Effects of phosphorus-solubilizing bacteria and biochar application on phosphorus availability and tomato growth under phosphorus stress.

BACKGROUND: Phosphorus-solubilizing bacteria (PSB) are vital in converting insoluble phosphorus into a soluble form that plants can readily absorb and utilize in soil. While previous studies have mainly focused on the extracellular secretion of microorganisms, few have explored the intricate intracellular metabolic processes involved in PSB-mediated phosphorus solubilization. RESULTS: Here, we uncovered that Ca3(PO4)2 could serve as a source of insoluble phosphorus for the PSB, Pseudomonas sp. NK2. High-performance liquid chromatography (HPLC) results indicated higher levels of organic acids released from insoluble phosphorus compared to a soluble phosphorus source (KH2PO4), with acetic acid released exclusively under insoluble phosphorus condition. Moreover, non-target metabolomics was employed to delve into the intracellular metabolic profile. It unveiled that insoluble phosphorus significantly enhanced the tricarboxylic acid cycle, glycolysis, glyoxylic acid metabolism, and other pathways, leading to the production of acetic acid, gluconic acid, oxalic acid, and citric acid for insoluble phosphorus solubilization. In our quest to identify suitable biochar carriers, we assessed seven types of biochar through the conjoint analysis of NBRIP medium culture and application to soil for 30 days, with cotton straw-immobilized NK2 emerging as the most potent phosphorus content provider. Lastly, NK2 after cotton straw immobilization demonstrated the ability to enhance biomass, plant height, and root development of Solanum lycopersicum L. cv. Micro Tom. CONCLUSIONS: Pseudomonas sp. NK2 with cotton straw biochar could enhance phosphorus availability and tomato growth. These findings bear significant implications for the practical application of phosphorus-solubilizing bacteria in agricultural production and the promotion of environmentally sustainable farming practices.

An Organic Acid-Alkali Coregulated Ionic Liquid Electrolyte Enabling Wide-Temperature-Range Proton Battery.

The broad applications of rechargeable batteries urge people to develop alternative energy storage devices with sustainable resources, high capacity, long cycling life, and wide-temperature operability. Aqueous proton batteries are considered as a state-of-the-art energy storage system due to their intrinsic safety and low cost. However, aqueous electrolytes have a low boiling point and narrow electrochemical stability window, limiting their applications in wide-temperature and high-energy batteries. Herein, a hybrid organic ionic liquid electrolyte with organic alkali 1-methyl-1,2,4-triazole (MTA) protonated by organic acid bis(trifluoromethysulfonyl)imide (HTFSI) as proton carriers and tetramethylene sulfone (TMS) as the solvent, noted as HTFSI-MTA-TMS, exhibited the stable electrochemical windows exceeding 5 V at -20 °C and 3.5 V at 80 °C. Benefiting from this electrolyte, the assembled MnO2-S//MoO3 button proton full battery can display an operation voltage up to 1.8 V, energy density of 44.8 Wh kg-1, and good cycling stability at room temperature when bis(trifluoromethanesulfonyl)imide manganese (II) salt (Mn(TFSI)2) is introduced into the electrolyte, and run well in a wide-temperature range (-20 °C-60 °C). The work reveals the potential of organic acid-alkali coregulated electrolytes to meet the need of energy storage in a wide-temperature range and will advance the development of high-energy proton batteries.

Screening of 1.17 million newborns for inborn errors of metabolism using tandem mass spectrometry in Shanghai, China: A 19-year report.

