Acid Methyl Ester Research Articles

Enhancement of Electron Transport Characteristics Using MXene-MnFeO3 Nanocomposite Integration with Fullerene Derivatives for the Perovskite-Based Solar Cells and Detectors.

In this study, we prepared a hybrid film incorporating the MnFeO3-decorated conducting two-dimensional (2D) MXene sheet-suspended [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) electron transfer layer (ETL) for the perovskite solar cells (PSCs) and detectors. The incorporation of MXene-MnFeO3 with the PCBM ETL could drive exceptional conducting features for the PSCs. Moreover, the presence of MXene-MnFeO3 facilitated superior charge transfer pathways, thereby enhancing the electron extraction and collection processes. This enhancement was directed to improve the electron mobility within the device, resulting in high photocurrents. The designed interface engineering with the MXene-MnFeO3 nanocomposite-tuned PCBM ETL has produced a remarkable power conversion efficiency of 17.79% ± 0.27. Moreover, X-ray detectors employing PCBM modulated with the MXene-MnFeO3 ETL achieved notable performance metrics including 18.47 μA/cm2 CCD-DCD, 5.53 mA/Gy·cm2 sensitivity, 7.64 × 10-4 cm2/V·s electron mobility, and 1.51 × 1015 cm2/V·s trap density.

Terrigenous or not? δ13C reveals the origin of the retene and dehydroabietic acid methyl ester

Retene and dehydroabietic acid methyl ester (DAME) are biomarkers linked mostly to terrigenous organic matter. However, their aquatic origin from algae and/or cyanobacteria has been discussed in the past few years. The complex origin of retene and DAME can lead to misinterpretation during biomarker interpretation, which can be minimalised with the support of isotopic analyses. This study contains the results of thirty-two compound-specific isotope analyses (CSIA) of δ13C performed on retene and forty-six CSIA analyses of δ13C performed on DAME. Obtained δ13C results were compared with simple biomarker results to tie isotopic data with the origin of organic matter. Pure aquatic retene and DAME were present within the Middle Cambrian and Early Ordovician samples, as the first appearance of plants was noted in the Middle Ordovician.CSIA was performed on a wide spectrum of the Cambrian-Silurian, Late Triassic-Middle Jurassic, and Neogene samples. Cambrian-Silurian strata include aquatic-origin retene and DAME, as evidenced by their comparatively low carbon isotopic signature. The average δ13C for retene and DAME within Cambrian-Silurian strata was equal to −31.7 ‰ and − 30.8 ‰, respectively. The Late Triassic-Middle Jurassic strata were dominated by terrigenous organic matter, resulting in higher δ13C values in comparison with the Cambrian-Silurian strata. The average δ13C for retene and DAME within the Late Triassic–Middle Jurassic strata was equal to −25.2 ‰ and − 26.3 ‰, respectively. The average δ13C for retene and DAME within the Neogene strata was equal to −27.3 ‰ in both cases, as these strata also contain a significant input of terrigenous organic matter. Some Neogene samples containing strong aquatic organic matter admixture are characterised by a lower δ13C for retene and/or DAME, oscillating around −28.0 ‰ to −30.0 ‰ for both compounds. Despite possible terrigenous input within some Silurian samples, the δ13C for retene and DAME still shows values typical for aquatic origin. These results suggest that retene and DAME within the Silurian strata should not be linked with non-vascular plants or that, due to their affinity with algae and cyanobacteria, the early plants were characterised by a relatively low δ13C composition, characteristic for phytoplankton organic matter. δ13C of retene and DAME were compared with δ13C of C16-C30n-alkanes and stigmastane, which supported the thesis about isotopic differences in aquatic and terrigenous retene and DAME.

The Allelopathic Effects of Persicaria salicifolia on the Growth and Antioxidant Enzymes of Synechocystis pevalekii and Tetradesmus bernardii

In recent years, there has been an increasing focus on the prospect of exploiting macrophytes as an alternative strategy to control undesired algal growth. The present research was conducted to study the effect of different concentrations of an aqueous stem extract of Persicaria salicifolia on the growth, some metabolites and antioxidant enzymes of the green microalgae Synechocystis pevalekii and Tetradesmus bernardii. Chlorophyll a, dry weight, total protein, total carbohydrate and proline contents of the tested algae decreased with increasing the crude extract concentrations of P. salicifolia. In general, catalase, superoxide dismutase and lipoxygenase activity of T. bernardii increased with increasing the aqueous extract of P. salicifolia. The identification of phytochemical components of the plant extract by gas chromatograph-mass spectrometry (GC-MS) revealed the presence of various biologically active compounds such as 11-Octadecenoic acid, methyl ester (18.03%) and 9,12-Octadecadienoic acid methyl ester (15.03%) that are capable of inhibiting the growth of S. pevalekii and T. bernardii. Therefore, P. salicifolia may provide a cheap and environmentally friendly alternative for controlling microalgae in aquatic ecosystems.

