• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.696-703
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• 2015

A gamma-aminobutyric acid (GABA)-producing microorganism was isolated from jeot-gal (anchovy), a Korean fermented seafood. The isolate, A156, produced GABA profusely when incubated in MRS broth with monosodium glutamate (3% (w/v)) at 37℃ for 48 h. A156 was identified as Lactobacillus sakei by 16S rRNA gene sequencing. The GABA conversion yield was 86% as determined by GABase enzyme assay. The gadB gene encoding glutamate decarboxylase (GAD) was cloned by PCR. gadC encoding a glutamate/GABA antiporter was located immediately upstream of gadB. The operon structure of gadCB was confirmed by RT-PCR. gadB was overexpressed in Escherichia coli BL21(DE3) and recombinant GAD was purified. The purified GAD was 54.4 kDa in size by SDS-PAGE. Maximum GAD activity was observed at pH 5.0 and 55℃ and the activity was dependent on pyridoxal 5'-phosphate. The K_m and V_max of GAD were 0.045 mM and 0.011 mM/min, respectively, when glutamate was used as the substrate.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1469-1476
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• 2007

Jeot-gal is a traditional Korean fermented seafood and has long been used for seasoning. We isolated 188 strains from shrimp, anchovy, and yellow corvina Jeot-gal, and screened sixteen strains that showed strong fibrinolytic activities on a fibrin plate. Among those strains, the strain that had the largest halo zone was chosen and identified as Bacillus licheniformis by using 16S rDNA sequencing and an API CHB kit. The fibrinolytic activity of Bacillus licheniformis was characterized and designated as bpKJ-31. The active component of bpKJ-31 was identified as a 37 kDa protein, designated bacillopeptidase F, by internal peptide mapping and N-terminal sequencing. The optimum activity of bpKJ-31 was shown at pH 9 and $40^{\circ}C$, with a chromogenic substrate for plasmin. It had high degrading activity for the $B{\beta}$-chain and $A{\alpha}$-chain of fibrin(ogen), and also acted on thrombin, but not skim milk and casein. The amidolytic activity of bpKJ-31 was inhibited by 1 mM phenylmethanesulfonyl fluoride, but 1 mM EDTA did not affect the enzyme activity, indicating that bpKJ-31 is an alkaline serine protease, like a plasmin. The bpKJ-31 showed approximately 14.3% higher fibrinolytic activity than the plasmin. These features of bpKJ-31 make it attractive as a health-promoting biomaterial.

• 한국식품위생안전성학회지
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• 제12권4호
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• pp.333-339
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• 1997

The effects of kind of vegetables and of the kind and amounts of fermented fish sauce on the formation of nitrosamine (NA) during kimchi fermentation were investigated. Kimchies made of Chinese cabbage, cucumber, and radish with fermented shrimp, anchovy and liquid sauces were fermented at 4$^{\circ}C$ for 6 weeks and the changes in the content of nitrate, nitrite, trimethylamine (TMA), dimethylamine (DMA) and NA were studied. Nitrate content in kimchies made of Chinese cabbage, cucumber, and radish increased at the initial period of fermentation, but it decreased at the later period. Nitrite was not detected at the later period of kimchi fermentation. Overall, there have not been great changes in the contents of nitrite and nitrate. However, there have been considrable changes in the contents of TMA and DMA as fermentation progressed. Only nitrosodimethylamine (NDMA) at the level of 0.5~10.3 $\mu\textrm{g}$/kg was formed in three kinds of kimchies. More NDMA was formed in radish and cucumber kimchies than in Chinese cabbage kimchi. The pH was lowered faster in radish and cucumber kimchies than in Chinese cabbage kimchi. More NDMA was formed in Chinese cabbage kimchi made with fermented shrimp sauce than those with anchovy or liquid sauces. Shrimp sauce contained higher amount of DAM than anchovy and liquid sauces. The contents of NDMA tended to increase as the amount of shrimp sauce increased. The kind and amount of fermented fish sauce used for kimchi preparation may be an important factor affecting the formation of NDMA.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.

