nanocomposites (Cu2O@Au) through in situ growth of Au nanoparticles on the surface of cuprous oxide (Cu2O) nanospheres. Upon delivery into cancer cells, the released Cu2O could consume endogenous H2S within colorectal cancer cells to form Cu31S16 nanoparticles, while the released Au NPs could catalyze glucose to generate H2O2 and gluconic acid. The self-supplying endogenous H2O2 and lower acidity could amplify the Cu ion-induced Fenton-like reaction. Meanwhile, the consumption of glucose would reduce GSH generation by disrupting the pentose phosphate pathway. Additionally, the Cu2+/Cu+ catalytic cycle promotes the depletion of GSH, leading to lipid peroxide accumulation and ferroptosis. It was found that the onset of ferroptosis triggered by Cu2O@Au could initiate immunologic cell death, promote dendritic cell maturation and T-cell infiltration, and finally enhance the antitumor efficacy of the PD-L1 antibody. In summary, this collaborative action produces a remarkable antitumor effect, which provides a promising treatment strategy for colorectal cancer.

Galactonate bio-preparation from cheese whey waste and its application as a novel bio-retarder

Cheese whey, as the major byproduct in cheese making, contains significant amounts of lactose, which can be efficiently hydrolyzed to glucose and galactose. Therefore, it is a potential resource for producing gluconic acid (GA) and galactonic acid (GalA) by Gluconobacter oxydans (G. oxydans). The glucose can be preferentially and rapidly bio-oxidized into GA by G. oxydans, however, the preserved GA and galactose would be simultaneously metabolized, meaning that the GA and GalA cannot be co-produced. Therefore, based on the kinetics of biphasic trend for glucose and galactose metabolism, a novel approach involving the integration of bio-oxidation and electrodialysis techniques was developed to sequentially convert glucose and galactose into GA and GalA, correspondingly. As a result, 79.2 g/L GA and 75.1 g/L GalA could be co-produced step by step from the enzymatic hydrolysate that contain approximately 80 g/L glucose and 80 g/L galactose. Furthermore, in this study, the evaluation experiment of GalA as cement additive suggested that it could be used as a novel bio-retarder with an excellent retarding effect, providing a new idea for cheese whey waste utilization.

Manganese(III) Phthalocyanine Complex Nanoparticle-Loaded Glucose Oxidase to Enhance Tumor Inhibition through Energy Metabolism and Macrophage Polarization.

Elevated levels of reactive oxygen species (ROS) have demonstrated efficacy in eliminating tumor cells by modifying the tumor microenvironment and inducing the polarization of tumor-associated macrophages (TAMs). Nevertheless, the transient nature and limited diffusion distance inherent in ROS present significant challenges in cancer treatment. In response to these limitations, we have developed a nanoparticle (MnClPc-HSA@GOx) that not only inhibits tumor energy metabolism but also facilitates the transition of TAMs from the M2 type (anti-inflammatory type) to the M1 type (proinflammatory type). MnClPc-HSA@GOx comprises a manganese phthalocyanine complex (MnClPc) enveloped in human serum albumin (HSA), with glucose oxidase (GOx) loaded onto MnClPc@HSA nanoparticles. GOx was employed to catalyze the decomposition of glucose to produce H2O2 and gluconic acid. Additionally, in the presence of MnClPc, it catalyzes the conversion of H2O2 into •O2- and 1O2. Results indicate that the nanoparticle effectively impedes the glucose supply to tumor cells and suppresses their energy metabolism. Simultaneously, the ROS-mediated polarization of TAMs induces a shift from M2 to M1 macrophages, resulting in a potent inhibitory effect on tumors. This dual-action strategy holds promising clinical inhibition applications in the treatment of cancer.