Investigation into the Fuel Characteristics of Biodiesel Synthesized through the Transesterification of Palm Oil Using a TiO2/CH3ONa Nanocatalyst

Biodiesel is a renewable and sustainable alternative fuel to petrol-derived diesel. Decreasing the operating costs by improving the catalyst’s characteristics is an effective way to increase the competitiveness of biodiesel in the fuel market. An aqueous solution of sodium methoxide (CH3ONa), which is a traditional alkaline catalyst, was immersed in nanometer-sized particles of titanium dioxide (TiO2) powder to prepare the strong alkaline catalyst TiO2/CH3ONa. The immersion method was used to enhance the transesterification reaction. The mixture of TiO2 and CH3ONa was calcined in a high-temperature furnace in a range between 150 and 450 °C continuously for 4 h. The heterogeneous alkaline catalyst TiO2/CH3ONa was then used to catalyze the strong alkaline transesterification reaction of palm oil with methanol. The highest content of fatty acid methyl esters (FAMEs), which amounted to 95.9%, was produced when the molar ratio of methanol to palm oil was equal to 6, and 3 wt.% TiO2/CH3ONa was used, based on the weight of the palm oil. The FAMEs produced from the above conditions were also found to have the lowest kinematic viscosity of 4.17 mm2/s, an acid value of 0.32 mg KOH/g oil, and a water content of 0.031 wt.%, as well as the highest heating value of 40.02 MJ/kg and cetane index of 50.05. The lower catalyst amount of 1 wt.%, in contrast, resulted in the lowest cetane index of 49.31. The highest distillation temperature of 355 °C was found when 3 wt.% of the catalyst was added to the reactant mixture with a methanol/palm oil molar ratio of 6. The prepared catalyst is considered effective for improving the fuel characteristics of biodiesel.

Study on gas–liquid sulfonation reaction under annular flow pattern in micro-reactor: Mechanism, model and process optimization

Micro-sulfonation is a new sulfonation method with great development potential. The gas–liquid micro-sulfonation are safe, efficient and low-cost, however, limited by the research progress and application scope of micro-reactors, the development of gas–liquid micro-sulfonation technique is far from enough. The gas–liquid sulfonation reaction process under annular flow pattern in micro-reactor is experimentally studied in this paper. The maximum MESA (fatty acid methyl ester sulfonic acid) yield under the experimental conditions in this study achieves 89.771 %, which is obviously higher than that (64.1 % for gas–liquid sulfonation and 76.82 % for liquid–liquid sulfonation) in conventional reactors and should be higher if the micro-reactor structure or operating conditions being further optimized. Based on the analyses of experimental results, the effect mechanisms of mass transfer and reaction on the gas–liquid micro-sulfonation efficiency are explored, and the sulfonation efficiency models and pressure drop model of four micro-reactors are established by dimensional analysis method. On account of both the mass transfer characteristics of gas–liquid two-phase flow and the high-viscosity of sulfonation products, enhancing the local disturbance of liquid phase can significantly improve the reaction efficiency. Finally, the operating conditions of two-phase flow rates and reaction time are optimized to ensure the high sulfonation product yield meanwhile reduce the fluid pressure drop or energy consumption of sulfonation process using the improved NSGA-II algorithm.

Phytochemical screening and quantitative analysis, FTIR and GC-MS analysis of Costus pictus D. Don ex Lindl. Leaf extracts – A potential therapeutic herb

Many medicinal plants play an essential role in medicine to prevent diseases due to the presence of several active chemicals. An effective strategy to combat non-communicable disease epidemics has been to introduce bioactive compounds from natural sources. Costus pictus is a versatile species which have exhibited beneficial properties against a variety of diseases. Multiple bioactive substances found in C. pictus have properties that are hypolipidemic, anti-hypertension, and anti-diabetic. GC-MS profiling revealed that the presence of (1alpha,2beta,5alpha)-2,6,6-trimethyl bicyclo [3.1.1] heptane, (Z)-9-Octadecenoic acid methyl ester, 1,2,4-Benzenetricarboxylic acid,-dodecyl dimethyl ester, 1-Hexanol, 2-ethyl-, 2,4-bis(1,1-dimethyl ethyl)-phenol, 2-Methoxy-4-vinylphenol, Benzeneethanamine, D-delta-tocopherol, Hexadecanoic acid, methyl ester, Methyl stearate, Phytol, and Phytol, acetate, β-Lapachone, 1,2,3-Propanetriol, 1-acetate, 2,6-Dihydroxynaphthalene, Benzene, (1- methyldodecyl)-, Curan-17-oic acid, 2,16-didehydro-20-hydroxy-, methyl ester, Phytol, (R)-(−)-(Z)-14-Methyl-8-hexadecen-1-ol, and Docosatrienoic acid and FTIR spectrum confirmed the presence of identified chemical compounds in C. pictus. The current findings support the necessity for further scientific studies that are beneficial to human health and therapeutic potential.

