Optimum pH Value Research Articles

Maximizing Bio-Hydrogen Production from an Innovative Microbial Electrolysis Cell Using Artificial Intelligence

In this research work, the best operating conditions of microbial electrolysis cells (MECs) were identified using artificial intelligence and modern optimization. MECs are innovative materials that can be used for simultaneous wastewater treatment and bio-hydrogen production. The main objective is the maximization of bio-hydrogen production during the wastewater treatment process by MECs. The suggested strategy contains two main stages: modelling and optimal parameter identification. Firstly, using adaptive neuro-Fuzzy inference system (ANFIS) modelling, an accurate model of the MES was created. Secondly, the optimal parameters of the operating conditions were determined using the jellyfish optimizer (JO). Three operating variables were studied: incubation temperature (°C), initial potential of hydrogen (pH), and influent chemical oxygen demand (COD) concentration (%). Using some measured data points, the ANFIS model was built for simulating the output of MFC considering the operating parameters. Afterward, a jellyfish optimizer was applied to determine the optimal temperature, initial pH, and influent COD concentration values. To demonstrate the accuracy of the proposed strategy, a comparison with previous approaches was conducted. For the modelling stage, compared with the response surface methodology (RSM), the coefficient of determination increased from 0.8953 using RSM to 0.963 using ANFIS, by around 7.56%. In addition, the RMSE decreased from 0.1924 (using RSM) to 0.0302 using ANFIS, whereas for the optimal parameter identification stage, the optimal values were 30.2 °C, 6.53, and 59.98 (%), respectively, for the incubation temperature, the initial potential of hydrogen (pH), and the influent COD concentration. Under this condition, the maximum rate of the hydrogen production is 1.252 m3H2/m3d. Therefore, the proposed strategy successfully increased the hydrogen production from 1.1747 m3H2/m3d to 1.253 m3H2/m3d by around 6.7% compared to RSM.

Silver ions immobilized on thiourea/formaldehyde resin for solid phase extraction of iodide ions from aqueous solution

Iodine has been found to have considerable effects on tropospheric photochemistry, which in turn affects climate by lowering ozone's radiative forcing and air quality by lowering extreme O3 concentrations in polluted areas. The majority of the iodine that naturally occurs in the water is in the form of aqueous iodide and iodate. To extract iodide from the aqueous solution, thiourea-formaldehyde resin (TF) was prepared by condensation polymerization and then loaded with Ag(I) ions (Ag-TF). TF resin was characterized by a specific surface area close to 111.3 m2 g−1, and nitrogen and sulphur content of 20.57 and 10.01 mmol g−1, respectively. After calculation of the adsorbed amount of Ag(I) ions, the prepared Ag-TF adsorbent was introduced for the solid phase extraction of iodide anions under various operational parameters of pH (e.g., 1.6 – 10.7), adsorbent dose (e.g., 0.5 – 5.0 g L−1), primary iodide concentrations (e.g., 0.075 – 3.96 mmol L−1), and residence time (e.g., 5 – 400 min), and sonication time (e.g., 5–45 min). The findings revealed that the adsorption of iodide onto as-produced TF adsorbent was matched with the Langmuir model with a prominent loading capacity of 1.26 mmol g−1, under an optimized pH value of 2.7. The study of uptake kinetics investigates the influence of the mode of agitation; comparing more specifically the performance of mechanical agitation with those obtained with ultrasonication (at frequencies of 37 and 80 kHz). The ultra-sonication treatment decreased interestingly the adsorption equilibrium time from 400 min to only 45 min. Overall, the present study illustrates the susceptibility of Ag-TF adsorbent as a promising material for the efficient elimination of I− anions from an aqueous medium.

Improving Catalytic Activity, Acid-Tolerance, and Thermal Stability of Glutathione Peroxidase by Systematic Site-Directed Selenocysteine Incorporation.

