• 한국식품영양과학회지
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• 제45권11호
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• pp.1638-1648
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• 2016

마늘의 함량에 따른 김치를 제조하여 품질 특성을 비교한 결과 마늘의 함량이 적을수록 pH의 감소와 산도의 증가 속도가 빠른 경향을 보여 김치의 적숙기에 빠르게 도달하였다. 또한, 마늘을 첨가하지 않을 경우 초기 균수가 많아서 발효가 빨리 진행되고, 마늘의 함량이 증가할수록 초기 발효가 느리게 진행되는 것을 확인할 수 있었다. 이러한 결과는 유기산과 유리당의 변화에서도 확인할 수 있었다. 유기산의 경우 초기 김치에서는 acetic acid를 제외한 5종의 유기산이 검출되었으며, lactic acid와 acetic acid는 저장기간 동안 증가하였다. 특히 초기 김치에서 citric acid는 마늘 함량이 많을수록 그 함량이 많았으며, lactic acid는 마늘 함량이 많을수록 그 함량이 적게 나타났다. 주된 유리당은 maltose, glucose, galactose, fructose, mannitol이었으며, 모든 처리군에서 glucose와 fructose가 가장 큰 비중을 차지하였다. Glucose는 저장 초기에 많이 감소한 반면에 fructose는 저장 초기보다는 후기에 감소하는 경향을 나타내었다. 향기 패턴은 마늘의 함량이 높을수록 제1주성분인 F1이 negative(-)에서 positive(+)로 이동하는 경향을 나타내었을 뿐만 아니라 처리군 간의 차이도 큰 것을 확인할 수 있었다. 관능적 특성에서는 마늘 첨가군의 경우 마늘의 함량이 많을수록 초기 발효 진행이 느려 이취, 이미의 점수는 낮고, 조직감에서 높은 점수를 받았다. 따라서 김치 제조 시 마늘을 첨가하지 않은 것보다 첨가하는 것이, 그리고 그 함량이 많을수록 김치의 적숙기에 늦게 도달하는 것으로 생각한다.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1529-1533
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• 2010

The inulinase gene (INU1) from Kluyveromyces marxianus NCYC2887 was overexpressed by using the GAL10 promotor in a ${\Delta}ga180$ strain of Saccharomyces cerevisiae. The inulinase gene lacking the original signal sequence was fused in-frame to a mating factor ${\alpha}$ signal sequence for secretory expression. Use of the ${\Delta}ga180$ strain allowed for the galactose-free induction of inulinase expression using a glucose-only medium. Shake-flask cultivation in YPD medium produced 34.6 U/ml of the recombinant inulinase, which was approximately 13-fold higher than that produced by K. marxianus NCYC2887. It was found that the use of the ${\Delta}ga180$ strain improved the expression of inulinase in the recombinant S. cerevisiae in both aerobic and anaerobic conditions by about 2.9- and 1.7-fold, respectively. A 5-l fed-batch fermentation using YPD medium was performed under aerobic condition with glucose feeding, which resulted in the inulinase production of 31.7 U/ml at the $OD_{600}$ of 67. Ethanol fermentation of dried powder of Jerusalem artichoke, an inulin-rich biomass, was also performed using the recombinant S. cerevisiae expressing INU1 and K. marxianus NCYC2887. Fermentation in a 5-l scale fermentor was carried out at an aeration rate of 0.2 vvm, an agitation rate of 300 rpm, and with the pH controlled at 5.0. The temperature was maintained at $30^{\circ}C$ and $37^{\circ}C$, respectively, for the recombinant S. cerevisiae and K. marxianus. The maximum productivities of ethanol were 59.0 and 53.5 g/l, respectively.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.522-532
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• 2022