Interpenetrated Donor-Acceptor Heterojunctions in 2D Conjugated Dibenzo[g,p]chrysene-Based Kagome Covalent Organic Frameworks.

Dibenzo[g,p]chrysene can be viewed as a constrained propeller-shaped tetraphenylethylene with reduced curvature and has been utilized to construct dual-pore kagome covalent organic frameworks (COFs) with tightly packed two-dimensional (2D) layers owing to its rigid and more planar structural characteristics. Here, we introduce 2D COFs based on the node 4,4',4″,4‴-(dibenzo[g,p]chrysene-2,7,10,15-tetraphenyl)tetraamine (DBCTPTA) featuring extended conjugation compared to the dibenzo[g,p]chrysene-3,6,11,14-tetraamine (DBCTA) node. We establish two exceptionally crystalline imine-linked 2D COFs with a hexagonal dual-pore kagome structure based on the DBCTPTA core. The newly synthesized thienothiophene (TT) and benzodithiophene (BDT)-based DBCTPTA COFs show a tight stacking behavior between adjacent layers. Furthermore, we obtained an unprecedented, interpenetrated electron-donor/acceptor host-guest system with an electron-donating BDT DBCTPTA COF synthesized in situ with the soluble fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) serving as molecular acceptor. The BDT DBCTPTA COF@PCBM film shows a much shorter amplitude-averaged PL lifetime of 7 ± 2 ps compared to 30 ± 4 ps of the BDT DBCTPTA COF film, indicating the light-induced charge transfer process. The successful in situ formation of interpenetrated donor-acceptor heterojunctions within 2D COFs offers a promising strategy for establishing D-A heterojunctions in diverse framework materials with open channel systems.

Unveiling the Bioactive Potential of Bacterial Isolates from Extreme Environments of Pakistan by In Vitro and In Silico Approaches.

The soil hosts a wide array of bacterial species capable of producing diverse bioactive compounds. This research aimed to screen bacterial isolates for their bioactive potential from extreme environments in Pakistan. Out of the 69 isolates examined, only 7 exhibited antagonistic activity against Bacillus sp. and Escherichia coli test strains. Notably, the B. cereus DS-2 strain demonstrated the highest antibacterial potential (31mm and 15mm) against the Bacillus and E. coli test strains, respectively. Mode-of-action studies suggested that the crude extract might have induced morphological abnormalities in the Bacillus sp. (test strain), causing cell contraction, chain breakage, and deformation. Furthermore, the B. cereus DS-2 strain displayed significant antioxidant potential (64.8%) as revealed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Thin-layer chromatography (TLC) of the DS-2crude extract led to the separation of six components, with only spots 3 and 4 exhibiting the antibacterial potential (3mm and 5mm, respectively). Subsequently, gas chromatography-mass spectrometry (GC-MS) analysis of the bioactive fraction extracted from TLC revealed the presence of diisooctyl phthalate, dibutyl phthalate, hexadecanoic acid methyl ester, and octadecanoic acid methyl ester. Molecular docking analysis of diisooctyl phthalate and dibutyl phthalate revealed their binding affinity against E. coli and Bacillus sp. targets. ADMET analysis confirmed the solubility, toxicity, and drug-like properties of the ligands based on Lipinski's rule of five. Current findings suggest that these compounds hold promise as antibacterial agents in drug development. This study underscores the diverse microbial community present in extreme environments and highlights the versatile applications of natural products derived from these strains.

