Optimal Conditions For Production Research Articles

Deciphering the nature and statistical optimization of antimicrobial metabolites of two endophytic bacilli

In this study, Allium sativum, garlic, was selected to isolate endophytic bacteria and to evaluate the antimicrobial, antiviral, antioxidant, and cytotoxic activities of their produced metabolites followed by identification of the biosynthetic gene cluster of the antimicrobial metabolites using Oxford Nanopore Technology (ONT). Two bacterial isolates, C6 and C11, were found to have a broad-spectrum antagonistic effect against four standard microbial strains and were molecularly identified using 16 S ribosomal RNA sequence analysis and deposited in a local culture collection as B. velezensis CCASU-C6, and B. subtilis CCASU-C11, respectively. Optimization for the maximum production of antimicrobial metabolites revealed that a four-day incubation period was optimal, with sucrose and tryptone serving as the best carbon and nitrogen sources for the fermentation media. Response surface methodology model using the central composite design was created resulting in a 1.2-fold and 1.8-fold improvement in antimicrobial metabolite(s) production of C6 and C11 isolates, respectively. The optimal production conditions were found to be a temperature of 33 °C, pH of 7, and an agitation rate of 200 rpm for C6 metabolite, and a temperature of 37 °C, pH of 7, and an agitation rate of 250 rpm for C11 metabolite. Both bacterial isolates displayed antioxidant and antiviral activity and mild cytotoxic action. Genomic sequence and antiSMASH analysis showed that the biosynthetic gene clusters of bacillomycin, mycosubtilin, fengycin, and macrolactin H in B. velezensis CCASU-C6 and bacillibactin and Macrolactin H in B. subtilis CCASU-C11 showed 100% conservation.

Extracellular Lipase from Pseudomonas aeruginosa SB-37: Production by Solid State Fermentation, Immobilization, and Characterization

Native lipase is still promising as an industrial biocatalyst. This study aimed to investigate the production of native local lipase using solid state fermentation (SSF) methods, immobilization the lipase by Ca-alginate entrapment, and characterization based on substrate preferences. To obtain high lipase production using SSF methods, we optimized the type of agro-wastes substrates, fermentation time, oil induction percentage and volume of preculture percentage. The optimal condition for lipase production via solid-state fermentation involved a 7% (v/v) preculture of Pseudomonas aeruginosa SB-37, utilizing palm kernel meal as the substrate, supplemented with 6% (v/w) oil induction (soybean oil:tween 80 = 75:25) at 50 °C for 24 h. This gave a lypolitic activity value of 2 U/gds (gram dry weight substrates). Since the protein profile of extracellular lipase has a few protein bands, we perform direct immobilization on crude protein supernatant. Immobilization by Ca-alginate entrapment results in loading capacity and recovery activity values of 86.84% and 148%, respectively. The immobilized lipase retained 92% activity until four batch repetition and keep 40% activity at tenth batch. The highest hydrolytic activity of immobilized lipase was 0.9 U/g gel on the pNP_8 substrates. While the highest transesterification activity was observed with acetonitrile solvent and substrates of pNP_8 and isopropanol with the activity value at 0.6 U/g gel. This present study emphasized the feasibility of producing lipase as a biocatalysts using economical agro-industrial wastes and efficient immobilization using entrapment method. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Mapping the landscape of WCO biolubricant studies: A Comprehensive bibliometric review with vosviewer

This study explores the growing field of biolubricants as sustainable alternatives to petroleum-based lubricants. This paper highlights the gap in the current literature regarding biolubricants from Waste Cooking Oil (WCO) using a mixed-methods approach of bibliometric analysis and systematic literature review (SLR). A bibliometric analysis was conducted using data from the Scopus database, covering 650 publications from 2000 to 2024. Furthermore, a systematic literature review provides a comprehensive analysis of the methods used for synthesizing biolubricants from WCO, particularly evaluating the types of catalysts and methods employed that influence the physicochemical properties. The findings show a significant increase in research activity from 2018 to 2022, with Malaysia and India leading in this area. Key research trends identified include catalysts, oxidation stability, and transesterification processes. Optimal conditions for biolubricant production from WCO were achieved using an Amberlyst catalyst at 81°C, yielding a 99% conversion rate. These results highlight the potential of WCO-derived biolubricants to support more sustainable industrial applications. This study is the first to combine bibliometric analysis and systematic literature review methods to provide a comprehensive overview of research on WCO-based biolubricant production. Through a systematic review of existing studies, this research provides a useful resource for industry professionals and renewable energy policymakers in their efforts.