Glutathione peroxidase (GPx) is an important antioxidant enzyme. Selenocysteine (Sec)-containing GPxs (Sec-GPxs) are usually superior to their conventional cysteine-containing counterparts (Cys-GPxs), which make up the majority of the natural GPxs but display unsuitable activity and stability for industrial applications. This study first heterologously expressed and characterized a Cys-GPx from Lactococcus lactis (LlGPx), systematically exchanged all the three Cys to Sec and introduced an extra Sec. The results showed that the insertion of Sec at the active site could effectively increase the enzyme activity and confer a lower optimal pH value on the mutants. The double mutant C36U/L157U increased by 2.65 times (5.12 U/mg). The thermal stability of the C81U mutant was significantly improved. These results suggest that site-directed Sec incorporation can effectively improve the enzymatic properties of LlGPx, which may be also used for the protein engineering of other industrial enzymes containing catalytic or other functional cysteine residues.

Chemically Activated Carbon Based on Biomass for Adsorption of Fe(III) and Mn(II) Ions from Aqueous Solution.

Rice husk was converted into activated carbon (AC) as a byproduct of agricultural waste in an electric furnace at 700 °C and chemically activated using three distinct processes: NaOH AC(C), acetic acid AC(C-1), phosphoric acid AC(C-2), and carbonization AC(C-3) without any chemical activation. To characterize the activated carbon and the removal efficiencies of Fe(III) and Mn(II) from aqueous solutions, various analytical tools were used. The results revealed that the capacities of the four adsorbents to adsorb Fe(III) or Mn(II) from an aqueous solution differ significantly. AC(C-3) was chosen for additional research. The impact of different operational factors, including pH, contact time, adsorbent dosage, starting metal ion concentration, interfering ions, and temperature, were investigated. The optimum pH values for Fe(III) and Mn(II) adsorption were found to be pH 3 and pH 6, respectively. The results obtained were utilized to assess the kinetics and thermodynamics of the adsorption process. The sorption of Fe(III) and Mn(II) ions was found to be a pseudo-second-order kinetic process, and the equilibrium data were fitted with the Langmuir isotherm. Additionally, the evidence suggests that an endothermic mechanism governs the adsorption process. The maximum adsorption capacities of Fe(III) and Mn(II) were 28.9 and 73.47 mg/g, respectively.

Adsorption mechanism of Cr(VI) on woody-activated carbons

To provide guidance for the selection of woody-activated carbon in the treatment of wastewater containing hexavalent chromium (Cr(VI)), the adsorption tests on two varieties of commercial woody-activated carbon powder from different manufacturers were carried out. The physicochemical properties and structural characteristics of activated carbon were studied by using elemental, chemical, and instrumental analyses. The adsorption mechanism of Cr(VI) was discussed by investigating the factors affecting the removal of hexavalent chromium. The two kinds of woody-activated carbon have microporous and mesoporous structures. Commercial woody-activated carbon No.1 (ACI) has a more extensive specific surface area and a better-developed pore structure. While ACI exhibits a higher adsorption capability when the content of Cr(VI) is high, commercial woody-activated carbon No.2 (AC) can remove hexavalent chromium fast when the concentration is low. A rise in pH value is not helpful for the materials to remove Cr(VI) from solutions. For Cr(VI) removal, the optimum pH value is 2. The adsorption of Cr(VI) by AC and ACI followed the pseudo-second-order kinetic model and Langmuir isothermal adsorption equation. The maximum adsorption value of Cr(VI) is 154.56 mg/g for AC and 241.55 mg/g for ACI. There is chemical adsorption during the Cr(VI) removal. A lot of Cr (Ⅲ) was formed by Cr(VI). The abundance of pores and the reducing ability of the materials are essential for the removal of Cr(VI).

Growth Kinetics of Kazachstania unispora and Its Interaction with Lactic Acid Bacteria during Qymyz Production

