• 한국미생물·생명공학회지
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• 제27권2호
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• pp.96-101
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• 1999

Various side-chains are introduced to the 7-amino position of 7-aminocepha-losporanic acid (7-ACA) to make semi-synthetic cephalosporin antibiotics. In order to convert cephalosporin C (CPC) to 7-ACA, two enzymatic reactions are generally imployed. Glutary1-7-aminocephalosporanic acid (Gl-7-ACA) acylase is involved in the second step where the reaction intermediate, Gl-7-ACa is converted into 7-ACA. It was recently reported that CPC amidase can convert CPC directly into 7-ACA in a single enzymatic reaction. A study was undertaken to screen microorganisms conferring enzyme activity to convert Gl-7-ACA or CPC into 7-ACA by one or two enzymatic reactions. In order to screen the microorganisms rapidly, a non-$\beta$-lactam model compund, glutaryl-$\rho$-nitroanilide, was utilized in an early stage, thereafter the selected microorganisms were examined with real substrates. One microorganism exhibiting both Gl-7-ACA acylase and CPC amidase activities was obtained by the colorimetry method and HPLC assay, and was identified as a strain of Serratia species, designated as Serratia sp. N14.4. The optimal fermentation conditions for Serratia sp. N14.4 was pH9.0 and 3$0^{\circ}C$.

• 한국미생물·생명공학회지
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• 제17권1호
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• pp.46-50
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• 1989

최소 생산배지에 포함된 25mM 이상의 무기인(Inorganic phosphate)은 Cephalosporium acremonium의 생육은 증대시켰으나, cephalosporin C(CPC) 생산은 감소시켰다. Phosphate-starved 휴지세포계를 이용하여 균체내의 ATP, ADP와 AMP를 측정하였다. 그 결과로부터 무기인은 adenylated nucleotide의 농도의 비율로 표시되는 energy charge를 조절하여 CPC 생산성에 영향을 주는 것으로 밝혀졌다. 또한, 무기인에 의한 CPC 생합성은 repression 효과에 의한 것이 아니라 inhibition 효과에 의해 조절받는 것을 알 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.459-464
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• 2004

The objective of this study is to improve cephalosporin C (CPC) production byoptimization of medium and culture conditions. A statistical method was introduced to optimize the main culture medium. The main medium for CPC production was optimized using a statistical method. Glucose and corn steep liquor (CSL) were found to be the most effective factors for CPC production. Glucose and CSL were optimized to 2.84 and $6.68\%$, respectively. CPC produc­tion was improved $50\%$ by feeding of $5\%$ rice oil at day 3rd and 5th day during the shake flask culture of C acremonium M25. The effect of agitation speeds on CPC production in a 2.5-L bio­reactor was also investigated with fed-batch mode. The maximum cell mass (54.5 g/L) was obtained at 600 rpm. However, the maximum CPC production (0.98 g/L) was obtained at 500 rpm. At this condition, the maximum CPC production was improved about $132\%$ compared to the re­sult with batch flask culture.

• Journal of Microbiology and Biotechnology
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• 제5권4호
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• pp.229-233
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• 1995

Acremonium chrysogenum was immobilized in ionotropic gel beads to develop semi-continuous production of cephalosporin C (CPC). Barium alginate beads were more stable than calcium alginate or strontium alginate beads in chemically defined media. The gel stability of Ba-alginate was further increased by cross-linking with polyethyleneimine (PEI). The presence of carboxymethyl cellulose inside Ba-alginate beads did not reduce mass transfer resistance. Ba-alginate microbeads that had little diffusion limitation increased CPC production rate 1.6 fold higher than that of normal beads. CPC fermentation with immobilized cells in Ba-alginate microbeads was performed continuously for 40 days by way of repeated fed-batch operations. Mathematical modeling was developed to describe the repeated fed-batch fermentation system. Results of the computer simulation agreed well with the experimental data, which made it possible to predict an optimal feeding rate that could maximize total CPC productions.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1120-1124
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• 2006

Supplementation with rice oil and its major components (oleic acid and linoleic acid) was found to have a significant influence on cephalosporin C (CPC) production and cell growth by A. chrysogenum M35 in shake flask cultures. Five percent (v/v) rice oil had the most robust effect and 5% (v/v) oleic acid was the second most efficient on cell growth, whereas 3% (v/v) linoleic acid was found to be optimal for CPC production. Rice oil, oleic acid, and linoleic acid also significantly improved the rates of glucose consumption. When glucose was almost consumed, CPC production was initiated and, on the addition of rice oil, lipase activity increased steadily to 1.56 U/ml for 4 days. These results suggest that rice oil and fatty acids are used as carbon source to produce CPC by A. chrysogenum M35. Moreover, a mixture, composed of 40% (v/v) oleic acid and 60% (v/v) linoleic acid, had the strongest stimulatory effect on CPC production, due to a synergistic effect of the two fatty acids. Consequently, the maximum CPC titer (7.44 g/l) was improved about 4.5-fold.

