• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.72-78
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• 2001

It is possible ot prepare protoplasts of the zygomycete fungus, Phycomyces blakesleeanus, by digesting the cell wall of spore germlings with commercially available chitinase and chitosanase. However, the cells without any cell walls immediately form large aggregates, and thus, it is difficult to isolate the individually separated protoplasts. Inherent problem with the formation of aggregates in preparing protoplasts could be solved by the use of bovine serum albumin (BSA). As a result, we were able to prepare a large number of single protoplsts quickly and easily. We took time-lapse photomicrographs of the formation of protoplasts, and found that there were certain regions of the cell wall of spore germlings that were sensitive to chitinase and chitosanase, although the cell wall of the original spores is known to be insensitive to these enzymes. There are two kinds of cell walls on a spore germling; one with a bound wheat germ agglutinin (WGA), and the other a bound concanavalin A (ConA). Furthermore, only cells with walls which had bound WGA were able to regenerate, while those with walls with bound ConA were not able to regenerate.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.105-111
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• 1979

Phycomyces sp. has been isolated from Meju and its lipid composition was investigated. The lipid content was 18.2 % of dry weight and composed of 69.2 % neutral lipids. 24.3 % glycolipids and 6.5 % phospholipids. It was possible to identify the presence of carotene, hydrocarbons, esterified sterols, fatty acid esters, triglycerides. free fatty acids and free sterols in the neutral lipid fraction. Major components in the neutral lipid fraction were free fatty acids and triglycerides. Twelve molecular species of triglycerides and 8 molecular species of diglycerides were fractionated by argentation TLC. The major fatty acids in total lipids were stearic, linoleic, arachidic and linolenic acids, and those in the free fatty acid fraction were stearic, linoleic and arachidic acids.

• Journal of Photoscience
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• v.1 no.1
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• pp.69-73
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• 1994

Sporangiophores (spphs) of Phycomyces blakesleeanus are positively phototropic to unilateral visible (blue) light over a range of fluence rates 10$^{-9}$ to 1 W/m$^2$. The maximal bending angle is always 70-75$\circ$ from the vertical. Many mutants with abnormal phototropism have been isolated. Complementation tests revealed that the genetic grouping is completely consistent with the phenotypic classification scheme, based on sensory responses other than those to light. The spph of the piloboloid mutant, the growth zone of which gradually ceases elongation but expands spherically, and the $\beta$-carotene-overproducing mutant show negative phototropism, in contrast to the wild type spph. We hypothesized that the phototropic orientation of spph is determined by the ratio of the maximal light fluenee rate at the proximal side to that at the distal side of the spph. Based on this hypothesis, we found that the maximal bending angle was larger in thin spphs than in thick ones, and larger in spphs containing smaller amount of $\beta$-carotene than in carotene-rich spphs. In addition to our hypothesis, gravitropic experiments revealed that the maximal bending angle of the wild type spph results from a balance among positive phototropism, negative gravitropism, and the optical properties of the spph. For further advancement of this study, we developed a mutant with a high proportion of uninucleate spores, and designed an efficient microinjection method for obtaining transformants.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.27-40
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• 2009

Six strains of Phycomyces blakesleeanus (DEL, A56, C9, C47, C111, and G5) were cultured in continuous light condition for 6 days. The increase in fresh and dry weight after the culture period was similar in all strains. However, the increase in fresh weight was sustained throughout the culture period in all strains, whereas the increase in dry weight was prominent only during the first 3 days of culture. The development and phototropism of macrophores was observed after 3 days of culture, These results suggest that the development and phototropism is ascribed to the increase in turgor pressure in sporangiophores where water entered. A56 and G5 showed a higher sensitivity to light than C9 and C47, whereas C111 showed no photosensitivity. Antagonistic relations were observed between photosensitivity and development of microphores, suggesting that the development and phototropism of macrophores is regulated by a common recognition factor (photoreceptor).

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.389-394
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• 1996

This study was carried out to determine the causative agent of dermatophytosis in 7 horses, and to examine the skin mycofloras on 84 healthy and 7 diseased horses which were derived from Jae-ju and Kyonggi, Korea in 1994~1995. Specimens of hair and scale were collected from skin lesions(or normal skins) and inoculated directly on potato dextrose agar and mycobiotic agar. These agar plates were incubated at $25^{\circ}C$ for 2 weeks. Growing fungi were isolated and identified by the morphological and nutritional characteristics. Lesions were found on the hind legs of an infected horses and each lesion was round or oval(1~4 cm) in shape accompanied by severe itching. The causative agent of the 7 equine dermatophytosis was identified as Trichophyton equinum. The skin mycofloras were Penicillium(69.0%), Aspergillus(63.2%), Cladosporium(51.7%), Fusarium(31.0%), Mucor(28.7%), Absidia(18.4%), Alternaria(17.2%), Acremonium(11.5%), Paecilomyces and Phycomyces(6.9%), Rhizopus(5.6%), Trichoderma(4.6%), Scopulariopsis and Trichophyton(3.5%), Beauveria(2.3%), Tritiracheum, Sporothrix, Curvularla, Aureobasidium and Chaetomium(1.2%), and Yeast(27.6%).

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.4
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• pp.263-274
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• 2000

Carotenoids are widely distributed natural pigments which are in an increasing demand by the market, due to their applicatins in the human food, animal feed, cosmetics, and pharmaceutical industries. Although more than 600 carotenoids have been identified in nature, only a few are industrially important (${\beta}$-carotene, astaxanthin, lutein or lycopene). To date chemical processes manufacture most of the carotenoid production, but the interest for carotenoids of biological origin is growing since theire is an increased public concern over the safety of artificial food colorants. Although much interest and effort has been devoted to the use of biological sources for industrially important carotenoids, only the production of biological ${\beta}$-carotene and astaxanthin has been reported. Among fungi, several Mucorales strains, particularly Blakeslea trispora, have been used to develop fermentation processes for the production of ${\beta}$-carotene on almost competitive cost-price levels. Similarly, the basidiomycetous yeast Xanthophyllomyces dendrorhous (the perfect state of Phaffia rhodozyma), has been proposed as a promising source of astaxanthin. This paper focuses on recent findings on the fungal pathways for carotenoid production, especially the structure and function of the genes involved in the biosynthesis of carotenoids in the Mucorales. An outlook of the possibilities of an increased industrial production of carotenoids, based on metabolic engineering of fungi for carotenoid content and composition, is also discussed.