BACKGROUND: Inborn errors of metabolism (IEMs) frequently result in progressive and irreversible clinical consequences if not be diagnosed or treated timely. The tandem mass spectrometry (MS/MS)-based newborn screening (NBS) facilitates early diagnosis and treatment of IEMs. The aim of this study was to determine the characteristics of IEMs and the successful deployment and application of MS/MS screening over a 19-year time period in Shanghai, China, to inform national NBS policy. METHODS: The amino acids and acylcarnitines in dried blood spots from 1,176,073 newborns were assessed for IEMs by MS/MS. The diagnosis of IEMs was made through a comprehensive consideration of clinical features, biochemical performance and genetic testing results. The levels of MS/MS testing parameters were compared between various IEM subtypes and genotypes. RESULTS: A total of 392 newborns were diagnosed with IEMs from January 2003 to June 2022. There were 196 newborns with amino acid disorders (50.00%, 1: 5910), 115 newborns with organic acid disorders (29.59%, 1: 10,139), and 81 newborns with fatty acid oxidation disorders (20.41%; 1:14,701). Phenylalanine hydroxylase deficiency, methylmalonic acidemia and primary carnitine deficiency were the three most common disorders. Some hotspot variations in eight IEM genes (PAH, SLC22A5, MMACHC, MMUT, MAT1A, MCCC2, ACADM, ACAD8), 35 novel variants and some genotype-biochemical phenotype associations were identified. CONCLUSIONS: A total of 28 types of IEMs were identified, with an overall incidence of 1: 3000 in Shanghai, China. Our study offered clinical guidance for the implementation of MS/MS-based NBS and genetic counseling for IEMs in this city.

Epinecidin-1 and lactic acid synergistically inhibit Aeromonas hydrophila through membrane disruption.

Epinecidin-1 (Epi-1) is an antimicrobial peptide originated from fish with various pharmacological activities but carries the risk of acquiring resistance with long-term use. In the present study, we use L-lactic acid to enhance the antibacterial activity of synthesized Epi-1 against the aquaculture and food pathogen Aeromonas hydrophila. The results showed that 5.5 mmol/L lactic acid increased the inhibitory and bactericidal activity of 25 µmol/L Epi-1 against two strains of A. hydrophila. The laser confocal images proved that lactic acid pre-treatment improved the attachment efficiency of Epi-1 in A.hydrophila cells. In addition, lactic acid enhanced the damaging effect of Epi-1 on the cell membrane of A. hydrophila, evidenced by releasing more nucleic acids, proteins, and transmembrane pH ingredients decrease and electromotive force dissipation. SEM images showed that compared with the single Epi-1 treatment, the co-treatment of Epi-1 and lactic acid caused more outer membrane vesicles (OMVs) and more severe cell deformation. These findings proved that lactic acid could enhance the efficiency of Epi-1 against A. hydrophila and shed light on new aspects to avoid resistance of pathogens against Epi-1.

Immunostimulatory effects of dietary verjuice (Vitis vinifera) on immune response and transcription of immune-related genes in juvenile rainbow trout (Oncorhynchusmykiss).

The development of green aquaculture practices has led to the supplementation of fish diets with natural immunostimulants such as organic acids. This study aimed to assess the dietary effects of verjuice (VJ; unfermented unripe grapes; Vitis vinifera) on hematological parameters, skin mucosal immunity, transcriptional immune responses, and antibacterial serum activity against Aeromonas hydrophila in rainbow trout. The fish (51.0 ± 2.4 g) were randomly distributed into 15 tanks and fed ad-libitum thrice daily with diets containing different levels of VJ including 0 (control; VJ-0), 3 (VJ-3), 6 (VJ-6), 9 (VJ-9), and 12 (VJ-12) mL/kg VJ for 56 d. Results showed that immuno-hematological parameters (total white blood cells, neutrophils, and monocytes) were improved in VJ-added groups (P < 0.05). In addition, dietary VJ (9 mL/kg) modulated serum immunological parameters. Skin mucus immunology exhibited a notable increase in alkaline phosphatase, lysozyme activity, alkaline protease, total protein, total immunoglobulin, and esterase levels in VJ-9 group compared with those in the control group (P < 0.05). The mRNA expression of interleukin-1ß, interleukin-6, interleukin-8, and immunoglobulin M were significantly higher in VJ-9 group than in the control (P < 0.05). Furthermore, the results of the antibacterial evaluation showed that A. hydrophila growth was significantly inhibited in the serum samples from VJ-3 to VJ-9 groups after the 56th day and in all VJ-treated groups after the 70th (P < 0.05). In conclusion, dietary VJ is a novel immunostimulant and the optimal dietary supplementation level of 6.65-7.46 mL/kg can effectively improve immune responses in rainbow trout.

