• Journal of Life Science
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• v.27 no.1
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• pp.67-71
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• 2017

Foulbrood disease is infected by Paenibacillus larvae on larval stage of honeybee, and is lethal disease to result in population death. This disease was manifested in 2008 in Korea, is still suffered by the secondary damages. In this study, we are to examine diagnostic PCR approaches to manage the Foulbrood disease. PCR amplification of 16S rRNA is generally using for microbial infection, but the specificity is little poor for the correct diagnosis. Therefore, we are to identify specific genes expressed in Paenibacillus larvae, and perform PCR analysis. We selected five distinct genes from literature references. Those genes are commonly known as toxic genes for host infection, and include Toxin1, Toxin2A & 2B, SplA, CBP49, and SevA&SevB. PCR amplification for these genes is difficult to detect at the first time. So, we performed the second PCR using the first PCR product as a template. This approach using the nested PCR was very useful for detecting large marker genes. When Paenibacillus larvae was cultured in the medium containing plant extracts, PCR amplification of the identified genes is correlated with the microbial growth inhibition. Therefore, these results suggest that the identified genes might be useful to study diagnostic PCR markers for honeybee Foulbrood disease.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.28-34
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• 2017

Biocatalytic modification of natural resources can be used to generate novel compounds with specific properties, such as higher viscosity and reactivity. The production of hydroxy fatty acids (HFAs), originally found in low quantities in plants, is a good example of the biocatalytic modification of natural vegetable oils. HFAs show high potential for application in a wide range of industrial products, including resins, waxes, nylons, plastics, lubricants, cosmetics, and additives in coatings and paintings. In a recent study, Pseudomonas aeruginosa strain PR3 was used to produce 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) from oleic acid. This present study focused primarily on the utilization of three natural nut oils obtained from the Philippines -pili nut oil (PNO), palm oil (PO), and virgin coconut oil (VCO)- to produce DOD by P. aeruginosa strain PR3. Strain PR3 produced DOD from PNO and PO only, with PNO being the more efficient substrate. An optimization study to achieve the maximum DOD yield from PNO revealed the optimal incubation time and medium pH to be 48 h and 8.0, respectively. Among the carbon sources tested, fructose was the most efficiently used, with a maximum DOD production of 130 mg/50 mL culture. Urea was the optimal nitrogen source, with a maximum product yield of 165 mg/50 mL culture. The results from this study demonstrated that PNO could be used as an efficient substrate for DOD production by microbial bioconversion.

• Journal of Environmental Science International
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• v.25 no.11
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• pp.1575-1582
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• 2016

In this study, to provide basic information for design of a large-scale recycling system for fishery by-products, the food nutrient components, fertilizer components, and microbial composition of fertilizers and feed which were made of fishery by-products were analyzed before and after fermentation. The results of the analysis of the edible portion of fishery by-products indicated that calories per 100 g of crustaceans were the highest followed by those of fish and brown algae in order of precedence with values as follows; Korean Krill 94 Kcal, Portunus trituberculatus 65 Kcal, Lophiomus setigerus 58 Kcal, and Undaria pinnatifida 16 Kcal. As for changes in amino acids per 100 g of fishery by-products between before and after fermentation, calories per 100 g of P. trituberculatus decreased by 74.7% from 15.7 g to 4.0 g, that of L. setigerus decreased by 61.1% from 11.9 g to 4.6 g, that of Korean Krill decreased by 53.5% from 11.6 g to 5.4 g, and that of U. pinnatifida decreased by 49.4% from 1.7 g to 0.9 g. Among amino acids, those contained in fishery by-product fertilizers (liquid fertilizer) in large amounts were shown to be Glutaminic acid, Aspartic acid, Glycine, Lysin, and Leucine. The lipid content of Korean Krill decreased by 11.9% from 3.2 g to 2.8 g, that of L. setigerus increased by 2.0 times from 1.1 g to 2.2 g, that of P. trituberculatus increased by 4.5 times from 0.4 g to 1.7 g, and that of U. pinnatifida increased by 9.4 times from 0.2 g to 1.9 g. The ash (mineral) content of P. trituberculatus decreased by 82.5% from 26.2 g to 4.6 g, that of U. pinnatifida increased by 27.6% from 3.3 g to 4.2 g, that of Korean Krill increased by 21.9% from 3.1 g to 3.8 g, and that of L. setigerus increased by 88.7% from 1.2 g to 2.2 g. The microbial composition of liquid fertilizer using recycled fishery by-products was shown to be Bacteria, Actinomycetes, Fungi, Yeast, and Lactobacillus sp.

