• YAKHAK HOEJI
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• v.44 no.2
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• pp.197-203
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• 2000

The enzymatic properties of $\beta$-galactosidases from Aspergillus oryzae, bovine liver and Saccharomyces pragilis have been studied using enzyme-linked lectin assay based on the RC $A_{120}$ and BS-II lectins which specifically bind to terminal galactose and GlcNAc residue, respectively. Asialofetuin, a monomeric glycoprotein with approximately 48 kDa in molecular weight, was used as a substrate. This glycoprotein contains three N-linked triantennary complex type carbohydrate chains with each of which terminating in Ga1$\beta$P1 longrightarrow4G1cNAc (74%). Their optimal pHs were 3.5 and 6.5 (A. oryzae), and 3.5~5.5 (bovine liver and S. fragilis) at 37$^{\circ}C$ during 24 hrs, and the effective concentrations were 0.9, 2.9, and 1.7 mg/ml, respectively The enzyme from A oryzae requires 100 mM N $a^{+}$ or $K^{+}$, while the enzyme from bovine liver requires $Ba^{2+}$ for activity. However all of the three $\beta$-galactosidases were inactivated by SDS and C $u^{2+}$. These results indicate that the hydrolysis of glycoprotein such as asialofetuin depends on the reaction conditions of $\beta$-galactosidases and some metal ions. ions.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.217-224
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• 2021

Rice blast caused by Pyricularia oryzae, which is a major threat to food security worldwide, markedly decreases the yield of rice. Some rhizobacteria called 'plant growth-promoting rhizobacteria' inhibit plant pathogens and improve plant growth by secreting iron-chelating siderophores. The decreased availability of iron adversely affects the survival of pathogens, especially fungal pathogens, in the rhizosphere. This study aimed to determine the morphological diversity of siderophore-producing bacteria, analyze the type of siderophores produced by the bacteria, and examine their growth-inhibitory activity against Pyricularia oryzae. The rhizobacteria were isolated from the rhizosphere of Sembada Hitam variety of black rice plants in Pakem, Sleman, Yogyakarta, Indonesia. In total, 12 distinct isolates were screened for the production of siderophores. It was found that 9 out of 12 bacteria produced siderophore and most of them were Gram positive bacteria. The best siderophore-producing isolates with different type of siderophore were used in further studies. The IS3 and IS14 isolates were found to be the best siderophore producer that produced hydroxamate and mixed type of hydroxamate-carboxylate type of siderophore, respectively. In the dual culture assay, IS14 showed a strong antagonistic effect against Pyricularia oryzae by the 81.17% inhibition.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.191-200
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• 2014

Nuruk samples collected from various regions in Korea were investigated in terms of fungal contents and diversity. In measurement of colony forming unit (CFU) in Nuruk suspensions on DRBC agar, Nuruk samples MS4, MS8, and MS10 were among the highest fungal density, with $1,278.9{\pm}21.6$ (${\times}10^4$), $1,868.0{\pm}27.7$ (${\times}10^4$), and $775.1{\pm}19.2$ (${\times}10^4$) were among the samples showing the highest fungal density. CFU per 20 mg Nuruk, respectively. The majority of fungal components were yeasts, including Pichia anomala, P. kudriavzevii, Kluyveromyces marxianus, and Saccharomycopsis fibuligera, whereas Aspergillus oryzae and Rhizopus oryzae, the representative Nuruk fungi, were predominant only in the low fungal density Nuruks (MS2, MS5, and MS11). Saccharification capability of the fungal isolates was assessed by measurement of amylase activity in the culture broth. The highest amylase activity was found in A. niger and A. luchuensis, followed by S. fibuligera. A. oryzae and R. oryzae showed fair amylase activity but significantly lower than those of the three fungal species. R. oryzae was suggested to play an additional role in degradation of ${\beta}$-glucan in crop component of Nuruk since R. oryzae was the only fungus that showed ${\beta}$-glucanase activity among the fungal isolates. To confirm the safety of Nuruk, aflatoxigenicity of the isolated Aspergillus was estimated using the DNA markers norB-cypA, aflR, and omtA. All of the isolates turned out to be non-aflatoxigenic as evidenced by the deletion of gene markers, norB-cypA and aflR, and the absence of aflatoxin in the culture supernatants shown by TLC analysis.

• Mycobiology
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• v.45 no.2
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• pp.119-122
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• 2017

Herein, nuruks derived from non-glutinous and glutinous rice inoculated with Aspergillus oryzae N159-1 (having high alpha-amylase and beta-glucosidase activities) were used to produce Korean alcoholic beverages. The resultant beverages had enhanced fruity (ethyl caproate and isoamyl alcohol) and rose (2-phenethyl acetate and phenethyl alcohol) flavors and high taste scores.