Peroxydisulfate-Driven Reductive Dechlorination as Affected by Soil Constituents: Free Radical Formation and Conversion.

We report a previously unrecognized but efficient reductive degradation pathway in peroxydisulfate (PDS)-driven soil remediation. With supplements of naturally occurring low-molecular-weight organic acids (LMWOAs) in anaerobic biochar-activated PDS systems, degradation rates of 12 γ-hexachlorocyclohexanes (HCH)-spiked soils boosted from 40% without LMWOAs to a maximum of 99% with 1 mM malic acid. Structural analysis revealed that an increase in α-hydroxyl groups and a diminution in pKa1 values of LMWOAs facilitated the formation of reductive carboxyl anion radicals (COO•-) via electrophilic attack by SO4•-/•OH. Furthermore, degradation kinetics were strongly correlated with soil organic matter (SOM) contents than iron minerals. Combining a newly developed in situ fluorescence detector of reductive radicals with quenching experiments, we showed that for soils with high, medium, and low SOM contents, dominant reactive species switched from singlet oxygen/semiquinone radicals to SO4•-/•OH and then to COO•- (contribution increased from 30.8 to 66.7%), yielding superior HCH degradation. Validation experiments using SOM model compounds highlighted critical roles of redox-active moieties, such as phenolic - OH and quinones, in radical formation and conversion. Our study provides insights into environmental behaviors related to radical activation of persulfate in a broader soil horizon and inspiration for more advanced reduction technologies.

A comprehensive review of recent advances in the applications and biosynthesis of oxalic acid from bio-derived substrates.

Organic acids are important compounds with numerous applications in different industries. This work presents a comprehensive review of the biological synthesis of oxalic acid, an important organic acid with many industrial applications. Due to its important applications in pharmaceuticals, textiles, metal recovery, and chemical and metallurgical industries, the global demand for oxalic acid has increased. As a result, there is an increasing need to develop more environmentally friendly and economically attractive alternatives to chemical synthesis methods, which has led to an increased focus on microbial fermentation processes. This review discusses the specific strategies for microbial production of oxalic acid, focusing on the benefits of using bio-derived substrates to improve the economics of the process and promote a circular economy in comparison with chemical synthesis. This review provides a comprehensive analysis of the various fermentation methods, fermenting microorganisms, and the biochemistry of oxalic acid production. It also highlights key sustainability challenges and considerations related to oxalic acid biosynthesis, providing important direction for further research. By providing and critically analyzing the most recent information in the literature, this review serves as a comprehensive resource for understanding the biosynthesis of oxalic acid, addressing critical research gaps, and future advances in the field.

Dietary citric acid decreased the theront number of Cryptocaryon irritans (Ciliata) in seawater-adapted tilapia (Oreochromis niloticus).

Cryptocaryoniasis remains a major parasitic disease and economic challenge for marine aquaculture. Cryptocaryoniasis in marine fish is caused by Cryptocaryon irritans (Ciliata). A theront is a motile, free-swimming stage in the life cycle of C. irritans, which is typically the infective stage that actively seeks out a host to initiate infection. Population density and growth rate of theronts were investigated in Nile tilapia, Oreochromis niloticus fed with citric acid-supplemented feed. The experiment involved feeding three diets with graded levels of citric acid (0, control diet, 0.5, 1 and 1.5 g kg-1 diet), to seawater-adapted Nile tilapia (O. niloticus) juveniles for 21 days. The results showed that citric acid in the fish feed had an impact on the theront number of C. irritans in a manner of dose-dependent. In the experimental cohort administered a diet supplemented with 1.5 g kg-1 citric acid, the population density of theronts was observed to be significantly reduced, measured at 29 ± 3.34, as opposed to 473.34 ± 16.48 in the control group at the culmination of the experiment. The observed population growth rate of theronts was significantly higher in the control group than in the group administered the citric acid feed (p < .005). The growth rate (r d-1 ) was 0.12 in control, 0.05 in 0.5 g kg-1 , 0.031 in 1 g kg-1 , and - 0.031 in 1.5 g kg-1 citric acid-supplemented groups. Fish growth and feed conversion ratio were not affected by the citric acid in the feed. In conclusion, the findings of this investigation provide a valuable addition to our understanding of the potential protective effects of citric acid supplementation for fish against the C. irritans parasite. This is evidenced by the observed reduction in theronts present in the water.