Qymyz is a traditional acidic and ethanolic beverage in central Asian countries made from mare milk fermentation with lactic acid bacteria (LAB) and yeasts. Modeling the growth of microorganisms during fermentation is one of the methods used to control the quality of fermented products. The objective of the study was, firstly, to model the growth kinetics of Kazachstania unispora found in qymyz, and, secondly, to understand their interaction with Lacticaseibacillus casei and Lactobacillus kefiri during the fermentation of mare milk. The K. unispora optimum values of pH and temperature were 4.81 ± 0.22 and 30.16 ± 0.53 °C, respectively, with an optimal growth rate (µopt) of 0.56 ± 0.02 h−1. K. unispora had an ethanol production rate of 6.1 × 10−8 mg·CFU−1. Growth, in terms of limiting substrates showed a lower Ks value for galactose at 0.13 ± 0.04 mg·mL−1 with µopt of 0.45 ± 0.01 h−1, while, for glucose, the Ks was 0.24 ± 0.03 mg·mL−1 with the same µopt. Cocultures of K. unispora were conducted with L. casei and L. kefiri in a synthetic medium and mare milk. The results showed that K. unispora growth was limited and, thus, its ethanol production capacity was inhibited. VOC analysis of mare milk fermented with the studied strains and their cocultures resulted in 37 major volatile compounds. Statistical analysis of the VOC profiles showed that K. unispora modulates the aroma production in coculture with LAB.

Impact of temperature and pH on calcite inhibition using innovative green scale inhibitors

This experimental study aimed at predicting firstly the critical mixing ratio of two incompatible aqueous phases of formation water and seawater by PHREEQC (pH-redox-equilibrium conditions) at temperatures of 40, 70, and 90 °C. Secondly, the performance of two green scale inhibitors (SI) of folic acid and inulin was experimentally studied through standard static jar tests in order to determine the optimum concentration and pH at which the calcite mitigation would be maximized. The optimum pH values of 4 and 6 were respectively found for folic acid and inulin, at three investigated temperatures. Interestingly, the inhibition efficiency of these SIs increased with temperature which is advantageous for the oil reservoirs. SEM (Scanning Electron Microscopy) and TGA (thermogravimetric analysis) analyses were also carried out to discern the SIs’ inhibition mechanisms and thermal performance. The SEM results showed that folic acid and inulin would inhibit precipitation under the crystal modification and threshold inhibition mechanisms, respectively. Furthermore, TGA analysis showed that these green SIs would sustain high temperatures, although their weight losses (heating rate of 10 °C /min and T < 100 °C) were almost 3.25 % and 9.15 % for folic acid and inulin, respectively.

Adsorption/desorption behavior of ionic dyes on sintered bone char

The aim of this study was to investigate the regularity and differences in the adsorption/desorption behavior of bovine rib char (BC) as an adsorbent material for the cationic Malachite Green (MG) and anionic Sunset Yellow (SY) dyes. The effects of pyrolysis temperature, adsorbent dosage, solution pH, initial concentration, contact time, and adsorption temperature were investigated. The pore characteristics of BC were determined by the Brunauer-Emmett-Teller (BET) method. The changes in functional groups before and after the adsorption of BC were analyzed by Fourier transform infrared spectroscopy. And the chemical composition and surface morphology of BC were characterized by X-ray diffraction and scanning electron microscopy. The experimental data were further analyzed using different isotherm models, kinetic models, and thermodynamic equations, and an understanding of the adsorption studies was carried out. The results show that BC is 90% mesoporous with a BET specific surface area of approximately 150 m2/g. BC is rich in active sites at 700 °C and performs best in the adsorption process. The adsorption of MG increases with increasing pH, while the opposite is true for SY, with optimum pH values of 7 and 3, respectively. Ionic dyes bind to BC easily (the fitted values for the Freundlich model 1/n are all less than 0.5, R2 > 0.748). The maximum adsorption capacity (Qmax) of MG was much higher than that of SY (the Langmuir model indicated Qmax of 1168.4 mg/g and 47.0 mg/g, respectively, R2 > 0.830). The adsorption of ionic dyes on BC was mainly non-homogeneous surface chemisorption, which was spontaneous (ΔG<0, ΔH>0). The desorption of BC after adsorption of MG and SY in HCl and NaOH solutions, respectively, was better. Analysis of the adsorption contribution of the BC fraction showed that the mineral fraction played an important role in the adsorption process (about 94%), while the organic fraction contributed about 6%. The experimental results indicate that the adsorption mechanism of MG and SY on BC can be attributed to the filling of mesopores, electrostatic interaction between the ionic polar sites of BC and the different charged dyes, the formation of chemical bonds between the oxygen-containing functional groups on the surface of BC and the dyes, and the ionic exchange between the polar sites of BC such as Ca2+, PO43−, CO32− and OH−.

