• Journal of Life Science
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• v.19 no.7
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• pp.845-851
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• 2009

A vector harboring double cassettes; a heterologous gene expression cassette of pHCE-InaN-antigen and a ghost formation cassette of pAPR-cI-E lysis 37 SDM was constructed and introduced to E. coli DH5a. For the production of a bacterial ghost vaccine, bacterial ghosts from E. coli / Streptococcus iniae with four different types of antigens - enolase, GAPDH, sagA and piaA - were produced by the optimization of fermentation parameters such as a glucose concentration of 1 g/l, agitation of 300 rpm and aeration of 1 vvm. Efficiency of ghost bacteria formation was evaluated with cultures of OD$_{600}$=1.0, 2.0 and 3.0. The efficiency of the ghost bacteria formation was 99.54, 99.67, 99.99 and 99.99% with inductions at OD$_{600}$=3.0, 1.0, 2.0 and 1.0 for E. coli/S. iniae antigens enolase, piaA, GAPDH and sagA, respectively. Ghost bacteria as a vaccine was harvested by centrifugation. The antigen protein expressions were analyzed by SDS-PAGE and western blot analysis, and the molecular weights of the enolase, piaA, GAPDH and sagA were 78, 26, 67 and 26 kDa, respectively. The molecular weights of the expressed antigens were consistent with theoretical sizes obtained from the amino acid sequences.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.210-215
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• 2003

When Kimchi is cooked, it is very import to find an appropriate level for the salt content of the cabbage to makes the best tasting Kimchi. Therefore, in this article, attempts were made to find the best salted cabbage condition using difference salt solution concentration, temperatures and fermentation periods. In the experiments with the difference of the salt solutions, 10 and 15%, the salted cabbages were packed in polyethylene bags, and incubated at 10, 15, 20 and 25$^{\circ}C$ for 0, 2, 4, 6, 8, 10, 12, 14, 16 and 20 hrs. As a result, the best tasting Kimchi, in terms of texture characteristic, were found with storage times of 10 and 6-8 hrs, with salt solution concentrations of 10 and 15%, respectively, both of these at 25$^{\circ}C$. The best conditions, in terms of the kimchi taste characteristics, where 6-10 hrs, with the salt solution concentrations of 10 & 15%. With storage conditions of 10 hrs and a salt solution concentraction of 10%, and 6-8 hrs and a salt solution concentration of 15%, both at 25$^{\circ}C$, the texture characteristics were fresh. clear and coot. Also, the points of the appropriate salt content differ with temperature. Therefore, the appropriate conditions for the salting time, storage temperature and salt solution concentrations will make the best tasting, most nutritious Kimchi, in the least time and most economically.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.673-677
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• 2002

To develop a new traditional liquors using purple-fleshed sweet potato, the condition of alcohol fermentation was investigated by adding different concentrations $(5{\sim}75%)$ of cooked purple-fleshed sweet potato into mash and 10% nuruk, and fermenting for $5{\sim}15$ days. The maximum amount of ethanol (15.4%) was produced when 20% cooked purple-fleshed sweet potato and 10% nuruk were added into mash and fermented by S. cerevisiae at $25^{\circ}C$ for 15 days. The acceptability and physiological functionalities of the purple-fleshed sweet potato liquors were also investigated and compared. PSP-10 purple-fleshed sweet potato liquor prepared by adding 10% cooked purple-fleshed sweet potato into mash showed the best acceptability in the sensory evaluation test and color test $(pink{\sim}red)$; its fibrinolytic, electron-donating, and tyrosinase inhibitory activities were better than those of other purple-fleshed sweet potato liquors and wine.

• Food Engineering Progress
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• v.14 no.1
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• pp.65-74
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• 2010

Culture conditions of L. plantarum TJ-LP-002, the garlic resistant strain isolated from pakimchi (green onion kimchi), were investigated for the use of feed additives. Acetic acid, citric acid, lactic acid, and tartaric acid were detected in the culture supernatant, and especially the concentrations of lactic acid and acetic acid significantly increased during cultivation. The antimicrobial activity of L. plantarum TJ-LP-002 was not affected by proteases, calatase or cellulase, which showed that the antimicrobial activity might be due to the production of acids rather than proteinaceous antimicrobial substances. L. plantarum TJ-LP-002 was resistant to neomycin sulfate, spectinomycin dihydrochloride, and lincomycin hydrochloride, sensitive to streptomycin sulfate, and intermediate resistant to ampicillin trihydrate, chloramphenicol, erythromycin, tetracycline hydrochloride, and kanamycin sulfate. The optimum initial pH of medium, fermentation temperature and time for the cell growth and antibacterial activity were pH 7.0, 30${^{\circ}C}$ and 24hr, respectively. The optimal composition of culture medium for the cell growth and antimicrobial activity was 3%(w/v) glucose as a carbon source, 3%(w/v) yeast extract as a nitrogen source, and manganese sulfate and ammonium citrate as inorganic salts. The combinatorial supplementation of these inorganic salts, rather than sole addition as an inorganic salt, resulted in better antibacterial activity.