Ultrasound-assisted sustainable recycling of valuable metals from spent Li-ion batteries via optimisation using response surface methodology

In this study, the use of response surface methodology was proposed to optimise a novel green leaching process for recovering Li and Co from spent lithium-ion batteries (LIBs), assisted by ultrasonic irradiation and gluconic acid. This work investigated various parameters such as temperature, time, gluconic acid concentration, and ultrasound power (US power). To enhance the interpretability and optimisation of experimental data on metal leaching, the central composed design (CCD) was utilised to establish a predictive model. A statistical analysis using the analysis of variance (ANOVA) test was conducted to validate the quadratic model and determine the significant operating parameters, indicated by p-values (< 0.05). The model exhibited Adj R2 values of 0.98 for Li leaching and 0.96 for Co leaching, respectively. To confirm the results, additional characterisations of the solid residues were performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transformation infrared spectrometer (FT-IR/NIR). The leach liquor was subjected to precipitation and crystallisation methods to recover Li and Co. The purity of Li2CO3 and Co3O4 was confirmed to be ≥ 99% and ≥ 98.8%, respectively, through ICP-OES analysis. Finally, the recovered Li2CO3 and Co3O4 were utilised in a 1:1 molar ratio for regenerating new LiCoO2 cathode materials using a solid-state method. The resulting cathode materials exhibited high purity (≥ 99.43%) as confirmed by ICP-OES analysis. The obtained results demonstrate that ultrasound irradiation significantly enhanced the dissolution of metal oxides within the mixture. Furthermore, gluconic acid exhibited a dual function, acting as both an oxidising and reducing agent. Consequently, this process presents a promising and sustainable alternative for recycling valuable metals from spent LIBs.

Zinc solubilization and organic acid production by the entomopathogenic fungus, Metarhizium pingshaense sheds light on its key ecological role in the environment

We report for the first-time higher zinc (Zn) solubilization efficiency and plant growth promotion by an entomopathogenic fungus (EPF), Metarhizium pingshaense IISR-EPF-14, which was earlier isolated from Conogethes punctiferalis, a pest of global importance. The Zn solubilizing efficiency of the fungus varied depending on the type of insoluble source of Zn used, which was observed to be 1.6 times higher in Zn3(PO4)2–amended media compared to ZnO media. In liquid media, there was a 6.2-fold increase in available Zn in ZnO–amended media, whereas a 20.2-fold increase in available Zn was recorded in Zn3(PO4)2 medium. We ascribe the production of various organic acids such as gluconic, keto-gluconic, oxalic, tartaric, malonic, succinic and formic acids, which in general, interact with insoluble Zn sources and make them soluble by forming metal cations and displacing anions as the major mechanism for Zn solubilization by M. pingshaense. However, the type and amount of organic acid produced in the media varied depending on the source of Zn used and the incubation period. Application of the fungus alone and in combination with insoluble Zn sources enhanced various plant growth parameters in rice and cardamom plants. Moreover, the uptake of Zn in rice plants was enhanced up to ~2.5-fold by fungal application. The fungus also exhibited various other plant growth-promoting traits, such as production of Indole-3-acetic acid, ammonia, siderophores, solubilization of mineral phosphate, and production of hydrolytic enzymes such as α-amylase, protease, and pectinase. Hence, apart from its use as a biological control agent, M. pingshaense has the potential to be used as a bio-fortifier to enhance the solubilization and uptake of Zn from nutrient poor soils under field conditions. Our findings shed light on the broader ecological role played by this fungus and widen its scope for utilization in sustainable agriculture.

Effects of different colors of plastic-film mulching on soil temperature, yield, and metabolites in Platostoma palustre

Platostoma palustre is an annual herb and an important medicinal and edible plant in southern China. Plastic-film mulching is an effective agronomic practice in the cultivation system of P. palustre, of which black-film mulching is the most common. However, fewer researches have been focused on the use of other colors of plastic films in P. palustre cultivation. In this study, different colors (white, black, red, and green) of plastic film were adopted, and the effects of different colors of plastic film mulching on the soil temperature, yield, and metabolites of P. palustre were investigated. The results showed that the fresh weight of a single plant of the green film treatment was significantly higher than that of the white film treatment (n = top 28). Based on the results of three temperature measurements, the soil temperature was almost the highest in the red film treatment and lowest in the white film treatment. The metabolomic analysis revealed that a total of 103 differential metabolites were identified. Among these, the gluconic acid, deoxyribose, and N-Acetylmannosamine in the red film treatment presented the highest abundance compared with the other treatments, meanwhile, the abundances of the five monosaccharides in the red film treatment were significantly higher than those of the green film treatment. Moreover, the sucrose, trehalose, and D-(+)-trehalose in the green film treatment exhibited the highest abundance, and the abundances of eight different amino acids in the red film treatment were almost the lowest while those in the black film treatment were almost the highest. Further analysis of the membership function values indicated that the black and red film treatments might be more suitable for the cultivation and quality production of P. palustre in comparison with the other two treatments. This study will provide a theoretical basis for improving the efficient cultivation technology of P. palustre and forming a theoretical system of P. palustre film mulching cultivation.