PH shifting effect on anionic dye removal by surfactant-modified sugar beet pulp: Modeling of column studies

pH shifting effect on the adsorption of anionic RBB dye was tested by using untreated and CTAB-treated SBP as adsorbent in both batch and continuous systems. Characterization of the sorbents revealed the effects of surface modification. Enhanced binding sites and more porous surface structure resulted in improved adsorption capability. Flow rate and initial RBB concentration effects were tested in packed bed column. Optimum pH value of the adsorption, which was determined as 2.0 in the batch studies with untreated SBP, shifted to 8.0 with 20 g/L CTAB treated SBP. Experimental data in column studies showed the decreasing capacity with increasing flow rate and enhanced performance with increasing inlet RBB concentration for both sorbents. Maximum capacities of the columns were found as 36.9 and 2.6 mg/g with dried SBP at pH 2.0 and 8.0, respectively, at a maximum inlet RBB concentration of 500 mg/L and a minimum flow rate of 0.8 mL/min. The highest capacity value at pH 8.0 was found as 140.0 mg/g under the same operating conditions, which reveals positive effect of the treatment on adsorptive performance. Langmuir isotherm was found to be most convenient model for the all equilibrium cases in the column. Moreover, Thomas model accurately predicted the breakthrough curves of each system. This is the first study reporting the modeling data of an anionic dye adsorption in a packed bed column by using modified SBP.

Ultrasound assisted preparation, characterization, and application of biosorbent for Rhodamine 6G removal from wastewater

AbstractNatural adsorbents offer promise for application in environmental protection mainly based on the cost efficiency and biodegradable nature. In the current work, a biosorbent has been synthesized from coconut shell (a common agrochemical waste) in the presence of ultrasound with an objective to improve the microstructure of the carbon coupled with activation using mixture of HNO3 with H2SO4 (7:3 proportion). SEM analysis clearly confirmed that ultrasound induced cavitational effects improved the porous structure of the sample. FTIR and XRD results confirmed the favorable adsorption characteristics for the synthesized activated carbon with no negative changes due to the use of ultrasound. The synthesized adsorbent was used for the removal of a toxic dye, Rhodamine 6G present in effluent at a level of 25 mg L−1. The detailed study into effect of operating parameters elucidated that optimum treatment time for maximum dye removal was 22 min whereas the optimal value of biosorbent loading and pH were 8 gL−1 and 10, respectively. The equilibrium data was fitted into different types of adsorption isotherm models, and Langmuir isotherm model was elucidated as the best fitted model with an adsorption capacity of 90.9 mg g−1. Similarly, the kinetic studies revealed that pseudo second order model fitted better than all the other models. Overall, the efficacy of prepared adsorbent in the presence of ultrasound was effectively demonstrated for the Rhodamine 6G removal from wastewater, also demonstrating the effect of different operating conditions during the adsorption.

Investigation of the effects of pesticides on 'Jonagold' apple (Malus x domestica) polyphenol oxidase enzyme activity