Effects of MCPA and difenoconazole on glyphosate degradation and soil microorganisms

Modern agriculture relies heavily on pesticide use to meet the demands of food quality and quantity. Therefore, pesticides are often applied in mixtures, leading to a diverse cocktail of chemicals and their metabolites in soils, which can affect non-target organisms such as soil microorganisms. Pesticides are tested for their single effects, but studies on their interactive effects are scarce. This study aimed to determine the effects of up to three simultaneously applied pesticides on the soil microbial community and on their special function in pesticide degradation. Agricultural soil without previous pesticide application was exposed to different mixtures of the herbicide glyphosate (GLP), the phenoxy herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid) and the fungicide difenoconazole (DFC) for up to 56 days. Isotopic and molecular methods were used to investigate effects of the mixtures on the microbial community and to follow the mineralization and utilization of GLP. An initial increase in the metabolic quotient by up to 35 % in the presence of MCPA indicated a stress reaction of the microbial community. The presence of multiple pesticides reduced both gram positive bacterial fatty acid methyl esters (FAMEs) by 13 % and the abundance of microorganisms with the genetic potential for GLP degradation via the AMPA (aminomethylphosphonic acid) pathway. Both the number of pesticides and the identities of individual pesticides played major roles. Surprisingly, an increase in 13C-labelled GLP mineralization of up to 40 % was observed while carbon use efficiency (CUE) decreased. Interactions between multiple pesticides might alter the behavior of individual pesticides and be reflected in the microbial community. Our results highlight the importance of investigating not only single pesticides, but also pesticide mixtures and their interactions.

Microbial dynamics, chemical profile, and bioactive potential of diverse Egyptian marine environments from archaeological wood to soda lake

Halophilic archaea are a unique group of microorganisms that thrive in high–salt environments, exhibiting remarkable adaptations to survive extreme conditions. Archaeological wood and El–Hamra Lake serve as a substrate for a diverse range of microorganisms, including archaea, although the exact role of archaea in archaeological wood biodeterioration remains unclear. The morphological and chemical characterizations of archaeological wood were evaluated using FTIR, SEM, and EDX. The degradation of polysaccharides was identified in Fourier transform infrared analysis (FTIR). The degradation of wood was observed through scanning electron microscopy (SEM). The energy dispersive X–ray spectroscopy (EDX) revealed the inclusion of minerals, such as calcium, silicon, iron, and sulfur, into archaeological wood structure during burial and subsequent interaction with the surrounding environment. Archaea may also be associated with detected silica in archaeological wood since several organosilicon compounds have been found in the crude extracts of archaeal cells. Archaeal species were isolated from water and sediment samples from various sites in El–Hamra Lake and identified as Natronococcus sp. strain WNHS2, Natrialba hulunbeirensisstrain WNHS14, Natrialba chahannaoensis strain WNHS9, and Natronococcus occultus strain WNHS5. Additionally, three archaeal isolates were obtained from archaeological wood samples and identified as Natrialba chahannaoensisstrain W15, Natrialba chahannaoensisstrain W22, and Natrialba chahannaoensisstrain W24. These archaeal isolates exhibited haloalkaliphilic characteristics since they could thrive in environments with high salinity and alkalinity. Crude extracts of archaeal cells were analyzed for the organic compounds using gas chromatography–mass spectrometry (GC–MS). A total of 59 compounds were identified, including free saturated and unsaturated fatty acids, saturated fatty acid esters, ethyl and methyl esters of unsaturated fatty acids, glycerides, phthalic acid esters, organosiloxane, terpene, alkane, alcohol, ketone, aldehyde, ester, ether, and aromatic compounds. Several organic compounds exhibited promising biological activities. FTIR spectroscopy revealed the presence of various functional groups, such as hydroxyl, carboxylate, siloxane, trimethylsilyl, and long acyl chains in the archaeal extracts. Furthermore, the archaeal extracts exhibited antioxidant effects. This study demonstrates the potential of archaeal extracts as a valuable source of bioactive compounds with pharmaceutical and biomedical applications.

A CHEMCAD Software Design Approach for Non-Conventional Biodiesel Production Using Methyl Acetate as Feedstock