• 한국식생활문화학회지
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• 제19권3호
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• pp.273-284
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• 2004

This study is on the changing pattern of fish-and-shellfish uses during the last two thirds of Chosun period on the premise that they are influenced by development of fishing technology. With a literary approach, this paper researches how fish-and-shellfish production and consumption pattern changed, especially in relation to technological development of fisheries. First, we examine into the changes of fishery production. And next, we analyze the kind and cooking method of fish-and-shellfish in [Eum-sik-di-mi-bang](1670) and [Gyu-hap-chong-seo](1815). The analysis of two books revealed that there were significant differences in fish-and-shellfish uses. Because the two books were written with a gap of 145 years and the development of fishing technology and remarkable changes of fishery production affected on the fish-and-shellfish uses. Due to primitive fishing tools and skills, fresh-water and reverse-river-fish and shellfish had been caught in substantial amount until the middle ages of Chosun period. As a result, the availability of seafood were limited extremely even in the upper classes. These situations are evidenced by the analysis of [Eum-sik-di-mi-bang]. Only 12 kinds of fish-and-shellfish are described in [Eum-sik-di-mi-bang]. Most of the sesfoods is mollusc which is easy to catch. As for the salt-water fish, dried cod and dried herring were mentioned. Mullet, the reverse-water-fish, is used most frequently. Only one kind of 'Hoe', which needs extreme freshness, is described. This means that the use of fresh fish-and-shellfish was very limited to some kinds which could be caught near the village. As the netting fishery began to be developed in the 18th century, the production of some salt-water fishes, such as anchovy, shrimp, yellow corvina, pollack, and herring, had increased remarkably to make marine resources more available. Small fish, such as anchovy and shrimp were preserved as 'Jeot-gal' and sold nationwide. Therefore, 'Jeot-gal' and seafood could be used in Kimchi around this time and had a deep influence on the change of Kimchi in taste and nutrition. In [Gyu-hap-chong-seo], 33 kinds of fish-and-shellfish are described. Including cod and herring, 17 kinds of sea water fish and mollusc are mentioned. Some of these are consumed in fresh state, neither as dried nor as salted. Because the merchants promoted the transport of seafoods to other regions according to the growth of commercial economy. As a result the diet of the people could be enriched by the various seafoods.

• 한국식품조리과학회지
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• 제17권6호
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• pp.625-633
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• 2001

염장 토하젓 부산물인 토하액즙으로 제조한 토하액젓 배추김치와 다른 젓갈(무첨가, 멸치액젓, 새우젓)을 첨가해서 제조한 김치의 맛과 숙성에 관여하는 발효 미생물의 생육 및 김치의 보존성에 미치는 영향을 조사하였다. 김치의 발효 숙성 중 pH 변화는 발효가 진행됨에 따라 계속 감소되다가 pH 4.0부근에서 변화속도가 둔화되었으며, 총산도는 pH와는 반대로 증가하는 경향을 나타내었고, 모든 시료에서 숙성 7일동안 빠르게 증가하다가 그 이후로 28일 동안 거의 완만한 변화를 보였다. 산화환원전위는 전체적으로 대조구에서 전위값의 변화가 적었으며, 각 시료간에 큰 차이는 없었지만 토하액젓을 첨가한 김치가 가장 느리게 변하였고 휘발성 산도는 모든 시료에서 발효 숙성됨에 따라 증가하다가 35일 이후에는 감소하였다. 환원당은 발효숙성 4일까지 서서히 감소하다가 숙성적기 7일째에는 빠르게 감소하였으나 그 이후에는 대체로 완만히 감소하였다. 비타민 C는 발효숙성 4일에는 모든 김치가 약간 증가했으며, 7일 이후부터는 감소하는 경향이었는데 토하액젓을 첨가한 김치가 다른 군들에 비해 다소 높게 나타났다. 김치의 발효숙성 중 경도는 숙성 전 기간동안 감소하는 경향이었으며, 토하액젓을 첨가한 김치가 다른 시료에 비해 조직이 덜 물러지는 것으로 나타났다. 김치 발효숙성 중 총균수는 숙성 7일까지는 모든 시료가 비슷하게 증가하였으며, 숙성 28일에 모든 시료에서 감소하는 경향이었다. 총 젖산균수는 대조구에 비해 젓갈첨가 김치가 발효 전 기간 중 많은 것으로 나타났다. 총 효모의 수는 토하액젓을 첨가한 김치에서 가장 적은 변화를 관찰할 수 있었는데, 이것은 토하액젓에 함유되어 있는 chitin oligosaccharide에 의한 산막효모의 증식이 억제되는 것으로 사료된다. 관능검사 결과 김치 담금 초기에는 멸치액젓을 첨가한 김치가 전체적인 기호도에 있어서 가장 높게 나타났지만 김치의 숙성기간이 길어질수록 토하액젓을 첨가한 김치가 유의적으로 좋은 점수를 얻었다.