this study, the effects of a number of commonly used pesticides on the activity of the polyphenol oxidase (PPO) enzyme from pesticide-free and pesticide-applied 'Jonagold' apples were comparatively evaluated. Substrates 4-methylcatechol, pyrocatechol, pyrogallol and L-tyrosine were used to determine the substrate specificity of the PPO enzyme obtained from apple. According to the results, on the contrary, PPO enzyme from 'Jonagold' apple did not show any activity against L-tyrosine substrate which is a monophenolic substrate, the enzyme had high affinity against 4-methylcatechol, pyrocatechol and pyrogallol which are di and tri phenolic substrates. Km values of PPO enzyme obtained from pesticide-free apples against 4-methylcatechol, pyrocatechol, and pyrogallol substrates were determined as followed 0.27 mM, 2.27 mM, and 0.37 mM, respectively. Vmax values were found as 0.133 mM/min, 0.081 mM/min, and 0.051 mM/min. Optimum pH values were found to be 4.5 for 4-methylcatechol, 7.0 for pyrocatechol, and 7.5 for pyrogallol. Optimum temperature values were determined as 40 °C for 4-methylcatechol, 10 °C for pyrocatechol, and 50 °C for pyrogallol. Km values for PPO enzyme activity obtained from pesticide-treated apples against 4-methylcatechol, pyrocatechol, and pyrogallol substrates were 0.98 mM, 3.94 mM, and 0.37 mM, Vmax values were 0.08 mM/min, 0.02 mM/min, and 0.034 mM/min. Optimum pH values were found to be 7.0 for 4-methylcatechol and pyrocatechol and 7.5 for pyrogallol. Optimum temperature values were determined as 50 °C for 4-methylcatechol, 30 °C for pyrocatechol, and 40 °C for pyrogallol. Overall, the results showed that the PPO enzyme from pesticide-free apples had higher activity than pesticide-treated apples. The effects of metals and storage stability on PPO enzyme activity were also investigated. The results reveal that pesticide use affects PPO enzyme activity. The obtained data bring to light new pesticide functional features of great interest in the medicinal, agro-chemical and environmental circles.

DEGRADATION OF ORGANIC POLLUTANTS IN FLOCCULATED LIQUID DIGESTATE USING PHOTOCATALYTIC TITANATE NANOFIBERS: MECHANISM AND RESPONSE SURFACE OPTIMIZATION

<List> <ListItem> <ItemContent> ● Titanate NFs were synthesized and photodegraded liquid digestate for the first time. </ItemContent> </ListItem> <ListItem> <ItemContent> ● The long titanate NFs (bandgap of 3.16 eV) have a high VFA removal rate of 72.9%. </ItemContent> </ListItem> <ListItem> <ItemContent> ● RSM has been used to optimize the VFA, COD, and color removal rate. </ItemContent> </ListItem> <ListItem> <ItemContent> ● The quadratic model and the effects of photocatalytic dosage were significant. </ItemContent> </ListItem> </List> Titanate nanofibers (TNFs) were synthesized using a hydrothermal method and were employed for the first time in this study to photocatalytically degrade organic pollutants found in flocculated liquid digestate of poultry litter. The photocatalytic performance of TNFs, with a bandgap of 3.16 eV, was tested based on degradation of organic pollutants and removal of color. Five combinations of pollutant concentration and pH were examined (0.2 to 1.3 g·L⁻¹ at pH 4 to 10). Central composite design (CCD) and response surface methodology (RSM) were applied in order to optimize the removal rates of volatile fatty acids (VFA) and chemical oxygen demand (COD), and the decolorization rate. There were no significant differences between the regression models generated by the CCD/RSM and the experimental data. It was found that the optimal values for pH, dosage, VFA removal rate, COD removal rate and decolorization rate were 6.752, 0.767 g·L⁻¹, 72.9%, 59.1% and 66.8%, respectively. These findings indicates that photocatalytic TNFs have potential for the posttreatment of anaerobic digestion effluent, as well as other types of wastewater.

Optimization of the photocatalytic degradation of phenol using superparamagnetic iron oxide (Fe3O4) nanoparticles in aqueous solutions.

The present work was carried out to remove phenol from aqueous medium using a photocatalytic process with superparamagnetic iron oxide nanoparticles (Fe3O4) called SPIONs. The photocatalytic process was optimized using a central composite design based on the response surface methodology. The effects of pH (3-7), UV/SPION nanoparticles ratio (1-3), contact time (30-90 minutes), and initial phenol concentration (20-80 mg L-1) on the photocatalytic process were investigated. The interaction of the process parameters and their optimal conditions were determined using CCD. The statistical data were analyzed using a one-way analysis of variance. We developed a quadratic model using a central composite design to indicate the photocatalyst impact on the decomposition of phenol. There was a close similarity between the empirical values gained for the phenol content and the predicted response values. Considering the design, optimum values of pH, phenol concentration, UV/SPION ratio, and contact time were determined to be 3, 80 mg L-1, 3, and 60 min, respectively; 94.9% of phenol was eliminated under the mentioned conditions. Since high values were obtained for the adjusted R2 (0.9786) and determination coefficient (R2 = 0.9875), the response surface methodology can describe the phenol removal by the use of the photocatalytic process. According to the one-way analysis of variance results, the quadratic model obtained by RSM is statistically significant for removing phenol. The recyclability of 92% after four consecutive cycles indicates the excellent stability of the photocatalyst for practical applications. Our research findings indicate that it is possible to employ response surface methodology as a helpful tool to optimize and modify process parameters for maximizing phenol removal from aqueous solutions and photocatalytic processes using SPIONs.