Increasing the value of jackfruit cobs as agricultural waste materials for syrup production by enzymatic hydrolysis using pectinase and cellulose

This research aimed to investigate the optimal working conditions for pectinase and cellulase, evaluate the quality of jackfruit cob syrup, and assess its physical and chemical properties and consumer acceptance. The study began with exploring the optimal conditions for syrup production from jackfruit cobs. The factors studied were the amount of pectinase in 3 levels: 0.04, 0.06, and 0.08%; the amount of cellulase in 2 levels: 0.1 and 0.2%; and the incubated temperature in 3 levels: 40, 45, and 50 °C; the incubated time in 3 levels: 30, 90, and 150 minutes. All 54 conditions were obtained in Factorial experiments in Completely Randomized Design (CRD). The physical and chemical properties were analyzed, and the optimal conditions were determined through hierarchical clustering, along with evaluating the physical and chemical properties and consumer acceptance. It was found that the optimum conditions for extraction of jackfruit cob juice include 0.08% pectinase, 0.2% cellulase, incubated temperature at 40 °C, and a curing time of 90 minutes, respectively. The properties of jackfruit cob syrup were as follows: brightness (L*) of 22.77 ±0.04, (a*) of -0.74 ±0.06, and (b*) of 9.16 ±0.43. The light transmittance was 1.99 ±0.01, viscosity was 14.00 ±0.05 centipoise, and pH was 4.75 ±0.10, indicating prebiotic properties. The overall liking score was 7.96. After being informed about the nutritional benefits of jackfruit cob syrup, 85.00% of consumers indicated a willingness to purchase the product. It will add value to the waste jackfruit cob in agriculture to 86 baht per kilogram. Therefore, jackfruit cob syrup is a value-added product that enhances the utilization of agricultural by-products, reduces agricultural waste, and meets consumer demand for healthy food options.

Characterization and application of biochar derived from greenhouse crop by-products for soil improvement and crop productivity in South Korea

AbstractThe study examined the optimal production conditions and application rates of biochar derived from greenhouse crop by-products to enhance soil improvement and increase crop yield, thereby promoting sustainable agriculture in South Korea. The expansion of greenhouse cultivation has resulted in significant waste management challenges, and biochar production has emerged as a promising recycling solution for these by-products. Biochar was produced from red pepper stalks through pyrolysis at 200 to 600 °C, and its chemical properties, including pH, EC, T-C, and T-N, were analyzed. In this study, the chemical properties of biochar showed a significant increase in pH (from 5.8 to 10.3), EC (from 46.0 to 119.5 dS m⁻¹), and T-C (from 47.7 to 63.1%) with rising pyrolysis temperatures, while T-N decreased due to nitrogen volatilization above 300 °C. In the lettuce cultivation experiment, biochar application significantly improved fresh weight yield, with the biochar-treated group achieving a maximum of 83.3 g pot− 1 in the first cropping season, compared to 62.8 g pot− 1 in the NPK-only treatment group. However, excessive biochar application rates (≥ 800 kg ha⁻¹) led to yield reductions in the second cropping season, likely due to increased soil pH and EC. These results suggest the potential of recycling greenhouse crop residues into biochar to enhance soil fertility and crop productivity while indicating the need to manage application rates to minimize negative impacts from excessive use.

