• Korean Journal of Materials Research
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• v.28 no.3
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• pp.182-188
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• 2018

Nitrogen (N)-doped protein-based carbon as platinum (Pt) catalyst supports from tofu for oxygen reduction reactions are synthesized using a carbonization and reduction method. We successfully prepare 5 wt% Pt@N-doped protein-based carbon, 10 wt% Pt@N-doped protein-based carbon, and 20 wt% Pt@N-doped protein-based carbon. The morphology and structure of the samples are characterized by field emission scanning electron microscopy and transmission electron micro scopy, and crystllinities and chemical bonding are identified using X-ray diffraction and X-ray photoelectron spectroscopy. The oxygen reduction reaction are measured using a linear sweep voltammogram and cyclic voltammetry. Among the samples, 10 wt% Pt@N-doped protein-based carbon exhibits exellent electrochemical performance with a high onset potential of 0.62 V, a high $E_{1/2}$ of 0.55 V, and a low ${\Delta}E_{1/2}=0.32mV$. Specifically, as compared to the commercial Pt/C, the 10 wt% Pt@N-doped protein-based carbon had a similar oxygen reduction reaction perfomance and improved electrochemical stability.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.1028-1041
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• 2023

BACKGROUND/OBJECTIVES: This study aimed to analyze the potential of school meals in South Korea as a sustainable tool to reduce carbon emissions by focusing on animal- vs. plant-based protein foods. MATERIALS/METHODS: By using a stratified proportional allocation method, 536 out of the 11,082 schools nationwide were selected including 21 kindergartens, 287 elementary-, 120 middle- and 108 high schools. A total of 2,680 meals served for 5 consecutive days (June 21-25, 2021) were collected. We analyzed the average serving amounts of protein foods (animal- vs. plant-based) per meal and then, calculated the estimated average amounts of carbon emission equivalents per meal by applying the conversion coefficients. The t-test and analysis of variance were used for statistical analyses (α = 0.05). RESULTS: The average serving amount of animal-based protein foods per meal was 12.5 g, which was approximately 3 times higher than that of plant-based ones (3.8 g) (P < 0.001); the Meat-group had the highest average amount of 17.0 g, followed by Egg-group (9.6 g), Fish-group (7.6 g), and Beans-and-Nuts-group (3.8 g) (P < 0.05). Specifically, pork (25.1 g) was ranked first, followed by poultry (19.6 g), processed meat products (18.0 g). The estimated average amount of carbon emission equivalents of animal-based protein foods per meal was 80.1 g CO₂e, which was approximately 31 times higher than that of plant-based ones (2.6 g CO₂e) (P < 0.001); the Meat-group had the highest average amount of 120.3 g CO₂e, followed by Fish-group (44.5 g CO₂e), Egg-group (25.9 g CO₂e), and Beans-and-Nuts-group (2.6 g CO₂e) (P < 0.05). Specifically, processed meat products (270.8 g CO₂e) were ranked first, followed by pork (91.7 g CO₂e), and processed fish products (86.6 g CO₂e). CONCLUSIONS: The results implied that school meals with plant-based alternatives could be a sustainable tool to improve carbon footprint.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• Journal of Korean Society on Water Environment
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• v.37 no.5
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• pp.344-354
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• 2021

Optical methods such as UV and fluorescence spectrophotometers can be applied not only in the qualitative analysis of dissolved organic matter (DOM), but also in real-time quantitative DOM monitoring for wastewater and natural water. In this study, we measure the UV₂₅₄ and fluorescence excitation emission spectra for a sewage treatment plant influent and effluent, and river water before and after sewage effluent flows into the river to examine the composition and origin of DOM. In addition, a correlation analysis between quantified DOM characteristics and dissolved organic carbon (DOC) was conducted. Based on the fluorescence excitation emission spectra analysis, it was confirmed that the protein-type tryptophan-like DOM was the dominant substance in the influent, and that the organic matter exhibited relatively more humic properties after biological treatment. However, DOM in river water showed the fluorescence characteristics of terrestrial humic-like and algal tyrosine-like (protein-like) organic matter. In addition, a correlation analysis was conducted between the DOC and optical indices such as UV₂₅₄, the fluorescence intensity of protein-like and humic-like organic matter, then DOC prediction models were suggested for wastewater and river monitoring during non-rainfall and rainfall events. This study provides basic information that can improve the understanding of the contribution of DOC concentration by DOM components, and can be used for organic carbon concentration management in wastewater and natural water.

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.87-101
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• 1988

The effect of hepatic injury produced by CCL, was studied on rats receiving a low protein-high carbohydrate (7% casein), standard protein (20% casein) and a high protein diet (30% casein). The rats fed low protein diet are resistant to CCl$_4$ in its effects on the liver as judged by histology, serum enzymes(guanase, ALT) and the content of hepatic protein. On the other hand, the pretreatment of hydrocortisone before injection of CCl$_4$ to the rats fed a standard diet, slightly decreased both serum ALT and guanase activities. In the pretreatment of actinomycin D, the liver and serum guanase activities were significantly decreased. It indicates that the cause of increasing serum guanase is based on the alteration of membrane permeability and the result of accelerated enzyme synthesis in liver cells of CCl$_4$ intoxicated rats.