Re-evaluation of the Fungal Diversity and Pathogenicity of Cytospora Species from Populus in China.

Poplar is widely cultivated in China because of its strong ecological adaptability, fast growth, easy reproduction, and short rotation period. However, it suffers from severe threat from canker disease caused by Cytospora species. The present study revealed the presence of Cytospora species from Populus in China. A total of six species of Cytospora were isolated from Populus in six provinces in China, including five known species (C. ailanthicola, C. chrysosperma, C. donglingensis, C. paratranslucens, and C. sophoriopsis) and one novel species (C. populi) based on morphological and phylogenetic analyses of ITS, act, rpb2, tef1-α, and tub2 gene sequences. Cytospora ailanthicola, C. chrysosperma, C. paratranslucens, and C. sophoriopsis are confirmed as pathogens by pathogenicity tests of which C. paratranslucens showed the strongest virulence, followed by C. ailanthicola, C. chrysosperma, and C. sophoriopsis. The mycelial growth rates of isolates from the six species had 22.5 to 27°C as the optimum temperatures, and the optimum pH values were 5.9 to 7.1. The effectiveness of six carbon sources on the mycelial growth showed that colonies grew the fastest in the presence of fructose and grew the slowest using xylose. This study represents a significant evaluation of Cytospora causing poplar canker disease in China.

Functional properties of glutelin from Camellia oleifera seed cake: Improvement by alkali-assisted phosphorylation through changes in protein structure

To explore the effect and its mechanism of alkali-assisted phosphorylation on the functional properties of Camellia Oleifera seeds cake glutelin (CSCG), CSCG was treated with different concentration of sodium trimetaphosphate (STMP, 1.0, 2.0, 3.0, 4.0, and 5%, w/v) in different pH environment (3.0, 5.0, 7.0, 9.0, and 11.0). The results showed that alkali assist improved the phosphorylation degree of CSCG, and the optimum pH value is 9.0. FT-IR and XPS confirmed the successful modification of phosphate groups on CSCG through covalent interaction. Alkali-assisted phosphorylation decreased the particle size and increased electronegativity of CSCG, as well as changed in its surface hydrophobicity, crystallinity, and intrinsic fluorescence. All these changes of protein structure triggered by alkali-assisted phosphorylation led to the improvement of water solubility, water/oil absorption capacity, emulsifying ability, foamability, and in vitro digestibility of CSCG. This work could provide a theoretical basis for industrial production of CSCG with excellent functional properties.

Cost-effective fibrinolytic enzyme production by microalga Dunaliella tertiolecta using medium supplemented with corn steep liquor.

A fibrinolytic enzyme from the microalga Dunaliella tertiolecta was produced under mixotrophic conditions using different corn steep liquor (CSL) concentrations ( 0 ≤ CLS ≤ 0.75%), purified using a combination of salting out and ion-exchange chromatography, and then biochemical characterized. Cultivation of this microalga using 0.5% CSL led to the highest maximum cell concentration (1.960±0.010 mg L-1) and cell productivity (0.140g L-1 day-1), besides a high fibrinolytic activity of the extract obtained by the homogenization method (102 ±1 U mL-1). The enzyme extracted from the microalgal biomass was 5-fold purified with a 20% yield and was found to have a specific activity of 670 U mg-1. The enzyme, whose molecular weight determined by fibrin zymography was 10 kDa, was shown to be stable at pH 3.0-9.0 and up to 70°C with optimal pH and temperature values of 8.0 and 50°C, respectively. When compared to other fibrinolytic enzymes, this protease stood out for its high fibrinolytic activity, which was enhanced by Fe2+, inhibited by Zn2+, Cu2+, Mg2+, and Ca2+, and strongly inhibited by phenylmethylsulfonyl fluoride, suggesting that it belongs to the serine metalloprotease family. Moreover, thanks to its thermal stability, the enzyme may be easily preserved and activated under high-temperature conditions.

