Organic Oxygen Research Articles

Biocontrol potential of Burkholderia gladioli STPT16 on postharvest decay of litchi fruit caused by Peronophythora litchii and Colletotrichum fructicola

Litchi downy blight (LDB) caused by Peronophythora litchii and anthracnose (AD) caused by Colletotrichum species are major pre- and postharvest disease of litchi fruit. Biocontrol agents such as Burkholderia has been applied for controlling postharvest fruit decay. In this work, an endophytic strain SZPT16 isolated from health litchi branch was identified as Burkholderia gladioli and exhibited strong antagonistic activity against mycelial growth and conidia/sporangia germination of two postharvest pathogens. Dual incubation of pathogen and biocontrol agents caused alterations in hyphal and conidial/sporangial structures and severe cell morphology changes such as mycelia deformation, cell wall collapse and cellular disorganization. Cell-free culture filtrates (CF, diluted at 25-fold) of B. gladioli SZPT16 showed an efficient inhibition on postharvest litchi decay by preharvest application (74.77 % protection) and postharvest application (64.68 % and 71.14 % protection for LDB and AD, respectively). Furthermore, UPLC-MS/MS metabolomic analysis identified 41 up-regulated differential metabolites, which mainly included nucleosides, nucleotides, and analogues, organic acids and derivatives, organic oxygen compounds, and organoheterocyclic compounds. This study firstly reported the efficacy of CF of B. gladioli SZPT16 in protecting postharvest litchi fruit against natural and inoculated pathogen infections. The overall results provide a promising alternative to chemical fungicides to control litchi postharvest decay.

Anticancer Properties Against Select Cancer Cell Lines and Metabolomics Analysis of Tender Coconut Water.

Tender Coconut Water (TCW) is a nutrient-rich dietary supplement that contains in bioactive secondary metabolites and phytohormones with anti-oxidative and anti-inflammatory properties. Studies on TCW's anti-cancer properties are limited and the mechanism of its anti-cancer effects have not been defined. In the present study, we investigate TCW for its anti-cancer properties and, using untargeted metabolomics, we identify components form TCW with potential anti-cancer activity. Cell viability assay, BrdU incorporation assay, soft-agar assay, flow-cytometery, and Western blotting were used to analyze TCW's anticancer properties and to identify mechanism of action. Liquid chromatography- Tandem Mass Spectroscopy (LC-MS/MS) was used to identify TCW components. TCW decreased the viability and anchorage-independent growth of HepG2 hepatocellular carcinoma (HCC) cells and caused S-phase cell cycle arrest. TCW inhibited AKT and ERK phosphorylation leading to reduced ZEB1 protein, increased E-cadherin, and reduced N-cadherin protein expression in HepG2 cells, thus reversing the 'epithelial-to-mesenchymal' (EMT) transition. TCW also decreased the viability of Hep3B hepatoma, HCT-15 colon, MCF-7 and T47D luminal A breast cancer (BC) and MDA-MB-231 and MDA-MB-468 triplenegative BC cells. Importantly, TCW did not inhibit the viability of MCF-10A normal breast epithelial cells. Untargeted metabolomics analysis of TCW identified 271 metabolites, primarily lipids and lipid-like molecules, phenylpropanoids and polyketides, and organic oxygen compounds. We demonstrate that three components from TCW: 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, iondole-3-carbox aldehyde and caffeic acid inhibit the growth of cancer cells. TCW and its components exhibit anti-cancer effects. TCW inhibits the viability of HepG2 hepatocellular carcinoma cells by reversing the EMT process through inhibition of AKT and ERK signalling.

