• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.869-872
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• 2009

The cyclic undecapeptide cyclosporin A (CyA), one of the most valuable immunosuppressive drugs, is produced nonribosomally by a multifunctional cyclosporin synthetase enzyme complex by the filamentous fungus Tolypocladium niveum. To increase CyA productivity by wild-type T. niveum (ATCC 34921), random mutagenesis was first performed using an antifungal agar-plug colony assay (APCA) selection approach. This generated a mutant strain producing more than 9-fold greater CyA than the wild-type strain. Additionally, a foreign bacterial gene, Vitreoscilla hemoglobin gene (VHb), was transformed via protoplast regeneration and its transcription was confirmed by RT-PCR in the UV-irradiated mutant cell. This led to an additional 33.5% increase of CyA production. Although most protoplast-regenerated T. niveum transformants tend to lose CyA productivity, the optimized combination of random mutagenesis and protoplast transformation described here should be an efficient strategy to generate a commercially valuable, yet metabolite low-producing, fungal species, such as CyA-producing T. niveum.

• 한국환경보건학회지
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• 제31권4호
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• pp.327-331
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• 2005

Micromonosporas purpurea로부터 효율적 gentamicin 생산을 위해 protoplast fusion와 protoplast mutagenesis 방법이 검토 되었다. $CO^{60}\;irradiation\;(2.3{\times}10^5$ units, UV 3 min) 방법에 의해서 MP3-112, MP3-141, MP3-143을 분리 했다. 특히 MP3-143균주는 최대 gentamicin생산량이 얻어졌다. 개량된 MP3-143균주를 이용해서 탄소원 소비, 균체성장, 그리고 gentamicin 생산량이 batch culture에서 비교되었다. MP3-413와 parent 균주의 glucose 소비는 배양 2일과 3일 후에 각각 완전히 이루어졌다. 그러나 균체성장과 Soybean oil 소비는 비슷한 결과 얻어졌다. Gentamicin최대 생산량은 배양 5일 후 29756 U/ml였다. 이 결과는 parent 균주에 비해 생산량이 5.6배 증가했다.

• Archives of Pharmacal Research
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• 제12권4호
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• pp.249-253
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• 1989

High producers or blocked mutants of aminoglycoside antibiotic-producing Streptomyces spp. were selected by application of an agar plug method and by culturing individual colonies in broth. The productivities of aminoglycoside antibiotic producing organisms were increased by selection of a high producer from colonies obtained by spreading spores of wild strain, or survived from treatment of a mutagen or from the colonies regenerated from protoplast-formation and cell-wall regenerations. Some mutagen treated colonies lost the ability to produce antibiotics (5-8%). Some A-factor negative and deostreptamine or streptidine negative mutants were obtained by N-methyl-N'-nitro-N-nitrosomethylguanidine (MNNG) treatment. Many of the survivors from the MNNG treatment lost the ability to produce antibiotics. Major colonies produced less amount of antibiotics ; only few survived colonies produced more antibiotics than the parent. Resistance of Streptomyces spp. against the antibiotics produced by itself was also markedly affected by mutagen treatment.

• 환경위생공학
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• 제23권4호
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• pp.23-29
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• 2008

This study was performed to develop mutant strain using a combination of UV irradiation procedures with protoplast mutagenesis in order to achieve an effective kasugamycin production from Streptomyceskasugaensis. Whenlessthan 1.0g/lof Linoleic acid was used, the cell growth was not inhibited. On the other hand, the cell growth was greatly inhibited when more than 1.6 g/l of linoleic acid was used. Among the various mutant strains, SK-12 was obtained in medium containing 1.6g/l of linoleic acid, showing the highest rate of both cell growth and kasugamycin production. In order to compare kasugamycin production with the SK-12 and the parent strain using soybean oil, cultures were performed in a flask. The production of kasugamycin was increased with the increase time. The maximum kasugamycin concentration was 1.2g/l after 6 days of culture. The product yield from soybean oil was 0.05g/l/g consumed carbon source, which was roughly 5.0 fold higher than the parent strain. These results show that it was effective method for obtaining a mutant resistant to linoleic acid for the effective production of kasugamycin from soybean oil.

• 한국균학회지
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• 제40권2호
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• pp.93-97
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• 2012

본 연구는 큰느타리버섯(Pleurotus eryngii)에 감마 방사선을 조사하여 형태적, 생리적 특성이 향상된 새로운 큰느타리버섯 품종을 개발하기 위하여 수행되었다. 큰느타리버섯에서 분리한 원형질체에 0.25-1.25 KGy의 감마 방사선을 조사하였다. 원형질체는 YPMGA 배지에서 80%의 치사율을 나타냈고 이들 중 무작위로 500개의 변이체를 선발하여 PDA 배지에 배양하였다. 그 결과, 대부분의 변이체가 대조구와 비슷한 형태와 생장률을 나타냈으며, 이 중 100개의 변이체가 대조구와 약간의 차이를 보였다. 67개 변이체에 대해 cellulase 활성과 laccase 활성을 조사하였다. 그 결과, 대체적으로 대조구와 유사한 효소 활성을 나타내었고, 5개의 변이체가 대조구에 비해 더 높은 cellulase 활성을 나타내었다. 또한 감마 방사선 조사 변이체의 유전적 변이를 조사하기 위하여 UFPF-PCR을 이용하여 다형성을 조사하였다.