Biochemical characteristics of point mutated Capra hircus lysosome α-mannosidase.

Locoweeds, a type of poisonous weedare, are widely distributed throughout the world and have a significant impact on the development of herbivore animal husbandry. Swainsonine (SW), the main toxin in locoweeds, can competitively inhibit lysosomes α-mannosidase (LAM) in animal cells, resulting in α-mannosidosis. However, the specifics of the interaction between SW and LAM are still unclear. Here, we used molecular docking to predicte the interaction points between SW and LAM, built mutated lysosomes α-mannosidase (LAMM), and analyzed its biochemical properties changes in presumption points. The Trp at the 28th position and the Tyr at the 599th position of the LAM were interaction point candidates, and the above two amino acids in Capra hircus LAM (chLAM), were successfully mutated to glycine by constructing recombinant yeast GS115/PIC9K- LAMM. The results showed that the sensitivity of Capra hircus LAMM (chLAMM), to SW decreased significantly compared with wild-type LAM, the enzyme activity of LAM decreased approximately threefold, the optimum temperature of LAMM decreased from 55°C to 50°C, the optimum pH value increased from 4.5 to 5.0, and the effects of Mn2+, Fe3+, Al3+, Co2+, Cr3+, and ethylenediaminetetraacetic acid (EDTA) on LAM enzyme activity before and after point mutation changed significantly. These findings help us better understanding the molecular mechanism of the interaction mechanism between SW and chLAM, and provide new reference for solving locoweeds poisoning.

Sustainable Use of Traditional Plant Extracts for the Formulation of Herbal Shampoos

Skin and hair care products described with natural bioactive compounds have been considered as a better alternative to synthetic ones. Therefore, this study aimed to develop a natural shampoo using traditional plant extracts. With an emphasis on safety and efficacy, its physicochemical properties were evaluated and compared with the marketed shampoo. Each plant material was ground and extracted using 70% hydro-alcoholic solvent for 5-7 days. Shampoo formulation was prepared using sprouted fenugreek seeds extract and pea fruit extract as key ingredient along with other natural ingredients including: reetha, amla, marigold, orange peel, castor oil, glycerine and distilled water. The physicochemical parameters and antioxidant activity of both formulations were ascertained to ensure the safety and efficacy of the designed formulation. According to the present study, the developed shampoo (F1 &amp; F2) was yellowish green and brown in color, had a good odor and optimum pH value of 5.32–5.96. The viscosity of F1 and F2 was found to be 2.3 to 2.08 poise; both formulations reduced the surface tension to 49.08 and 50.7dynes/cm respectively. While the solid content of F1 &amp; F2 shampoos was found to be 20.57 and -21.87%. The developed shampoo (F1 &amp; F2) exhibited significant antioxidant activity with IC 50 values of 53.46 (F1) &amp; 69.4 µ/ml (F2), respectively. The findings of this study demonstrated that shampoo formulations were found to have functionality comparable to physicochemical features of marketed shampoo. However, further studies are necessary to validate the performance and quality of the shampoo. Keywords: herbal shampoo, shampoo formulation, traditional plant extracts. https://doi.org/10.55463/issn.1674-2974.50.4.14

SOURCE IDENTIFICATION AND VARIATION IN THE CHEMICAL COMPOSITION OF RAINWATER IN THE COASTAL AND INDUSTRIAL AREAS: A CASE STUDY OF IKOT ABASI, SOUTH-EASTERN NIGERIA