Innovative RGO-bridged S-scheme CuFe2O4@Ag2S heterojunction for efficient Sun-light-driven photocatalytic disintegration of Ciprofloxacin

Antibiotics contamination in water bodies poses a significant threat to public health and the environment, necessitating advanced methods for their removal from wastewater. In response to this issue, developing a novel magnetic nanocomposite (RGO/CuFe2O4@Ag2S) as an efficient photocatalyst for the degradation of pharmaceuticals like ciprofloxacin (CIP) is of great importance. The synthesized nanocomposite underwent comprehensive characterization to elucidate its crystalline structure, chemical bonding, surface morphology, elemental composition, internal structure, optical properties, surface area, particle size distribution, and magnetic properties. Under optimized conditions (pH=9, nanocomposite dose =0.5 g/L, CIP concentration of 20 mg/L, and duration of 200 minutes), the nanocomposite demonstrated complete degradation of CIP. Moreover, post-treatment analysis revealed significant reductions in total organic carbon (TOC) and chemical oxygen demand (COD) of 70.08% and 85.08%, respectively, indicating extensive mineralization of the antibiotic. Mechanistic investigations revealed a unique S-scheme heterojunction in the RGO/CuFe2O4@Ag2S nanocomposite, where RGO acts as an electronic bridge between CuFe2O4 and Ag2S. This innovative architecture facilitates efficient charge separation and transfer, significantly enhancing the photocatalytic activity. Reusability tests demonstrated the robust nature of the photocatalyst, with only a modest 6% decline in efficiency after six consecutive cycles. To further assess the system's effectiveness in real-world applications, its performance was evaluated in treating pharmaceutical wastewater. The biodegradation efficiency was quantified by measuring the Average Oxidation State (AOS) and Carbon Oxidation State (COS) of the wastewater samples before and after treatment.

Metabolomics reveals a key role of salicylic acid in embryo abortion underlying interspecific hybridization between Hydrangea macrophylla and H. arborescens.

Embryo abortion at the heart-shaped stage is the main reason for the failure of interspecific hybridization of hydrangea, and salicylic acid plays a key role during embryo abortion. Difficulties in obtaining seeds from interspecific hybridization between Hydrangea macrophylla and H. arborescens had severely restricted the process of breeding new hydrangea varieties. To clarify the cause of reproductive barriers, an interspecific hybridization was made between H. macrophylla 'Endless Summer' (female parent) and H. arborescens 'Annabelle' (male parent). The results showed that both parents' floral organs developed normally, 'Annabelle' had high pollen viability (84.83% at 8h after incubation), and the pollen tube could enter into the ovule of 'Endless Summer' at 72h after pollination. Therefore, the pre-fertilization barrier was not the main reason for the failure of interspecific hybridization. However, observation of the embryo development by paraffin sections showed that the embryo was aborted at the heart-shaped stage. In addition, salicylic acid (SA) content was significantly higher (fourfold, P < 0.01) at 21 days after pollination (DAP) as compared to that of 17 DAP, which means SA may be closely correlated with embryo development. A total of 957 metabolites were detected, among which 78 were significantly different. During the embryo abortion, phenylpropanoids and polyketides were significantly down-regulated, while organic oxygen compounds were significantly up-regulated. Further analysis indicated that the metabolic pathway was enriched in the shikimic acid biosynthesis pathway, which suggests that more SA was synthesized. Taken together, it can be reasonably speculated that SA plays a key role leading to embryo abortion underlying the interspecific hybridization between Hydrangea macrophylla and H. arborescens. The result is helpful to direct the breeding of hydrangea through distant hybridization.

Differential serum metabolites in patients with pregnancy-associated venous thromboembolism analyzed using GC-MS/LC-MS untargeted metabolomics

Untargeted metabolomics can be used for the comprehensive analysis of metabolite profiles in biological samples without preset targets, making them particularly suitable for exploring metabolic characteristics and potential mechanisms in complex diseases. Therefore, in this study, we employed gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) techniques to analyze the serum metabolic characteristics of patients with pregnancy-associated venous thromboembolism (PA-VTE). In this study, 11 pregnant women with VTE and 11 healthy pregnant women were included in the experimental and control groups, respectively. Using GC-MS, we identified 325 metabolites, with the highest proportion being organic oxygen compounds. Using LC-MS, we identified 3104 metabolites, with the highest proportion being acylcarnitine. The results revealed significant differences in the levels of lipids, organic compounds, and other metabolites between patients compared to healthy pregnant women. Pathways such as pyrimidine metabolism, linoleic acid metabolism, and mineral absorption differed between patients with PA-VTE and controls. Furthermore, we identified biomarkers associated with metabolic processes, such as fatty acids and amino acids (2-hydroxyhexanedioic acid, hexadecenal, palmitoylethanolamide, glycerol-1-phosphate, and N-acetyl-beta-D-glucosamine). These findings revealed the metabolic characteristics of PA-VTE and provided important clues for further research on its pathophysiological mechanisms. Our findings may contribute to the development of new diagnostic markers and support early diagnosis and treatment of PA-VTE.