• Korean Journal of Microbiology
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• v.6 no.2
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• pp.68-74
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• 1968

Effects of gibberellin on alpha and beta-amylase activities of Aspergillus orygae var. microsporus have been studied. Results obtained are as follows: 1. The growth of mycelium and dry weight of surface ped was accelerated by 0, 0001% gibberellin solution, spores of Aspergillus oryzae var. microsporus. were preveously soaked for three days. 2. Adding to culture media with 0, 0015% gibberellin, alpha-amylase was increased 50% much as beta-Amylase was as much as 50%.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.624-627
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• 2004

A bile acid derivative, methyl chalate （1）, was isolated from EtOAc extract of the fungus Rhizopus oryzae as a cholesterol biosynthesis inhibitor. It showed moderate inhibitory activity on cholesterol biosynthesis in human Chang liver cells. Compound 1 exhibited inhibitory effect on the later step of cholesterol biosynthesis, indicating that its action mode is different from that of statins that act on the HMG-CoA reductase.

• Food Science and Preservation
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• v.8 no.2
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• pp.199-205
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• 2001

Red mold was isolated from meju prepared by traditional mtehod and characterized. The isolated red mold grew well on potato dextrose agar medium, In microscopic observation, it had a septum in mycelium and ellipsoidal spore. Optimal temperature and pH for growth were 30$\^{C}$ and 6.0, respectively. Enzyme activities such as protease, a-amylase and glucoamulase in ted mold were lower than those in Aspergillus oryzae. A competitive growth between red mold and Asp. oryzae was greatly affecten by cultivation temperature. The growth of isolated red mold on meju was predominant at below 30$\^{C}$ as compared with Asp. oryzae.

• Research in Plant Disease
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• v.25 no.4
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• pp.205-212
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• 2019

Analysis of differentially expressed genes has assisted discovery of gene sets involved in particular biological processes. The purpose of this study was to identify genes involved in appressorium formation in the rice blast fungus Magnaporthe oryzae via analysis of cDNA-amplified fragment length polymorphisms. Amplification of appressorial and vegetative mycelial cDNAs using 28 primer combinations generated over 200 differentially expressed transcript-derived fragments (TDFs). TDFs were excised from gels, re-amplified by PCR, cloned, and sequenced. Forty-four of 52 clones analyzed corresponded to 42 genes. Quantitative real-time PCR showed that expression of 23 genes was up-regulated during appressorium formation, one of which was the MCK1 gene that had been shown to be involved in appressorium formation. This study will be providing valuable resources for identifying the genes such as pathogenicity-related genes in M. oryzae.

• Korean Journal of Microbiology
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• v.23 no.3
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• pp.209-214
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• 1985

The optimum conditions of protoplasts formation from Pyricularia oryzae were investigated with lytic enzymes and osmotic stabilizers. The mycelia were begun to refease the protoplasts in response to the complex enzyme solution after 30-60 minutes and reached to maximum after 2-3hrs. Among the lytic enzymes tested, the mixture solution containing ${\beta}-Glucuronidase$(0.01 ml/ml), Cellulase ONOZUKA-RS(20mg/ml), Driselase (10mg/ml), and Macerozyme R-10 (10mg/ml) resulted in the highest rate of protoplasts releasing of Pyricularia oryzae. The best stabilizer was 0.6M KCl at pH 7.0. Shen the mycelia were digested with enzyme mixture, the stationary culture was better than shaking culture for higher protoplast formation.

• Korean Journal of Microbiology
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• v.17 no.2
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• pp.58-64
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• 1979

Studies on some properties of cellulase isolated from Piricularia oryzae. Crude cellulases were prepared from dried rice plant powder (Tong-il, Pal-dal) culture of P. oryzae(N-2, C-8, T-2). The best yield of enzyme was obtained from the medium using Tong-il rice plant powder for P. oryzae cav. N-2 and 2%-sucrose concentration in preculture media. Two units of the enzyme were incubated at $60^{\circ}C$ for 1 hour with 1.0ml, 0.6% Na-CMC. The optimum temperature for the enzyme activity was at $60^{\circ}C$ and the optimum pH was at pH4.0. When Na-CMC was used as substrate the $K_m$ values of crude enzyme were calculated to be $1.05{\times}10^{-4}\;mM\;and\;V_{max}$ was 2.8 mmole/hour. A 10-fold partial purification was achieved by $(NH_4)_2SO_4$ precipitation followed by column chromatography on DEAE Sephadex A-25.