• Food Engineering Progress
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• v.14 no.1
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• pp.14-20
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• 2010

The objective of the current study was to determine the cryoprotective effects of trehaolse on lactic acid bacteria in the frozen yoghurt during long-term frozen storage conditions. The frozen yoghurts were prepared using starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus, as well as trehalose and sorbitol as a cryoprotectant. The viable cell numbers of lactic acid bacteria in frozen yoghurt did not significantly decreased during six weeks frozen storage conditions. The MRS broth, which contains either trehalose or sorbitol, cultured with L. bulgaricus and/or S. thermophilus, and then the cultured medium was kept in the frozen condition for six weeks. The results indicated that lactic acid bacteria viability significantly increased with trehalose addition (2 and 5%) in the media compared to those of control and sorbitol supplement groups. The lactic acid bacteria viability in the yoghurts was examined on the effects of repeated freeze and thaw events. The freeze-thaw resistance of lactic acid bacteria significantly increased with trehalose supplement in the yoghurt. The major volatile aroma compounds (acetaldehyde, acetone, ethanol, diacetyl, and acetoin) in yoghurt were separated and indentified by headspace GC-FID analysis. Distinct flavor components and their ratios are known as important quality factors for yoghurt notes. Trehalose addition to the yoghurt was not influenced these factors during lactic acid fermentation. The results in this study demonstrated that trehalose potentially can be applicable as an effective cryoprotectant for lactic acid bacteria in the frozen yoghurt products.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.224-232
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• 2019

This study evaluated the physicochemical and microbial quality characteristic of seasonal commercial kimchi for hygienic safety levels. The pH of seasonal commercial kimchi was 3.84-6.36 and the titratable acidity and salinity of the samples were 0.21-1.16 and 1.19-1.54%, respectively. The content of nitrate and nitrite in the commercial kimchi were lower in the spring and summer, which was affected by acidic condition of the kimchi depending on fermentation. Heavy metal contents in commercial kimchi are not an issue because they were detected only at very low levels. The total aerobic bacteria and coliforms counts ranged from 5.25 to 8.44 Log CFU/g and 0.00 to 5.08 Log CFU/g, respectively. The total aerobic bacteria and coliforms were detected more in summer than in the other seasons. E. coli was detected in three of the samples tested. Food-borne pathogens were not detected in any of the samples except for B. cereus. B. cereus was detected in the fall in more than 70% of samples. These results suggest that commercial kimchi distributed in the fall maintain the quality properties and the microbiological safety of kimchi compared to the other seasons. Therefore, further studies as an effective distribution system for the particular seasons will be needed to guarantee the hygienic safety levels of commercial kimchi required by the consumers.

• Journal of Life Science
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• v.32 no.5
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• pp.411-419
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• 2022

Carotenoids are red, orange, and yellow fat-soluble pigments that exist in nature, and are known as physiologically active substances with various functions, such as provitamin A, antioxidant, anti-inflammatory, and anticancer. Because of their physiological activity and color availability, carotenoids are widely used in the food, cosmetics, and aquaculture industries. Currently, most carotenoids used industrially use chemical synthesis because of their low production cost, but natural carotenoids are in the spotlight because of their safety and physiologically active effects. However, the production of carotenoids in plants and animals is limited for economic reasons. Carotenoids produced by bacteria have a good advantage in replacing carotenoids produced by chemical synthesis. Since carotenoids produced from bacteria have limited industrial applications due to low productivity, studies are continuously being conducted to increase the production of carotenoids by bacteria. Studies conducted to increase carotenoid production from bacteria include the activity of enzymes in the bacterial carotenoid biosynthesis pathway, the development of mutant strains using physical and chemical mutagens, increasing carotenoid productivity in strain construction through genetic engineering, carotenoid accumulation through stress induction, fermentation medium composition, culture conditions, co-culture with other strains, etc. The aim of this article was to review studies conducted to increase the productivity of carotenoids from bacteria.

