Optimal Carbon Research Articles

Extended material requirement planning (MRP) within a hybrid energy-enabled smart production system

A smart production system can be made energy-efficient using renewable energy and is considered to maintain the extended material requirement planning under a logistics system by using radio frequency identification. The tracking technology provides information about products with real-time notification. This study investigates renewable energy usage within a smart production system as renewable energy can contribute to Net Zero Emissions. The logistics framework involves an autonomation technology-based production system, optimum cash flow, logistics, and carbon emissions. Time is an essential influencer for material requirement planning. The model is solved with a Laplace integral transformation, where an associated matrix method is utilized by the input–output analysis. The theoretical concept is elaborated through an illustrative numerical example, where the energy consumption and corresponding net present values are evaluated. Numerical and graphical studies prove the effectiveness of the model for the use of renewable energy within for material planning under a reverse logistics system. The result reveals that efficient renewable energy consumption can save considerable costs and reduce the negative net present value of the system. It is found that skilled workers are worthy of a smart production system, not only in a qualitative aspect but also in an economic aspect.

Multi-variable optimization of a geothermal power plant integrated with water electrolyzer and methanol production

Renewable energy-based routes for methanol generation are recognized as essential strategies for eco-friendly energy conversion. Thus, the current study focuses on developing an innovative combined energy system for methanol production using direct carbon dioxide hydrogenation powered by geothermal energy. This is important because it addresses the need for sustainable and environmentally friendly methods of methanol production while also harnessing the potential of geothermal energy as a renewable resource. Therefore, in order to achieve multigeneration energy production, this work introduces and optimizes a novel configuration that benefits from an innovative heat design process. This configuration integrates an organic Rankine cycle, a single-flash geothermal power plant, an ammonia-water absorption chiller, a proton exchange membrane electrolyzer, and a methanol generation unit. Using the Aspen HYSYS tool, the multigeneration energy system is modeled and analyzed. As a result, the system is assessed using energy, exergetic, environmental, and economic evaluations. Furthermore, performance evaluations are carried out in the following modes: single generation, multigeneration, cooling, heat and power generation, and cooling. Furthermore, a genetic algorithm is employed to optimize the system in terms of economy and exergy. The energy and exergy efficiency are determined to be 32.57 % and 76.3 %, respectively, under the base case results. Furthermore, the rate of overall costs is 377.38 $/h. Furthermore, the precise output of carbon dioxide is −0.043 kg/kWh. The optimal unit cost and exergy efficiency for all items, taking into account the optimization scenario, are 3.34/GJ and 78.35 %, respectively. In addition, the optimum carbon dioxide and hydrogen rates for methanol generation are 92.49 mol/h and 200.51 mol/h, respectively.

Interlaminar toughening of carbon fiber/epoxy composites via interleaving co‐polyamide (Co‐PA) veils

AbstractThermoplastic veil interlayers offer a promising approach to improve interlaminar reinforcement in composite materials. This study investigates co‐polyamide (Co‐PA) interleaved veils, fabricated through the hot melt adhesive (HMA) technique. These veils are then applied with varying areal weight densities as interleaves to simultaneously toughen and strengthen carbon fiber/epoxy (CF/EP) composites, utilizing the vacuum‐assisted resin infusion (VARI) method. Integrating Co‐PA veils with a low melting point in the interlaminar of CF/EP composites improves compatibility and promotes strong adhesion between thermoplastics and epoxy resins. As result, The Co‐PA laminates exhibited significant improvements compared with the untoughened composites, with a maximum enhancement of 148.1% and 67.8% for Mode‐I (GIC) and Mode‐II (GIIC), respectively. Moreover, ILSS, tensile strength, and flexural strength improvements were also 20.9%, 34.9%, and 14.5%, respectively. The fracture surface analysis via scanning electron microscopy directly revealed the crack propagation on the fracture surfaces of Mode‐I and Mode‐II specimens. This analysis revealed that Co‐PA demonstrated excellent compatibility with epoxy resin, melts during the stage of epoxy curing, and undergoes phase separation in the later stage, resulting in the formation of “bead‐like” structures within the fibrous network. Remarkably, this structure significantly enhanced the toughness of the CF/EP composites. The Co‐PA veils can improve the interlaminar toughness of CF/EP composites due to their compatibility with the epoxy matrix and high inherent toughness and strength. This method is straightforward to manage and can be utilized for manufacturing large‐scale composite materials incorporating CF fabrics, demonstrating promise for industrial applications.Highlights With its low melting point, co‐polyamide helps prevent structural failure or excessive damage and is proposed to be utilized in composites to enhance the interlaminar fracture toughness properties. The effects of Co‐PA veils of different areal densities on the mechanical characteristics of interlaminar composites were examined. Co‐polyamide particles with fiber‐carbon laminates offer superior fatigue properties and an optimum carbon fiber‐bridging mechanism. Co‐polyamide veils with CF/EP laminates are feasible for structural use in high‐tech automotive applications.