Optimization of Eco Enzyme Production Using Bacterial Starters and Fermentative Fungi

Eco Enzyme is a natural fermentation product made from organic waste such as leftover fruits and vegetables, which has various benefits, including serving as an environmental cleaner and pollution reducer. This research aims to optimize the production of Eco Enzyme by using specific fermentative bacterial starters to enhance fermentation efficiency and the quality of the final product. In this study, the types of fermentative bacteria used are Lactobacillus bulgaricus, Lactobacillus acidophilus, and the fungi Saccharomyces cerevisiae and Aspergillus niger. Parameters such as pH, temperature, and fermentation duration are strictly regulated and monitored to identify optimal conditions for Eco Enzyme production. The research results indicate that the use of certain fermentative bacterial starters can accelerate fermentation time by up to 30% and increase enzyme activity by 20% compared to natural fermentation processes without starters. The characteristics also show the same results, namely acidic pH, characteristic fresh aroma, fresh eco enzyme value and normal TDS (ranged 1,030 ppm - 1,700 ppm). This optimization not only produces a more efficient and high-quality Eco Enzyme product, but it can also serve as an innovative step towards more sustainable and environmentally friendly organic waste management.

Cold-active lipase from Psychrobacter alimentarius ILMKVIT and its application in selective enrichment of ω-3 polyunsaturated fatty acids in flax seed oil.

Lipases are one of the ubiquitousenzymes thatbelong tothehydrolases familyand have a wide variety of applications. Cold-active lipases are of major attraction as they can act in lower temperatures and low water conditions because of their inherent greater flexibility. One of the novel applications of lipase is the enrichment of ω-3 polyunsaturated fatty acids (PUFA) in plant and fish oils. This study is aimed at theisolation and identification of cold-active lipase producing bacterium from marine sources, preliminary optimization of medium constituents and conditions, purification of lipase using chromatographic techniques, biochemical characterization, and ultimately theexploration of its application in the enrichment of ω-3 PUFA in flax seed oil. Psychrobacter alimentarius ILMKVIT was identified as the potential cold-active lipase producing bacterium based on its lipolytic activity in rhodamine B agar, titrimetric, and p-nitrophenyl palmitate (p-NPP) assays. One factor at a time (OFAT) analysis, revealed, an incubation time of 4.5days, alkaline pH of9,thetemperature of 25°C, peptone, and yeast extract as nitrogen sources, olive oil as inducer sources, 1% inoculum size, and NaCl as mineral sources as optimum production medium constituents and conditions for lipase production. Lipase purification was achieved by ion exchange and gel-filtration chromatography with a 9.27% yield and 37.51-fold purification. Biochemical characterization reported that the lipase is cold-active, alkaline, enhanced by Fe3+ metal ions, and tolerant to organic solvents, detergents, and inhibitors. P. alimentarius ILMKVIT lipase-hydrolysis followed by urea complexation of flax seed oil resulted in the enrichment of ω-3 PUFA, especially α-linolenic acid (ALA). Hence, the novel cold-active lipase from P. alimentarius ILMKVIT could be used to enrich ω-3 PUFA in flax seed oiland developed further as a prominent nutrient supplement for health benefits.

Optimized production of bacterioruberin from “Haloferax marinum” using one-factor-at-a-time and central composite design approaches

Haloarchaea represents a unique group of microorganisms that have adapted to thrive in high-salt environments. These microbes produce distinctive biomolecules, some of which exhibit extraordinary properties. One such biomolecule is bacterioruberin, a prominent red-pigmented C50 carotenoid commonly found in halophilic archaea, renowned for its antioxidant properties and potential as a functional resource. This study aimed to enhance the culture conditions for optimal production of C50 carotenoids, primarily bacterioruberin, using “Haloferax marinum” MBLA0078. The optimization process involved a combination of one-factor-at-a-time (OFAT) and statistical methodology. Under OFAT-optimized conditions, fed-batch fermentation, and response surface methodology (RSM) optimization, carotenoid production reached 0.954 mg/L, 2.80 mg/L, and 2.16 mg/L, respectively, in a 7-L laboratory-scale fermenter. Notably, RSM-optimized conditions led to a 12-fold increase in productivity (0.72 mg/L/day) compared to the basal DBCM2 medium (0.06 mg/L/day). These findings suggest that strain MBLA0078 holds significant promise for commercial-scale production of bacterioruberin.Graphical

Novel Approach for Enhancing Challenging Terrains Using an Integrated Pyrolysis and Furrow-Diking Technology