Enhanced bacterial cellulose production in Komagataeibacter sucrofermentans: impact of different PQQ-dependent dehydrogenase knockouts and ethanol supplementation

BackgroundBacterial cellulose (BC) is a biocompatible material with unique mechanical properties, thus holding a significant industrial potential. Despite many acetic acid bacteria (AAB) being BC overproducers, cost-effective production remains a challenge. The role of pyrroloquinoline quinone (PQQ)-dependent membrane dehydrogenases (mDH) is crucial in the metabolism of AAB since it links substrate incomplete oxidation in the periplasm to energy generation. Specifically, glucose oxidation to gluconic acid substantially lowers environmental pH and hinders BC production. Conversely, ethanol supplementation is known to enhance BC yields in Komagataeibacter spp. by promoting efficient glucose utilization.ResultsK. sucrofermentans ATCC 700178 was engineered, knocking out the four PQQ-mDHs, to assess their impact on BC production. The strain KS003, lacking PQQ-dependent glucose dehydrogenase (PQQ-GDH), did not produce gluconic acid and exhibited a 5.77-fold increase in BC production with glucose as the sole carbon source, and a 2.26-fold increase under optimal ethanol supplementation conditions. In contrast, the strain KS004, deficient in the PQQ-dependent alcohol dehydrogenase (PQQ-ADH), showed no significant change in BC yield in the single carbon source experiment but showed a restrained benefit from ethanol supplementation.ConclusionsThe results underscore the critical influence of PQQ-GDH and PQQ-ADH and clarify the effect of ethanol supplementation on BC production in K. sucrofermentans ATCC 700178. This study provides a foundation for further metabolic pathway optimization, emphasizing the importance of diauxic ethanol metabolism for high BC production.

Yoga meditation: A path to holistic health and healing

The word meditation is derived from a Latin word ‘madri’ which means “to heal”. Meditation can certainly be considered as a great healing process - spiritual, mental, and emotional - with proven benefits to physical well-being. In the current communication, an attempt has been made to explain some of these benefits and provide science based evidence to explain them. Meditation develops our ability to maintain inner peace at all times in our actions and thereby achieve the best physical and mental health. With psychosomatic ailments, meditation provides the vital element that modern therapies lack. During Yogic breathing, some of the oxygen generates •OH free radicals according to the Haber Weiss process, which immediately react with glucose molecules to oxidize them. Some of these oxidation products are very useful, such as gluconic acid, which removes some undesirable metals from the body. Additionally, glucuronic acid is another product, and it is part of the natural detoxification process found in the body. It removes harmful toxins and is used in the treatment of prostate cancer. Another product, D-glucarate, has been shown to decrease lung, skin, liver, breast, and colon cancers by 60%. The product Calcium-D-glucarate lowers cholesterol by 12%, LDL by 28%, and triglycerides by 43%. Lastly, D-glucono 1,4 lactone, with further reactions with •OH, is converted to D-glucaro 1,4 lactone and is a powerful liver detoxifier. Meditation boosts intelligence, IQ score, and increases the gray matter of the brain. The relaxation response decreases breathing rate and oxygen consumption by 20%. It lowers heart rate and brings blood pressure to normal levels. During meditation alpha waves of the brain are generated. This brings relaxation and serenity of mind, helping people to better cope with stress. According to the British Heart Foundation, 15 minutes of meditation a day can reduce the risk of death, heart attack and stroke by 48%. According to Dr. Dean Ornish, meditation can help in reversing heart disease. Meditation has the power to change our negativity of mind and reshape our thoughts into a more positive direction to improve our mental well-being.