White root rot of Bletilla striata: the pathogen, biological characterization, and fungicide screening.

Bletilla striata is an endangered traditional medicinal herb in China. In May 2020, the emergence of white root rot severely impacted the quality and yield of B. striata, affecting about 5% of the plants at plant nurseries of the Chengdu Academy of Agricultural and Forestry Sciences. Through a series of experiments and evaluations, the pathogen was identified as Fusarium solani. This is the first report of B. striata white root rot caused by F. solani in Sichuan, China. To better understand this disease and provide data support for its control, a combination of morphological, molecular characterisation and pathogenicity determination was used in this study for assessment. Meanwhile, the effects of different carbon and nitrogen sources, culture medium, temperature, photoperiod and pH on mycelial growth and spore production of F. solani were investigated. In addition, effective fungicides were screened and the concentration ratios of fungicides were optimized using response surface methodology (RSM). The experimental results showed that sucrose was the optimum carbon source for the pathogen, and the optimum temperature and pH were 25°C and pH 7, respectively, while light did no significant effect. Effective fungicides were screened, among which difenoconazole showed the strongest inhibition with EC50 of 142.773 µg/mL. The optimum fungicide concentration scheme (difenoconazole, pyraclostrobin, and thiophanate-methyl at 395.42, 781.03, and 561.11 µg/mL, respectively) was obtained using response surface methodology (RSM) to improve the inhibition rate of 92.24 ± 0.34%. This study provides basic data for the pathogen characterization of B. striata white root rot and its potential fungicides in Sichuan, China. In addition, the optimal fungicide concentration ratios were obtained through response surface methodology (RSM) optimization, which significantly enhanced the fungicidal effect and provided a scientific basis for the future control of B. striata white root rot.

Coin‐Shaped Carbon Prepared with Cerbera manghas Fibers via Multistage Carbonization and Activation for High‐Performance Symmetrical Supercapacitors

AbstractSupercapacitor energy storage devices and activated carbon (AC) manufacturing materials for producing high‐performance supercapacitors have received extensive attention from researchers. Biomass‐based AC has been extensively studied due to its environmental friendliness, abundant availability, porous structure, and high specific surface area. This work focuses on developing biomass‐based carbon electrodes derived from Cerbera manghas fiber (CMF) with variations in carbonization temperature to obtain optimum supercapacitor cell performance. The prepared CMF AC was characterized using energy dispersive X‐ray, Fourier transform infrared, X‐ray diffraction, scanning electron microscope, and nitrogen isothermal adsorption–desorption. CMF AC with the optimum carbonization temperature (CMF‐600) produced a fibrous structure with a lot of mesoporous so that the specific surface area and specific capacitance were high, namely, 721.495 m2 g−1 and 221 F g−1 at scan rate 1 mV s−1, respectively. The results of this study indicate that selecting the optimum temperature can enhance the performance of supercapacitor cells and make AC based on CMF biomass potential for cheap and efficient energy storage applications.