Cheonggukjang is a traditional fermented food in Korea, which is known to exert beneficial effects on health. In this study, we evaluated the effects of cheonggukjang fermented by Bacillus subtilis SCGB 574 (B574) on high fat diet (HFD)-deteriorated large intestinal health. Rats were fed with HFD or HFD supplemented with 10.1% cheonggukjang (B574). Fecal microbiota was analyzed based on 16S rRNA gene sequences, and the fecal and serum metabolome were measured using GC-MS. Our results showed that SCGB574 intake significantly reduced body weight, restored tight junction components, and ameliorated inflammatory cell infiltration. SCGB574 also shifted gut microbiota by increasing the abundance of short chain fatty acid producers such as Alistipes and Flintibacter, although it decreased the abundance of Lactobacillus. Serum and fecal metabolome analyses showed significantly different metabolic profiles between the groups. The top five metabolites increased by SCGB574 were i) arginine biosynthesis, ii) alanine, aspartate, and glutamate metabolism; iii) starch and sucrose metabolism; iv) neomycin, kanamycin, and gentamicin biosynthesis; and v) galactose metabolism. These results showed that cheonggukjang fermented by SCGB574 ameliorates adverse effects of HFD through improving intestinal health.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.354-359
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• 1994

An isolate, 90-GT-302, was found to produce antibiotics inducing typical mycelial swelling in Magnaporthe grisea and Fusarium solani. This isolate formed yellow substrate and white rectiflexbiles aerial mycelia in the early stages of growth. The aerial mycelium gradually changed its color to white and finally formed a gray spore mass. Analysis of the cell wall acid hydrolysate revealed the presence of LL- and meso-diaminopimelic acids, glycine, and galactose, which indicated cell wall type X. This result placed our isolate in genus Kitasatosporia. A comparison of isolate 9O-GT-302 with reference strains of Kitasatosporia spp., which not only demonstrated several differences in their physiological properties but also novelty of the active compounds produced by this isolate, led us to designate the isolate as Kitasatosporia kimorexae.

• 한국미생물·생명공학회지
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• 제22권1호
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• pp.13-17
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• 1994

We estabilished the procedure for isolation of Streptococcus salivarius subsp. thermophilus from raw milk. First, urease-producing lactic acid bacteria in raw milk were screened on the HY agar medium containing urea. Thereafter the urease-producing colonies were tested the ability to ferment maltose and to grow at43$\circ $C. We obtained about 400 maltose-negative colonies that grew at 43$\circ $C. No significant difference in carbohydrate fermentation test for isolated and type strains(S. salivarius subsp. thermophilus ATCC 19258 and ST-4) was found. And all of the isolated strains were able to ferment galactose. Furthermore, it was investigated that the cellular fatty acid profiles of isolated strains were similar to that of type strains. These results indicated that the isolated strains from raw milk were S. salivarius subsp. thermophilus. But when the isolated and type strains were incubated in 12% reconstituted skim milk at 43$\circ $C, the isolates produced lactic acid more slowly than the type strains.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.419-422
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• 2002

Fermentative hydrogen production by Citrobacter sp. Y 19 was investigated in batch culture. Optimal hydrogen production activity was observed at pH 6 - 7 and temperature of $36^{\circ}C$, and hydrogen yield and maximal hydrogen production rate were 1.12 mmol/mmol glucose and 32.3 mmol/g cell${\cdot}$h, respectively. With glucose as a substrate, the bacterium produced ethanol, acetate, and carbon dioxide as major glucose fermentation by-products. Y19 could utilize various sugars such as galactose, fructose, lactose, sucrose, and starch for cell growth and hydrogen production.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권5호
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• pp.303-305
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• 2003

Scale-up of hirudin production from Saccharomyces cerevisiae from bench-scale to pilot-scale was carried out based on constant volumetric oxygen transfer coefficient (K$\sub$L/a). Fed-batch mode of cultivation using step-wise feeding strategy of galactose was employed for the production of hirudin in a 30-L and a 300-L pilot-scale fermentor. The final hirudin concentrations were achieved 390 mg/L and 286.1 mg/L, and the volumetric productivities were 80.4% and 90.7% with the 30-L and 300-L fermentors, respectively, compared to the productivity of the 5-L bench-scale fermentor.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1760-1766
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• 2009

Enzymatic syntheses of water soluble Bakuchiol glycosides were carried out in di-isopropyl ether organic media using amyloglucosidase from Rhizopus mold. The reactions were carried out under conventional reflux conditions and in supercritical $CO_2$ atmospheric conditions. Out of the eleven carbohydrate molecules employed for the reaction, D-glucose, D-ribose and D-arabinose gave glycosides in yields of 9.0% to 51.4% under conventional reflux conditions. Under supercritical $CO_2$ atmosphere (100 bar pressure at 50 ${^{\circ}C}$), bakuchiol formed glycosides with Dglucose, D-galactose, D-mannose, D-fructose, D-ribose, D-arabinose, D-sorbitol and D-mannitol in yields ranging from 9% to 46.6%. Out of the bakuchiol glycosides prepared, 6-O-(6-D-fructofruranosyl)bakuchiol showed the best antioxidant (1.4 mM) and ACE inhibitory activities (0.64 mM).

