• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.261-267
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• 2016

The present study examined the effect of the dietary administration of a halophilic bacterium Bacillus sp. Mk22 on the growth improvement of black tiger shrimp, Penaeus monodon, and reduced shrimp infection by Vibrio parahaemolyticus and white spot syndrome virus (WSSV). The shrimp were fed 45 days using three experimental diets: no addition (control), commercial probiotic, and Bacillus sp. Mk22. The shrimp treated with the halophilic bacterium Mk22 showed a significant improvement of growth (7.1 ± 0.21 g), survival (94.3 ± 0.58%), weight gain (178 ± 4.93 g), and reduced feed conversion rate (0.8 ± 0.03 g) compared with the shrimp in the other groups. The shrimp treated with Bacillus sp. Mk22 also showed a lower Vibrio count (0.02 ± 0.01 × 10² CFU/ml) in the shrimp culture water compared with the other groups. The shrimp in the three groups were challenged with either Vibrio or WSSV. For the Vibrio infection, no mortality was observed from water infection or oral feeding infection in the commercial probiotic group and Mk 22 group. For the WSSV infection, a 68% survival rate from water infection and 20% survival rate from oral feeding infection was observed on day 45 in the Mk22 group, while 100% mortalities were recorded at a much earlier time in both the control and commercial probiotic groups. The antioxidant enzyme activities, indicators of oxidative stress, such as catalase and superoxide dismutase, significantly decreased in both the Vibrio and WSSV-infected Mk22 groups compared with the other groups, indicating that Bacillus sp. Mk22 was effective in reducing oxidative stress, possibly due to the reduced infection.

• Mycobiology
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• v.43 no.2
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• pp.137-149
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• 2015

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration ($LC_{50}$) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.522-529
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• 2019

A Bacillus strain, SJ4, exhibiting strong fibrinolytic activity was isolated from saeu (shrimp, Acetes chinensis) jeotgal, a Korean traditional fermented food and was identified as B. subtilis. The B. subtilis SJ4 strain can grow at a NaCl concentration of up to 15% (w/v). The fibrinolytic activity of B. subtilis SJ4 (152.0 U/ml) cultured in Luria-Bertani (LB) broth for 48 h at 37℃ with aeration was higher than that of B. subtilis SJ4 cultured in TSB (124.5 U/ml) under same culture conditions. The major proteins in the LB culture supernatant of B. subtilis SJ4 were analyzed by SDS-PAGE, which revealed three major bands (23, 25, and 28 kDa). The band (23 kDa) with strong fibrinolytic activity, analyzed on fibrin zymogram, was observed at 60-96 h of cultivation. The aprESJ4 gene encoding the major fibrinolytic enzyme, AprESJ4, was cloned by PCR. The aprESJ4 gene sequence exhibited high similarities with the fibrinolytic gene sequences of other Bacillus species. The amino acid sequence of AprESJ4 exhibited 98.9 and 98.4% similarity with subtilisin NAT and AprE2 of B. subtilis, respectively. Hence, B. subtilis SJ4 can be a potential starter culture for jeotgal products.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1393-1400
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• 2009

A bacteriocin-producing strain PI80 was isolated from the gut of Penaeus indicus (Indian white shrimp) and identified as Streptococcus phocae PI80. The bacteriocin was purified from a culture supernatant to homogeneity as confirmed by Tricine SDS-PAGE. Reverse-phase HPLC analysis revealed a single active fraction eluted at 12.94 min, and MALDI-TOF mass spectrometry analysis showed the molecular mass to be 9.244 kDa. This molecular mass does not correspond to previously described streptococcal bacteriocins. The purified bacteriocin was named phocaecin PI80 from its producer strain, as this is the first report of bacteriocin production by Streptococcus phocae. The bacteriocin exhibited a broad spectrum of activity and inhibited important pathogens: Listeria monocytogenes, Vibrio parahaemolyticus, and V. fischeri. The antibacterial substance was also sensitive to proteolytic enzymes: trypsin, protease, pepsin, and chymotrypsin, yet insensitive to catalase, peroxidase, and diastase, confirming that the inhibition was due to a proteinaceous molecule (i.e., the bacteriocin), and not due to hydrogen peroxide or diacetyl. Phocaecin PI80 moderately tolerated heat treatment (up to $70^{\circ}C$ for 10 min) and resisted certain solvents (acetone, ethanol, and butanol). A massive leakage of $K^+$ ions from E. coli $DH5\alpha$, L. monocytogenes, and V. parahaemolyticus was induced by phocaecin PI80, as measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES). Therefore, the results of this study show that phocaecin PI80 may be a useful tool for inhibiting L. monocytogenes in seafood products that do not usually undergo adequate heat treatment, whereas the cells of Streptococcus phocae PI80 could be used to control vibriosis in shrimp farming.

