• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.722-728
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• 2002

Eight strains producing bacterial cellulose (BC) were isolated from rotten fruits and traditionally fermented vinegars. One of the isolated strains from the rotten grape in Gwangju, Korea, maintained a relatively stable BC production in shaking cultures. This isolated strain proved to be Acetobacter xylinum, based on several biochemical and morphological tests. It was shown that the slant-baffled flask was more efficient than the conventional flask for the BC production in shaking cultures. To determine the most suitable carbon and nitrogen sources for the production of BC, various compounds were examined. Fructose was found to be the most effective carbon source with an optimal concentration of 2%. Mixed carbon source (glucose:fructose=1:3) was also better than glucose or fructose alone. Optimal nitrogen source, when basal medium was used, was 10% (v/v) com steep liquor (CSL). When com steep liquor was used with a mixed carbon source (glucose:fructose=1 :3),4% CSL exhibited the best BC production. Based on these results, a defined medium was developed for the BC production by Acetobacter xylinum KJ-1. When this medium was used under optimal culture conditions, the BC production was 7.2 g/1, which was approximately 3 times higher than that with the traditional HS medium.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1388-1391
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• 2005

Temporal changes of cell growth pattern and intracellular content of $\beta$-D-glucans were investigated with off-gas data in Agaricus blazei culture where glucose was intermittently fed. It was observed that the time point of carbon source depletion coincided with the point of sudden drop in the carbon dioxide evolution rate (CER), and that the sole supplementation of glucose was not enough to maintain active cell growth and glucan content. On the other hand, when yeast extract, a typical nitrogen source, was supplemented together with glucose when the CER suddenly dropped because of carbon source depletion, an active cell growth could be maintained until the end of the culture and the glucan content did not decrease with culture time, significantly enhancing glucan productivity.

• 한국식품영양과학회지
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• 제19권6호
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• pp.641-645
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• 1990

In order to study the influence of culture conditions on cell growth and lipid formation by Mucor sp, various carbon and nitrogen sources initial pH and C./N ratio of medium were investigated. Glucose was found to be suitable carbon source in terms of lipid yield and ${\gamma}$-linolenic acid(GLA) content. When NH4Cl and (NH4)2SO4 were used as nitrogen source lipid content was high(19-21%) but GLA content was low(15-17%) On the other hand when NaNO3 and KNO3 were used lipid content was low(about 13%) but GLA content was high(22-23%). The highest production of lipid was obtained at a C/N ratio of 40 using glucose and (NH4)2SO4 as carbon and nitrogen source respectively. it was found that lipid yield was high at pH4.6 Also this fungus did not grow at 35$^{\circ}C$ and lipid yield was highr at 15$^{\circ}C$ than $25^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1200-1210
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• 2004

Metabolic flux analysis was established by adapting previous stoichiometric model developed during growth with cellulose to cell grown with cellobiose for further direct comparison of the bacterial metabolism. In carbon limitation with cellobiose, a shift from acetate-ethanol fermentation to ethanol-lactate fermentation is observed and the pyruvate overflow is much higher than with cellulose. In nitrogen limitation with cellobiose, the cellodextrin and exopolysaccharide overflows are much higher than on cellulose. In carbon and nitrogen saturation with cellobiose, the cellodextrin, exopolysaccharide, and free amino acids overflows reach the highest levels observed but all remain limited on cellulose. By completely shunting the cellulosome, the use of cellobiose allows to reach much higher carbon consumption rates which, in return, highlights the metabolic limitation of C. cellulolyticum. Therefore, the physical nature of the carbon source has a profound impact on the metabolism of C. cellulolyticum and most probably of other cellulolytic bacteria. For cellulolytic bacteria, the use of soluble carbon substrate must carefully be taken into consideration for the interpretation of results. Direct comparison of metabolic flux analysis from cellobiose and cellulose revealed the importance of cellulosome, phosphoglucomutase and pyruvate-ferredoxin oxidoreductase in the distribution of carbon flow in the central metabolism. In the light of these findings, future directions for improvement of cellulose catabolism by this bacterium are discussed.

• 대한환경공학회지
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• 제29권4호
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• pp.460-465
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• 2007

본 연구에서는 고농도 암모니아성질소로 오염된 고체배지로부터 분리해 낸 Leclercia adecarboxylata를 이용하여 암모니아성질소의 제거특성 및 기작을 파악하여 폐수처리의 적용가능성에 대해 살펴보았다. 질소제거에 있어서 가장 널리 알려진 생물학적 질산화와 후탈질에 의한 질소의 대기로의 방출이 아닌 질소합성균주를 이용한 질소의 체내합성을 이용한 영양물질의 제거 가능성에 대해 접근해 보았다. L. adecarboxylata는 무염분조건에서 암모니아성질소의 제거와 균체중식이 가장 왕성했으나, 염분이 4%를 넘어서게 되면 그 효율은 급격히 저하되었다. 약 80 mg/L의 암모니아성질소는 20시간 이내에 거의 대부분 제거되었으나, 500 mg/L인 시료는 탄소원의 부족으로 인해 50시간 이상 처리후에도 50%의 제거율에도 미치지 못해 탄소원이 많을수록 질소제거율은 높음을 알 수 있었다. 탄소원이 모두 소모되고 난 이후에는 더 이상 질소제거는 이루어지지 않았으나, 탄소원을 추가로 공급했을 때 제거효율은 다시 증가했다. 시료의 pH는 미생물의 증식에 의해 8에서 6.36까지 감소했다. 암모니아성질소가 제거되는 동안 아질산성질소와 질산성질소의 축적은 일어나지 않았고, TKN값은 큰 차이를 보이지 않은 것으로 미루어 볼 때 유기질소로의 합성을 추측할 수 있었다. 유기질소 중 단백질의 농도를 측정해 본 결과 초기시료에서는 불검출 되었으나, 48시간 경과후의 시료에는 193.1 mg/L의 단백질이 검출 되었다. 따라서 L. adecarboxylata는 암모니아성질소를 유기질소로 합성하는 능력이 탁월하여 폐수중의 암모니아성질소의 제거에 이용가치가 클 것으로 판단된다.

