• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.439-440
• /
• 2000

This study was conducted to preserve viability of Aspergillus sp. PS-104, a phosphate-solubilizing fungus, for more than 6 months. The number of Aspergillus sp. PS-104 conidia stored at $25^{\circ}C$ with various concentrations of additives was counted on potato dextrose agar at the intervals of 2 weeks. When PEG 200 was added with concentration of 0.1%, viability of the conidia was increased more than 10 times to compare with control.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.3
• /
• pp.265-270
• /
• 1999

The stabilization of Aspergillus sp. $\alpha$-amylase was attained by modification with periodate-oxidized sol-uble starch. The pH stability of modified enzyme was increased at pH 3~4 and 9~11 in the presence of $\alpha$-cyclodextrin($\alpha$-CD) compared with that of native enzyme. Thermal stability of the modified enzyme was increased. After treatment at 6$0^{\circ}C$ for 30min the activity remained 20% for the enzyme modified at pH 9.7 in the presence of $\alpha$-CD and tested in the presence of $\alpha$-CD 10% for the enzyme modified at pH 9.7 in the presence of $\alpha$-CD 0% for the native enzyme. The native enzyme and modified enzyme showed one peak in HPLC. The substrate specificity of the modified enzyme was not changed in HPLC analysis of reaction product.

• Mycobiology
• /
• v.37 no.4
• /
• pp.267-271
• /
• 2009

A fungal strain producing a high level of cellulase was selected from 320 fungal isolates and identified as Aspergillus sp. This strain was further improved for cellulase production by sequential treatments by two repeated rounds of $\gamma$-irradiation of $Co^{60}$, ultraviolet treatment and four repeated rounds of treatment with N-methyl-N'-nitro-N-nitrosoguanidine. The best mutant strain, Aspergillus sp. XTG-4, was selected after screening and the activities of carboxymethyl cellulase, filter paper cellulase and $\beta$-glucosidase of the cellulase were improved by 2.03-, 3.20-, and 1.80-fold, respectively, when compared to the wild type strain. After being subcultured 19 times, the enzyme production of the mutant Aspergillus sp. XTG-4s was stable.

• The Korean Journal of Mycology
• /
• v.5 no.1
• /
• pp.7-12
• /
• 1977

For this study 3 samples of the home-made meju and 3 samples of the improved meju were selected according to their characteristics. A total of 25 strains of true fungi were isolated from the samples of the home-made meju and identified by the Key of Alexopoulos and Raper, using a strain Aspergillus oryzae A-113 as a control. Amylolytic and proteolytic enzyme activities of the isolated strains were investigated ana the results obtained were as follows. 1. The 25 strains from the home-made meju were identified into 2 Aspergillus oryzae, 14 Asp. flavus, 6 Penicillum spp. 1 Candida sp 1 Spicaria sp and 1 Rhizopus sp. 2. The 3 strains from the improved meju were all identified as Aspergillus oryzae. 3. Aspergillus flavus, A-B, from the home-made meju was found to he the strongest strain in ${\alpha}-amylase$ activity and also to be similar to the strains of Aspergillus orzae from improved meju. 4. Aspergillus flavus, A-7, from the home-made meju was found to be the strogest strain in ${\beta}-amylase$ activity and stronger than that from the improved meju. 5. Aspergillus flavus B-3, was found to be the strongest strain in protease activity and stronger than that from the improved meju. 6. Some of the strains from the home-made meju turned out to be harmful strains, such as Penicillium spp. which secrete antibiotics, Asp. flavus which secretes mycotoxin, Candida sp which causes skin diseases, Spicaria sp. which is a insect pathogen. 7. Rhizopus sp was also found but it has not been proved to be harmful.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.873-876
• /
• 1999

Aspergillus sp. CX-l strain grown on microcrystalline cellulose resulted in the accumulation of high levels of cellulase and xylanase activities that were higher by two to four folds than those from the conventional commercial producer, Trichoderma reesei QM9414. Aspergillus sp. CX-1 demonstrated greater thermo stability and better catalytic characteristics of total cellulase activity (FPase) as compared to T. reesei and Aspergillus niger F-2039.