Biodiesel is a sustainable and renewable fuel generated from renewable resources, including vegetable oil or animal fats. It is thought to be a non-toxic fuel that degrades gradually and causes no harm to the environment. In the present study, a non-conventional supercritical method for industrial biodiesel production is investigated. The non-conventional method refers to a single-step interesterification reaction between triglycerides and methyl acetate resulting in methyl esters of fatty acids and triacetin as a secondary product. Process flowsheet modeling, using CHEMCAD chemical engineering software, was used as an investigation tool. The production capacity was set to 25,000 kg/h biodiesel. Methyl acetate requested in the biodiesel production is produced from methanol esterification with acetic acid using an intensified reactive distillation unit. Methanol, in turn, is obtained using synthetic gas derived from biomass as a raw material, the process representing a new method at the industrial level to solve problems related to the energy that is required, storage and disposal of residual materials, and pollution through the release of pollutants into the air. The methanol synthesis process is similar to the one based on natural gas, consisting of three main steps, namely: (i) synthesis gas production, followed by (ii) methanol production, and (iii) methanol purification. Acetic acid is an essential chemical product, generated in the proposed approach by a sustainable method with low energy consumption and low air emissions, more exactly methanol carbonylation. All the processes previously mentioned: (i) biodiesel production, (ii) methyl acetate production, (iii) acetic acid production, and (iv) methanol production were modeled and simulated, leading to the desired biodiesel productivity (e.g., 25,000 kg/h) with the obtained purity being higher than 99%. Relevant discussions regarding the design assumptions used, the simulation and validation results, as well as other technical issues (i.e., electricity and thermal energy consumption) for the system being simulated, are provided, leading to the conclusion that the proposed route is well suited for the desired application and can deliver significant results. The simulation outcomes have provided confidence in the feasibility and effectiveness of the chosen process design, making it a viable option for further development and implementation.

Influence of Solid Alkaline Photocatalysts Irradiated with UV Light on Fuel Properties of Palm Oil Biodiesel.

TiO2 nanoparticles are full of porosity that can be impregnated with a strong alkaline catalyst CH3ONa to form a TiO2/CH3ONa catalyst. TiO2 of the anatase phase, which is a semiconductor material, has been a prominent photocatalyst due to its excited photocatalyst activity, chemical and biological stability, and nontoxicity. The CH3ONa compound has been widely used as a catalyst for transesterification. Although the synthesized photocatalyst TiO2 powder with CH3ONa is anticipated to greatly enhance the transesterification efficiency, leading to improving biodiesel properties, relevant studies have not been found. After the photocatalyst was prepared, a reactant mixture of palm oil, methanol, and heterogeneous catalyst TiO2/CH3ONa was illuminated by ultraviolet (UV) light from light-emitting diode (LED) lamps. The experimental results revealed that the formation of fatty acid methyl esters was significantly increased to 98.4% with ultraviolet-light illumination for the molar ratio of methanol/palm oil equal to 6 and 3 wt % catalyst addition. The decrease of the catalyst amount to 2 wt % resulted in a slight decrease of the fatty acid methyl esters to 97.06 wt %. The lowest kinematic viscosity and acid value and the highest distillation temperature, heating value, and cetane index were observed under the above reaction conditions. The distillation temperature and cetane index were increased while the acid value was decreased under ultraviolet illumination on the reactant mixture. Consequently, the optimum preparing conditions for biodiesel production were 6 and 3 wt % for the molar ratio of methanol/palm oil and catalyst addition under UV-light irradiation.

Upconversion-nanoparticle-assisting near-infrared photosensitive effect at 1550 nm in organic photorefractive devices

The near-infrared (NIR) photosensitive photorefractive device is a promising optoelectronic unit in the optical signal/information processing and telecommunication. In this work, the upconversion-assisting NIR photosensitive device is presented by adding the upconversion nanoparticles (UCNPs) to the photorefractive composite with (Vlieg et al., 2022; Vlieg et al., 2022) [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as visible photosensitizer. The XRD and TEM results indicated the hexagonal β-phase nanoparticles of UCNPs. The PL measurement under the 1550-nm excitation showed the upconversion emission peaks of NaYF4:Er@NaYF4 nanocrystals at the visible lights of 525 nm, 545 nm and 650 nm. The SEM images revealed that the CRA-DR1 photorefractive composite takes on a good morphology due to the uniform distribution of UCNPs. The two-beam coupling (TBC) experiment without external electric filed indicated the coupling gain coefficient of 77.4 cm−1 at 1550 nm in the CRA-DR1/ECZ/PC61BM/(5 %)UCNPs composite. This upconversion-assisting photosensitive effect will open up the novel approaches for organic NIR photorefractive devices.

Comparative Study of Immobilized Biolipasa-R for Second Generation Biodiesel Production from an Acid Oil.

The primary objective of this work is to develop a sustainable biocatalytic transesterification process for low-grade oils, aligning with EU green technology requirements for the shift to second generation biodiesel. Thus, we investigated the immobilization and subsequent application of the lipase Biolipasa-R on transesterification processes to produce fatty acid methyl esters (FAMEs) from both a sunflower oil and an acid oil which is a bioproduct of the biodiesel industry. The lipase was immobilized on biomaterials, such as diatomaceous earth, with a yield of 60 %, and commercial carriers such as methacrylic resins with a yield of 100 %. The enzyme demonstrated superior activity when immobilized on diatomaceous earth, particularly in reactions involving the acid oil, outperforming the benchmark enzyme Novozym® 435 (95.1 % and 35 % conversion respectively). This work highlights the potential of Biolipasa-R as a cost-effective and efficient biocatalyst for biodiesel production and emphasizes the environmental benefits of utilizing industrial byproducts and eco-friendly immobilization techniques. The findings suggest that Biolipasa-R is a promising candidate for industrial applications in biodiesel production, offering a sustainable solution for waste management and energy generation.