Poultry-processing industries generate substantial quantities of waste, posing significant environmental challenges due to the complexity of handling and disposal. This study explores an innovative solution that combines thermochemical treatment of poultry waste with furrow-diking technology to transform non-recyclable feathers and bones into biochar—a nutrient-rich soil amendment. The research identifies optimal pyrolysis conditions for biochar production and evaluates its effects on soil moisture retention, compaction reduction, and erosion control. Experimental trials on sloped terrains reveal that incorporating biochar into compartmentalized furrows enhances water-holding capacity and soil structure, providing a sustainable approach to addressing agricultural challenges. Pyrolyzing poultry waste at 500 °C produced biochar with high nitrogen content and stability, capable of retaining up to 90% of its mass in water and significantly reducing soil compaction. Furthermore, applying 10 metric tons of biochar per hectare can sequester 5–8 metric tons of carbon annually, contributing to long-term carbon mitigation and regenerative agriculture. This integrated methodology combines waste valorization with ecological restoration, unlocking new opportunities for scalable and sustainable soil-management solutions.

Optimal conditions for efficient ion acceleration and neutron production in deuterium gas-puff z-pinches

Abstract Deuterium gas-puff z-pinches are researched primarily as efficient sources of DD fusion neutrons. The first experiment with a deuterium gas jet was carried out in 1978 (J. Shiloh, A. Fisher, and N. Rostoker, Phys. Rev. Lett. 40, 515518, 1978). Since then, several D2 gas-puff experiments have been performed on various pulsed-power generators. The highest, so far published, DD neutron yields of 4×1013 were observed on the Z-machine at Sandia National Laboratories around 2005 (C.A. Coverdale, et al. Phys. Plasmas 14, 022706, 2007). More recently, z-pinch experiments with a plasma shell on a deuterium gas puff were carried out on GIT-12 higher-impedance pulsed-power generator at 3 MA currents. On GIT-12, unique results were high neutron and ion energies, which approached 60 MeV. Comparison of deuterium gas-puff experiments on different generators allows the identification of the parameters essential for optimizing neutron production. These parameters include the optimal mass, preionization, short deuterium gas-injection time, and zippering towards a cathode. Neutron yields appear to depend not only on a current, but also on other parameters of a generator, such as an impedance and the energy stored in a capacitor bank. Our conclusions regarding the optimal conditions were tested on the Hawk generator (NRL, Washington, DC). At a current of 0.7 MA, Hawk accelerated deuterons up to 15 MeV producing one neutron pulse with the yield of the order of 1010 and a broad energy spectrum in the axial and radial direction. These results show that ion acceleration mechanisms in deuterium gas-puff z-pinches could be very efficient and attractive, with a variety of potential applications in high-energy-density physics, materials science, and controlled thermonuclear fusion research.

Feasible cultivation of Verrucodesmus verrucosus on sterile raw wastewater for energy purposes: a case study in Mexico.

In this study, wastewater from a sewage treatment plant was used to culture the microalga, Verrucodesmus verrucosus. The ability of microalgae to adapt to adverse environments and produce high lipid concentrations was evaluated using different media, including sterile and non-sterile media and a control medium. The analysis showed that the control medium (distilled water sample enriched with fertilizer) removed 80.35% ammonium, 32.71% phosphate, and 83.86% nitrate. The sterile raw effluent removed 78.91% of ammonium, 83.44% of phosphate, and 98.82% of nitrate. The optimal conditions for biomass production were sterile raw wastewater, which produced 383.3mg L-1 of biomass, 2.5% of total lipids, and an average lipid production of 9.31mg L-1. Microalgae can grow and consume inorganic nutrients under adverse environmental conditions such as in raw wastewater, which is of great importance because it is a pollutant that negatively affects the environment and society. However, wastewater may represent a viable alternative substrate, allowing the generation of high-value products, such as lipids. Furthermore, the specificity of microalgal morphotypes must be evaluated, because each has specific metabolic plasticity. Verrucodesmus verrucosus is a microalga that has not been evaluated in bioremediation processes of wastewater with and without the presence of biotic factors. Therefore, the present study provides a viable alternative for this biological process, with the potential to store metabolites of interest in the industry.