Effects of conductive phase content on magnetic sensitivity of spiral conductive polymer composite

Flexible magnetic field sensors are essential for small dimensions, excellent precision, and flexibility in narrow gap or pipe environments. A spiral conductive polymer composite has been proposed for magnetic field detection. To investigate how conductive phase content impacts its magnetic sensitivity, the relationship between magnetic flux density and voltage difference/magnetic sensitivity was examined with different carbon nanotube contents (1 wt%∼20 wt%). From the perspectives of the equivalent network and magnetic susceptibility, the voltage difference /magnetic sensitivity of the composite was analysed by varying its carbon nanotube content. The addition of carbon nanotubes creates a contradiction in the magnetic sensitivity caused by internal equivalent impedance or induced current. The experiments demonstrate that the interpolar voltage difference /magnetic sensitivity first increases and then sharply decreases with increasing carbon nanotube content within composites. The optimum carbon nanotube content is about 8 wt%, which can be an optimal sensitive material choice for a flexible magnetic sensor.

Biomass valorization of Mangifera Indica into hierarchical carbon materials with self-doping oxygen assisted carbonization for supercapacitor applications

ABSTRACT The exploration of biocompatible energy storage media for future generations has been continuously carried out. This includes the investigations of electrode materials that are renewable, environmentally friendly, cost-effective, and rich in heteroatoms. The electrode materials undergo carbonization as a promising thermochemical process to create an active material with a porous structure of well-defined and controlled geometry. The main objective of this study is to thoroughly examine the conversion process of electrode materials derived from Mangifera Indica Seed Shells (MIS) using carbonization and activation methods for supercapacitor applications. Pyrolysis at various temperatures was carried out to determine the definitive influence of carbonization temperature on the capacitive performance of MIS active materials. The optimum carbonization temperature of 600°C significantly enhances mesoporosity, which is positively correlated to the specific surface area, hierarchical structure, and the presence of self-doping oxygen, leading to a substantial increase in capacitive behavior. In the experiment, the MIS samples were used as electrodes for supercapacitor cells, and they were found to exhibit a specific capacitance of 255 Fg−1. The goal of this study is to offer a sustainable solution by using biomass as an active material for high-performance supercapacitor cells that can be utilized in energy storage applications.

An efficient method of preparing Si–Fe–Al–Ca alloy from coal gasification fine slag via plasma smelting and alternating current magnetic field

It is of great significance to solve the environmental problems caused by the unreasonable treatment of coal gasification slag. This study successfully produced Si–Fe–Al–Ca alloy from low-carbon fine slag with petroleum coke as reducing agent in a plasma furnace with an alternating current magnetic field, which solved the problem of the high reactivity requirement of carbon reductant for plasma smelting. The optimum carbon content of the mixed low-carbon fine slag and petroleum coke is 105% of the theoretical value. As the strength of the alternating current magnetic field increased (from 0% to 100% of the maximum power), the yield of the alloy (from 25.46% to 58.19%) and the recovery ratios of each element (Si, Fe, Al, Ca, Ti) increased. In addition, as the magnetic field strength increased, the pores inside the alloy became smaller, the composition of the alloy became more homogeneous, and a better separation of the alloy from the slag was observed. The main composition of the alloy at the strongest alternating current magnetic field is Si: 51.14 wt%, Fe: 28.41 wt%, Al: 9.14 wt%, Ca: 7.15 wt%, Ti: 2.03 wt%. We attribute the enhanced smelting effect of the alternating current magnetic field to the resistive heat and Lorentz force produced by the induced current. In addition, the skin effect concentrated the induced current on the surface of the oxide particles and carbon particles, which increased the temperature of the reaction interface and promoted the carbothermal reduction reaction.