• Korean journal of food and cookery science
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• v.27 no.1
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• pp.63-73
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• 2011

Cabbage (Baechu) Kimchi in its truncated form was placed in four different packing materials, Ny/PE/LLDP, OPP/AL/PE, PP and PET, and quality changes were observed during storage. Changes in pH and total acidity showed an x-shaped cross-curve as pH decreased and total acidity increased during storage. PP tray showed the slowest change at $5^{\circ}C$ with time. The pH was initially 6.25, but decreased to 4.12~4.16 at 20 days, and total acidity showed a 4 to 4.8-fold increase after 20 days of storage compared to the initial value. During storage at $5^{\circ}C$, total bacterial count and lactic acid bacterial count rapidly increased after 4 days. The total bacterial quantity decreased after a period of time and there were differences according to packaging material; OPP/AL/PE packaging showed the most dramatic decrease. Change in microbial count mostly followed a similar pattern to that of total acidity for all packaging materials. Changes in the color of Kimchi liquid, when examined by color index in $L{\cdot}b$/a form, rapidly decreased over time, similar to pH. Small Ny/PE/PP and OPP/AL/PE packages of Kimchi were examined for changes in free volume inside the packaging. After 13 days of storage at $5^{\circ}C$, the volume was 243 mL, but storage at $20^{\circ}C$ resulted in a volume of 372 mL, a more than 1.5-fold increase in free volume. There were changes in the quality characteristics of small package Kimchi according to storage temperature and packaging material, and large changes in pH, total acidity, and microbial count were evident upon storage at $5^{\circ}C$ for 8 days, which was the optimum palatability period. Mostly, PP treatment showed the slowest quality changes upon storage at $5^{\circ}C$. However, due to small package Kimchi's fast consumption system, the appropriate choice of packaging material must consider the product's turnover ratio. Further, the varieties of small package Kimchi should be diversified according to different consumer preferences by offering Kimchi with different maturity levels. Further, since the leading consumer base ranges in age from the teens to thirties, the development of various products targeting such consumers is necessary.

• Food Science and Preservation
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• v.13 no.2
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• pp.259-268
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• 2006

We investigated food preservation hurdles used for Korean traditional side dishes. As a first step of the research preparation and cooking recipes of the side dishes were surveyed, which are commonly used in Korean households. As next step, compositional and microbial quality attributes were measured onto the samples collected from the market. Antimicrobial ingredient added in the preparation are reasoned to work as important hurdles based on the scientific principles. Heating processes such as blanching, boiling, braising, hard-boiling and frying help to keep the produce decontamination or water activity adjustment. Measured salt contents of most side dishes were in the range of 1-5% with those of salt-preserved vegetables being higher. pH values were 4.7-6.4 with those of salt-preserved vegetables being lower and those of hard boiled fishes being higher. Soluble solids of braised or hard-boiled dishes were usually above $40^{\circ}Brix$, while those of blanched and seasoned vegetables had lower values. Water activity values were 0.93-0.95 for seasoned vegetables and 0.77-0.88 for hard-boiled or semi dried beans and seafoods. Product with processing steps of braising or blanching showed lower bacterial load of 102-104 cfu/g, while seasoned or salt-preserved vegetables and seafoods had aerobic bacterial count above 106 cfu/g. Korean traditional side dishes were found to apply the appropriate combinations of heating preparation process, water activity and pH adjustment and salting, providing the required preservation properties.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.61-70
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• 2019

This study aimed to investigate the physicochemical characteristics of fish meal, bone meal, and sesame oil cake, which are readily available by-products from agriculture and fisheries, during the process of liquid fertilizer fermentation, and to examine the effects of liquid fertilizer application on seed germination and growth of tomatoes. During processing the fermentation for liquid fertilizers by using fish meal, bone meal, and sesame oil cake liquid fertilizers, the pH of the fertilizer increased in the order of bone meal > fish meal > sesame oil cake, and the concentration increased rapidly up to 30 days in all types of liquid fertilizer. The nitrogen content of the liquid fertilizers increased as fermentation progressed in the order of fish meal > bone meal > sesame oil cake. The phosphorus content increased as fermentation progressed and the highest was 1.0 % in the liquid fertilizer of sesame oil cake. The germination rate and its index of radish seeds were compared for different dilutions of each of the liquid fertilizers. Excluding the 10-fold dilution of the fish meal and oil cake liquid fertilizer, all the treatment groups showed a germination rate ≥ 95 % and the germination index tended to increase with dilution rate of liquid fertilizers. For responses of tomato growth, there were no significant differences among the liquid fertilizer treatment groups; however, the organic content, microbial density, and microbial biomass C in the soil were higher than chemical fertilizer treatment. These results demonstrated that there were differences in the characteristics of liquid fertilizers depending on the materials used, and that liquid fertilizer can be used for nutrition management for the organic crop cultivation.