Screening, Identification, and Optimization of Enzyme Production for Bacteria with High Efficiency of Bovine Blood Protein Degradation from Slaughterhouses

Blood waste originating from slaughterhouse activities in China is considered to be massive, and improper handling may cause epidemic diseases and environmental pollution. This research aimed to obtain a potential bacterial strain for blood protein degradation by isolating indigenous bacteria from slaughterhouses. Isolation was carried out by using dilution plate coating, while blood agar and casein plates were used to screen potential strains. Morphological, physiological, and biochemical characterizations, as well as 16S rRNA sequencing, were performed to identify the selected strain. The optimization of enzyme production was performed by using the Plackett–Burman test and response surface methodology. A strain coded NwMCC01910137 was isolated and screened to effectively degrade bovine blood protein and was identified as Bacillus subtilis. The optimum culture conditions for enzyme production included a fermentation temperature of 37.4 °C, an initial pH of 7.7, a soybean meal powder addition amount of 3.00% (w/v), a glucose level of 3.8% (w/v), a NaCl level of 0.3 g/L, a phosphate concentration of 2.5 g/L, an inoculum size of 2.5 g/L (4%), and a fermentation time of 48 h. Under the optimum condition, the strain showed enzyme activity of 166.83 U/mL. Hence, the isolated B. subtilis showed good activity in bovine blood protein degradation and has good application potential for slaughterhouse waste processing.

The Influence of Temperature on Rheological Parameters and Energy Efficiency of Digestate in a Fermenter of an Agricultural Biogas Plant

This investigation specifically aims to enhance the understanding of digestate flow and mixing behavior across typical temperatures in bioreactors in agricultural biogas plants, facilitating energy-efficient mixing. Experimental tests confirmed that digestate exhibits non-Newtonian characteristics, allowing its flow behavior to be captured by rheological models. This study validated that digestate rheology significantly varies with temperature, which influences flow resistance, mixing efficiency and overall energy requirements. Two rheological models—the Bingham and Ostwald models—were applied to characterize digestate behavior, with the Ostwald model emerging as the most effective for Computational Fluid Dynamic (CFD) simulations, given its balance between predictive accuracy and computational efficiency. Specifically, results suggest that, while three-parameter models, like the Herschel–Bulkley model, offer high precision, their computational intensity is less suitable for large-scale modeling where efficiency is paramount. The small increase in the accuracy of the shearing process description does not compensate for the significant increase in CFD calculation time. Higher temperatures were found to reduce flow resistance, which in turn enables increased flow rates and more extensive mixing zones. This enhanced mass transfer and mixing potential at elevated temperatures are especially pronounced in peripheral areas of the bioreactor, farthest from the agitators. By contributing a model for rheological behavior under realistic bioreactor conditions, this study supports the optimization of energy use in biogas production. These findings emphasize that temperature adjustments within bioreactors could serve as a reliable control strategy to maintain optimal production conditions while minimizing operational costs.

Optimizing Fermentation Parameters for Bioethanol Production from Areca Nut Leaves using Artificial Neural Networks and Response Surface Methodologies

The research covered the entire process, from collecting the Areca nut leaves to purifying the produced bioethanol. Materials and Methods: The Areca nut leaves were pre-treated with sulfuric acid and sodium hydroxide, followed by enzymatic hydrolysis using cellulose enzymes. The hydrolyzed biomass was then fermented by Saccharomyces cerevisiae for 12–72 h to produce bioethanol. The produced bioethanol was purified through distillation using a rotary flask evaporator. To optimize the fermentation process and bioethanol production, the researchers employed two modeling approaches: Artificial neural networks (ANN) and response surface methodology (RSM). Variables such as pH, fermentation time, and disodium hydrogen phosphate (Na2HPO4) concentration, identified from the Plackett- Burman design, were optimized using the central composite design of RSM. Results and Discussion: The R² value for the RSM model was 91.72%, and the adjusted R² was 84.72%. In addition, an ANN algorithm model with 3 input neurons, 10 hidden layer neurons, and 1 output neuron was developed to investigate the relationship between bioethanol production and fermentation parameters. The ANN model achieved an R² of 99.78%, indicating higher accuracy and reliability compared to the RSM approach. The optimal conditions for bioethanol production were identified as pH 5.5, 60 h fermentation time, and 0.45 g of Na2HPO4. Under these conditions, the experimental bioethanol concentration reached 36.54 g/L. Conclusion: This study demonstrates the effective utilization of Areca nut leaves, a readily available agricultural waste, to produce bioethanol. The combination of statistical and machine learning techniques, such as ANN and RSM, allowed for the optimization of the fermentation process and the enhancement of bioethanol yield, showcasing the potential of this approach for sustainable biofuel production.

