• 한국축산식품학회지
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• 제29권4호
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• pp.423-429
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• 2009

The objective of this study was to investigate the potential of the application of lactic acid bacteria (LAB) from kimchi as a starter culture in the production of fermented sausages. To achieve this, a submerged model medium that contained LAB as part of a complex system of kimchi (0.5, 1.0, 1.0, 3.0, and 5.0%) and lyophilized kimchi powder (0.2 and 0.5%) was fermented for 120 h. During the fermentation period, the growth of total viable organisms and LAB, and the changes in the pH and the titratable acidity, were investigated. The initial LAB counts ranged from 6.4 to 7.7 Log CFU/mL for the kimchi media, and from 6.9 to 6.9 Log CFU/mL for the kimchi powder media. In all the kimchi batches, the LAB increased logarithmically, and the highest LAB counts (around 9 Log CFU/mL) were reached in 24 h. An evident lag phase of the LAB was observed in the kimchi powder samples and reached 8.8 Log CFU/mL in 8 h. The decrease in the pH and the formation of lactic acid were rapid in the kimchi batches, and reached pH values of 3.4-3.5 in 12 h. With these results, the LAB that was integrated with the addition of kimchi or kimchi powder demonstrated its potential utility as a substitute for starter culture.

• Journal of Microbiology and Biotechnology
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• 제20권7호
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• pp.1114-1120
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• 2010

A chitosan-degrading fungus, BSF114, was isolated from soil. The culture preparation showed strong chitosanolytic enzyme activity at an optimum pH of 4.0 and optimum temperature of $60^{\circ}C$ after 36-40 h fermentation. The rapid decrease in the viscosity of the chitosan solution early in the reaction suggested an endo-type cleavage of the polymeric chitosan chains. To identify the isolated fungus, molecular biological and morphological methods were used. The fungal internal transcribed spacer (ITS) region 1 was amplified, sequenced, and then compared with related sequences in the GenBank database using BLAST. The phylogenetic relationships were then analyzed, and the results showed that the fungus belongs to Aspergillus fumigatus. Morphological observations were also used to confirm the above conclusion. The chitooligosaccharides (COS) obtained through hydrolyzing the colloidal chitosan showed that A. fumigatus BSF114 is suitable for degrading chitosan and producing chitooligosaccharides on a large scale. High concentrations of the COS (1,000 and 500 ${\mu}g/ml$) significantly proliferated mice marrow cells.

• Journal of Microbiology
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• 제43권3호
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• pp.301-307
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• 2005

The feasibility of laccase production by immobilization of Pleurotus ostreatus 1804 on polyurethane foam (PUF) cubes with respect to media composition was studied in both batch and reactor systems. Enhanced laccase yield was evidenced due to immobilization. A relatively high maximum laccase activity of 312.6 U was observed with immobilized mycelia in shake flasks compared to the maximum laccase activity of free mycelia (272.2 U). It is evident from this study that the culture conditions studied, i.e. biomass level, pH, substrate concentration, yeast extract concentration, $Cu^{2+}$ concentration, and alcohol nature, showed significant influence on the laccase yield. Gel electrophoretic analysis showed the molecular weight of the laccase produced by immobilized P. ostreatus to be 66 kDa. The laccase yield was significantly higher and more rapid in the packed bed reactor than in the shake flask experiments. A maximum laccase yield of 392.9 U was observed within 144 h of the fermentation period with complete glucose depletion.

• 한국식품영양과학회지
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• 제25권3호
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• pp.539-549
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• 1996

Large bowel cancer correlates tightly to dietary factors such as dietary fiber and fat. Dietary fiber prevents the large bowel cancer in different modes of action which depend upon physicochemical and fermentable properties. Water-soluble fiber is fermented easily by intestinal microbes producing short chain fatty acids ; in contrast, water-insoluble fiber occurs effectively more rapid transit time due to greater bulk of gut content, though it is unfermentable. Not only short chain fatty acid is utilized in the proximal and distal colon as primary energy source, but also it lowers pH in the colon to normalize cellular differentiation and helps to stimulate peri staltic movement by acting as an osmotic laxative. In particular, butyric acid may also regulate gene expression and cell growth, though it is an important respiratory fuel for the colonocyte. Since dietary fiber and non-digestible oligosaccharides are the major source of butyric acid, this provides a possible link between dietary fiber and oligosaccharide and prevention of large bowel cancer. But, as with many links between dietary fiber and large bowel cancer, a direct casual association has not been established. In addition, RDA of dietary fiber which is 20~25g/day for adult Japanese, appears to be reasonable for the defecation once daily and the prevention of large bowel cancer.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.801-806
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• 2002

A multiplex competitive polymerase chain reaction (PCR) method was developed for the rapid identification and quantification of Leuconostoc mesnteroides and Lactobacillus plantarum populations which are the key microorganisms in kimchi fermentation. The strain-specific primers were designed to selectively amplify the target genes encoding 165 rRNA of L. plantarum and dextransucrase of L. mesenteroides. There was a linear relationship between the band intensity of PCR products and the number of colony forming units of each model organism. The PCR quantification method was compared with a traditional plate-counting method f3r the enumeration of the two lactic acid bacteria in a mixed suspension culture and also applied to a real food system, namely, watery kimchi. The population dynamics of the two model organisms in the mixed culture were reliably predictable by the competitive PCR analysis.