Microbial hyaluronic acid production in the 21 century: a roadmap toward high production, tailored molecular weight

Hyaluronic acid is a biopolymer that has gained attention from both researchers and the public since its discovery in 1934. In 2022, its global annual demand was 667 MT, with a market value of 9.4 billion dollars and an expected compound growth rate of 7.7% from 2024 and 2030. Such popularity lies in its many applications, which ranges from pharmaceutical to Tissue Engineering. Its molecular weight (MW) determines which application hyaluronic acid is better suited for: high MW (over 1 MDa) is used in medical applications such as osteoarthritis and ophthalmology, and low MW (less than 0.05 MDa) are suited for moisturizing cosmeceuticals. This makes hyaluronic acid molecular weight an important parameter for its production. The first industrial process was based on extraction from rooster combs. However, it shifted toward microbial production with Streptococcus zooepidemicus. Studies focus on improving its production and tailoring its molecular weight by accessing optimum temperature, pH, aeration, agitation, carbon, and nitrogen sources concentration and origin. his review aims to provide an overview of the current knowledge on the effects of metabolic and environmental factors in microbial hyaluronic acid production. The review shows that there has been extensive research in optimizing cultivation medium composition, temperature, pH, and aeration between 2018 and 2023, but further studies are required to optimize the metabolism of S. zooepidemicus towards maximum biopolymer production and molecular weight.

Identification the Pathogen Cause a New Apple Leaf Blight in China and Determination the Controlling Efficacy for Five Botanical Fungicides.

Alternaria leaf blight has recently been described as an emerging fungal disease of apple trees which is causing the significant damage in the apple-growing areas of Tianshui and Jingning, Gansu, China. In the present study, the pathogen species involved in apple leaf blight and its biological characteristics were identified, and the inhibitory activity of different botanical fungicides against the pathogen was evaluated in vitro. Four strains were isolated from the symptomatic areas of necrotic apple leaves, and initially healthy leaves showed similar symptoms to those observed in orchards after inoculation with the ABL2 isolate. The ABL2 isolate was identified as Alternaria tenuissima based on the morphological characteristics of its colonies, conidiophores, and conidia, and this was also confirmed by multi-gene sequence (ITS, OPA10-2, Alta-1, and endoPG) analysis and phylogenic analysis. The optimum temperature, pH, carbon source, and nitrogen source for the growth of A. tenuissima mycelia were 28 °C, 6-7, soluble starch, and soy flour, respectively. In addition, the botanical fungicide eugenol exhibited the highest inhibitory effect on the mycelial growth and conidia germination of A. tenuissima, and the median effective concentration (EC50) values were 0.826 and 0.755 μg/mL, respectively. The protective and curative efficacy of eugenol were 86.85% and 76.94% after inoculation in detached apple leaves at a concentration of 4 μg/mL. Our research provides new insights into the control of apple leaf blight disease by applying botanical fungicides.

Insights into microplastics (MPs) removal using aquatic plant-derived biochar from Taihu Lake at varying carbonization temperatures

Microplastics (MPs), recognized as significant emerging contaminants, are prevalent in both terrestrial and aquatic ecosystems. This study investigates the potential of biochar derived from Polygonum amphibium L. (PAL) sourced from Taihu Lake and processed through a low-temperature carbonization method, for in the removal of MPs. This approach addresses the escalating presence of MPs in aqueous environment, especially during the COVID-19 pandemic, simultaneously tackles the issue of waste biomass contributing to eutrophication. The study focused on the impact of carbonization temperatures (450℃-550℃) on physicochemical properties of biochar. Additionally, the effect of contact time, initial concentration of MPs, and environmental factors at various carbonization temperatures were also examined. The results reveal that the biochar yield and adsorption performance of biochar are significantly influenced by carbonization temperature. The adsorption capacity of biochar for MPs removal increases with the carbonization temperature up to 500 ℃, attributed to enhanced diffusion, surface adsorption, interactions, and cation-π electron interactions between the biochar and MPs. However, at a pyrolysis temperature of 550 ℃, the increase in adsorption capacity of biochar-550 is marginal due to increased competitive binging and destabilization of biochar under basic conditions. Overall, the optimum carbonization temperature is identified as 500 ℃, yielding a char rate is 32.23% and an adsorption capacity for MPs of 80.3 mg/g, thereby offering a promising solution for MP removal and water eutrophication management.

Efficiency of thermostable purified laccase isolated from Physisporinus vitreus for azo dyes decolorization.