Characterization of a GDS(L)-like hydrolase from Pleurotus sapidus with an unusual SGNH motif

The GDS(L)-like lipase from the Basidiomycota Pleurotus sapidus (PSA_Lip) was heterologously expressed using Trichoderma reesei with an activity of 350 U L−1. The isoelectric point of 5.0 was determined by isoelectric focusing. The novel PSA_Lip showed only 23.8–25.1%, 25.5%, 26.6% and 28.4% identity to the previously characterized GDSL-like enzymes phospholipase, plant lipase, acetylcholinesterase and acetylxylan esterase, from the carbohydrate esterase family 16, respectively. Therefore, the enzyme was purified from the culture supernatant and the catalytic properties and the substrate specificity of the enzyme were investigated using different assays to reveal its potential function. While no phospholipase, acetylcholinesterase and acetylxylan esterase activities were detected, studies on the hydrolysis of ferulic acid methyl ester (~ 8.3%) and feruloylated carbohydrate 5-O-transferuloyl-arabino-furanose (~ 0.8%) showed low conversions of these substrates. By investigating the hydrolytic activity towards p-nitrophenyl-(pNP)-esters with various chain-lengths, the highest activity was determined for medium chain-length pNP-octanoate at 65 °C and a pH value of 8, while almost no activity was detected for pNP-hexanoate. The enzyme is highly stable when stored at pH 10 and 4 °C for at least 7 days. Moreover, using consensus sequence analysis and homology modeling, we could demonstrate that the PSA_Lip does not contain the usual SGNH residues in the actives site, which are usually present in GDS(L)-like enzymes.

Utilization of opium poppy seed oil for biodiesel production: A parametric characterization and statistical optimization

Consuming traditional petroleum-derived diesel fuel has long been associated with issues such as the depletion of natural energy resources. To solve these challenges, an alternate source like as biodiesel is an appealing option. Seed oils have long been recognized as an abundant and diverse source of biodiesel. In this study, poppy seed oil from the poppy (Papaver somniferum) was investigated for biodiesel production. Poppy seed biodiesel was generated and refined using acid-pretreated esterification with sulphuric acid prior to transesterification, as well as single-step alkaline catalyzed transesterification with methanol and potassium hydroxide. Finally, the percentage yield was compared. Using Statistica, the Box-Behnken design was applied to optimize process variables like time, temperature, catalyst concentration, and methanol-oil ratio to produce maximum yield. The relationship of process variables was also shown with the help of the Response Surface Methodology. A maximum yield of 94.87 % was obtained at optimized conditions, i.e., 90min reaction time, 60 °C of temperature, 0.25 mg of catalyst concentration, and 3v/v% alcohol-oil ratio. The fuel properties of biodiesel produced, such as acid value, moisture content, saponification value, iodine value, specific gravity, percentage of free fatty acids, refractive index, viscosity, boiling point, and peroxide value, were measured and compared with the American Society for Testing and Materials (ASTM) D6751 and European Standards (EN) 14214. Further results were studied and discussed using Fourier Transfer Infrared (FTIR) analysis, which showed maximum similarity of raw material to formed biodiesel. Gas Chromatography-Mass Spectrometry (GC-MS) analysis was performed to identify and quantify various fatty acid methyl esters. The results obtained were in accordance with various international standards for biodiesel fuel. Thus, poppy seeds can be used to obtain biodiesel.