Techno-economic analysis of a biogas power plant: Moving to sustainable energy supply and green environment through waste management

The feasibility of establishing an anaerobic digestion power plant for producing electricity, heat, and bio-fertilizer using a combined heat and power system using municipal solid waste in Sanandaj has been designed and simulated. The optimal condition for biogas production will be identified using an experimental design, and subsequently, modeling under optimal conditions was performed using Aspen Plus. The anaerobic digestion process was simulated under thermophilic conditions at a temperature of 55 °C, pressure of 1 atm, and retention time of 15 days. The daily biogas production amounted to 32,174 m3 from 380 tonnes of municipal solid waste. The daily production of electricity and heat was 2.9 MW and 3.3 MW, respectively. The daily production of bio-fertilizer was 48 tonnes. The electricity produced can meet approximately 3 % of Sanandaj's total demand. In addition to energy production from waste, the economic evaluation indicated that the project's net present value over a 20-year operational period was approximately 6333,333 €, demonstrating the project's economic viability. Furthermore, establishing this power plant will prevent 85,023 tonnes of CO2 annually. The results indicated the effectiveness of the designed plant in replacing power generation with fossil fuel and reducing greenhouse gas emissions.

The effect of ambient temperature and relative humidity in postpartum dairy cows on productive and reproductive performance and biochemical blood indices in the subsequent lactation

Abstract This study evaluated the effects of ambient temperature (T) and relative humidity (RH) during the postpartum transition period on dairy cows’ milk performance, fertility, and immunometabolic blood indices in the subsequent lactation. A total of 100 Polish Holstein-Friesian cows originating from five commercial dairy farms were categorized into three groups based on average T (<16 °C, 16-20 °C and >20 °C) and RH (<65%, 65-75%, and >75%) on the calving day (0d), and days 7, 14, 21 after calving. With increasing T and RH postpartum, the average daily milk yield during the first 150 days in milk decreased gradually, and the differences between T <16 °C and >20 °C and RH <65% and >75% groups were approx. 3.48 and 2.78 kg, respectively. Milk of cows exposed to increased T and RH was lower in protein, and lactose and higher in fat, milk urea, and somatic cell count. It was also characterized by altered fat composition. Ambient T during the postpartum period had a negative effect on cows’ fertility, which, however, was not affected by RH. The increasing T from <16 °C to >20 °C resulted in the later manifestation of the first estrous (by 27.7 days), a more extended artificial insemination service period (by 19.4 days), a higher number of insemination services per conception (by 0.92 on average), more days open (by 43.3 days), and a longer calving interval (by 43.3 days). Within ranges used in this study, increasing T and RH during the period from d 0 to d 14 postpartum led to decreased body condition score on day 21 by approx. 0.48 and 0.51 points, respectively. Furthermore, T and RH on a calving day were associated with altered biochemical blood indices on d 21 after calving, indicating a more severe negative energy balance and a state of inflammation. The results of this study suggest that dairy cows that calve when T >16 °C should be provided cooling to ensure optimal environmental conditions for high milk production and prevent economic losses associated with reduced milk yield and low fertility.

Comparative Study of Cobalt Oxide and Cobalt-Molybdenum Oxide Electrodes for Seawater Electrolysis