• The Journal of Fisheries Business Administration
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• v.50 no.1
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• pp.39-54
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• 2019

The purpose of this paper is to analyze the difference of seafood dining consumer behavior by demographic characteristics (age, gender). This research surveyed 251 people in Busan, Korea. t-test, one-way ANOVA, and MDS were used to identify the difference of consumer behavior by demographics. The result of the research revealed the difference between demographic characteristics and seafood dining consumption. 20's showed to accept the trendy dining culture represented by salmon, sushi and shrimp, and 30's also have similar tendency. 40's have higher spending tendency to seafood dining like tuna restaurants. 50's and 60's showed conservative consumption propensity represented by grilled fish, braised fish and raw fish restaurants. In gender analysis, male have higher frequency than female about grilled eel. In the future, the seafood dining market would be reorganized with the expansion of sushi, salmon and shrimp dishes, which can be classified as a new dining market. In this research, we suggested fisheries supply and production strategies according to age and gender.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1736-1745
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• 2016

The interactions of microbiota in the gut play an important role in promoting or maintaining the health of hosts. In this study, in order to investigate and compare the effects of dietary supplementation with Lactobacillus pentosus HC-2 (HC-2), Enterococcus faecium NRW-2, or the bacteria-free supernatant of a HC-2 culture on the bacterial composition of Litopenaeus vannamei, Illumina sequencing of the V1-V2 region of the 16S rRNA gene was used. The results showed that unique species exclusively existed in specific dietary groups, and the abundance of Actinobacteria was significantly increased in the intestinal bacterial community of shrimp fed with the bacteria-free supernatant of an HC-2 culture compared with the control. In addition, the histology of intestines of the shrimp from the four dietary groups was also described, but no obvious improvements in the intestinal histology were observed. The findings in this work will help to promote the understanding of the roles of intestinal bacteria in shrimps when fed with probiotics or probiotic supernatant.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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• pp.744-753
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• 2005

This study was carried out to investigate Chinese in Beijing and Shanghai perception and preference for Korean Kimchi. The results were as follows: A questionnaire was examined on male 145(45.7%) and female 172(54.3%) of residing in Beijing, and on male 139(49.5%) and female 142(50.5%) of residing in Shanghai. In foods of eating with Kimchi resulted the highest Chinese foods 40.3% on male, and Korean. Chinese foods 25.3% on female in Beijing(p< .05), Korean, Chinese foods 26.7% and 25.3% on male respectively, and Korean foods 50.7% on female in Shanghai. In Kimchi used dishes Beijing resulted high Kimchi Ramyon 61.5%, Kimchi Kuk 51.3%, and Kimchi Chigae 44.9%, and Shanghai were Kimchi Ramyon 51.2%, Kimchi Kuk 41.3%, and Kimchi Fried Rice 22.4% in order. In evaluation by kinds of Kimchi, the taste resulted high onion juice Kimchi(M=6.55) of the third days, and overall acceptability resulted high onion juice Kimchi(M=6.18) of the third days, similary in Beijing, and Kimchi added in shrimp(M=5.70) of two days, and overall acceptability resulted high Kimchi added in shrimp(M=5.70) of the third days, similary in Shanghai. In Sensory evaluation by used Kimchi, the taste resulted high in the order of Kimchi Fried Rice and Chinese style Kimchi Fried Pork(M=6.27), and overall acceptability resulted Kimchi Fried Udong(M=6.40), Chinese style Kimchi Fried Pork(M=6.27), Kimchi Dumpling(M=6.20) in Beijing, and Kimchi Chige(M=6.70), Kimchi Fried Rice(M=6.67) and Kimchi Pancake(M=6.44), and overall acceptability resulted Kimchi Fried Udong, Kimchi Chige(M=6.50), Kimchi Fried Rice and Kimchi Pancake(M=6.44) in Shanghai.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.225-230
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• 1983

