• Mycobiology
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• v.33 no.3
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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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• v.18 no.1
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• pp.89-94
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• 2003

• ALGAE
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• v.18 no.1
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• pp.95-100
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• 2003

• Journal of Microbiology
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• v.41 no.3
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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.

• Journal of Life Science
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• v.14 no.1
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• pp.45-50
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• 2004

To investigate the effect of the cell wall on the pigmentation and branching in Aspergillus nidulans, ultrastructure of cell wall in suppressor mutant of the null pigmentation (SU-NPG, SU602) has been examined. Scanning electron microgrphs (SEM) revealed that the most outer layer of conidia wall peeled off in SU-NPG on day 6 from the complete conidiation. They also showed that hyphal growth and branching were not well developed in SU-NPG. Transmission electron micrographs (TEM) showed that the plasma membrane was not crenulated and the hyphal wall was thick in SU-NPG. These results indicated that the ultrastructure of cell wall in SU-NPC might be modified. Cytochemical analysis showed that the cell wall in SU-NPG was differentiated into Cl, C3, C2 and C4 layer in conidia and H1, H3, H2 and H4 layer in hyphae. C3 layer and H3 layer existed in SU-NPG. The increment of the diameter in SU-NPG hyphae might be caused by the thickness of H3 layer. These results suggest that SU-NPG may have an immature but the differentiated structure for the pigmentation in cell wall.

• ALGAE
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• v.18 no.1
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• pp.83-88
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• 2003

• ALGAE
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• v.28 no.1
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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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• v.35 no.4
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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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• v.5 no.1
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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.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.111-115
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• 2002

To produce yellow pigment selectively, mutants were induced from Monascus anka Nakazawa et Sato IFO 4478 (KCCM 11832 strain), and their characteristics were evaluated. Five kinds of auxotrophic mutants which required amino acids for growth and pigmentation, were isolated through a series of mutagenic treatments. Especially, asparagine auxotroph Y7 produced high ratio of yellow pigment. This mutant showed all the morphological characteristics of Monascuceae but the shape of colony and the diameter of conidia. Mutant Y7 was propagated by sexual reproduction more often than asexual reproduction, which could be effective in production of pigments. Yellow pigment produced extracellularly by the mutant Y7 was more soluble in polar solvents such as ethanol and water than in nonpolar solvents. Its productivity of yellow pigment was 2.2 times higher in the mutant Y7 than in parents. In addition, its yellow pigment showed characteristics of maximum absorption at 373 nm. Moreover, the hue of pigment produced by the mutant Y7 was bright yellow, and it was stable through the subculture over 10 generations.