Monoaromatic Compounds Biodegradation by Hydrocarbon-Oxidizing Actinobacteria

Monoaromatic substances belong to the most widespread and dangerous environmental pollutants. They are components of wastewater from oil refineries and the coal and chemical industries and are often found in soil, groundwater, and surface water. The use of actinobacteria for bioremediation of natural and industrial objects contaminated by these substances is an environmentally and economically advantageous alternative to physicochemical cleaning methods. Therefore, it is actual to search for new actinobacteria strains capable to assimilate of monoaromatic compounds for their further use in biotechnologies of purification of the environment polluted by these substances. Aim. To determine the ability of hydrocarbon-oxidizing strains of actinobacteria of the Ukrainian Collection of Microorganisms to assimilate monoaromatic compounds − derivatives of benzene and phenol. Methods. The strain cultivation was carried out in a liquid mineral medium at an initial concentration of monoaromatic compounds of 500 mg/L as the only source of carbon and energy. The expression activity of the catA gene encoding catechol 1,2-dioxygenase, the key enzyme at the initial stage of the monoaromatic compounds biodegradation, was assessed under culture growth conditions with phenol and glucose. Relative expression of the catA gene was evaluated using RT-qPCR. Fatty acid methyl esters were obtained by hydrolysis of cells in a 5 % solution of acetyl chloride in methanol, followed by extraction with an ether-hexane mixture. Methyl esters were identified using an Agilent 6800N/5973 inert GC/MS system (Agilent Technologies, US). Fatty acid content was determined by AgilentChemStation software. Results. It was established that the studied strains of actinobacteria belonging to the species Dietzia maris, Gordonia rubripertincta, Rhodococcus aetherivorans, and Rhodococcus erythropolis differ in their ability to assimilate monocyclic aromatic compounds − benzene and phenol derivatives. Most strains grew better in media with benzene and its derivatives. All strains well grew on a mixture of ethylbenzene, ortho-, meta-, and para-xylene (EX), most of them grew with different intensities on a mixture of benzene, toluene, and ortho-xylene (BTX), and on monosubstrates – benzene, benzotriazole, and benzoate. Toluene was used by 50 % of the studied strains, and only one of them (R. aetherivorans UCM Ac-602) grew on ortho-xylene. A smaller amount of strains grew in media with phenol derivatives. They did not assimilate ortho-cresol and hydroquinone but grew with different intensities on phenol, paranitrophenol, resorcinol, and catechol. Only a few strains grew in the presence of meta- and para-cresols. The widest range of monoaromatic substances was used by R. aetherivorans UCM Ac-602. It was shown that in the process of phenol assimilation by strain R. aetherivorans UCM Ac-602, the level of transcriptional activity of the catA gene encoding the key enzyme of an ortho-pathway of aromatic ring cleavage, catechol 1,2-dioxygenase, increased almost 2-fold after 48 h compared to 24 h of strain growth on this substrate and 3-fold compared to glucose. The obtained data indicate the ability of R. aetherivorans UCM Ac-602 strains to assimilate monoaromatic substances through theortho-cleavage way. During growth on benzene, toluene, BTX and EX substances, the fatty acid pool of cells of this strain was dominated by hexadecanoic C16:0 (32.73-39.81 %), hexadecenoic C16:1 cis-9 (5.66-15.11 %), and octadecenoic C18:1 cis-9 (7.09-11.83 %) acids, as well as 10-methyloctadecanoic 10-Me-C18:0 (29.88-34.76 %) acid. The composition of fatty acids of cells grown on aromatic compounds, unlike those grown on glucose, contained 2.4-4.0 times less unsaturated C18:1 cis-9 acid and 2.8-3.2 times more methyl-branched acid 10Me-C18:0. Conclusions. Assimilation of monoaromatic compounds − derivatives of benzene and phenol - is a strain-specific characteristic of the actinobacteria species. Using strain R. aetherivorans UCM Ac-602 as an example, it was shown that the assimilation of monoaromatic substances in studied actinobacteria occurs through the ortho-cleavage pathway. One of the adaptation mechanisms of strain R. aetherivorans UCM Ac-602 to the assimilation of these substances is a significant decrease in unsaturated fatty acids and an increase in methyl branched acids, which contributes to an increase in membrane rigidity and cell resistance to the toxic effect of these substrates. The data obtained indicate a high level of adaptation of actinobacteria to the assimilation of monoaromatic compounds and the prospects for their further study to be used in biotechnologies for environmental purification from these pollutants.

Direct application of tungstosilicic acid hydrate for the treatment of high free fatty acid in acidic crude palm oil and for biodiesel production

AbstractThis study explored the use of industrial acidic crude palm oil (ACPO) for biodiesel production, facing a significant obstacle due to its high free fatty acid (FFA) content, which complicates the biodiesel production process. Typically, esterification is employed to convert FFAs into fatty acid methyl ester (FAME). Herein, the effectiveness of tungstosilicic acid hydrate (TSAH) as an unsupported heteropoly acid (HPA) catalyst for FFA esterification in ACPO was investigated. The FFA content was reduced from 8.43% to 0.95% under optimum conditions (4 wt% catalyst dosage, a methanol to oil molar ratio of 10:1, 150 min and a temperature of 60°C). Noteworthy, the TSAH catalyst showed stability over 7 cycles. The kinetic analysis revealed that the FFA esterification process closely followed pseudo first‐order kinetics, with an R2 value of 0.94. Furthermore, the biodiesel produced from TSAH‐treated ACPO meets the standard specifications outlined by ASTM D6751 and EN 14214. This research highlights the effectiveness of TSAH in catalyzing FFA esterification without the need for additional support materials or modifications.