The proteolytic bacteria were isolated from the market foods such as ground beef, cooked shrimp meat, perch fillet, oyster meat, beef with textured vegetable protein and fish digest distributed at supermarket in Corvallis, Oregon, U.S.A. Two hundred and twenty-eight strains($30.8\%$) have proteolytic activity from 740 strains isolated from the examined samples and the strongest proteolytic strain among them was identified as a Streptococcus sp. Its maximum growth was showed at about 6 hours culture at $37^{\circ}C$ with shaking incubator in the medium added $0.15\%$ potassium phosphate monobasic and $0.4\%$ potassium phosphate dibasic, while the strongest activity of its extracellular protease was observed after 7 hours culture. The exoenzyme produced by the Streptococcus sp. was observed as a metal chelator sensitive protease, which are strongly inhibited by EDTA and o-phenanthroline but not affected by phenylmethylsulfonylfluoride and p-hydroxymercuribenzoate.

• Journal of the Korean Society of Food Culture
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• v.2 no.1
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• pp.45-54
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• 1987

This paper is a part of the regional characteristics of Korean chotkal. The kinds and materials of Korean chotkals are studied by interviewing local people living in 142 different regions which are bigger than 'myon' in size. Regions are classified according to the structural style of commoner's house. Regional characteristics of chotkal are analyzed and interpreted with natural environmental factor. The rest of my further interested subject will be followed in later issues ; the ways of preservation, period of fermentation according to the regional characteristics and uses of Korean chotkal. The results of this study can be summerized as follows, 1. There are 145 different kinds. 2. Raw materials of 145 kinds of chotkal are devided roughly into five groups ; (1) fishes in 87 kinds (2) Pelecypoda and Gastropoda in 14 kinds (3) Cephalopoda in 10 Kinds (4) Crustacea in 32 kinds and (5) Holothuroidea and Echinoidea in 2 kinds. They can also be classified according to the parts of individual material ; (1) body or flesh in 118 kinds (2) internal organs in 15 kinds and (3) eggs in 12 kinds. Regions are devided into four provinces ; 'Kwanso', 'Chungbu', 'Nambu', and 'Kwanbuk' in which the number of different kinds of chotkal are 32, 41, 99 and 34, respectively. Raw materials vary because of the distribution of marine life in different regions. Fishes and Cephalopoda are used in all four regions, Pelecypoda and Gastropoda in 'Kwanso', 'Chungbu' and western part of 'Nambu' regions. Different species of Crustacea used in each different regions ; sea crab and sea shrimp in the western coastal area, fresh water crab in the field area, fresh water shrimp in 'Chollado', mantis crab at 'Shihung-gun' in 'Kyonggi-do', Holothuroidea and Echinoidea are used in 'Nambu' regions. Chotkal are not used at all in six local districts which are located in inland areas where the transportation is inconvenient.

• Journal of the Korean Society of Food Culture
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• v.7 no.2
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• pp.141-148
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• 1992

To analyze cookery of meal in reception dishes of Choson dynasty, studied historic book 'Youngjeob Dogam Euigwae' described feast dishes for Chinese envoy in Choson Dynasty. The results obtained from this study are as follows. Kinds of dishes served a meal generally were noodles(麵), bun stuffed with seasoned meat and vegetables(饅頭), steamed bread(床花), soup(湯), fried fish and meat(煎魚肉), dried fish and meat(切肉), minced raw meat(肉膾), slices of boiled meat(片肉), stew(蒸, 乾南), rice cake(餠), patterned savory cake(茶食), various fruits preserved in honey(正果), fried cake made of wheat flour, honey and oil(造果), fried glutinous rice cake(强精), rice gruel(粥), salted fish shrimp and etc, jerked meat(佐飯), meat fish and others broiled with seasoning(炙), cooked potherbs and potherbs(菜), pickled vegetables(沈菜), fruits(實果), soysauce mixed with vinegar and pinenut meal(醋醬), mustard(茶子), soybean sauce(民醬), honey(追淸), honey water(水正果, 正味子水) and etc.