• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2005년도 2005 Annual Meeting & International Symposium
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• pp.233-244
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• 2005

Guanosine fermentation process can be well predicted and analyzed by the proposed state equations describing the dynamic change of a bioreactor. Pyruvate and alanine were found to be characteristically accumulated along with the decline of the guanosine formation rate during the mid-late phase of the process. The enzymological study of the main pathways in glucose catabolism and the quantitative stoichiometric calculation of metabolic flux distribution revealed that it was entirely attributed to the shift of metabolic flux from hexose monophosphate (HMP) pathway to glycolysis pathway. The process optimization by focusing on the restore of the shift of metabolic flux was conducted and the overcoming the decrease of oxygen uptake rate (OUR) was taken as the relevant factor of the trans-scale operation. As a result, the production of guanosinewas increased from 17 g/L to over 34 g/I.

• 한국식품영양과학회지
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• 제29권5호
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• pp.796-801
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• 2000

Kimchi is the Korean traditional food which is fermented properly from salted Korean cabbage of raddish with other various supplements. Kimchi therefore can be the major sources for various kinds of nutrients and other biological substances. The fermentation process accompanies with complicated reaction mechanism which bacteria, fungi and yeast are involved and they produced aroma, taste and bioactive components. To identify nucleoside, this study was conducted with freeze-dried mustard leaf, mustard leaf kimchi and fermented mustard leaf kimchi. Hexane, CH$_2$Cl$_2$, EtOAc and BuOH was used in order to extract their components. The isolated compounds I and II from mustard leaf and mustard leaf kimchi were identified as adenosine and uracil using UV, $^{1}H$-NMR, $^{13}C$-NMR and LC-MS, respectively. Compound I, II and nucleosides are the first report of its occurrence from mustard leaf and their kimchi, the standardized ratios of ingredients for kimchi were 10 of anchovy juice, 8 of red pepper powder, 3 of garlic, 1.5 of ginger, 6 of paste of glutinous rice. The nucleoside of mustard leaf and their kimchi was determined and compared. The order of nucleosides contents of mustard leaf was uridine>cytosine>uracil>adenine>guanosine>guanin, that of fresh mustard leaf kimchi was uridine>uracil>cytosine>guanine>adenosine>adenin>guanosine and that of fermented mustard leaf kimchi (5days at 15$^{\circ}C$) was guanine>adenine>adenosine>guanosine. The differences of nucleoside contents from those were due to various supplements and fermentation process.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.75-88
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• 2001

In this paper, the microbial production of riboflavin is reviewed and includes descriptions of riboflavin overproducers, and the biosynthesis and details of the key-enzyme genes related to riboflavin. There kinds of riboflavin overproducers are known; Bacillus subtilis and Candida famate utilize glucose as a carbon source, but the fungus Ashbya gossypii requires plant oil as its sole carbon source. The starting material in ribofalvin biosynthesis is guanosine triphospate (GTP), which is converted to riboflavin through six enzymatic reactions. Though Bacillus subtilis, Candida famate, and Ashbya gossypii operate via different pathways until GTP, they follow the same pathway from GTP to riboflavin. From the metabolic viewpoint, with respect to improved riboflavin production, the supplementation of GTP, aprocess-limiting precursor must be considered. The GTP fluxes originate from three sources, serine, threonine and glyoxylate cycles. The development of pathways to strengthen GTP supplementation using biotechnological techniques remains an issue fro future research.

• 한국식품과학회지
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• 제22권2호
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• pp.221-226
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• 1990

어육을 발효하여 정미성분 생산 가능성을 검토하기 위하여 명태육에 전분을 첨가한 발효기질에 8종의 곰팡이를 접종, 발효하여 성분의 변화를 검토하였다. 시험에 사용한 균주는 모두 어육발효 배지에서 왕성히 증식하였고, $30^{\circ}C$에서 48시간 배양 이후 특징적인 포자를 형성하였으며, 냄새는 균종에 따라 각각 다른 양상을 보였다. 발효어육의 $NH_2-N$ 함량은 명태육에 비하여 25-26배, Ex-N은 6-15배 증가하였고, 명태육으로부터 ADP 생성능력이 높은 균주는 IMP와 GMP 생성능력도 높았다. 발효어육 중의 유리아미노산은 사용균주에 따라 차이는 있으나 일반적으로 lysine 함량이 가장 높고 arginine, glutamic acid, leucine, alanine 순이었다. 발효어육 추출액의 관능검사한 핵산 관련물질, $NH_2-N$ 및 Ex-N의 함량과 아미노산 조성 등을 종합적으로 검토할 때 어육발효에 비교적 우수한 균주는 Aspergillus oryzae KFCC 11371, Asp. oryzae KFCC 32343, Penicillium roqueforti KFCC 11269 및 Asp. quercinus KFCC 11956이었다.