Mycorrhizal fungus Serendipita indica-associated acid phosphatase rescues the phosphate nutrition with reduced arsenic uptake in the host plant under arsenic stress.

Symbiotic interactions play a vital role in maintaining the phosphate (Pi) nutrient status of host plants and providing resilience during biotic and abiotic stresses. Serendipita indica, a mycorrhiza-like fungus, supports plant growth by transporting Pi to the plant. Despite the competitive behaviour of arsenate (AsV) with Pi, the association with S. indica promotes plant growth under arsenic (As) stress by reducing As bioavailability through adsorption, accumulation, and precipitation within the fungus. However, the capacity of S. indica to enhance Pi accumulation and utilization under As stress remains unexplored. Axenic studies revealed that As supply significantly reduces intracellular ACPase activity in S. indica, while extracellular ACPase remains unaffected. Further investigations using Native PAGE and gene expression studies confirmed that intracellular ACPase (isoform2) is sensitive to As, whereas extracellular ACPase (isoform1) is As-insensitive. Biochemical analysis showed that ACPase (isoform1) has a Km of 0.5977 µM and Vmax of 0.1945 Unit/min. In hydroponically cultured tomato seedlings, simultaneous inoculation of S. indica with As on the 14thday after seed germination led to hyper-colonization, increased root/shoot length, biomass, and induction of ACPase expression and secretion under As stress. Arsenic-treated S. indica colonized groups (13.33 µM As+Si and 26.67 µM As+Si) exhibited 8.28-19.14 and 1.71-3.45-fold activation of ACPase in both rhizospheric media and root samples, respectively, thereby enhancing Pi availability in the surrounding medium under As stress. Moreover, S. indica (13.33 µM As+Si and 26.67 µM As+Si) significantly improved Pi accumulation in roots by 7.26 and 9.46 times and in shoots by 4.36 and 8.85 times compared to the control. Additionally, S. indica induced the expression of SiPT under As stress, further improving Pi mobilization. Notably, fungal colonization also restricted As mobilization from the hydroponic medium to the shoot, with a higher amount of As (191.01 ppm As in the 26.67 µM As+Si group) accumulating in the plant's roots. The study demonstrates the performance of S. indica under As stress in enhancing Pi mobilization while limiting As uptake in the host plant. These findings provide the first evidence of the As-Pi interaction in the AM-like fungus S. indica, indicating reduced As uptake and regulation of PHO genes (ACPase and SiPT genes) to increase Pi acquisition. These data also lay the foundation for the rational use of S. indica in agricultural practices.

Response of growth and Pb accumulation characteristics of plants with intercropping Arabis alpina-Zea mays to exogenous oxalic acid.

In order to study the effects of oxalic acids on plant growth and Pb accumulation in different parts of the plants of intercropping Arabis alpina and Zea mays, pot experiment was conducted to investigate the changes of oxalic acid contents of the plants and Pb accumulation through exogenous oxalic acid addition (0, 5, 25 and 50 mmol kg-1). The results showed the root biomass of intercropped A. alpina and total biomass of Z. mays increased by 3.22 folds and 2.97 folds with 5 mmol kg-1 oxalic acid treatment. The oxalic acid contents of shoots and root secretions decreased by 86.5% and 44.3%, respectively. The BCF (bio-accumulation factor) and TF (translocation factor) of intercropping A. alpina reduced under 25 - 50 mmol kg-1 oxalic acid treatments. There were relationships between exogenous oxalic acid treatment concentrations and oxalic acid contents of A. alpina shoots, Z. mays root secretions. The Pb contents of shoots of A. alpina and Z. mays were related to exogenous oxalic acid additions and oxalic acid contents of shoots. In general, 5 mmol kg-1 oxalic acid treatment, that can improve plant growth of intercropped A. alpina and Z. mays, which Pb translocation and accumulation of A. alpina were promoted, whereas Pb accumulation of A. alpina was inhibited with 25 - 50 mmol kg-1 concentrations addition. This study will provide a basis for promoting the application of phytoremediation techniques and efficient crop production in heavy metal contaminated areas.

