• 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.

• Animal cells and systems
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• v.14 no.3
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• pp.225-236
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• 2010

We compared the composition of phospholipid fatty acids (PLFA) to assess the microbial community structure in the soil and rhizosphere community of non-transgenic watermelons and transgenic watermelons in Miryang farmlands in Korea during the spring and summer of 2005. The PLFA data were seasonally examined for the number of PLFA to determine whether there is any difference in the microbial community in soils from two types of watermelons, non-transgenic and transgenic. We identified 78 PLFAs from the rhizosphere samples of the two types of watermelons. We found eight different PLFAs for the type of plants and sixteen PLFAs for the interaction of plant type and season. The PLFA data were analyzed by analysis of variance separated by plant type (P<0.0085), season (P<0.0154), and the plant type${\times}$season interaction (P<0.1595). Non-parametric multidimensional scaling (NMS showed a small apparent difference but multi-response permutation procedures (MRPP) confirmed that there was no difference in microbial community structure for soils of both plant types. Conclusively, there was no significant adverse effect of transgenic watermelon on bacterial and fungal relative abundance as measured by PLFA. We could reject our hypothesis that there might be an adverse effect from transgenic watermelon with our statistical results. Therefore, we can suggest the use of this PLFA methodology to examine the adverse effects of transgenic plants on the soil microbial community.

• Mycobiology
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• v.50 no.6
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• pp.448-456
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• 2022

In this study, the roots and rhizosphere soil of Abies koreana and Taxus cuspidata were collected from sites at two different altitudes on Mt. Halla. Ectomycorrhizal fungi (EMF) were identified by Illumina MiSeq sequencing. The proportion of EMF from the roots was 89% in A. koreana and 69% in T. cuspidata. Among EMF in rhizosphere soils, the genus Russula was the most abundant in roots of A. koreana (p < 0.05). The altitude did not affect the biodiversity of EMF communities but influenced fungal community composition. However, the host plants had the most significant effect on EMF communities. The result of the EMF community analysis showed that even if the EMF were isolated from the same altitudes, the EMF communities differed according to the host plant. The community similarity index of EMF in the roots of A. koreana was higher than that of T. cuspidata (p < 0.05). The results show that both altitude and host plants influenced the structure of EMF communities. Conifers inhabiting harsh sub-alpine environments rely strongly on symbiotic relationships with EMF. A. koreana is an endangered species with a higher host specificity of EMF and climate change vulnerability than T. cuspidata. This study provides insights into the EMF communities, which are symbionts of A. koreana, and our critical findings may be used to restore A. koreana.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.389-396
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• 2000

To determine whether the Tricholoma matsutake (pine mushroom, Songyi) is symbiotic or parasitic to Pinus densiflora, structural change in their natural ectomycorrhizas were examined. The mycorrhizal samples were collected at three progressional points in the natural hypogeous colony(shiro) : colony front edge, near the fruiting point and 20cm back. The fine roots in the colonies were typical ectomycorrhizas with fungal mantle and Hartig net. However, the T. matsutake mycorrhizas had unique characteristics compared to other types of ectomycorrhizas. That is, spatially the fungal mantle and Hartig net of the T. matsutake mycorrhizas continued to develop along the growing tip, while temporally those structures declined to shrink changing to black brown in the older part of the roots behind the actively growing tip portion. However, there was no mark that the fungal hyphae penetrated into either the cortical cells, endodermal cell layers or stele. The apical tips of the blackened roots remained alive to form new mycorrhizas with other fungi later. Therefore, we conclude that the mycorrhiza of T. matsutake+P. densiflora is rather a dynamic symbiosis that changes its position spatiotemporally as the root grows than either a simple parasitism or symbiosis.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.189-196
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• 1997

A producer of inhibitor against ${\beta}-glucosidase$ of Penicillium sp.-L4 was screened from Actinomycetes, and the isolated strain was identified as Streptomyces sp. The inhibitor produced was very stable against heat, acidic and alkaline conditions, proteolytic and amylolytic enzymes. The inhibotor was purified from culture broth through activated carbon treatment, ultrafiltration, anion and cation exchange, activated carbon columm, acetone precipitation and preparative HPLC. It showed inhibitory activities against a variety of dissacharide hydrolyzing enzymes produced by P.sp.-L4, and the mode of inhibition was competitive. Its structure and molecular formular was elucidated by IR, $^1H\;and\;^{13}C$ NMR and FAB/Mass spectrometry, which was identified as 1-deoxynojirimycin (dNM). dNM showed inhibitory effects on the cell growth and hydrolytic enzyme action of P.sp.-L4 on agar plate and infected lemon peel.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1217-1220
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• 2007