Untargeted metabolomics unravels the effects of ginkgolide B-producing Lactiplantibacillus plantarum and co-induced fermentation of ginkgo kernel juice and their underlying vascular endothelial cell protection activity

The objective of this study was to investigate the fermentation mechanism of ginkgo kernel juice (GKJ) under unfermented (Group A), Ginkgolide B (GB)-producing Lactiplantibacillus plantarum fermented (Group B), and co-induced fermented (Group C) conditions. The conditions were optimized and further evaluated for their vascular endothelial cell protective effects in vitro. The co-induced fermented GKJ group extensively promoted GB and total phenol contents, reaching 109.94 and 599.57 μg/mL, respectively. While pH declined from 5.90 to 3.42 during fermentation, the highest total viable count (8.85 log CFU/mL) was detected at 16 h in the L. plantarum group. The co-induced group recorded the highest total phenol contents (594.05 μg/mL) and markedly induced the survival rate, reactive oxygen species formation, and lactate dehydrogenase assay cytotoxicity of H2O2-induced human umbilical vein endothelial cells. An untargeted metabolomics analysis identified 2633 metabolites in the groups. The principal component and orthogonal partial least squares discriminant score plots showed a clear metabolite distinction among the fermentation groups. From the Kyoto Encyclopedia of Genes and Genomes analysis, 309 differential accumulated metabolites (DAMs) were up-regulated and 604 were down-regulated in the A vs. B group, while 702 downregulated and 304 upregulated DAMs were exhibited in the B vs. C group. These DAMs were primarily lipids and lipid-like molecules, organic acids and their derivatives, organoheterocyclic compounds, organic oxygen compounds, benzenoids, phenylpropanoids and polyketides, and unclassified compounds at the superclass level. Overall, the results indicated that L. plantarum and co-induced fermentation improved the cell protection efficacy of GKJ, showing excellent potential for drug delivery applications.

Improving Undernutrition with Microalgae.

Undernutrition is an important global health problem, especially in children and older adults. Both reversal of maternal and child undernutrition and heathy ageing have become United Nations-supported global initiatives, leading to increased attention to nutritional interventions targeting undernutrition. One feasible option is microalgae, the precursor of all terrestrial plants. Most commercially farmed microalgae are photosynthetic single-celled organisms producing organic carbon compounds and oxygen. This review will discuss commercial opportunities to grow microalgae. Microalgae produce lipids (including omega-3 fatty acids), proteins, carbohydrates, pigments and micronutrients and so can provide a suitable and underutilised alternative for addressing undernutrition. The health benefits of nutrients derived from microalgae have been identified, and thus they are suitable candidates for addressing nutritional issues globally. This review will discuss the potential benefits of microalgae-derived nutrients and opportunities for microalgae to be converted into food products. The advantages of microalgae cultivation include that it does not need arable land or pesticides. Additionally, most species of microalgae are still unexplored, presenting options for further development. Further, the usefulness of microalgae for other purposes such as bioremediation and biofuels will increase the knowledge of these microorganisms, allowing the development of more efficient production of these microalgae as nutritional interventions.

