• 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.

• Korea-Australia Rheology Journal
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• 제17권1호
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• pp.15-20
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• 2005

In this study, the relationship between morphology and viscosity of the main culture broth of Cephalosporium acremonium M25 was investigated in a 2.5 L bioreactor. The differentiation of C. acremonium M25 showed a complex pattern during the main culture. The morphological changes of C. acremonium M25 were related to the rheological properties of the culture broth and it was well agreed with the power law model. As a result of rheology study, it was found that rheological properties of the main culture broths of C. acremonium M25 in bioreactor were closely related to morphological changes. Also, fractal dimension fairly predicted morphological and rheological changes in the main culture broth.

• 한국미생물·생명공학회지
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• 제15권5호
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• pp.361-367
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• 1987

DL-seleno-methionine에 내성을 갖는 변이주, Cephalosporium acremonium MS-92는 무기황과 메치오닌의 Uptake rate가 모균보다 우수하였으며, 세포내에 과량의 메치오닌과 S-adenosylmethionine (SAM)을 축적하였다. 또 C. acremonium에서 무기황의 uptake rate는 시스테인에 의해 크게 저해되었다. Crude enzymes extracts에서 변이주 MS-92 는 cell내에 cysteine을 적게 형성하였다 즉, L.-serine sulfhydrylase 활성이 모균보다 낮았으며 세포내에 시스테인의 양을 간접적으로 알 수 있는 시스테인 분해효소인 cysteine desulfhydrylase 활성치 변이주에는 모균의 약 반이였다. 이상의 결과에서 C. acremonium에서 메치오닌을 만드는 효소들의 조절에는 A. nidulans와 비슷하게 시스테인이 관여한다는 것을 추측할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.683-688
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• 2005

A transformation system mediated by Agrobacterium tumefaciens is routinely used for the genetic engineering of plants. Here, we report an efficient and stable method for transformation of heterogeneous genes into an industrial Cephalosporium acremonium by using a similar transformation system established in plants. Both the phleomycin-resistant gene and vgb gene were used as screening markers to confirm the success of transformation by either Southern hybridization or PCR amplification. It was found that acetosyringone (AS) was necessary only for protoplast transformation and the heterogeneous genes transferred were integrated into the genome of C. acremonium. The transformation efficiency obtained with this system was much higher than the conventional techniques used for transformation of C. acremonium.

• Korea-Australia Rheology Journal
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• 제14권1호
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• pp.11-16
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• 2002

Cephalosporium acremonium is a filamentous microorganism producing cephalosporin C. The morphological differentiation of C. acremonium in submerged culture is closely related with the rheological properties of culture broth and production of cephalosporin C. In this study, the rheological and morphological properties of culture broth of C. acremonium were investigated. In the seed broths of shake-flask and fermenter culture, the Herschel-Berkley equation was in excellent agreement with experimental results in the whole range of shear rate. In the seed broths of shake-flask culture, morphological differentiation into arthrospores affected to changes of apparent viscosity. But results in the fermenter culture, morphological factors such as mean hyphal thickness and the number of tips gave more effect on changes of apparent vitacosity than differentiation into arthrospores. Overall, it suggested that the morphological parameters measured by image analysis can be used as a good parameter to indicate the rheological properties of culture broth of C. acremonium M25.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.215-221
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• 1991

YIp5를 사용하여 Cephalosporium acremonium ATCC 2033으로부터 Saccharomyces cerevisiae SHY3에서 발현되는 자율복제 기점 (ARS)를 분리하였다. 자율복제 기점을 갖는 40종의 vector 가운데 가장 안정성 (stability)이 높은 plasmid를 pCY-2라 명명하였으며 pCY-2는 C.acremonium에서 유래하는 3.7kb의 단편을 갖고 있었다. 또 Southern hybridization과 재형질전환을 통해 pCY-2가 효모내에서 자율적으로 복제되고 있다는 것을 확인하였다. 또한 pCY-2는 형질전환율과 안정성에 있어 효모의 ARS를 갖는 YRp7 vector보다 우수하였다.

• 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.

• 미생물학회지
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• 제25권3호
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• pp.205-211
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• 1987

Cephalosporium acremonium MAR-80, a strain of methionine analogue-resistant mutant, showed good activity of sulfate utilization as only sulfur source. The effect of methionine on the sulfate uptake system was investigated by using $Na_{2}^{35}SO_{4}$ as a tracer in the resting cell system. From this result, it was revealed that sulfate permease of this strain was less repressed and/or less inhibited by methionine than parent type. This deregulation was due to low actibity of methionine uptake, which was operated by somewhat simple diffusion. From these studies, it could by anticipated that the improved productivity of cephalosporin C and lower dependence of cephalosporin C production on methionine were related to increased uptake rate of sulfate.

• 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.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.971-976
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• 2005

In a 30-1 bioreactor culture, whole differentiation occurred from 48 h, and then proceeded rapidly. As swollen hyphal fragments and arthrospores increased, cephalosporin C (CPC) production increased exponentially to $1.85\;g/1^{-1}$ at 72 h. To explain the morphological changes of Cephalosporium acremonium M25 more quantitatively, specific differentiation rates and fractal analysis were employed. Specific differentiation rates of morphological factors varied greatly during the period of culture time from 48 h to 72 h, when CPC production increased significantly. Changes of fractal dimensions showed a pattern similar to that of the specific rate of arthrospores. Furthermore, it was inversely related to the specific rate of tips. Overall, it was suggested that the fractal dimension had potential for a new morphological parameter of fungal morphology, showing complex differentiation patterns.