Laccases are versatile biocatalysts that are prominent for industrial purposes due to their extensive substrate specificity. Therefore, this research investigated producing laccase from Physisporinus vitreus via liquid fermentation. The results revealed that veratryl alcohol (4mM) was the most effective inducer 7500U/L. On the other hand, Zn ions inhibited laccase production. The optimum carbon and nitrogen sources were glucose and tryptone by 5200 and 3300 U/L, respectively. Moreover, solvents exhibited various impacts on the enzyme activity at three different solvent concentrations (5%, 10% and 20%), however, it showed a highest activity at 5% of the investigated solvent. Ferric ions inhibited the enzyme activity. In addition, the enzyme has a high ability to decolorize azo dyes when using syringaldehyde as a mediator. The purified laccase from Physisporinus vitreus is a promising substance to be used for industrial and environmental applications due to its stability under harsh conditions and efficiency in decolorization of dyes.

Production and Optimization of L-glutaminase from Halophilic Fusarium solani-melongenae Strain CRI 24 under Submerged and Solid State Fermentation

L-glutaminase is a unique enzyme with catalytic activity and the ability to modulate glutamine levels, making it a valuable enzyme with numerous potential applications. L-glutaminase triggers a distinctive reaction by converting L-glutamine into glutamic acid while releasing ammonia concurrently. This enzymatic process holds potential applications across diverse industries, notably in food and pharmaceuticals. The primary objective of the present research was to identify and isolate a fungal strain proficient in L-glutaminase production from soil found in maritime environments. The physical and nutritional conditions were optimized for maximum synthesis of L-glutaminase under solid state fermentation (SSF) and submerged fermentation conditions (SmF). The isolated organism was identified as Fusarium solani-melongenae strain CRI 24 by morphological and 18S rRNA analysis. The optimum carbon source under SmF and SSF was found to be starch (0.2% w/v). Wheat bran as solid substrate among others showed optimum enzyme activity. On the seventh day of incubation, at pH 8.0 and 0.7% L-glutamine concentration under SSF and SmF, the highest enzyme activity was detected. The greatest enzyme activity in SSF was seen at a moisture content of 10%. Fusarium solani-melongenae species produced the enzyme under optimal conditions and 4.20 and 4.73-fold increase (from 0.8 U/mL to 3.61 U/mL and from 0.781 U/mL to 3.69 U/mL) was achieved after optimization in submerged and in solid state fermentation, respectively. The selective isolation and optimization processes described in this work are a promising technique for the industrial production of L-glutaminase and can be applied in the pharmaceutical and food industries.

Biogas intake pressure and port air swirl optimization to enhance the diesel RCCI engine characteristics for low environmental emissions

Exhaust emission and combustion control in RCCI (reactivity-controlled compression ignition) focused mainly on the direct-injected fuel parameters, urging to investigate the advantages of port-fuel intake parameters. The engine was modified for port injection of Biogas at the valve and RCCI mode. The influence of port swirl ratio (PSR, 0 – 80%) and biogas injection pressure (BIP, 1 – 4 bar) on the diesel RCCI combustion and emissions was tested and optimized at varied loads and 1600 rpm in a port injection at the valve (PIVE) approach. Established kinetic mechanisms were combined with multi-objective optimization to further investigate, predict, and analyze emissions occurrence and trade-offs for reduced environmental impacts. The results show that the radiation absorption triggered by increased CO2 lowers combustion temperature, resulting in prolonged ignition. Setting the airflow to swirl lowers the in-cylinder pressure at elevated BIP while raising the heat generated across the BIPs. Increasing the PSR slows the combustion while BIP speeds up the process. BIP and PSR show great trade-off reduction ability among all emission parameters. The optimum unburned hydrocarbon, nitrogen oxide, particulate, and carbon monoxide emissions for the injection at the valve were found to be 109.58, 0.577, and 2.336 ppm, and 0.103%, respectively, at low-load, low-BIP, and high-PSR. The emissions were lowered by 6.58, 91.26, 80.65, and 13.45% compared to the premixed RCCI mode, respectively. Therefore, introducing low-pressure biogas amid high swirling air at the valve elevates the in-cylinder condition while lowering the emissions, mitigating their environmental implications.