Moderate effects of distance to air-filled macropores on denitrification potentials in soils

AbstractDenitrification is a major source of the greenhouse gas N2O. As a result of spatial heterogeneity of organic carbon, oxygen and nitrate, denitrification is observed even under relatively dry conditions. However, it is unclear whether denitrification potentials of microbial communities exhibit spatial patterns relative to variations in distance to soil pores facilitating oxygen exchange and nutrient transfer. Thus, we determined genetic and process-level denitrification potentials in two contrasting soils, a cropland and a grassland, with respect to the distance to air-filled pores. An X-ray computed tomography aided sampling strategy was applied for precise sampling of soil material. Process-level and genetic denitrification potentials in both soils were spatially variable, and similar with respect to distance to macropores. In the cropland soil, a minor increase of process-level potentials with distance to pores was observed and related to changes in NO3− rather than oxygen availability. Genetic denitrification potentials after the short-term incubations revealed a certain robustness of the local community. Thus, distance to macropores has a minor impact on denitrification potentials relative to the observed spatial variability. Our findings support the notion that the impact of macropore induced changes of the environmental conditions in soil does not overrule the high spatial variability due to other controlling factors, so that the rather minor proportion of spatial heterogeneity of functional genes and activity potentials related to macropore distances in soil need not be considered explicitly in modelling denitrification.

Study on Enzyme Activity and Metabolomics during Culture of Liquid Spawn of Floccularia luteovirens.

To comprehensively investigate the physiological characteristics and metabolic processes of the mycelium of Floccularia luteovirens (F. luteovirens), a wild edible fungus unique to the plateau region, we conducted an in-depth analysis of the mycelium enzyme activity and metabolites during different culture periods. The activity of seven enzymes all followed a trend of initially increasing and then decreasing. The intra- and extracellular activity peaks of three hydrolases-amylase, protease, and cellulase-all occurred on the 20th day, except for the extracellular amylase, which peaked on the 15th day. In contrast, the peak activity of laccase occurred on the 10th day. Moreover, three types of oxidoreductases in the mycelium (catalase (CAT), superoxide dismutase (SOD), and 2,3,5-triphenyltetrazolium chloride (TTC)-dehydrogenase (TTC-DH)) also exhibited significant changes in activity. CAT and SOD activity reached their maximum on the 20th day, whereas TTC-DH showed high activity on both the 10th and 20th days. Through a comprehensive assessment of the evolving trends of these physiological parameters, we determined that the optimal cultivation cycle for F. luteovirens liquid spawn is 20 days. An untargeted metabolomic analysis revealed that 3569 metabolites were detected in the F. luteovirens mycelium, including a variety of secondary metabolites and functional components, with terpenoids being particularly abundant, accounting for 148 types. By comparing three different culture stages (10 days, 20 days, and 30 days), 299, 291, and 381 metabolites, respectively, showed different accumulation patterns in the comparison groups of 10d vs. 20d, 20d vs. 30d, and 10d vs. 30d. These differential metabolites were primarily concentrated in carboxylic acids and their derivatives, fatty acyl groups, organic oxygen compounds, and lipid compounds. In addition, there were several amino acids whose abundance continued to grow during culturing. The metabolism of amino acids greatly affects mycelium growth and development. This research delineates the interplay between mycelium growth and metabolism, offering empirical support for a cultivation strategy for liquid F. luteovirens, and an exploration of its metabolites for potential applications.

Chemical Isotope Labeling and Dual-Filtering Strategy for Comprehensive Profiling of Urinary Glucuronide Conjugates.