• Journal of Life Science
• /
• v.21 no.7
• /
• pp.992-996
• /
• 2011

Endophytic fungi were isolated from the roots of plants growing naturally on the island of Dokdo. Plant samples, such as Miscanthus sinensis, Achyranthus japonica and Echinochloa crusgali were isolated from Dongdo, and those such as Honkenya peploides and Artemsia koidzumii were isolated from Seodo. Twenty one strains of endophytic fungi were isolated from these plants. To identify the strains, PCR (polymerase chain reaction) amplification of the partial ITS (Internal Transcribed Spacer) regions was done with universal primers ITS-1 and ITS-4 to determine the nucleotide sequence of the ITS regions. Of the strains isolated from Miscanthus sinensis, 75% were Penicillium sp. and 25% were Aspergillus sp. Fifty five percent of strains isolated from Achyranthus japonica were Penicillium sp., 30% were Aspergillus sp. and 15% were Zygorhynchus sp. Strains isolated from Echinochloa crusgali were Penicillium sp. (50%), Aspergillus sp. (12%), Giberella sp. (13%), Talaromyces sp. (9%) and Umbelopsis sp. (8%). Of the strains isolated from Honkenya peploides, 76% were Penicillium sp. and 24% were Pestalotiopsis sp. Strains isolated from Artemisia koidzumii were Penicillium sp. (81%) and Mucor sp. (19%). As a result of bioassay, Ec-3-1 strain isolated from Echinochloa crusgalli showed plant growth-promotion activity. Of all the endophytic fungi isolated, Penicillium sp. was the most abundantly distributed fungal strain in all plants used in this study.

• Korean Journal of Soil Science and Fertilizer
• /
• v.28 no.3
• /
• pp.278-286
• /
• 1995

Phosphate-solubilizing microorganisms were isolated from agricultural area in Korea, and the solubilizing potential of microorganisms was evaluated in vitro. Of the several microorganisms Pseudomonas putida, Penicillium sp., and Aspergillus niger showed solubilization in all phosphatic compounds such as hydroxyapatite, tricalcium phosphate, aluminium phosphate and rock phosphate tested. Inorganic P solubilization was directly related to the pH drop by each microorganisms. Aspergillus niger was found to be more active in solubilizing phosphate than Pseudomonas putida and Penicillium sp.. The maximum concentration of phosphorus released from each of aluminium phosphate, hydroxyapatite and tri-calcium phosphate by Aspergillus niger in liquid culture was 776ppm, 665ppm and 593ppm, respectively when $KNO_3$ was added as nitrogen source. For rock phosphate, it was 411ppm with ammonium sulfate as nitrogen source.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.5
• /
• pp.636-642
• /
• 1993

To improve the quality of mirin, various molds were screened for mutants with high acid carboxypeptidase (ACPase) by the method of ultraviolet radiation. Mutants, Aspergillus oryzae 9-12 and Aspergillus shiroussamii 6082-60 showed activities of ACPase about 2~6 times higher than their parent strains. Aspergillus oryzae 9-12 and Aspergillus shirosamii 6082-60 were the most suitable strains for preparing koji in mirin by the conventional or improved methods. The results showed that total sugar, reducing sugar and total nitrogen were almost the same values in mirin prepared by both methods. The yield of mirin was higher in the improved method than in the conventional method. The clouding formation of mirin appeared in the conventional method ; however, mirin prepared with the mutant koji by the improved method did not show clouding formation.

• Microbiology and Biotechnology Letters
• /
• v.8 no.4
• /
• pp.237-245
• /
• 1980

Microorganisms growing on Dried-Persimmon have heed isolated ana identified. Fluorescent substance were extracted from a putrefactive Dried-Persimmon after invaded Toxigenic Fungi, and compared with Aflatoxin by Thin layer chromatography and u. v. absorption spectra. The results obtained were summarized as follows: 1) Fungal invasion was frequently appeared at the beginning of storage, and after then Bacteria invasion was followed. 2) Several Genera of microorganisms (Aspergillus sp., Escherichia sp., Mucor sp., Alternaria sp., Penicillium sp. ) were observed in Dried-persimmon during storage. Aspergillus sp., one of all Genus was predominant. 3) Two strains (Aspergillus flavus Group, Penicillium citrimum Series) of 6 Fungi had Fluorescent substance, which was presumed Aflatoxin-like substance. 4) The Rf value of T. L. C. ana λ max of u. v. absorption spectra showed the same value as the standard of Aflatoxin. It is suppose that the Fluorescent substance in Dried-Persimmon is a Aflatoxin-like substance.

• Microbiology and Biotechnology Letters
• /
• v.38 no.4
• /
• pp.373-378
• /
• 2010

Studies on standardization and quality upgrade of nuruk which is a basic component in brewing are required to increase the quality level of Korean traditional rice wines and to develop the technology for practical use of it. It is important to isolate best strains, to improve the properties and effectively preserve them for brewing industry. In this study, 16 commercial nuruk samples were obtained from the commercial markets located in Chungcheong areas in Korea. 174 fungal strains were isolated from the samples on DG18 medium using a dilution plating method and then screened for enzyme activity and acid production. The active strains were identified based on the morphological characteristics and ITS sequence analysis. Out of 174 strains, 12 strains showed high amylase activity. Especially, Rhizopus sp. CN084, CN174, Aspergillus sp. CN161 and Mycocladus sp. CN042 showed high saccharogenic power and dextrinogenic enzyme activity on cooked wheat bran medium. On the other hand, Aspergillus sp. CN010, CN161, Rhizopus sp. CN105, CN168 and Rhizomucor sp. CN088 produced high acid production on the same medium. Our results showed that the active strains may be used as microbial sources for nuruk starter with good quality in brewing.