Studies on precipitation Chemistry were carried out with the aim to understand the nature and sources of rainwater at Utaewa (Location 1), a coastal village and Ikpetim, near Ibom Power Station (Location 2), all in Ikot Abasi Local Government Area, southern, Nigeria. These locations respectively represent the coastal and industrial regions. The rainwater samples, collected at these locations, were analyzed for major cations, anions, electrical conductivity and pH with the aim of identification of variation in the physiochemical compositions of the rainwater samples. The analysis of the rainwater samples gave a pH at locations 1 and 2 as 5.62 ± 0.26 and 5.77± 0.25 respectively during the wet season, while the pH of the rainwater at locations 1 and 2 during dry season were 5.41 ± 0.14 and 5.84 ± 0.21 respectively. The pH values indicated acidic water and were below the World Health Organisation (WHO) Standard of 6.5 to 8.5, but close to the World Meteorological Organisation (WMO) optimum pH value of 5.6 for rainwater from unpolluted continental areas. The predominance of 𝐶𝑙−and𝑁𝑎+ were observed in the coastal environment whereas, calcium, sulphate, nitrate and ammonium ions predominate in industrial environment where there are power generating plants, Aluminium smelting company and gas station. The total anion (37.9%) at Utaewa is less influenced by anthropogenic activities whereas total anion (72.5%) at Ikpetim, near Power Plant is influenced by pollutants emitted by anthropogenic activities. The ratio:𝐻+/(NO3- + SO42-) was observed as 0.04 and 0.008 for Utaewa and Ikpetim respectively, which are close to zero, indicating that 99 % of acidity in the rainwater is neutralized in the study area with no consequence of acidity impact on the soil, surface waters and groundwater in the study area. Ca2+ , K+ and Na+ play important roles in neutralization of acidic ions in rainwater. For source identification, correlation matrix analysis was established, which showed that at locations 1 and 2,strong correlation exists between the acidic ions SO42- and NO3-, indicating their origin from anthropogenic activities. This is viewed to be attributed to the similarity in their behaviour in precipitation and the co-emissions of their precursors, which are SO2 and NO2. The major ion enrichment factors (EF) followed the order at location 1 during the dry season;𝐶𝑎2+𝑁𝑎+⁄ (8.58) &gt;𝐾+𝑁𝑎+⁄ (4.32) &gt;𝑆𝑂42−𝑁𝑎+⁄ (0.68) &gt;𝐶𝑙−𝑁𝑎+⁄ (0.11), while the enrichment factor (EF ) during the wet season at location 1 followed the order , 𝐶𝑎2+𝑁𝑎+⁄ (11.92 )&gt;𝐾+𝑁𝑎+⁄ (3.78) &gt;𝑆𝑂42−𝑁𝑎+⁄ (0.88) &gt;𝐶𝑙−𝑁𝑎+⁄ (0.11).

Dual-template imprinted polymer electrochemical sensor for simultaneous determination of malathion and carbendazim using graphene quantum dots.

Malathion (MAL) and carbendazim (CBZ) are organophosphate pesticides and fungicides, respectively. They are often used simultaneously in agriculture, and both have been shown to have harmful effects on humans and animals. Therefore, it is important to be able to measure both of these toxins simultaneously in order to assess their potential risks. This study aims to design a dual template electrochemical sensor using a cost-effective graphite-epoxy composite electrode (GECE) modified with molecularly imprinted polymers (MIPs) coated on graphene quantum dots (GQDs) for simultaneous detection of MAL and CBZ in real samples. GQDs were synthesized initially, and their surface was coated with MIPs that were formed using MAL and CBZ as the template molecules, ethylene glycol dimethyl acrylate as the cross-linker, and methacrylic acid as the functional monomer. The GQDs@MIP were characterized using Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray scattering spectroscopy. Parameters affecting the sensor response, such as the percentage of GQDs@MIP in the fabricated electrode, the pH of the rebinding solution and analysis solution, and the incubation time, were optimized. The optimum pH values of the rebinding solution were verified using density functional theory (DFT) calculations. Under the optimized conditions, differential pulse voltammetry (DPV) response calibration curves of MAL and CBZ were generated, and the results showed that the sensor had a linear response to MAL in the range of 0.02-55.00 μM with a limit of detection (LOD) of 2 nM (S/N = 3) and to CBZ in the range of 0.02-45.00 μM with a low LOD of 1 nM (S/N = 3). The results also demonstrated the proposed sensor's long-term stability and anti-interference capability. The practical applicability of the fabricated electrode was evaluated for real sample analysis, and good recovery values were obtained.