Hyperaccumulators intercropped with crops will remediate heavy metal soils or mitigate the damage caused by heavy metals to plants through oxalic acid secretion by the root system. However, the effect of oxalic acid changes on plant growth and Pb accumulation is lacking. Our study investigated the changes in oxalic acid content at different concentrations and sites affected the ability of intercropped plants to grow and accumulate Pb. This work shown that under intercropping conditions, exogenous oxalic acid promotes intercropped plant growth as well as soil pH reduction, Pb content in shoots both Arabis alpina and Zea mays is influenced by exogenous oxalic acid content, while lower Z. mays roots Pb content is determined by a combination of exogenous addition and aboveground oxalic acid content. Low concentrations of oxalic acid promoted Pb enrichment in roots of A. alpina, while reducing the uptake of Pb content in Z. mays. This article gives us a better understanding for the response of intercropping plants to the use of organic acids under heavy metal stress and how to modify their environment so as to favor growth.

A Versatile Aldehyde: Ferredoxin Oxidoreductase from the Organic Acid Reducing Thermoanaerobacter sp. Strain X514.

Aldehyde:ferredoxin oxidoreductases (AORs) have been isolated and biochemically-characterized from a handful of anaerobic or facultative aerobic archaea and bacteria. They catalyze the ferredoxin (Fd)-dependent oxidation of aldehydes to acids. Recently, the involvement of AOR in the reduction of organic acids to alcohols with electrons derived from sugar or synthesis gas was demonstrated, with alcohol dehydrogenases (ADHs) carrying out the reduction of the aldehyde to the alcohol (AOR-ADH pathway). Here, we describe the biochemical characterization of an AOR of the thermophilic fermentative bacterium Thermoanaerobacter sp. strain X514 (AORX514). The putative aor gene (Teth514_1380) including a 6x-His-tag was introduced into the genome of the genetically-accessible, related species Thermoanaerobacter kivui. The protein was purified to apparent homogeneity, and indeed revealed AOR activity, as measured by acetaldehyde-dependent ferredoxin reduction. AORX514 was active over a wide temperature (10 to 95 °C) and pH (5.5 to 11.5) range, utilized a wide variety of aldehydes (short and branched-chained, aliphatic, aromatic) and resembles archaeal sensu stricto AORs, as the protein is active in a homodimeric form. The successful, recombinant production of AORX514 in a related, well-characterized and likewise strict anaerobe paves the road towards structure-function analyses of this enzyme and possibly similar oxygen-sensitive or W/Mo-dependent proteins in the future.

Insights into metal tolerance and resistance mechanisms in Trichoderma asperellum unveiled by de novo transcriptome analysis during bioleaching.

This study investigates the genetic responses of the fungus Trichoderma asperellum (T. asperellum) during bioleaching of ore and tailing samples, comparing one-step, two-step, and spent media bioleaching processes. HPLC analysis quantified oxalic acid, citric acid, and propionic acids, with oxalic acid identified as the primary organic acid involved in metal bioleaching. Metal analysis revealed differences in recovery between ore and tailing samples and among bioleaching processes. The two-step bioleaching process yielded the highest zinc (>54%) and nickel (>60%) recovery in tailings and ore, respectively. Nickel's efficient recovery in ore bioleaching was attributed to the presence of manganese, while its precipitation as nickel oxalate in tailings hindered recovery. Additional metals such as Co, Mn, Mg, Cu, and As were also successfully recovered. Transcriptomic analyses showed significant upregulation of genes associated with biological processes and cellular components, particularly those related to cell membrane structure and function, indicating T. asperellum's adaptation to environmental stresses during metal bioleaching. These findings enhance our understanding of the diverse mechanisms influencing metal recovery rates in bioleaching processes.