• 한국식품영양과학회지
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• 제24권5호
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• pp.734-743
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• 1995

This study was conducted to summarize the known kinds and characteristics of traditional special kimchies in Pusan and Kyungnam province. The taste of kimchi varies from region to region within Korea. In the southern part of the country, where the weather is much warmer, more salt is added along with salted anchovy(Myulchi Jeot), and the kimchi is less juicy and richer in flavor. More than 180 different varieties of kimchi are reported in Korea, but there are 30~40 different kinds of kimchi in Pusan and Kyungnam province depending on the main ingredients are known. Puchu kimchi(leek kimchi), Uung kimchi(burdock kimchi), Kongnip kimchi(soybean leaf kimchi) are the typical traditional special kimchi in Pusna and Kyungnam province. Todays, dietary cultures has been gradually changed, and diminished the local characteristics. Also, these tendency appears in the taste of the traditional special kimchi. However, it still remains the distinciton in the taste, ingredients and the methods of preparation of kimchies of Pusan and Kyungnam province. In this paper, the dispersed informations on the kinds, characteristics, and the preparation method of the special kimchies known in literatures and inherited persons in Pusan and Kyungnam province were tried to put together.

• 동아시아식생활학회지
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• 제7권4호
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• pp.512-518
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• 1997

알루미늄 등 중금속 오염이 점점 심화되고 있는 서해안 일부지역에서 포획되고 있는 46종의 어패류 중 알루미늄 함량의 평균은 88.38$\pm$189.03ppm으로 그 범위는 0.97-827.70ppm이었는데 24종의 생선 중 알루미늄 함량은 그 범위가 0.97ppm에서 45.12ppm으로 건실치에 가장 많았고 도미에 가장 적게 함유되어 있었다. 15종의 연체류가 함유하고 있는 알루미늄 함량은 3.40ppm에서 827.70ppm으로 그 차이가 매우 컸는데 복족류인 소라에 3.40ppm으로 가장 적게 함유되어 있었고 이매패류인 대합에 826ppm, 해락에 812.55ppm으로 가장 많이 함유되어 있었다. 7종의 젓갈의 알루미늄 함량은 2.50-295.15ppm으로 그 차이가 컸는데 황새기젓과 한치젓에는 그 함유량이 낮았지만 조개젓과 곤쟁이젓에는 많은 양의 알루미늄이 함유되어 있었다 생선과 연체류 및 젓갈중에 함유되어 있는 알루미늄 함량간의 유의차를 검증한 결과 연체류의 알루미늄 함량이 생선과 젓갈에 비해 유의적으로 높았다(p＜0.01), 이는 일생동안 주거지를 크게 움직이지 않는 생육조건을 갖는 이매패류의 특성때문으로 사료된다.

• 생명과학회지
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• 제15권3호
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• pp.434-438
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• 2005

멸치 액젖을 이용하여 ammonium sulfate침전, ion exchange, gel filtration, ethanol침전등의 과정을 거쳐 혈전분해 효소(myulchikinase, MK)를 분리 및 정제하였다. 이 정제된 효소를 SDS-PACE gel 전기영동한 결과 분자량은 약 28 kDa 이었다. MK의 활성에 대한 특성을 조사한 결과 NaCl $30\%$까지 활성이 $80\%$이상 유지되는 것으로 보아 내염성 효소로 판단된다. 온도에 대한 효소활성을 조사한 결과, MK의 온도에 대한 안정성은 $40^{\circ}C$까지는 안정하였으나 $50^{\circ}C$이상의 온도에서는 급격하게 활성 떨어졌고, 최적온도는 $40^{\circ}C$였다 MK의 활성은 $pH6\~9$범위에서 매우 안정하였고, 최적 pH는 8이였다. 또한 2가 금속 양이온에 대한 효과는 $Hg^{2+} (1mM)$에 의하여 완전히 활성저해를 보였고, $Zn^{2+}(1mM)$에 의하여 약 $50^{\circ}C$의 저해되는 것을 알았다. Fibrinogen-rich plate와 Fibrinogen-free plate에서 활성을 측정 한 결과, Fibrinogen-rich plate에서는 fibrin 분해능이 있었지만 Fiberinogen-free Plate에서는 분해활성이 없는 것으로 보아 본 효소는 plasminogen activator type의 혈전용해효소로 사료된다.