• Natural Product Sciences
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• v.20 no.3
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• pp.137-145
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• 2014

The biological activities of licorice F1 (Glycyrrhiza glabra ${\times}$ G. uralensis) lines (G) were investigated, revealing strong radical scavenging activity targeting 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl (${\cdot}OH$) radicals. At a concentration of $100{\mu}g/mL$, most of the licorice F1 lines scavenged DPPH and ${\cdot}OH$ by more than 80%. Gs-1, -2, and -6 can be considered good scavengers of DPPH radical and G-7 have higher antioxidant activity against ${\cdot}OH$ radical. In addition, licorice F1 lines exerted effective anti-microbial activities against Escherichia coli (Gs-12, -17, and -18) and Staphylococcus aureus (Gs-3, -4, -5, -21, and -26). Moreover, Gs-2, - 20, -31, and -32 effectively inhibited the growth of Helicobacter pylori. Among licorice F1 lines, Gs-25 exhibited high anti-inflammatory effects on nitric oxide produced by lipopolysaccharide- and interferon-${\gamma}$-activated RAW 264.7 cells. Furthermore, Gs-1, -12, and -20 inhibited the growth of AGS human gastric adenocarcinoma cells by more than 60% at a concentration of $100{\mu}g/mL$ and Gs-5, -11, -19, and -32 showed inhibitory effects against rat lens aldose reductase ($IC_{50}$ values, 1.69, 6.07, 6.12, and $4.54{\mu}g/mL$, respectively). The total content of glycyrrhizin (1), glycyrrhetinic acid (2), glabridin (3), and isoliquiritigenin (4) in licorice F1 lines was high in Gs-11, -15, and -30. The present study therefore indicated that Gs-2, -26, -31, and -32 of licorice F1 possessing strong anti-oxidative, anti-microbial, anti-inflammatory, anti-cancer, and aldose reductase inhibitory effects may be used as a possible source material for natural health supplements in the future.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.39-44
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• 2010

The process of the preparation of branched-chain amino acid (BCAA)-enriched hydrolysates from corn gluten was optimized through the parameters of pre-treatment (heating and cellulosic hydrolysis), hydrolysis method (acid, protease, and microbe plus protease), concentration, and spray drying condition. The protein yield of corn gluten was increased by heating and cellulase treatments. Among three different hydrolysis methods, the combined use of microbes and protease was the most effective in terms of free amino acid (FAA) and BCAA content of the corn gluten hydrolysates. In addition, the FAA and BCAA content in the hydrolysates prepared by microbial and enzymatic combined treatment were improved by a concentration process. Spray drying conditions for the preparation of the powder from the hydrolyzed reactant were an inlet temperature of $185^{\circ}C$, outlet temperature of $80^{\circ}C$, and the use of maltodextrin as an anticaking agent. Thus, this study established an economical process for preparation of value-added hydrolysates of excellent productivity and quality, in terms of high BCAA content and product stability.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.943-953
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• 2014

The XylH gene (1,167-bp) encoding a novel hemicellulase (41,584 Da) was identified from the genome of Microbacterium trichothecenolyticum HY-17, a gastrointestinal bacterium of Gryllotalpa orientalis. The enzyme consisted of a single catalytic domain, which is 74% identical to that of an endo-${\beta}$-1,4-xylanase (GH10) from Isoptericola variabilis 225. Unlike other endo-${\beta}$-1,4-xylanases from invertebrate-symbiotic bacteria, rXylH was an alkali-tolerant multifunctional enzyme possessing endo-${\beta}$-1,4-xylanase activity together with ${\beta}$-1,3/${\beta}$-1,4-glucanase activity, which exhibited its highest xylanolytic activity at pH 9.0 and 60oC, and was relatively stable within a broad pH range of 5.0-10.0. The susceptibilities of different xylosebased polysaccharides to the XylH were assessed to be as follows: oat spelts xylan > beechwood xylan > birchwood xylan > wheat arabinoxylan. rXylH was also able to readily cleave p-nitrophenyl (pNP) cellobioside and pNP-xylopyranoside, but did not hydrolyze other pNP-sugar derivatives, xylobiose, or hexose-based materials. Enzymatic hydrolysis of birchwood xylan resulted in the product composition of xylobiose (71.2%) and xylotriose (28.8%) as end products.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.235-240
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• 2022

In this study, the delivery conditions and microbial contamination in Mille-feuille Nabe and fresh spring roll meal kits purchased online were assessed. The average surface temperature on the product arrival was 14.4℃. The average number of total aerobic bacteria and coliforms in Mille-feuille Nabe was 3.27 log CFU/g and 1.27 log CFU/g, respectively, in meat, and 6.66 log CFU/g and 2.94 log CFU/g, respectively, in vegetables. The average number of total aerobic bacteria and coliforms in fresh spring rolls was 3.82 log CFU/g and 1.93 log CFU/g in meat, and 5.62 log CFU/g and 3.31 log CFU/g in vegetables, respectively. Escherichia coli was detected in bok choy and perilla leaves, with an average of 0.86 log CFU/g. Salmonella spp. and E. coli O157:H7 were not detected in any of the samples; however, Listeria monocytogenes was detected in all three beef samples. Therefore, before consuming meal kits, sufficient washing and heating are recommended to prevent occurrences of food poisoning.