Glucuronidation, a crucial process in phase II metabolism, plays a vital role in the detoxification and elimination of endogenous substances and xenobiotics. A comprehensive and confident profiling of glucuronate-conjugated metabolites is imperative to understanding their roles in physiological and pathological processes. In this study, a chemical isotope labeling and dual-filtering strategy was developed for global profiling of glucuronide metabolites in biological samples. N,N-Dimethyl ethylenediamine (DMED-d0) and its deuterated counterpart DMED-d6 were used to label carboxylic acids through an amidation reaction. First, carboxyl-containing compounds were extracted based on a characteristic mass difference (Δm/z, 6.037 Da) observed in MS between light- and heavy-labeled metabolites (filter I). Subsequently, within the pool of carboxyl-containing compounds, glucuronides were identified using two pairs of diagnostic ions (m/z 247.1294/253.1665 and 229.1188/235.1559 for DMED-d0/DMED-d6-labeled glucuronides) originating from the fragmentation of the derivatized glucuronic acid group in MS/MS (filter II). Compared with non-derivatization, DEMD labeling significantly enhanced the detection sensitivity of glucuronides, as evidenced by a 3- to 55-fold decrease in limits of detection for representative standards. The strategy was applied to profiling glucuronide metabolites in urine samples from colorectal cancer (CRC) patients. A total of 685 features were screened as potential glucuronides, among which 181 were annotated, mainly including glucuronides derived from lipids, organic oxygen, and phenylpropanoids. Enzymatic biosynthesis was employed to accurately identify unknown glucuronides without standards, demonstrating the reliability of the dual-filtering strategy. Our strategy exhibits great potential for profiling the glucuronide metabolome with high coverage and confidence to reveal changes in CRC and other diseases.

Compound Bacillus improves eggshell quality and egg metabolites of hens by promoting the metabolism balance of calcium and phosphorus and uterine cell proliferation

Probiotics have beneficial effects on improving egg quality, but there is little research about the effect of probiotics on metabolite composition, and the mechanisms are not yet fully understood. The aim of this study was to investigate the potential mechanisms by which compound Bacillus improves egg quality and metabolite composition. A total of 20,000 Jingfen No. 6 laying hens at 381 d old were randomly divided into two treatments: control group with a basal diet, and the basal diet with compound Bacillus supplementation (Ba) group. The trial lasted eight weeks. The results showed that compound Bacillus improved the gloss and strength of eggshells and reduced the ratio of sand-shell eggs by 23.8%. Specifically, the effective layer of eggshell was thicker and its calcite column was closely connected. Compound Bacillus increased the contents of beneficial fatty acids in the egg yolk, and lipids and lipid-like molecules in the albumen (P < 0.01), while decreased the contents of total cholesterol, triglycerides, and benzene ring compounds in the egg yolk and organic oxygen compounds in the albumen (P < 0.01). In addition, the compound Bacillus increased the calcium absorption in the duodenum by up-regulating the expression of transporters and serum hormone synergism (P < 0.05), and promoted metabolic balance of calcium and phosphorus. Simultaneously, uterine transcriptome showed that the expression of ChaC glutathione specific gamma-glutamylcyclotransferase 1 (CHAC1), glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1), phosphatidylinositol-4-phosphate 5-kinase type 1 beta (PIP5K1B), methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), brain enriched myelin associated protein 1 (BCAS1), and squalene epoxidase (SQLE) genes were increased (P < 0.01), indicating that nutrient metabolism activity was enhanced. The expression of the BCAS1, C1GALT1, KLF transcription factor 13 (KLF13), and leucine rich repeat neuronal 1 (LRRN1) was increased (P < 0.01), indicating that the cell proliferation was enhanced, which slowed uterus aging. In conclusion, compound Bacillus improved the eggshell strength and metabolite composition in the egg by promoting metabolic balance of calcium and phosphorus, cell proliferation, and nutrient metabolism in the uterus.

Living in mangroves: a syntrophic scenario unveiling a resourceful microbiome

BackgroundMangroves are complex and dynamic coastal ecosystems under frequent fluctuations in physicochemical conditions related to the tidal regime. The frequent variation in organic matter concentration, nutrients, and oxygen availability, among other factors, drives the microbial community composition, favoring syntrophic populations harboring a rich and diverse, stress-driven metabolism. Mangroves are known for their carbon sequestration capability, and their complex and integrated metabolic activity is essential to global biogeochemical cycling. Here, we present a metabolic reconstruction based on the genomic functional capability and flux profile between sympatric MAGs co-assembled from a tropical restored mangrove.ResultsEleven MAGs were assigned to six Bacteria phyla, all distantly related to the available reference genomes. The metabolic reconstruction showed several potential coupling points and shortcuts between complementary routes and predicted syntrophic interactions. Two metabolic scenarios were drawn: a heterotrophic scenario with plenty of carbon sources and an autotrophic scenario with limited carbon sources or under inhibitory conditions. The sulfur cycle was dominant over methane and the major pathways identified were acetate oxidation coupled to sulfate reduction, heterotrophic acetogenesis coupled to carbohydrate catabolism, ethanol production and carbon fixation. Interestingly, several gene sets and metabolic routes similar to those described for wastewater and organic effluent treatment processes were identified.ConclusionThe mangrove microbial community metabolic reconstruction reflected the flexibility required to survive in fluctuating environments as the microhabitats created by the tidal regime in mangrove sediments. The metabolic components related to wastewater and organic effluent treatment processes identified strongly suggest that mangrove microbial communities could represent a resourceful microbial model for biotechnological applications that occur naturally in the environment.