In-situ construction of solid electrolyte interphase for stable zinc anode via synergy of electrochemical reduction and chemical precipitation

Aqueous zinc ion batteries (ZIBs) feature high theoretical capacity, low cost, and high safety, but they suffer from moderate reversibility arising from electrolyte decomposition, Zn corrosion/passivation, and dendrite growth. To address this issue, an effective strategy is to construct a functional solid electrolyte interface (SEI) in situ. However, this is substantially challenging owing to the severe hydrogen evolution reaction (HER) and a lack of substances that can be decomposed to form SEI in the aqueous electrolytes. Herein, we propose the fabrication of a stable SEI in situ via a synergistic electrochemical reduction-chemical precipitation approach. By chemically capturing the hydroxide ions (OH−) from HER, fatty acid methyl ester ethoxylate (FMEE), as an aqueous electrolyte additive, undergoes ester group hydrolysis following by a combination with Zn2+ to form insoluble fatty acid-zinc, enabling intelligent growth of a SEI on the Zn anode surface. As a result, the enhanced Zn anode exhibits a prolonged cycling life of up to 2700 h at 1 mA/cm2 and 1 mAh/cm2. The Zn-V2O5 full cell with the designed electrolyte demonstrates excellent rate capability and significantly improved cycling stability. This study presents a simple and practical strategy for in-situ formation of SEI in aqueous electrolytes, advancing the development of high-performance aqueous batteries.

Antimicrobial metabolites from Probiotics, Pleurotus ostreatus and their co-cultures against foodborne pathogens isolated from ready-to-eat foods

BackgroundThe incidence of foodborne pathogens in ready- to-eat (RTE) can be attributed to various foodborne diseases. Most of the isolated microorganisms from RTE foods are resistant to common antibiotics and thus, resulted to treatment failure when commercially available antibiotics are administered. However, the secondary metabolites secreted by microorganisms can serve as alternative therapy that are reliable and safe. Secondary metabolites obtained from mono- and co-culture microorganisms can inhibit the growth of antibiotic-resistant microorganisms. Bioactive compounds in the secreted metabolites can be identified and utilized as sources of new antibiotics. In this study, antimicrobial activity of secondary metabolites from Lactobacillus fermentum, Saccharomyces cerevisiae, Pleurotus ostreatus, and their co-cultures were tested against foodborne pathogens isolated from RTE foods using agar well diffusion. The bioactive compounds in the metabolites were identified using gas chromatography-mass spectrometry.ResultsFrom a total of 100 RTE foods examined, Salmonella enterica, Shigella dysenteriae, Escherichia coli, Klebsiella pneumoniae (subsp ozaenae), Pseudomonas fluorescens, Clostridium perfringes, Bacillus cereus, Listeria monocytogens, and Staphylococcus aureus, Penicillium chrysogenum, Aspergillus flavus, and Aspergillus niger were isolated and displayed multiple antibiotic resistance. The secondary metabolites secreted by co-culture of L. fermentum + P. ostreatus + S. cerevisiae, and co-culture of P. ostreatus + S. cerevisiae have the highest (P ≤ 0.05) zones of inhibition (23.70 mm) and (21.10 mm) against E. coli, respectively. Metabolites from mono-cultured L. fermentum, P. ostreatus, and S. cerevisiae showed zones of inhibition against indicator microorganisms with values ranging from 8.80 to 11.70 mm, 9.00 to 14.30 mm, and 9.30 to 13.00 mm, respectively. Some of the bioactive compounds found in the metabolites of co-cultured microorganisms were alpha-linolenic acid (25.71%), acetic acid 3-methylbutyl ester (13.83%), trans-squalene (12.39%), pentadecylic acid (11.68%), 3- phenyllactic acid (30.13%), linolelaidic acid methyl ester (15.63%), and 4-O-methylmannose (53.74%).ConclusionRTE foods contain multiple antibiotics resistance pathogens. The pronounced antimicrobial activity of the secondary metabolites against microorganisms from RTE foods could be attributed to the presence of bioactive compounds in the metabolites. These metabolites can be exploited as alternative food preservatives, biopharmaceuticals and can be used towards better health delivering systems.