• Membrane Journal
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• v.32 no.5
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• pp.348-356
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• 2022

With the development of the bio industry, membrane chromatography with a high adsorption efficiency is emerging to replace the existing column chromatography used in the downstream processes of pharmaceuticals, food, etc. In this study, through the deacetylation reaction of two commercial cellulose acetate (CA) membranes with different pore sizes, the porous regenerated cellulose (RC) supports for membrane chromatography were obtained to attach the anion exchange ligands. The adsorptive membranes for anion exchange were prepared by attaching an anion exchange ligand ([3-(methacryloylamino) propyl] trimethylammonium chloride) containing quaternary ammonium groups on the RC supports by grafting and UV polymerization. The protein adsorption capacities of the prepared membranes were obtained through both the static binding capacity (SBC) and the dynamic adsorption capacity (DBC) measurement. As a result, the membrane chromatography with the smaller the pore size, the larger the surface area showed the highest protein adsorption capacity. Membrane chromatography which was prepared by using deacetylated commercial CA support with MAPTAC ligand (i.e., RC 0.8 + MAPTAC: 43.69 mg/ml, RC 3.0 + MAPTAC: 36.33 mg/ml) showed a higher adsorption capacity compared to commercial membrane chromatography (28.38 mg/ml).

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1727-1732
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• 2007

Phenylacetic acid (PAA) is produced by many bacteria as an antifungal agent and also appears to be an environmentally toxic chemical. The object of this study was to detect PAA using Pseudomonas putida harboring a reporter plasmid that has a PAA-inducible promoter fused to a green fluorescent protein (GFP) gene. Pseudomonas putida KT2440 was used to construct a green fluorescent protein-based reporter fusion using the paaA promoter region to detect the presence of PAA. The reporter strain exhibited a high level of gfp expression in minimal medium containing PAA; however, the level of GFP expression diminished when glucose was added to the medium, whereas other carbon sources, such as succinate and pyruvate, showed no catabolic repression. Interestingly, overexpression of a paaF gene encoding PAA-CoA ligase minimized catabolic repression. The reporter strain could also successfully detect PAA produced by other PAA-producing bacteria. This GFP-based bioreporter provides a useful tool for detecting bacteria producing PAA.

• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.170-175
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• 2022

3-Hydroxypropionic acid (3HP) is a platform chemical and can be converted into other valuable C3-based chemicals. Because a large amount of glycerol is produced as a by-product in the biodiesel industry, glycerol is an attractive carbon source in the biological production of 3HP. Although eight 3HP-producing aldehyde dehydrogenases (ALDHs) have been reported so far, the low conversion rate from 3-hydroxypropionaldehyde (3HPA) to 3HP using these enzymes is still a bottleneck for the production of 3HP. In this study, we elucidated the substrate binding modes of the eight 3HP-producing ALDHs through bioinformatic and structural analysis of these enzymes and selected protein engineering targets for developing enzymes with enhanced enzymatic activity against 3HPA. Among ten AbKGSADH variants we tested, three variants with replacement at the Arg281 site of AbKGSADH showed enhanced enzymatic activities. In particular, the AbKGSADH^R281Y variant exhibited improved catalytic efficiency by 2.5-fold compared with the wild type.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.65-68
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• 2008

Crop production in a country is very crucial not only in a country's crop self-sufficiency, but also in carbon recycle. Crop can capture and store the emitted $CO_2$ by cereal food consumption. However, imported cereal food is not concerned in carbon recycle and this hinders the accurate estimation of carbon recycle. Korea imports major grain products including wheat, corn, soybean, and rice and about 90% of the grain composition consists of carbohydrate, protein and lipid. Carbon portions in carbohydrate, protein and lipid are 45, 53, and 77%, respectively. When the carbon portions are digested and converted into $CO_2$ completely, one ton of rice, wheat, corn, and soybean can release 1.51, 1.63, 1.56, and 1.56 tons of $CO_2$ to the atmopshere, respectively. Based on this premise, the evolved $CO_2$ calculated from imported grains for the last 4 years in Korea was over 21 MT of $CO_2$. This amount is equivalent to 4.8 billion US dollars in the conception of carbon tax. These results suggest that a decrease in a cereal import(i.e, an increase in a country's crop self-sufficiency) can lower $CO_2$ release to the atmosphere.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.64-73
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• 2020

Producing animal products from farm to table emits massive amounts of greenhouse gases (GHGs). Modified meal plans, mainly including vegetables and grains, have been recommended to reduce GHG emissions. However, these meal plans have not been developed with regard to the micronutrient content, but rather with regard to the energy requirements of grains and vegetables, which could result in a nutritional imbalance. For this reason, we investigated a common Korean suggested meal plan (SMP) from the National Institute of Agricultural Sciences, in which nutritional conditions were considered, and evaluated its GHG emissions using the Life Cycle Assessment Inventory Database and nutritional values. The SMP, which included meat, was based on the Korean Nutrition Society for adult men age 19 to 29, and was changed to a vegan meal plan (VMP). Animal-based protein sources were substituted for meat alternatives, such as beans and tofu, for which carbon footprint data was available. To compare the nutritional differences, the 9^th Korean Food Composition Tables I and II were consulted. To calculate GHG emissions, the carbon footprint data of the food was converted to a CO₂ equivalent (CO₂e) using a procedure from the Foundation of Agriculture Technology Commercialization and Transfer. It was found that GHG emissions per calorie were 18% lower for the VMP when compared to the SMP. However, if GHG emissions per total amino acids were evaluated, the VMP GHG emissions per total amino acids were 0.12 g CO₂e/mg, while the corresponding value for the SMP was 0.06 g CO₂e/mg. The Korean daily meat intake reported by the Korea Agricultural Statistics Service was 37.1% lower than in the SMP, but when converted to a protein intake the figure was 17.0% lower. It was found that each SMP resulted in more GHG emissions than the VMP, but when considered as GHG emissions per total amino acids, the opposite pattern was apparent. There is a need to conduct more detailed studies of the variation in GHG emissions with different meal plans, using the daily meat intake per person.