Synergizing MBR and MCDI systems as a sustainable solution for decentralized wastewater reclamation and reuse

Decentralized wastewater reclamation and reuse systems have drawn much attention due to their capability for reducing the energy demand for water conveyance and reclaiming wastewater for local re-use. While membrane bioreactor (MBR) stands as a mature technology offering comprehensive solid and liquid separation, membrane capacitive deionization (MCDI) presents a promising avenue for ion separation. Unfortunately, MCDI has seldom been incorporated into decentralized wastewater reclamation and reuse systems. This study aims to exemplify the design and the operation of the synergistic integration of MBR and MCDI system with a practical capacity of 1 m3 d− 1, showcasing its efficacy in reclaiming and reusing water at regional level. The integrated system demonstrated significant high removal of total organic carbon (from 97 to 2 mg L− 1) and chemical oxygen demand (COD, from 218 to < 3 mg L− 1). Meantime, nearly complete transformation (approximately 91%) of NH3 to NO3− within the MBR effluent was observed with a hydraulic retention time of 4.3–4.8 h and a food-to-microorganism of 0.15–0.20 kg COD kg− 1 MLSS d− 1 which can be further removed through the MCDI system (> 92% TN removal). A significant milestone of MCDI unit was reached with the remarkable removal efficiency of total ions (93%) and water recovery (80%) using a stop-flow regeneration approach coupled with an optimized voltage of 2.0 V. The MCDI unit not only proved its high stability but also featured low energy consumption (0.44 kWh m− 3). Overall, synergizing MBR and MCDI systems emerges as a sustainable and effective solution for decentralized wastewater reclamation and reuse, contributing to a more environmentally friendly and resource-efficient water management paradigm.

SedaDNA reveals mid-to late Holocene aquatic plant and algae changes in Luanhaizi Lake on the Tibetan Plateau

Aquatic plants and algae are the primary producers in lake ecosystems, providing the organic matter and oxygen necessary for the nutrients and energy of most organisms. Climatic and environmental changes may have irreversible impacts on aquatic plants and algae communities, while direct observation and experiments can only provide a short-term perspective. As a record of the long-term variation of the ecosystem, sedimentary ancient DNA (sedaDNA) could offer evidence about aquatic plants and algae change over extended time scales and improve the taxonomic resolution than the traditional morphology methods such as pollen and macrofossil. In this study, we employed metagenomics in sedaDNA from Luanhaizi Lake (northeastern Tibetan Plateau) since 8.2 cal kyr BP, to characterize the aquatic plant and algae communities' response to the climatic and environmental change over an extended historical timeline. The results demonstrate that during 8130–4620 cal yr BP, pondweed (Stuckenia) was the dominating aquatic plant in Luanhaizi Lake, with a generally low diversity of aquatic plants and algae. During 3670–2290 cal yr BP, Luanhaizi Lake had an increased diversity and triggered a shift from Stuckenia to Eurasian watermilfoil (Myriophyllum). During 1810–50 cal yr BP, with the warming process, cyanobacteria appeared and diversity peaked. Correlation and redundancy analyses show that this process might be related to climatic and environmental changes, such as decreased salinity, increased temperature, and higher water levels. Our results signify that aquatic plants and algae communities are sensitive to paleoclimatic and environmental change, in the context of global warming, the studies on the past dynamics of aquatic plants and algae will help predict the potential changes of the lake ecosystem on the northeastern Tibetan Plateau in the future.