The saprophytic fungus Ulocladium atrum Preuss is a promising biological control agent for Botrytis cinerea in greenhouse- and field-grown crops. However, despite its known potent antifungal activity, no antifungal substance has yet been reported. In an effort to characterize the antifungal substance from U. atrum, we isolated an antibiotic peptide. Based on extensive spectroscopic analyses, its structure was established as a cyclopeptolide with a high portion of N-methylated amino acids, and its $^1H$ and $^{13}C$ chemical shifts were completely assigned based on extensive 1D and 2D NMR experiments. Compound 1 exhibited potent antifungal activity against the plant pathogenic fungus Botrytis cinerea and moderate activity against Alternaria alternate and Magnaporthe grisea.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2235-2240
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• 2007

3-Aryloxy methyl-4-(N-pyrazin-2'yl carboxamido)-5-mercapto-1,2,4-triazoles (3a1-a14) were prepared starting from potassium dithio carbazinates (2a1-a14). These triazoles were then employed in the synthesis of 3-aryloxy methyl-4-(N-pyrazin-2'yl carboxamido)-5-hydrazino-1,2,4-triazoles (4a1-a14). All the newly synthesized compounds were characterized by analytical, IR, NMR spectral studies. The compounds were screened for their antibacterial, antifungal, anti-inflammatory and analgesic properties. Most of the compounds have shown significant antifungal activity while few have shown excellent anti-inflammatory and analgesic activity. An attempt is made to study the structure activity relationship (SAR).

• Journal of Life Science
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• v.12 no.5
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• pp.632-648
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• 2002

The term polyketide defines a class of natural products synthesized through the successive condensation of small arboxylic acids, which results in products containing multiple carbonyl or hydroxyl groups, each separated by one arbon atom, as in the structural element CH$_2$C(=0)CH$_2$CH(OE)CH$_2$C(=0)-. Plant flavonoids, fungal aflatoxins, as well as undreds of compounds of different structures that can inhibit the growth of bacteria, viruses, fungi, parasites or human umor cells are included in this diverse group. Some of antifungal polyketides also have immunosuppresive activity. olyketides can vary widely in structure, and the diversity of polyketide structures reflects the wide variety of their iological properties. This review focuses on the biosynthesis of polyketides and recent progress in combinatorial iosynthesis of new hybrid polyketide compounds.

• Korean Journal of Environmental Biology
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• v.18 no.4
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• pp.441-446
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• 2000

Trichoderma harzianum is an aggressive causal agent of green mold disease on mushroom cultivation. Some bacterial strains isolated, from oyster mushroom compost in Wonju, were found to have in vitro antifungal activity against Trichoderma harzianum ATCC 6385, 6504, and our isolates Trichoderma spp. Y and G. Further in vitro antifungal studies on several strains of phytopathogenic fungi showed that all of 12 phytopathogenic fungal strains were significantly inhibited by the isolated antifungal bacteria in Petri dishes. Of these, KATB 99121 showed the broadest inhibiting effect and displayed as negative coagulase, negative sulfide production and rod shape. KATB 99121 was resistant to ampicillin, chlorampenicol, and kanamycin. Identification of isolates was determined by Biolog GN system, and KATB 99121 was identified as Photobacterium logei because of 96 probability, 0.65 similarity, and 4.97 disturbance. With electron microscopy, thin section of KATB 99121 strain revealed typical rod-like shaped cell (0.6-0.8${\mu}{\textrm}{m}$$\times$1.5-2.0${\mu}{\textrm}{m}$) with prokaryotic structure and organization.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.254-260
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• 1994

Magnaporthe grisea, a causal agent of blast, forms a specialized infection structure, an appressorium, to infect host. Hydrophobicity of contact surface and cAMP have been suggested as a primary environmental signal and a second messenger to trigger and mediate appressorium formation in this fungus, respectively. To generalize these factors in field isolates of M. girsea, twenty isolates originated from rice and other gramineous hosts were tested. Seventeen including rice and non-rice isolates formed appressoria on hydrophobic surface, but none of isolates formed appressoria on hydrophilic surface. Eighteen isolates formed appressoria on hydrophilic surface in the presence of IBMX, an inhibitor of phosphodiesterase, except two rice isolates. These results strongly support the hypothesis that appressorium formation by M. grisea is induced by hydrophobic hard surface and regulated by the endogenous level of cAMP in the cells. Understanding fungal development is not only of biological interest but provides new targets for novel disease control strategies.