Genetic electro-search optimization for optimum energy consumption in edge computing-based internet of healthcare things

AbstractEnergy consumption is a vital issue when optimum usage and carbon footprint are all considered in today’s Internet of Things (IoT) environments. Considering edge computing, that becomes too critical in terms of wireless devices with limited battery power. Especially in healthcare applications, the defined IoHT approach requires sustainability while future massive solutions may result negative outputs in terms of carbon footprint. So, optimum energy consumption seems positive in terms of multiple ways. In the literature, one trendy method is using clustering for lowering the energy consumption within the Internet of Healthcare Things (IoHT) environment on edge computing. In this study, optimization of energy consumption in IoHT was done via improved Genetic Electro-Search Optimization (GESO) algorithm. According to the obtained findings in the performed applications, GESO was effective enough in finding optimum conditions of energy consumption for an active IoHT setup.

Edamame caspian sea soygurt as plant-based yogurt alternatives

Caspian sea soygurt is made by fermenting edamame milk with Lactococcus lactis ssp. cremoris and Acetobacter orientalis as microbial cultures. To produce good soygurt, edamame milk fermentation requires ideal conditions, such as an optimum carbon source and starter concentration. This study aimed to determine the effect of the proportion of sucrose:skim and concentration of starter on the physical, chemical, microbiological, and sensory characteristics of Caspian sea soygurt. This study used a randomized block design with 2 factors: sucrose:skim proportion (2.5:7.5, 5:5 7.5:2.5) and starter concentration (8, 10, 12% of pasteurized edamame milk) repeated three times. Data were analyzed using ANOVA and continued with the Tukey test. These results was used to select the best treatment using the Zeleny Multiple Attribute Method. The best Caspian soygurt treatment was found in the proportion of sucrose:skim 5:5 (% w/v of pasteurized edamame milk) and starter concentration 12 (% v/v of pasteurized edamame milk), which produced a color (L*) 78.98, (a*) -2.86 ( b*) 23.79, viscosity 516.67 cP, protein 3.38%, antioxidant activity 43.12%, pH 4.35, total lactic acid bacteria 9.85 log CFU/mL with a preference level of 3.45 and an acceptance level of 3.55 for the greenness, a preference level of 3.79 and an acceptance level of 3.80 for the brightness, a preference level of 3.15 and an acceptance level 3.21 on the sour aroma, preference level of 3.04 and acceptance level of 3.11for the beany aroma, preference level of 3.04 and acceptance level of 3.18 for the beany flavor, preference level of 3.02 and acceptance level of 3.19 for the sour taste, preference level of 2.98 and acceptance level of 3.09 for sweet taste, preference level of 3.49 and acceptance level of 3.60 for the viscosity.

Optimization of Carbon and Nitrogen Source to Enhance Antibacterial Activity from a Sponge-derived Bacillus tequilensis

In our endeavor to find antibacterial from marine bacteria, we screened the microbiota from a Lithistid sponge, collected from Seribu Island, Jakarta. One of the promising strains was K 2.4.2. Identification of the strain using 16S rRNA Sanger sequencing resulted a sequence similarity of 100% to Bacillus tequilensis. Response surface methodology was applied to optimize the culture conditions for enhancing antibacterial activity of the strain. The optimization was carried out using Box-Behnken design experiment to determine the optimum carbon and nitrogen sources in order to produce maximum antibacterial activity. The optimum media with high antibacterial activity was marine broth with the addition of carbon and nitrogen concentration source of sucrose 2.15 % and peptone 1.08%, respectively. In addition, the optimum temperature was 31.18oC. The antibacterial activity response was predicted using a statistical model and compared to the activity in the experiment. The difference between the model and the laboratory experiment was less than 5% which showed a good accuracy. The results of this study once again showed that optimization method effectively reduced time, chemicals, and energy.