INTRODUCTIONThe quest for sustainable and efficient hydrogen production has led to the exploration of various catalyst materials for seawater electrolysis, a promising avenue for renewable energy generation. Seawater, abundant and accessible, offers a compelling resource for electrolytic hydrogen production, but its high salinity and corrosive nature pose challenges for catalyst stability and performance. The development of efficient catalysts capable of withstanding the harsh conditions of seawater while achieving high oxygen evolution efficiency (OEE) has captured the attention of researchers in this field.The development of high activity/high stability/low-cost oxygen evolution reaction (OER) catalysts for large-scale production is an important issue for academia and the industry today [1]. Although RuO2 and IrO2 noble metal oxides are considered the most efficient OER electrocatalysts, their high costs, apparent scarcity, and low stability have greatly impeded their large-scale application as OER electrocatalysts [2]. In recent years, manganese, cobalt, molybdenum and other transition metals have emerged as promising candidates for catalyzing the OER in seawater electrolysis applications.Cobalt oxide electrodes are well-known for their catalytic activity towards the OER and stability in alkaline medium specially when it modified with other transition metals such as Mo [3]. Some researchers use manganese as anodic catalysts for oxygen evolution from seawater or MnO2 decorated with Co3O4 yields the best performances in alkaline seawater splitting [4]. Also, these electrodes were applied on FTO surface in acid medium [5]. We consider testing cobalt (Co) and Co mixed with molybdenum are important challenge in acidic medium under high current density.The present work aimed to (i) determine the optimum conditions for production of durable Co/Ti and Co-Mo/Ti anodes using a fast and easy fabricated method. (ii) focus on durability test of these electrodes under high current density without using intermediate conductive layer (iii) comparative analysis involves evaluating various aspects including catalytic activity, stability, structural properties, and OEE.EXPERIMENTALFirst, the titanium substrate underwent a treatment for surface roughening. Subsequently, the treated titanium substrate was coated with cobalt oxide (Co3O4) through the calcination of cobalt nitrate hexahydrate (Co(NO3)2.6H2O) dissolved in a butanol solution, which was then brushed onto the substrate. Using the same method, a Co-Mo oxide was also prepared by calcinating butanol solutions of Co(NO3)2.6H2O and molybdenum chloride (MoCl5) at 450°C.The fabricated electrodes were characterized by XRD and EPMA to examine the structural and elemental properties of these electrodes. Moreover, electrochemical testing was conducted to evaluate the catalytic activity and stability of the electrodes during seawater electrolysis. The performance of the electrode was examined by electrolysis of 0.5 M NaCl solution at 1000Am-2. The OEE was estimated by the difference between the total charge passed during electrolysis and the formation charge of chlorine analyzed by iodometric titration. Polarization curves were measured using multi electrochemical measurement system. Correction for iR drop was made with a current-interruption technique. Durability test was measured using DC power supply 30V/5A.RESULTS AND DISCUSSIONThis study compares the performance of cobalt oxide electrodes, a well-established material for seawater electrolysis, with cobalt-molybdenum oxide composite electrodes. SEM images show the mesoporous structure for Ti/Co-Mo electrodes which is suitable for various applications (Fig. 1). X-ray diffraction clarified that all fabricated electrode consisted of free Co3O4 on Ti plate and cobalt molybdenum oxide composite on Ti plate. EPMA indicate that the samples contain Co, Ti, O and/or Mo for the modified electrode.Polarization curves and OEE analysis indicate that incorporating Mo to Co electrode enhances efficiency and reduces resistance. Additionally, the resulting electrode composition exhibits a porous structure expecting high performance in electrolysis. Mo addition led to a decrease in polarization potential, and the analysis of polarization curves showed that Mo addition increased the specific conductivity of the oxide. The value of the OEE is 18.98% for Co-Mo electrode compared to 13.15% for only Co electrode.Durability tests were conducted to evaluate the stability of both electrodes at a current density of 1000 A/m² over an extended period. The results indicate that the Co-Mo electrode exhibits inferior stability for two weeks and higher OEE compared to Co electrode under the same operating conditions.

Microwave-assisted biodiesel synthesis from waste cooking oil: Exploring the potential of carob pod-derived solid base catalyst