• 한국미생물·생명공학회지
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• 제22권3호
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• pp.296-303
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• 1994

An immobilized Trigonopsis variabilis cells having an high activity of D-amino acid oxidase(DAO) was used to convert CPC into GL-7-ACA. The optimal pH of the reaction system was 8.0-8.5, and the optimal temperature was 40$\circ$C. When immobilized cell was used repeatedly in semi-batchwise reaction, the system retained 80% of the initial activity after used of 12 times for over 12 hours. The storage stability of the immobilized cell was maintained for 30 days at 4$\circ$C. The CPC concentration for the maximal reaction rate was about 30 mM and 40 mM for free and immobilized cells, respectively. Substrate inhibition of CPC concentration more than 50 mM was overcomed by 20~25% by immobilization. Pure oxygen supply into reaction system was most efficient in D-amino acid oxidase reaction. Continuous conversion to GL-7-ACA from CPC has been developed with an bioreactor system containing immobilized T variabilis cells. By opera- tion of the reactor for 5 hours, the average conversion yield of >80% and GL-7-ACA production of 40~45 mM per hour could be obtained.

• 한국미생물·생명공학회지
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• 제13권4호
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• pp.339-344
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• 1985

항세균성 항생제인 세팔로스포린 C가 그 자신의 생산균주인 C. acremonium M-113의 생장을 저해하였다. 비슷한 저해현상이 C. acremonium ATCC 20339와 ATCC 14553에도 관찰되었다. 세팔로스포린C의 최소 생육 저지농도가 분생포자의 경우 200-500$\mu\textrm{g}$/$m\ell$이었고 균사의 경우 3,000-4,000 $\mu\textrm{g}$/$m\ell$이었다. 이 최소 생육 저지농도는 복합배지에서 더욱 상승되었다. 세팔로스포린C는 배양초기에 존재할 경우. 그 생육 저지 효과를 나타내었다. 세팔로스포린 C의 생육 저지 효과는 세팔로스포린 C가 아미노산의 세포 내로의 수송을 방해함으로써 나타나는 것으로 조사되었다. 생육 저지 기저에 세팔로스포린 C의 3' 기가 중요 역할을 하는 것으로 나타났다. 또한, 세팔로스포린 C는 배지에 질소원이 결핍될 때 질소원으로 이용될 수 있는 것으로 나타났다.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.178-182
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• 1992

Cephalosporium acremonium CSA-2.8A3 변이주로 부터 생성된 cephaloporin C를 정제하여 산업적 이용을 위해 ultrafiltration으로 균체를 제거하고 수종의 수지공정을 통하여 소디움염 형태의 cephalosporin C를 정제하였으며 역삼투막에 의한 농축과 분무건조를 행하였다. WA-30, HO-20, XAD-2000, SK-1B column chromatography를 통해 90% 이상의 높은 수율과 순도를 얻을 수 있었고, 특히 상기 수지들을 직렬로 연결하여 사용합으로써 수율은 96%까지 올릴 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.156-156
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• 2001

The objective of this study was to investigate the effects of nutrients and culture conditions on morphology during the seed culture of C. acremonium ATCC 20339 Morphological factors such as hyphal length number of tips number of arthrospores were observed to investigate the relationship between seed morphology and CPC production. During the time course of seed culture, hyphal length was shortened and the number of arthrospores increased rapidly On the other hand the number of tips deceased rapidly and this was closely related to the hyphal length Mixed nitrogen sources of 3% solybean meal and 1% cotton seed flour were determined as the proper organic nitrogen sources, in terms of the morphological factors in the seed culture. This fact was proven in batch culture for the production of Cephalosporin C. It was also found that a proper agitation speed enhanced the morphological differentiation of C. acremonium ATCC 20339, thus improving the production of Cephalosporin C.

• 한국미생물·생명공학회지
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• 제32권3호
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• pp.224-229
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• 2004

토양으로부터 강력한 CAH activity를 갖는 균주를 분리하여, 생화학적, 배양학적, 전자현미경 동정을 한 결과, Bacillus sphaericus로 확인되었으며, 이를 B. sphaericus 366M-9로 명명하였다. 또한 이 균으로부터 최초로 cephalosporin-C deacetylase(CAH)를 분리 정제하였다. 정제수율은 약 7.5% 였으며, B. sphaericus 366M-9에서 분리한 CAH-9의 최적활성 온도는 $50^{\circ}C$였으며, 효소안정 온도구간은 30～$50^{\circ}C$이다. 또한 최적 활성 pH는 7.0이었으며, 효소안정 pH구간은 pH 6.0～8.0으로 90% 이상의 잔존 활성도를 나타내었다. 효소반응속도에 미치는 기질의 영향에서는 $K_{m}$ 값은 0.87 mM 이며,$ V_{max}$는1.22 unit/ml이었다.다.