• Mycobiology
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• 제33권3호
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• pp.125-130
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• 2005

Pigmentation of ascospore-derived isolates from seven different natural specimens of Cordyceps militaris EFCC C-5888, EFCC C-7159, EFCC C-7833, EFCC C-7991, EFCC C-8021, EFCC C-8023 and EFCC C-8179 was observed on the plates of Sabouraud Dextrose agar plus Yeast Extract at $25^{\circ}C$ under continuous illumination (500 lux). Pigmentation of the wild-type isolates of C. militaris was diverse ranging from yellowish white to orange, while white color was believed as a mutant. Inheritance of pigmentation was found to be controlled by both parental isolates when F1 progeny were analyzed. Pigmentation and mating type were shown to be either independent or distantly linked each other due to the high percentage of non-parental phenotypes among F1 progeny. Crosses between white mutant isolates of C. militaris yielded progeny with wild type pigmentations, indicating that the albino mutations in the parents were unlinked to each other.

• ALGAE
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• 제18권1호
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• pp.89-94
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• 2003

• ALGAE
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• 제18권1호
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• pp.95-100
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• 2003

• Journal of Microbiology
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• 제41권3호
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• pp.224-231
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• 2003

The null pigmentation mutant (npgA1) of Aspergillus nidulans was previously characterized by its production of no pigment at any stage of its life cycle, its reduction in hyphal branching, and its delay in the asexual spore development. The chemical composition of the cell wall was also altered in npgA1 mutants that became more sensitive to Novozyme 234$\^$TM/, which is possibly due to a structural defect in the cell wall. To investigate the effects of the cell wall structure on these pleiomorphic phenomena, we examined the ultrastructure of the cell wall in the npgA1 mutant (WX17). Scanning electron micrographs (SEM) showed that after being cultured for six days, the outermost layer of the conidial wall of WX17 peeled off. Although this phenotype suggested that the cell wall structure in WX17 may be modified, examination using TEM of the fine structure of cross-sectioned hyphal wall of WX17 did not show any differences from that of FGSC4. However, staining for carbohydrates of wall layers showed that the electron-translucent layer of the cell wall was missing in WX17. In addition, the outermost layer H1 of the hyphal wall was also absent in WX17. The ultrastructural observation and cytochemical analysis of cell walls suggested that the pigmentation defect in WX17 may be attributed to the lack of a layer in the cell wall.

• 생명과학회지
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• 제14권1호
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• pp.45-50
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• 2004

A. nidulans의 색소결핍 억제돌연변이주(Suppressor mutant of the null pigmentation; SU-NPG)의 세포벽 구조가 색소형성 및 균사분지에 미치는 영향을 조사하여 다음의 결과를 얻었다. SEM으로 세포 표면구조를 관찰한 결과, 완전배지에서 배양된 SU-NPG의 분생포자벽은 최외각 층이 6일 째부터 박리되었으며, 균사생장이 저조하였다 TEM으로 관찰한 결과, 균사 세포벽은 매우 두꺼워졌다. 이러한 전자현미경관찰 결과는 이들 돌연변이주의 세포벽 구조가 NPG 및 야생형의 그것과는 다르다는 것을 시사한다. 균사에 탄수화물 염색을 한 후, 세포화학적 미세구조를 관찰한 결과, 분생포자벽은 C1, C2, C3와 C4 층으로 되어 있었고, 균사 세포벽은 H1, H2, H3와 H4층으로 되어 있었다. 이러한 C3층과 H3층은 세포분화 시 색소형성 및 균사 분지형성에 필수적인 세포벽 구조임 을 시사한다. SU-NPG는 FGSC4에서와는 다르게 비정상적인 균사생장을 하였지만, 색소결핍 돌연변이를 억제하는데, 이는 SU-NPG의 균사 세포벽에는 H3층이 형성되었으며, 세포벽 형성과정은 정상적으로 진행되기 때문으로 사료된다.

• ALGAE
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• 제18권1호
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• pp.83-88
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• 2003

• ALGAE
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• 제28권1호
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• pp.121-129
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• 2013

Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios.

• Journal of Microbiology
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• 제35권4호
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• pp.271-276
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• 1997

We isolated phenotypic suppressors of an absB (antibiotics synthesis suppression) strain. In the absB colonies, all four antibiotics including two pigmented antibiotics were blocked so that no pigmentation could be found. We assumed that in the colonies with the wuppressive(or reversive) mutation, both pigmentation would be restored so that the strains with suppressive mutation could be cisually detected. Harvested absB spores were treated with chemical mutagen along with electric shock, and were spread on specially fromulated minimal medium plates. The pigmented colonies were isolated from the unpigmented majorities. In one candidate strain, the restoration and significant overproduction of actinorhodin and undecylprodigiosin were recognized. In three other candidate strains, the overproduction of actinorhodin and restoraion of undecylprodigiosin were observed. The production of the two unpigmented antibiotics (CDA and methylenomycin) were visualized in the tested candidate strains. The strains with wuppressive mutations would be very useful in dlucidating the regulation network of antiviotics synthesis and overproduction of the antibiotics.

• Journal of Microbiology and Biotechnology
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• 제5권1호
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• pp.22-25
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• 1995

Bacillus licheniformis SSA3 can produce a dark-brown antimutagenic pigment. The optimal conditions for production of this pigment are reached at 0.1% tyrosine, in pH 6-8, within 7-9 days, at $30^{\circ}C$, and in aerobic condition. We cloned a DNA fragment involved in pigment synthesis from Bacillus licheniformis SSA3 using a mutant strain. The cloned DNA was 7kb in size, which can produce the same pigment even in E. coli.

• 한국미생물·생명공학회지
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• 제30권2호
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• pp.111-115
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• 2002

천연 황색소 생산을 위하여 Monascus anka Nakazawa et Sato IFO 4478(KCCM l1832 strain) 균주를 모균주로 하여 UV 조사 및 NTG(N-methyl-N'-nitro-N-nitrosoguanidine)처리 및 이들 방법을 병용하는 방법을 사용하여 모균주와는 색소생성 특성이 다르게 황색소를 단일성분으로 생성하는 변이주를 분리하고 그 특성을 조사하였다. leucine, cystein, aspartic acid, glutamic acid 와 asparagine 등 5종의 아미노산에 대한 영양요구주를 분리하였고 이중 asparagine 영양요구주 Y7은 colony 형태와 균사의 직경에서 약간의 차이를 나타내지만 전형적인 Monascus 균주의 특성을 지니고 있었으며 특히 유성생식에 의한 번식 특성이 강하여 색소 생성에 유리한 조건을 지니고 있었다. 그리고 Y7은 밝은 색조의 황색소를 단일 성분으로 생성하며 10대 이상의 계대배양에서도 색소 생성 특성이 안정하였고 색소 생성량이 모균주보다 약 2.2배 높은 값을 나타내고 있었다. 이때 생성된 황색소는 373 nm에서 단일 흡수 peak를 나타내고 물, 에탄올 등 극성용매에 대한 용해성이 높은 특성을 나타내며 생성된 색소의 대부분이 균체 밖으로 배출되는 특성을 지니고 있었다.