• 한국식품영양과학회지
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• 제43권12호
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• pp.1835-1842
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• 2014

본 연구에서는 가장 대중적인 한국의 전통주 막걸리의 제조과정이 기능성 분획에 미치는 영향을 확인하고자 하였다. Saccharomyces cerevisae 균주별, 발효온도별, 발효기간별로 다르게 만든 막걸리로부터 ethanol 침전법을 이용해 crude polysaccharides(CP-M)를 분리하여 peritoneal macrophage 활성화 효과와 세포 배양액 중의 interleukin(IL)-6와 -12 농도에 미치는 영향을 조사하였다. S. cerevisae 89-1-1, 98-2, 268-3, 113-4의 4가지 효모 중 S. cerevisae 113-4로 발효한 CP-M을 peritoneal macrophage에 $10{\mu}g/mL$ 처리했을 때 세포 배양액 중 nitric oxide(NO) 농도 $33.3{\mu}M$로 가장 높았으며, IL-6와 -12의 농도 역시 116.3 pg/mL와 59.8 pg/mL로 가장 높게 나타났다. S. cerevisae 113-4를 접종하여 온도별로 발효한 발효물에서 분리한 CP-M 중 $25^{\circ}C$에서 발효 후 얻은 CP-M을 peritoneal macrophage 세포에 처리했을 때, NO 농도가 Control 대비 2.7~3.3배, IL-6 농도는 5.7배까지 증가하였다. 그러나 15, 20, $30^{\circ}C$에서 발효하여 얻은 CP-M의 경우 peritoneal macrophage의 NO와 IL-6 생성량에는 Control(무처리구)과 비교하여 영향이 없었다. 발효기간별 영향을 관찰한 결과 5일째 술덧에서 분리한 CP-M에 의한 NO 생성량이 가장 높아 0일째 MCP에 비해 2.2배 증가하였다. 그러나 급격하게 IL-6와 -12의 농도가 감소한 10일째 MCP를 제외하고는 발효기간에 따른 IL-6와 -12의 유의적인 농도 차이는 없었다. 이상의 결과에서 가장 활성이 좋은 발효 조건은 S. cerevisae 113-4를 접종하여 $25^{\circ}C$에서 5일간 발효시킨 술덧의 CP-M이었다. 이때 CP-M의 조성은 neutral sugar 함량 78.6%, acidic polysaccharide 11.6%, 단백질 9.8%였다. 특히 neutral sugar의 구성당 비율은 mannose 47.8 mole%, glucose 29.6 mole%, galactose 12.7 mole%였다. 이상의 결과에서 면역증강 활성이 있는 기능성 조다당 CP-M은 mannose 함량이 높은 yeast 유래의 extracellular polysaccharide로 추정하였다.

• 한국균학회지
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• 제43권3호
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• pp.196-199
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• 2015

본 연구에서는 국내 전통누룩에서 분리한 증류식 소주용 효모의 생리적 특성을 조사하고 동정하였다. 분리균(N4)의 26S rDNA-D1/D2 염기배열은 Saccharomyces cerevisiae 표준균주(NRRL Y-12632)와 100% 상동성을 나타내었고 다극출아에 의해서 증식하였다. Glucose, galactose, maltose, sucrose를 발효할 수 있으며 trehalose, raffinose, methylglucoside를 자화할 수 있었다. $40^{\circ}C$ 이상에서는 증식하지 못했으며 50% glucose와 10% NaCl 농도에서 성장할 수 있었다. 염기배열, 형태관찰 및 생리적 특성을 종합하여 분리균을 S. cerevisiae로 동정하였다.