Preliminary studies of selected Lemna species on the oxygen production potential in relation to some ecological factors.

Dissolved oxygen is fundamental for chemical and biochemical processes occurring in natural waters and critical for the life of aquatic organisms. Many organisms are responsible for altering organic matter and oxygen transfers across ecosystem or habitat boundaries and, thus, engineering the oxygen balance of the system. Due to such Lemna features as small size, simple structure, vegetative reproduction and rapid growth, as well as frequent mass occurrence in the form of thick mats, they make them very effective in oxygenating water. The research was undertaken to assess the impact of various species of duckweed (L. minor and L. trisulca) on dissolved oxygen content and detritus production in water and the role of ecological factors (light, atmospheric pressure, conductivity, and temperature) in this process. For this purpose, experiments were carried out with combinations of L. minor and L. trisulca. On this basis, the content of oxygen dissolved in water was determined depending on the growth of duckweed. Linear regression models were developed to assess the dynamics of changes in oxygen content and, consequently, organic matter produced by the Lemna. The research showed that the presence of L. trisulca causes an increase in dissolved oxygen content in water. It was also shown that an increase in atmospheric pressure had a positive effect on the ability of duckweed to produce oxygen, regardless of its type. The negative correlation between conductivity and water oxygenation, obtained in conditions of limited light access, allows us to assume that higher water conductivity limits oxygen production by all combinations of duckweeds when the light supply is low. Based on the developed models, it was shown that the highest increase in organic matter would be observed in the case of mixed duckweed and the lowest in the presence of the L. minor species, regardless of light conditions. Moreover, it was shown that pleustophytes have different heat capacities, and L. trisulca has the highest ability to accumulate heat in water for the tested duckweed combinations. The provided knowledge may help determine the good habitat conditions of duckweed, indicating its role in purifying water reservoirs as an effect of producing organic matter and shaping oxygen conditions with the participation of various Lemna species.

Benefits from co-pyrolysis of biomass and refuse derived fuel for biofuels production: Experimental investigations

The application of renewable fuels and waste for energy production is crucial environmentally and economically. Co-pyrolysis of biomass and refuse derived fuel (RDF) offers a promising pathway for valuable products that combine various benefits including enhanced energy recovery, waste valorisation, improved product quality, and environmental sustainability. Consideration of specific feedstocks and optimization of process parameters are necessary to maximise the efficiency and effectiveness of the co-pyrolysis process. This work presents investigations of the co-pyrolysis process of lignocellulosic biomass wastes (rye straw and agriculture grass) and RDF. These biomasses ensure efficient decomposition. The RDF, high in carbon (78.5 %) and hydrogen (11.8 %), was predominantly plastic based. Based on Py-GC-MS studies at 600 °C, it was observed that the addition of RDF to biomass caused a significant decrease in the share of organic oxygen compounds among the released decomposition products. Laboratory tests were performed in a fixed-bed reactor for raw biomass and RDF and 1:1 and 3:1 biomass to RDF mass ratio. The results demonstrated that the yield of char production decreased with the addition of RDF, which promoted the bio-oil yield. Despite, RDF pyrolysis meets problems, it was proved that co-pyrolysis of biomass and RDF is a good solution for their utilization.

Study of Using a Phyto-nanosynthesis of Silver and Portulaca Oleracea Plant Extracts in Petroleum Spots Treatment