Fingerprinting of physical manufacturing properties of different acids for effervescent systems.

The study aimed to fingerprint the physical manufacturing properties of five commonly used acid sources in effervescent systems for designing the formulation and process of such systems. The hygroscopicity, texture properties, rheological torque, compressibility, tabletability, etc., were investigated to inspect 'powder direct compression (DC)' and 'wet granulation and compression' properties of citric (CA), tartaric (TA), malic (MA), fumaric (FA), and adipic acid (AA). The DC ability was evaluated by the SeDeM expert system. The results indicated that all acid powders failed to meet flowability requirements for DC, and plastic deformation dominated during compression. Furthermore, CA exhibited strong hygroscopicity and punch sticking, while MA demonstrated the best tabletability. TA had a large wet granulation space and was relatively the most suitable for DC. AA was extremely hygroscopic, and its flowability improved significantly as particle size increased. Finally, FA displayed the lowest hygroscopicity and ejection force as well as great compressibility and wet granulation space, and did not exhibit punch sticking, while the granule fragments dissolved slowly during disintegration. Generally speaking, the formulation or granulation affected the tabletability, indicating that pairing with other acids or suitable fillers could potentially improve its disadvantages. These multidimensional assessments effectively reduce the pre-exploration and enhance the efficiency of the development of effervescent systems.

Study on the changes and transformation characteristics of intermediate liquid products in hydrogen sulfide production from lignite degraded by sulfate-reducing bacteria.

The changes and transformation laws of intermediate liquid-phase products during the anaerobic degradation of lignite by sulfate-reducing bacteria in the formation of hydrogen sulfide play an important role in supplementing and improving the existing theories on the genesis of hydrogen sulfide gas in coal mines. In this paper, H2S gas and key intermediate liquid-phase products produced during the anaerobic degradation of lignite by sulfate-reducing bacteria were detected and analyzed by gas chromatography and gas chromatography-mass spectrometry. The results showed that the process of hydrogen sulfide production from lignite degradation by sulfate-reducing bacteria can be roughly divided into four stages: slow production phase, rapid growth phase, steady production phase, and slight decline phase. In this reaction system, the SO42- concentration showed a decreasing trend, the pH value showed an increasing trend, and the ORP value decreased and then slightly increased with time. Ten volatile component types were detected during the experiment: straight-chain alkanes, branched-chain alkanes, alcohols, aldehydes, ketones, olefins, amines, lipids, acids and phenols. The key components in the intermediate liquid phase products were straight chain alkanes, straight chain alkanes, acids, alcohols, phenols and amines. PAHs, alkanes, and phenols are closely related to H2S production, while amides stimulate nitrogen production. The process is divided into three stages: hydrolysis stage, H2S gas production stage, and decay stage. Liquid-phase intermediates play an important role in the formation process of coal mine BSR hydrogen sulfide and the mechanism of coal mine H2S genesis.

Chemical Constituents and Antioxidant Potential of Red Guava (Psidium cattleianum Sabine) from Southern Brazil in Different Edible Ripening Stages.

Ripening and growing location are important factors that can impact fruit quality characteristics. In this study, the influence of these factors on physicochemical characteristics, carbohydrates, aliphatic organic acids, phenolic compounds, and antioxidant capacity of red guava (Psidium cattleianum Sabine) was evaluated. Fruit ripening increased fructose and glucose (up to 22.83 and 16.42 g 100 g- 1 dry matter (DM), respectively), and decreased citric acid, the major organic acid (up to 135.35 mg g- 1 DM). Ripening and growing location also influenced the concentration of phenolic compounds and antioxidant capacity of red guava, in which a dependency between both factors was observed in most cases. Apigenin, galangin, isoquercitrin, among other phenolic compounds were quantified for the first time in red guava, in which isoquercitrin was the major (up to 13409.81 mg kg- 1 DM). The antioxidant potential of red guava was also confirmed by ferric reducing antioxidant power assay (up to 82.63 µmol Fe+ 2 g- 1 DM), Folin-Ciocalteu reducing capacity assay (up to 17.79 mg gallic acid equivalent g- 1 DM), and DPPH free radical scavenging assay (up to 25.36 mg ascorbic acid equivalent g- 1 DM). These results especially demonstrated the bioactive potential of red guava and provided knowledge regarding the influence of ripening and growing location on chemical and bioactive components encouraging its industrial exploitation.