• Applied Biological Chemistry
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• 제32권2호
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• pp.148-153
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• 1989

한국재래식된장에서 분리된 특향생성 Bacillus sp.의 NTG 변이주를 모균주로 하여 자외선에 의해 다시 돌연변이시킴으로써 amylase, protease의 증강과 동시에 deaminase가 감소되는, 한국된장의 발효시간 단축과 품질을 향상시킬 수 있는 우량변이주를 육종할 수 있었다. Amylase의 경우는 4.4배, protease의 경우는 4.2배까지 동시에 증강시킬 수 있는 우수한 변이주를 얻을 수 있었으며 두 효소 동시증강균주 중 deaminase 생성을 90%까지 저하시키는 한 균주를 개발할 수 있었다. 한편 각 변이주와 모균주와의 효소학적 특성은 거의 동일하였으며 고농도의 식염용액에서도 효소생산 및 작용에 큰 영향을 받지 않았다.

• 한국식품영양학회지
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• 제12권3호
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권6호
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• pp.419-425
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• 2001

A dense pellicular solid matrix has been fabricated by coating 4% agarose gel on to dense zironia-silica(ZS) spheres by watr-in-oil emulsification . The agarose evenly laminated the ZS bead to a depth of 30㎛, and the resultin gpellicular assembly was characterised by densities up to 2.39g/mL and a mean particle dimeter of 136 ㎛. In comparative fluidisation tests, the pellicular solid phase exhibited a two-fold greater flow velocity than commercial benchmark ad-sorbents necessary to achieve common values of bed expansion. Furthermore, the perlicular parti-cles were characterised by improved qualities of chromatographic behaviour, particularly with re-spect to a three-fold increase in the apparent effective diffusivity of lysozyme within a pellicular assembly modified with Cibacron Blue 3GA. The properties of rapid protein adsorption/desorp-tion were attributed to the physical design and pellicular deployment of the reactive surface in the solid phase. When combined with enhanced feedstock throughput, such practical advantages recommend the pellicular assembly as a base matrix for the selective recovery of protein products from complex, particulate feedstocks(whole fermentation broths, cell disruptates and biological extracts).

• 한국동물위생학회지
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• 제32권1호
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• pp.43-48
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• 2009

Salmonella enterica serovar Gallinarum is the causative agent of fowl typhoid (FT) and Salmonella enterica serovar Pullorum is pullorum disease (PD), a severe systemic disease of chick and it has the same antigenic fomula, the close relation but distinct pathogen. The traditional bacteriologic and serologic methods routinely used but tedious, time consuming. some of biochemical differences are helpful in differentiating the two organisms, however variation in the characteristics of some strains can be observed. During 2006 to 2008, there was isolated 30 strains. The biochemical characteristics of S. Gallinarum was nonmotile, fermentation of dulcitol, maltose but positive arginine (6.6%), lysine (83.3%) and arabinose (20.0%). The antimicrobial susceptibility test showed 100% sensitive to amikacin, ampicillin, amoxicillin/clavulanic acid and florfenicol, but resistant to penicillin (100%) and erythromycin (60.0%). This PCR method can be applied in the diagnosis between S. Gallinarum and S. Pullorum.

• 한국식품저장유통학회지
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• 제16권6호
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• pp.991-998
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• 2009

배술 제조 과정 중 pH, 산도, 에탄올 및 당도의 변화와 기호도를 조사하고 배 원료와 발효 배술의 유리아미노산, 유기산 및 페놀성 성분 등을 분석하였다. 배술의 관능을 개선하기 위하여 생강 첨가량을 달리하여 배술을 제조하였을 때 생강 첨가량에 따른 pH와 산도는 차이가 없었다. 에탄올 함량은 무 첨가구에 비하여 생강 0.1% 첨가구가 13%로 높게 나타났으며 맛, 색 및, 향의 관능검사는 생강 0.2% 첨가구에서 가장 높았다. 배술을 55, 60, 65 및 $70^{\circ}C$의 온도에서 각각 30분간 열처리 한 후 $30^{\circ}C$에서 60일간 저장하면서 pH와 산도의 변화를 검토하여 저장성을 검토한 결과 열처리하지 않은 배술은 저장 30일 이후부터 pH와 산도는 급격히 변화하였고 가장 변화가 적었던 처리구는 $60^{\circ}C$에서 30분간 열 처리구 가장 변화가 적었다. 유기산의 함량은 원료 배가 0.71%, 배술이 0.89%로 증가하였으며, 유리당은 발효에 의하여 12.05%에서 3.13%로 감소하였다. Phenolic compound는 원료 배중에 caffeic acid, catechin 및 epicatechin이 각각 1.64, 1.4 및 0.23 mg/100 mL로서 결합형으로 다량 존재하고 있었으며, 배술의 caffeic acid는 급격히 감소하여 0.12 mg/100 mL이었고, 유리형의 catechin은 0.28에서 1.16 mg/100 mL로 크게 증가하였다. 유리형 arbutin은 배 8.34 mg/100 mL, 배술 10.39 mg/100 mL로 증가하였다. 배의 유리 아미노산은 aspartic acid가 $118.5\;{\mu}g/100mL$로 가장 높았으며, serine, alanine, glutamic acid 순이었고, 배술의 aspartic acid는 급격히 감소하였으나 tyrosine, GABA, lysine, arginine은 크게 증가하였다.