• Clean Technology
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• v.16 no.1
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• pp.51-58
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• 2010

Methane was produced from the anaerobic digestion of marine macro-algae. Elemental analysis was first performed to estimate the theoretical methane production of three macro-algae (Undaria pinnatifida, Laminaria japonica, Hizikia fusiformis). Three algae were found to contain C 34 ~ 36%, H 5%, O 37 ~ 43%, N 2 ~ 4%, S 0.4 ~ 0.7%, and ash 14~21%, and the theoretical methane content was in the range of 56 ~ 60%, which can produce 442 ~ 568 mL $CH_4$ per g of volatile solid (VS). Using the biological methane potential (BMP) test, we found that L. japonica resulted in the highest yield of methane (52%). Moreover, various operational conditions, such as algae amount, pH, salinity, particle size, and pre-treatment, were investigated in order to find an optimal condition of anaerobic digestion. At pH 8.0, the autoclaved L. japonica (5g VS/200 mL), when used without washing salt, produced 268.5 mL/g VS which is 65% of the theoretical methane productions. Furthermore, using a CSTR (with the working volume of 7 L out of the total volume of 10 L), we have successfully operated the reactor for 65 days and obtained maximum methane production rate of 1.4 L/day with purity of 70%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.3
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• pp.197-208
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• 2007

This study was carried out to investigate effects of increasing moisture content with or without supplementing inoculant (Lactobacillus plantarum) in TMR (total mixed ration) on its feed value. In case of exposing TMR to air, the lower the moisture level of TMR was, the less its apparent condition was changed. The time of spreading of molds tended to be faster in TMR with the higher moisture level. And also the odor was influenced by moisture content and inoculant supplement that is, sour odor was smelled from 24 hour after exposing TMR containing 35% and 50% moisture to air, but TMR supplemented with inoculant had sweet odor. The inner temperature of TMR containing 35% and 50% moisture without inoculant tended to increase continually after the lapse of 6 hours when the TMR was exposed to air. The inner temperature of TMR containing 35% moisture with inoculant tended to increase dramatically after the lapse of 48 hours when exposed to air, but that of TMR containing 50% moisture with inoculant tended to increase after 6 hours. The pH of TMR containing 15% was consistent regardless of exposing time to air, but that of TMR containing 35% and 50% moisture considerably increased after 12 and 24 hours, respectively. The concentration of $NH_3-N$ of TMR supplemented with inoculant was increased from 6 hours after exposure to air, while that or TMR without inoculant increased from 12 hours. Nutrient content or TMR tended to be increased with the increase of exposing time to air and storage time under sealed condition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.251-258
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• 2005

This study was conducted to examine the effect of application of pig manure slurry(PMS) for rye cultivation in Paddy-land on rice productivity The field experiments were carried out from 1999 to 2002 on well-grown rice in Paddy-land at Kimje, Chunbuk province in Korea. PMS was manufactured by the fermentation for 6 months in natural condition. Amount of PMS was adjusted equal to total nitrogen value relative to its value of commercial chemical fertilizers. The amount of PMS were spread evenly over the soil surface two times; first in the autumn (before sowing, end of November) and second in the spring(regrowth of rye, middle of March). The field plots were consisted of four kinds (PMS $100\%$ treatment, PMS $200\%$ treatment PMS $100\%$ treatment with half of CF (CF $50\%$), Full of CF treatment (CF $100\%$). The experiment was designed as a randomized complete block. Each treatment was replicated three times. Rices are customarily gown under tropical korean condition as annuals. The results obtained from this study were summarized as fellows. Panicle length of rice was shorter in PMS $100\%$ than other treatments. Ripening grain ratio was the lower in CF treatment. In treatment of PMS $100\%$ and PMS $200\%$, 1000 grain weight was a downward trend as compared to that of full of CF treatments, whereas number of grains per $m^2$ was increased as compared to other treatments. Number of panicles reveals that there is an increase in order; CF $50\% + PMS\;100\%>\;PMS\;100\%\;>\;CF\;100\%\;>\;PMS\;200\%$. Yield of milled rice showed hi인 in CF $100\%$ and $CF 50\%+ PMS 100\%$, but were was no significant difference among treatments. There were did not a regular tendency in the ratio of leaf sheath bright, however the ratio of lodging area was higher in $CF50\%+PMS\;100\%$ treatment than other treatments. Based on the results of this experiment, $CF 50\%+PMS\;100\%$ may be the most effective in rice productivity under application of PMS for rye cultivation in Paddy-land.