• 방사선산업학회지
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• 제5권4호
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• pp.285-295
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• 2011

Mushrooms belonging to macrofungi have been consumed by humans for their nutritional and medicinal values for centuries throughout the world. Mushroom farming is practiced in more than 100 countries of the world, with production increasing at a rate of 7% per annum. High yield and good quality are always the principal goals for agriculturally important crops, including mushrooms. Several breeding methods are employed for strain improvement such as mass selection based on the natural chance mutation and induced mutation (mutation breeding), protoplast fusion technology, cross breeding and transgenic breeding. However, mutation breeding has shown prominent success in crop plant improvement. Though several-hundred mutant crop varieties have been developed around the world, the mutation breeding of mushrooms is limited. This review paper explores the potential application of radiation on the development of mutant varieties of mushrooms for breeding with desired traits such as better quality and productivity.

• 한국균학회지
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• 제15권2호
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• pp.80-86
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• 1987

자연계에서 섬유소분해능이 우수한 균을 분리하였고 섬유소분해능을 더욱 증진시키기 위한 기초단계로서 그 분리균주의 원형질체 생성과 융합의 최적조건을 조사하였다. 토양에서 채취한 시료로부터 섬유소분해능력이 우수한 Aspergillus sp., Penicillium sp., Trichoderma sp., 3균주를 분리 동정하였고 산업적으로 유용한 균주이며 cellulase activity가 있는 Aspergillus niger를 비교균주로 선택하여 각각의 효소활성도를 비교 조사한 결과, Aspergillus sp.가 가장 좋은 효소활성도를 보였으며 그 다음 Penicillium sp., Trichoderma sp., 그리고 Aspergillus niger 순이었다. 효소활성도가 가장 좋은 Aspergillus sp.에 자외선$(12erg/sec/mm^2)$을 4 분 30초 동안 조사하여 영양요구성 변이주를 유도, 분리하였다. 세포벽분해효소로는 pH6.0에서 ${\beta}-glucuronidase$가 효과적이었고 그 효소를 농도별로 처리해본 결과 5, 000unit/ml가 최적농도이었다. 재생률은 삼투안정제로 0.6M KCI을 사응하여 pH6.0에서보았을 때 야생형은 7.0%, met. 영양요구주는 7.5%, arg. 영양요구주는 5.2%이있다. 영양요구성변이주간의 원형질체융합에 필요한 PEG는 분자량이 6,000인 것이 좋았으며 최적농도는 $30^{\circ}C$ 이었다. 이때 융합율은 1.2%까지 획득하었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.144.1-144
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• 2003

Attenuated viruses can protect their hosts against challenge to their related viruses. Increasing evidence shows that mutations of the tobamoviral 126/183 kDa protein play a major role in the viral attenuation and contribute to the cross protection mechanism. In this study, four mutants of Pepper mild mottle virus (PMMoV) have been constructed by mutagenesis; two mutants, pTPpoly348 and pTPpoly762, were substituted in the middle of replicase gene, and the others, pTPL3D:: $\Delta$6207 and pTPL3D:: $\Delta$6219, were deletion mutants made by deleting some parts of pseudoknot structures of the 3' noncoding region (NCR) of the virus. Progeny viruses generated from the four mutants were infectious on N. benthamiana plants with symptomless or mild mosaic symptom. Replication efficiency and viral product accumulations of four mutants were assessed by Northern and Western blot analyses on BY-2 protoplast cells. Accumulation of CP for the pTPL3D:: $\Delta$6207 and pTPL3D:: $\Delta$6219 were lower than that of other mutants and wild type virus. These data suggest that the 3'-NCR mutations contribute to the viral gene expression in host tissues, while mutants of replicase gene rather govern the symptom expression.

• 한국균학회지
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• 제14권2호
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• pp.185-188
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• 1986

노랑 느타리버섯의 유전 연구 및 다른 느타리종과의 융합을 위해서 노랑 느타리의 담자포자에 자외선을 조사하여 영양요구성 균주를 선발하였다. 노랑 느타리 포자에 UV를 조사한 결과 UV조사시간이 $40{\sim}70$초이고 생존율 $0.4{\sim}1.4%$ 일때 많은 mutants를 얻을 수 있었고, 선발된 14 auxotrophic mutants의 유전 marker는 amino acid-requiring strain 3균주, nucleic acid base-requiring strain 1 균주, vitamin-requiring strain 3 균주, amino acid/nucleic acid base-requiring strain 2 균주, amino acid/vitamin-requiring strain 5 균주로 되었다.

• 한국균학회지
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• 제13권2호
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• pp.75-78
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• 1985

진균류의 균주개발과 유전연구에 필수적인 영양요구성 균주 선발을 위하여 느타리비섯과 사철느타리버섯의 월형질체에 자외선을 조사하여 얻은 결과를 요약하면 다음과 같다. 1. 원형 질체에 자외선을 조사하여 그 생존을이$0.83{\sim}15%$일 때 가장 많은 영양 요구성 균주를 선발하였다. 2. 느타리에서 Arg, Gly Ser 그리고 Ala Orn Tyr 3균주와 사철느타리버섯에서 Ribo-1, Ribo-2, Phen, 그리고, Ade Hyp 4군주를 선발하였으며 이들 중에서 Phen 균주는 back mutation 현상이 나타났다.