Potential low toxic alternative for Na-Cl cotransporter inhibition: A diuretic effect and mechanism study of Pyrrosia petiolosa.

BACKGROUND: Hydrochlorothiazide, a diuretic commonly used for the treatment of hypertension, is often associated with serious metabolic side effects. Pyrrosia petiolosa (Christ) Ching is a traditional Chinese medicine that possesses diuretic properties, without any obvious side effects. AIM: To evaluate the diuretic effect of P. petiolosa (Christ) Ching and to elucidate its underlying mechanism of action. METHODS: Extracts obtained from different polar components of P. petiolosa (Christ) Ching were analyzed for toxicity in a Kunming mouse model. The diuretic effects of the extracts were compared to that of hydrochlorothiazide in rats. In addition, compound isolation procedures, cell assays of Na-Cl cotransporter inhibition and rat diuretic test of monomeric compounds were conducted to identify the active ingredients in the extract. Subsequently, homology modeling and molecular docking were performed to explain the reason behind the diuretic activity observed. Finally, LC-MS analysis was used to elucidate the underlying mechanism of action of P. petiolosa (Christ) Ching. RESULTS: No toxicity was observed in mice administered P. petiolosa (Christ) Ching extracts. The ethyl acetate fraction showed the most significant diuretic effect. Similar results were obtained during the analysis for Na+ content in rat urine. Further separation of P. petiolosa (Christ) Ching components led to the isolation of methyl chlorogenate, 2',3'-dihydroxy propyl pentadecanoate, and ß-carotene. Results from cell assays showed that the Na-Cl cotransporter inhibitory activity of methyl chlorogenate was greater than that of hydrochlorothiazide. This result was again confirmed by the diuresis tests of monomeric compounds in rats. The molecular simulations explain the stronger interactions between the methyl chlorogenate and Na-Cl cotransporter. Of the compounds determined using LC-MS analysis, 185 were identified to be mostly organic acids. CONCLUSIONS: P. petiolosa possesses significant diuretic activities without any obvious toxicity, with least two possible mechanisms of action. Further study on this herb is warranted.

Metal-Organic Frameworks: Direct Synthesis by Organic Acid-Etching and Reconstruction Disclosure as Oxygen Evolution Electrocatalysts.

Metal-organic frameworks (MOFs) have emerged as promising oxygen evolution reaction (OER) electrocatalysts. Chemically bonded MOFs on supports are desirable yet lacking in routine synthesis, as they may allow variable structural evolution and the underlying structure-activity relationship to be disclosed. Herein, direct MOF synthesis is achieved by an organic acid-etching strategy (AES). Using π-conjugated ferrocene (Fc) dicarboxylic acid as the etching agent and organic ligand, a series of MFc-MOF (M=Ni, Co, Fe, Zn) nanosheets are synthesized on the metal supports. The crystal structure is studied using X-ray diffraction and low-dose transmission electron microscopy, which is quasi-lattice-matched with that of the metal, enabling in situ MOF growth. Operando Raman and attenuated total reflectance Fourier transform infrared spectroscopy disclose that the NiFc-MOF features dynamic structural rebuilding during OER. The reconstructed one showing optimized electronic structures with an upshifted total d-band center, high M-O bonding state occupancy, and localized electrons on adsorbates indicated by density functional theory calculations, exhibits outstanding OER performance with a fairly low overpotential (130 mV at 10 mA cm-2 ) and good stability (144 h). The newly established approach for direct MOF synthesis and structural reconstruction disclosure stimulate the development of more prudent catalysts for advancing OER.

Comparative network analysis reveals the dynamics of organic acid diversity during fruit ripening in peach (Prunus persica L. Batsch).