Corn cob usage as activated carbon using KOH as activator

The value of agroindustry waste like corn cob can be added as raw material for produced activated carbon. Activated carbon can be used as adsorbent in food, pharmacy, cosmetic industries, and waste water treatment. This research was conducted by using KOH as activator in the activation process for produced of activated carbon from corn cob. The methods include several steps, first step was particle size reduction. Second step was carbonization process in 500° C for an hour. Third step was activation process using solid KOH and liquid KOH, then heated at 900° C. Then, it will be washed until neutral and dried at 105° C. The activated carbon was observed for iodine adsorption, surface area, carbon content and morphology. The result for activation process using solid KOH: optimum iodine adsorption, optimum surface area, and optimum carbon content were 1233.87 mg/g, 2076.141 m2/g, and 93.59 %, respectively. Activation process using liquid KOH: optimum iodine adsorption, optimum surface area, and optimum carbon content were 595.16 mg/g, 716.271 m2/g, and 95.24 %, respectively. The morphology of activated carbon using solid KOH was cleaner and more open (porous). The Activated carbon can be applied for skin care product, like gel peel off mask.

Improved production of lactiplantibacillus plantarum RO30 exopolysaccharide (REPS) by optimization of process parameters through statistical experimental designs

BackgroundIn investigating of (exopolysaccharide) EPS from unconventional sources, lactic acid bacteria have a vital role due to their generally recognized as safe (GRAS) status. EPSs have diverse applications such as drug delivery, antimicrobial activity, surgical implants, and many more in many sectors. Despite being important, the main hindrance to the commercial application of these significant biopolymers is low productivity. Therefore, this study primarily focuses on optimizing physio-chemical conditions to maximize the previously produced EPS from probiotic Lactiplantibacillus plantarum RO30 (L. plantarum RO30) using one factor at a time (OFAT) and method Response Surface Methodology (RSM).ResultsThe EPS obtained from L. plantarum RO30 named REPS. The medium formulation for REPS production using the OFAT method revealed that sucrose (20 g/L, beef extract (25 g/L), and ammonium sulfate at 4 g/L concentration were the optimum carbon, organic and inorganic nitrogen sources, and REPS yield was increased up to 9.11 ± 0.51 g/L. RSM experiments revealed that, a greatly significant quadratic polynomial attained from the Central Composite Design (CCD) model was fruitful for specifying the most favorable cultural conditions that have significant consequences on REPS yield. The maximal amount of REPS (10.32 g/L) was formed by: sucrose (40 g/L), beef extract (25 g/L), pH (5.5), incubation temperature (30 °C), and incubation period (72 h). A high closeness was obtained between the predicted and experimental values and it displayed the efficiency of the RSM.ConclusionThis study was conducted to reinforce REPS production in the probiotic LAB L. plantarum RO30 by utilizing various experimental parameters. The maximum REPS yield of 10.32 g/L was attained under the circumstances optimized in the study.

Fabrication and Characterization of Activated Carbon from ‘Aking rice’ Waste

Rice as a staple food for most Indonesian people contributes a high amount of food waste. Indonesian people generally process cooked rice waste into ‘Aking rice’. ‘Aking rice’ is a result from the drying of cooked rice with the sun. ‘Aking rice’ is generally used as animal feed, but on the other hand, aking rice has the potential to be used as a source of activated carbon because it contains high carbon. We learn the optimum carbonization temperature for making activated carbon from aking rice by conducting several characterization tests on activated charcoal from each carbonization temperature. The fabrication method of activated carbon in this research occurs in two steps, carbonization first followed by chemical activation using HCl. The carbonization temperature variations are 300°C, 400°C, and 500°C. The optimum carbonization temperature is 500°C because all results comply with requirement. Activated carbon from carbonization temperature at 500°C has water content of 0,96%, ash content of 0,98%, volatile matter content of 19,30%, and fixed carbon content 79,72%. Variation of carbonization temperature does not give significant effect for ash content and water content, but give significant effect for volatile matter content and fixed carbon content.