• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.919-923
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• 2004

The sk10 isolated from kimchi was identified as W. kimchii on the basis of l6s-rDNA sequencing. Studies were made to analyze the metabolic flux shift of the sk10 on glucose under aerobic growth conditions. The sk10 produced 38.2 mM acetate, 16.3 mM ethanol, and 33.2 mM lactate under aerobic conditions, but 2.4 mM acetate, 48.0 mM ethanol, and 44.1 mM lactate under anaerobic conditions. The NADH peroxidase (NADH-dependent hydrogen peroxidase) activity of sk10 grown under aerobic conditions was 11 times higher than that under anaerobic conditions. Under the low ratio of $NADH/NAD^+$, the metabolic flux toward lactate and ethanol was shifted to the flux through acetate kinase without NADH oxidation. The kinds of enzymes and metabolites of sk10 were close to those in the pathway of Leuconostoc sp., but the metabolites produced under aerobic growth conditions were different from those of Leuconostoc sp. The stoichiometric balance calculated using the concentrations of metabolites and substrate was about 97%, coincident with the theoretical values under both aerobic and anaerobic conditions. From these results, it was concluded that the metabolic flux of W. kimchii sk10 was partially shifted from lactate and ethanol to acetate under aerobic conditions only.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.914-918
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• 2004

This study was carried out to analyze the metabolic flux of W. kimchii sk10 on pyruvate and ethanol as a carbon source. The sk10 grown on ethanol produced acetate under aerobic conditions rather than under anaerobic conditions. The lactate and acetate were produced on ethanol plus pyruvate by the sk10 grown under aerobic and anaerobic conditions, respectively. The resting cell of sk10 produced 99.1 mM acetate and 17.3 mM lactate under aerobic conditions and 51.1 mM acetate and 62.4 mM lactate under anaerobic conditions from ethanol plus pyruvate, respectively. This result is thought to be due to the difference in the $NADH/NAD^+$ ratio depending on the growth conditions. The 11-fold overproduction of NADH peroxidase results in a low $NADH/NAD^+$ratio under aerobic growth conditions. At the low $NADH/NAD^+$ ratio, the metabolic flux of pyruvate toward lactate has to be shifted to a flux toward acetate without NADH oxidation to $NAD^+$, and ethanol oxidation to acetate coupled to $NAD^+$ reduction to NADH has to be activated.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.246.1-246
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• 1979

A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80％ higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

• Applied Biological Chemistry
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• 제12권
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• pp.57-67
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• 1969

1. Furyl furamide 가 여름철 김치세균에 미치는 영향을 보기 위하여 두가지 여름김치에서 분리(分離)한 세균 Bacillus group 과 Lactic acid bacteria중 Bac. megaterium, Bac. subtilis 그리고 Bac. licheniformis등이 발효 초기(初期)의 젓갈김치에 우세 하였고 국물김치에서는 Lact. plantarum 과 Lact. buhneri등이 시종(始終) 매우 우세하였다. 2. 김치에서 분리(分離)된 Bacillus group 은 10 p.p.m. 이하(以下)의 AF-2 저농도(低濃度)에서 대단히 민감(敏感)하게 억제되었으나 Lactic acid bacteria의 group은 50 p.p.m.의 고농도(高濃度)에서도 저항(抵抗)하고 있었다. 3. 김치의 AF-2 첨가허용농도(添加許容濃度)는 최고(最高) 10 p.p.m.을 넘지 않아야 할 것이다. 4. 김치에 첨가(添加)된 고농도(高濃度)(50 p.p.m.)의 AF-2는 김치 발효를 heterofermentation 에서 Homofermentation으로 변화(變化)시키는 경향이 있었다. 5. AF-2 10 p.p.m. 농도(濃度)의 김치에서 bacterial flora는 약간 영향(影響)을 받고 있었으나, 50 p.p.m.의 고농도(高濃度)에서도 하절(夏節)김치의 산패(酸敗)는 억제할수가 없었다. 6. $23^{\circ}{\sim}25^{\circ}C$ 상태의 김치발효액중(醱酵液中)의 AF-2 소장(消長)은 산성(酸性)에서 비교적(比較的) 안전(安全)하다고 하나 4 일후(日後)에 약(約) 25%가 감소(減少)되고 pH 변화곡선(變化曲線)과 거의 평행(平行)한 변화(變化)를 보였다.