This work examined the potency of carob (Ceratonia siliqua) pod as a heterogeneous base catalyst for converting waste cooking oil (WCO) into biodiesel via a microwave irradiation system. The optimal calcination for the catalyst synthesis was achieved at 500 °C for 4 h. Various analytical techniques were employed to investigate the properties of the developed catalyst. The results indicate that the catalyst primarily consists of mesoporous particles abundant in potassium, with medium to strong basic sites, which are crucial for its catalytic function. WCO underwent pretreatment with H2SO4 before being converted to biodiesel. Optimum conditions for the biodiesel production were a methanol-to-WCO molar ratio of 9.87, 1.00 wt% catalyst dosage, 3.03 min reaction time, 450 rpm stirring speed, and 600 W microwave power, yielding 98.20 ± 0.81 wt% biodiesel. The low specific energy consumption value of 0.91 kWh/kg and specific CO2 emission of 0.73 kg/kg of biodiesel suggest the effective utilization of microwave energy in driving the transesterification reaction and in promoting a reduction in carbon footprint, respectively. The synthesized catalyst remained effective up to the 5th production cycle and the biodiesel produced met established specifications. The results of this study show that carob pod is a suitable candidate to be included in the database of biobased catalysts currently being developed for heterogeneous catalysis of cost-effective biodiesel production.

Enhanced vitamin B12 production by isolated Bacillus strains with the application of response surface methodology

BackgroundVitamin B12 is a crucial B-group vitamin, first isolated from the liver due to its role in combating pernicious anemia. It is distinguished by its unique and complex structure, which makes its chemical synthesis challenging and expensive. Consequently, vitamin B12 is alternatively obtained through microbial fermentations. Molasses, an affordable and safe agro-industrial waste, can be used as a carbon source for vitamin B12 production, offering a cost-effective alternative to expensive sugars in the production medium.ResultsA total of 87 yeast, actinomycete, and bacterial isolates were screened for vitamin B12 production, with 15 isolates showing high productivity. Bacillus isolates were selected for further analysis using MALDI-TOF and molecular identification. These isolates were identified as four strains of Bacillus subtilis (MZ08, JT10, BY11, and JT17), one strains of Bacillus sp. (CB09), and one strain of Peribacillus acanthi (MZ01). Genetic circuits associated with vitamin B12 production were demonstrated in a closely related strain of Peribacillus acanthi MZ01 strain. Three strains (MZ01, MZ08, and JT17) were selected for further evaluation of vitamin B12 productivity under different sugar types (glucose, sucrose, fructose, lactose, and galactose) and varying inoculum sizes. The inoculum size significantly impacted vitamin B12 production, with an increase from 5 to 10% enhancing yields. The ability of the strains to produce vitamin B12 varied depending on the type of sugar used. Peribacillus acanthi MZ01 strain showed the highest productivity and subsequently, selected for optimizing vitamin B12 production conditions using response surface methodology. Furthermore, the optimized conditions were then applied to molasses-based medium to achieve high vitamin B12 yields by MZ01 strain.ConclusionIn this study, Peribacillus acanthi was characterized for the first time as a vitamin B12 producer, demonstrating high productivity among various tested strains. The optimization of production conditions using response surface methodology, further enhanced vitamin B12 yields, showcasing the strain’s efficiency in microbial fermentations. This research also highlights the potential of using molasses as a cost-effective alternative carbon source, significantly reducing production costs.

Exploring Metalloprotease from Dunaliella sp.: Production, Regulation, and Structural Insight

A green microalgal strain, identified as Dunaliella sp., was isolated from the Tunisian southern region. The enhancement of its protein and protease production was performed through culture condition optimization using the response surface methodology. The optimal conditions for protein and protease production were found to be, respectively, (i) NaCl concentrations of 135 and 45.55 g/L, (ii) NaHCO3 concentrations of 0.5 and 1.5 g/L, (iii) temperature of 28 °C for both, and (iv) light intensities of 400 and 100 µmol photons/m2/s. The optimization led to an increase in microalgae protein content from 11.98% ± 0.26 to 18.39% ± 0.10 and microalgae proteolytic activity from 7.36 ± 0.74 U/mg to 12.54 ± 0.86 U/mg. Specific focus was attributed to ATP-dependent metalloprotease, namely, FtsH2, which is involved in numerous cellular processes including cell division, cell differentiation, signal transduction, and stress response. Differential expression of the FtsH2 gene under various stress conditions showed that this expression was upregulated in response to salt stress, gibberellic acid, and Indole-3-butyric acid. A 3D modeling demonstrated two possible arrangements where the ATPase ring shows either a perfect six-fold symmetry with an open circular entrance covering the crucial pore residues, or a translocated model triggered by substrate binding inward movement of the aromatic pore residues.