BACKGROUND: Organic acids are important components that determine the fruit flavor of peach (Prunus persica L. Batsch). However, the dynamics of organic acid diversity during fruit ripening and the key genes that modulate the organic acids metabolism remain largely unknown in this kind of fruit tree which yield ranks sixth in the world. RESULTS: In this study, we used 3D transcriptome data containing three dimensions of information, namely time, phenotype and gene expression, from 5 different varieties of peach to construct gene co-expression networks throughout fruit ripening of peach. With the network inferred, the time-ordered network comparative analysis was performed to select high-acid specific gene co-expression network and then clarify the regulatory factors controlling organic acid accumulation. As a result, network modules related to organic acid synthesis and metabolism under high-acid and low-acid comparison conditions were identified for our following research. In addition, we obtained 20 candidate genes as regulatory factors related to organic acid metabolism in peach. CONCLUSIONS: The study provides new insights into the dynamics of organic acid accumulation during fruit ripening, complements the results of classical co-expression network analysis and establishes a foundation for key genes discovery from time-series multiple species transcriptome data.

Phosphorus absorption kinetics and exudation strategies of roots developed by three lupin species to tackle P deficiency.

MAIN CONCLUSION: Different lupin species exhibited varied biomass, P allocation, and physiological responses to P-deprivation. White and yellow lupins had higher carboxylate exudation rates, while blue lupin showed the highest phosphatase activity. White lupin (Lupinus albus) can produce specialized root structures, called cluster roots, which are adapted to low-phosphorus (P) soil. Blue lupin (L. angustifolius) and yellow lupin (L. luteus), which are two close relatives of white lupin, do not produce cluster roots. This study characterized plant responses to nutrient limitation by analyzing biomass accumulation and P distribution, absorption kinetics and root exudation in white, blue, and yellow lupins. Plants were grown in hydroponic culture with (64 µM NaH2PO4) or without P for 31 days. Under P limitation, more biomass was allocated to roots to improve P absorption. Furthermore, the relative growth rate of blue lupin showed the strongest inhibition. Under + P conditions, the plant total-P contents of blue lupin and yellow lupin were higher than that of white lupin. To elucidate the responses of lupins via the perspective of absorption kinetics and secretion analysis, blue and yellow lupins were confirmed to have stronger affinity and absorption capacity for orthophosphate after P-deprivation cultivation, whereas white lupin and yellow lupin had greater ability to secrete organic acids. The exudation of blue lupin had higher acid phosphatase activity. This study elucidated that blue lupin was more sensitive to P-scarcity stress and yellow had the greater tolerance of P-deficient condition than either of the other two lupin species. The three lupin species have evolved different adaptation strategies to cope with P deficiency.

2-Methylglutaconic acid as a biomarker in routine urine organic acids leading to the diagnosis of glutaric acidemia type I in a low excretor.

GA1 (OMIM# 231670) is an organic aciduria caused by defective Glutaryl-CoA dehydrogenase (GCDH), encoded by GCDH. Early detection of GA1 is crucial to prevent patients from developing acute encephalopathic crisis and subsequent neurologic sequelae. Diagnosis of GA1 relies on elevated glutarylcarnitine (C5DC) in plasma acylcarnitine analysis and hyperexcretion of glutaric acid (GA) and 3-hydroxyglutaric acid (3HG) in urine organic acid (UOA) analysis. Low excretors (LE), however, exhibit subtly elevated or even normal plasma C5DC and urinary GA levels, leading to screening and diagnostic challenges. The measurement of 3HG in UOA is thus often used as the 1st tier test for GA1. We described a case of LE detected via newborn screen with normal excretion of GA, absent of 3HG and increased 2-methylglutaconic acid (2MGA), which was detected at 3 mg/g creatinine (reference interval <1 mg/g creatinine) without appreciable ketones. We retrospectively examined UOA of 8 other GA1 patients and the 2MGA level ranged from 2.5 to 27.39 mg/g creatinine, which is significantly higher than normal controls (0.05-1.61 mg/g creatinine). Although the underlying mechanism of 2MGA formation in GA1 is unclear, our study suggests 2MGA is a biomarker for GA1 and should be monitored by routine UOA to evaluate its diagnostic and prognostic value.