Petroleum spots has become a major global problem not only in terms of its increase, but also how it is treated, recycled or utilized. It contains suspended and dissolved solids, hydrocarbons and many types of organic matter and heavy metals. The reuse of petroleum spots faces the problem of removing organic pollutant compounds before discharging them into any natural stream. in this study, natural nano –coagulant material was used and their efficiency in removing turbidity, Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) from petroleum spots were compared. The study was conducted in the laboratories of the Ecology Sciences Department, University of Kufa, Iraq in 2022. By synthesizing Phyto-nanosilver as a Phyto-nano silver from Leaves of Portulaca oleracea plant extracts used to reduce turbidity and organic pollutants of the petroleum spots. Jar test experiments showed that 0.5 mg / L Phyto-nanosilver dose can remove 95.5 % of (COD), 87.3% of TOC and 85.2 % from turbidity. Also, removal of P. oleracea plant extracts in the 1 and 0.5 mg/L dose can removed turbidity, COD and TOC content of 91.9%, 87.5 % and 82.4% respectively of the petroleum spots. Moreover, when using the nano-sliver only, removal of TOC, COD, and turbidity would reach 75.3%, 80.4%, and 81.3 %, respectively. The results of the research showed the efficiency of Phyto-nano silver materials in treating and depositing pollutants without harming the environment.

Once through continuous mode electrocoagulation for tannery wastewater remediation: Process optimization and performance evaluation

The treatment of wastewater from tannery industries poses significant challenges due to high levels of tannic acid and chemical oxygen demand (COD), along with low biodegradability. To address this issue, we conducted a study focusing on the use of Electrocoagulation (EC) as a treatment process for synthetic tannery wastewater. Iron (Fe) electrodes have been used as anode and cathode as well. The electrodes size (7 cm × 7 cm) has been used in this process. The investigation of removal efficiencies entailed the assessment of total organic carbon (TOC) and chemical oxygen demand (COD) as indicators of organic contaminant levels within the wastewater. The influence of current density, pH, flowrate, and time on the treatment was measured. At a current density of 51 A/m2 with 83.54 % of COD removal and 27 % of TOC removal were observed. The maximum COD removal was found at pH 4.93, flowrate 5 ml/min, current 0.953 A and time 115 min. The current investigation demonstrated the efficacy of the electrocoagulation process in reducing both total organic carbon (TOC) and chemical oxygen demand (COD) levels in synthetic tannery wastewater.

Reconstruction of High Entropy Alloys on a Metal–Organic Framework Approaching Active Oxygen Reduction Electrocatalysts

Reconstruction of High Entropy Alloys on a Metal–Organic Framework Approaching Active Oxygen Reduction Electrocatalysts

Redox-switchable microemulsions with efficient phase separation and surfactant recycling

HypothesisSwitchable microemulsions (MEs) are those capable of adaptively responding to the action of internal or external stimuli. For redox-switchable MEs to obtain high-efficiency phase separation and surfactant recycling, it may be one of the keys to adequately turn off the interfacial activity of surfactants and reduce the solubility of the closed surfactants in the oil phase. ExperimentsMonophasic MEs consisting 11-butylselanyl-undecyl sulfate sodium (C4SeC11SO4Na), n-butanol, n-octane, and water were fabricated using the pseudo-ternary phase diagram method. Their structural features and droplets size were characterized by conductivity, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM), respectively. The redox response of MEs was studied using a combination of visual observations and DLS, cryo-TEM, nuclear magnetic resonance (NMR) and thin-layer tomography. The efficient recycling of C4SeC11SO4Na from a well-emulsified eluent is conceptually demonstrated. FindingsThe reversible transition between C4SeC11SO4Na and C4SeOC11SO4Na is achieved under the alternating action of H2O2 and N2H4, by which C4SeC11SO4Na-based monophasic MEs are able to efficiently demulsify and regenerate, respectively, regardless of their type. After H2O2-induced demulsification of the MEs, C4SeOC11SO4Na can be efficiently recycled with the water phase. We hope that such a redox-switching method may benefit some technological applications. For example, it offers exciting possibilities for simultaneous recycling C4SeC11SO4Na and removal of oil from a well-emulsified eluent. Around 97.1 ± 0.3 % of C4SeC11SO4Na could be recycled over five cycles with no apparent loss. After a simple and conventional treatment with anion-exchange resin and active carbon, the total organic carbon and chemical oxygen demand of the waste water were 17.4 ± 2.8 and 26.2 ± 1.4 mg/L, respectively.