• KSBB Journal
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• 제10권2호
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• pp.137-142
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• 1995

Sucrose를 탄소원으로 이용할 수 있는 대장균 W 를 A. eutrophus PHA 합성 유전자가 cloning된 높 은 복제수의 plasmid pSYL105로 형질전환하여 단 순배지에서 배양시 $0.21g/\ell$ 의 낮은 PHB 농도를 얻었다. 이에 107}지의 복합질소원을 소량 첨가하여 PHB 합성에 미치는 영향을 살펴 보았다. Tryptone, casamino acids, casein hydrolysate, 혹은 soy bean hydrolysate의 첨가시 PHB 합성 이 10배 이 상 증대되었다. 또한 이때 sucrose로부터의 PHB 수율도 10배 이상 증가하여 이 네 가지 복합질소원 을 척정 농도로 첨가함으로써 sucrose로부터 효과적인 PHB 생산이 가능함을 알았다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.227-230
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• 2000

Batch cultivations of Anaerobiospirillum succiniciproducens have been systematically studied for the economical production of succinic acid from wood hydrolysate with corn steep liquor(CSL) as a nitrogen source. CSL was found to be an alternative complex nitrogen source for A. succiniciproducens when glucose and wood hydrolysate were used as carbon sources. Compared with polypeptone and/or yeast extract, CSL had similar effects on fermentation performance such as succinic acid yield and a ratio of succinic acid to acetic acid in the fermentation of wood hydrolysate as well as glucose. This means that succinic acid can be produced more economically from wood hydrolysate and CSL than relatively expensive carbon and nitrogen sources. Besides its low cost, the alternative medium served as a green technology for succinic acid production because it gives a net-zero effect on global warming.

• 한국물환경학회지
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• 제39권1호
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• pp.61-75
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• 2023

Denitrifying bacteria convert nitrate to nitrogen gas using an external carbon source as an electron donor. The external carbon source affects the denitrification performance and bacterial community structure. Although methanol is a cheap and effective external carbon source, the addition of diverse carbon sources may improve the total nitrogen removal rate and biomass characteristics, such as settleability. In this study, denitrifying reactions were performed using solely methanol and mixed carbon sources of methanol, glucose, and acetate in a sequencing batch reactor. The denitrifying reactor using methanol resulted in a total nitrogen removal rate of 0.39 ± 0.025 kg-N/m³-day while the suspended biomass transformed into dark brown granules. Methyloversatilis discipulorum had the highest predominance at 43.84%. The individual denitrifying biomasses, which were separately enriched with methanol, glucose, and acetate, showed the same total nitrogen removal performance of 0.39 ± 0.016 kg-N/m³-day. However, the addition of mixed carbon sources showed an improved total nitrogen removal rate of 0.42 ± 0.043 kg-N/m³-day, with the domination of Candidatus Saccaribacteria at 25.61%. The denitrifying granules turned pale yellow color. Influent COD/NO₃^--N ratios of 3.5, 5, and 7.5 exhibited COD/NO₃^--N consumptions of 4.3 ± 0.4, 4.4 ± 0.8, and 5.2 ± 0.7, and the consistent predominance of Candidatus Saccharibacteria.

• 미생물학회지
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• 제16권1호
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• pp.21-29
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• 1978

In the fed-batch fermentation of penicillin specific uptake rates of carbon source and ammonia nitrogen, and specific production rate of penicillin as the most important process variables were evaluated over the fermentation course and their effects on the productivity studied. As the results, glucose and lactose each as a major carbon source showed the following values, respectively ; the specific uptake rates of 47-93 mg hexose per gm-DCW per he and 37-44 mg hexose per gm-DCW per hr, the specific uptake rates of 4.6-6.8 mg $NH_3-N$ per gm-DCW per hr, and 1.2 mg $NH_3-N$ per gm-DCW per he and the specific production rates of 32-42 arbitrary unit per gm-DCW per hr and 46-50 arbitrary unit per gm-DCW per hr. The productivity of penicillin could be improved by controlling the feed rates of glucose and ammonia nitrogen to meet the uptake rates.

• 한국약용작물학회지
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• 제2권1호
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• pp.44-50
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• 1994

1. 2.4-D 0.5mg/1에서 배발생캘러스 생장과 발생빈도가 가장 양호하였다. 2. 배지 중에서 MS배지가 체세포배 형성과 생육에 좋았으며, 1X MS배지 보다 1/2X MS배지가 배형성에 더 효과적이었다. 3. 탄소원으로는 sucrose가 효과적이었다. 농도는 1%처리가 가장 양호하였으며 농도가 높아짐에 따라 체세포배 형성이 억제되었다. 4. Sucrose 대신 sugar 처리에서도 체세포배 형성이 앙호하였다. 5. 질소원으로는 $KNO_3\;825mg\;/\;l$ 와 $NH_{4}NO_3$ 238mg /l 처리가 배발생에 가장 효과적이었다.