• Mycobiology
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• v.42 no.3
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• pp.291-295
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• 2014

Mycoflora was assessed in the commercial meju from four well-separated geographic origins. A total of 112 fungal isolates were identified by phenotypic characteristics and molecular taxonomy using sequencing the internal transcribed spacer of the rDNA and revealed 19 species from 13 genera. Enzymatic characteristics of protease and amylase, and mycotoxin production were analyzed.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.175-182
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• 1989

To find ${\alpha}-amylase$ inhibitors produced by microorganisms from soil, a strain which had a strong inhibitory activity against bacterial ${\alpha}-amylase$ was isolated from the soil sample collected in Korea. The morphological and physiological characteristics of this strain on several media and its utilization of carbon sources showed that it was one of Streptomyces species according to the International Streptomyces Project method. The amylase inhibitor of this strain was purified by active carbon adsorption, silicagel column chromatography, SP-Sephadex C-25 column chromatography, adsorption on Amberlite XAD-2. The inhibitor was oligosaccharide which was composed of glucose. The inhibitor had inhibitory activity against other amylase such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and gluco-amylase.

• Journal of the Korean Society of Food Culture
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• v.33 no.6
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• pp.580-587
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• 2018

The baking properties of rice bread with polydextrose (3, 6, and 9%), enzymes (0.006, 0.009, and 0.018%) and egg (1.32 and 2.64%) were investigated. The specific gravity and color (L, a, b) of the dough, as well as the appearance, color (L, a, b) and texture of the rice bread were analyzed. The springiness, chewiness, gumminess (p<0.01) and hardness (p<0.001) of the rice bread tended to increase as the amount of added polydextrose increased. Replacement of rice flour with hemicellulase, glucose oxidase and fungal amylase are effective for producing rice bread. Replacement of rice flour with 0.009% glucose oxidase and 0.006% fungal amylase had a significant effect on increasing the volume and decreasing the hardness of the rice bread (p<0.001). Replacement of rice flour with 1.32% egg white also had a significant effect on increasing the volume and decreasing the hardness of the rice bread (p<0.001). These results suggest that replacement of rice flour with 0.009% glucose oxidase and 0.006% fungal amylase, and 1.32% egg white are effective for producing rice bread with good volume and hardness.

• 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.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.283-289
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• 1994

The production of maltose utilizing swollen extrusion starch seems to have many technical advantages, such as, high reaction rate and high yield, production of high purity concentrated maltose, and low energy consumption, over the conventional method utilizing liquefied starch. The characteristics of maltose formation in heterogeneous enzyme reaction system comtaining swollen extrusion starch was investigated using fungal $\alpha $-amylase. The influence of extrusion conditions on structure of extruded starch, such as, degree of gelatinization, water absorption index, and water solubility index was analyzed. The relationship between the structural features and maltose forming reaction was investigated, and the result was analyzed in terms of surface reaction of insoluble extruded swollen starch. The characteristics of maltose formation from swollen sxtrusion starch was compared using endo-type fungal $\alpha $-amylase and exo-type $\beta $anylase, and the structural trasformation of extruded starch was also observed to clarify the reaction mechanism.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.290-295
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• 1991

Direct conversion of raw starch without liquefaction to maltose using maltose-forming fungal a-amylase (Fungamyl) was carried out in an agitated bead enzyme reactor (bioattritor). The reaction rate in bioattritor was comparable with conventional method which utilized liquefied soluble starch. Moreover the extent of maltose formation increased substantially compared with conventional method; from 150 g / I of raw starch, around 95 g/l of maltose was formed and 72% of maltose content in sugar mixture was achieved. Especially, pH influenced greatly not only on total sugar formation from raw starch in bioattritor but also on maltose content in sugar mixture. The optimal pH for maltose formation from raw starch was shifted into the weak alkaline pH, the optimal pH of 8.0~9.0 in bioattritor contrast to pH of 5.0~5.5 for liquefied starch. The maltose formation and content were also affected by the amounts of Fungamyl added and raw starch concentration. Consumption of maltose-forming Fungamyl can be substantially reduced by supplementary addition of starch liquefying a-amylase (Termamyl).

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• Archives of Pharmacal Research
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• v.8 no.2
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• pp.67-75
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• 1985

To find emylase inhibitors produced by microorganisms from soil, a strain which had a strong inhibitory activity against bacteria .alpha.-amylase was isolated from the soil smaple collected in Seoul. The morphological and physiological characteristics of this strain on several media and its utilization of carbon sources showed that it was one of Streptomyces specties according to the international Streptomyces Project method. The amylase inhibitor of this strain was purified by means of acetone precipitation, adsorption on Amberlite XAD-2, and column chromatography on Amberlite CG-50 and SP-Sephadex C-25. The inhibitor was stable at the pH range of 1-10 and at 100.deg.C for half an hour, and had inhibitory activities against other amylases such as salivary .alpha.-amylase, pancreatic .alpha.-amylase, fungal .alpha.-amylase and glucoamylase. The kinetic studies of the inhibitor showed that its inhibitory effect on starch hydrolysis by .alpha.-amylase was non-competitive.

• Mycobiology
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• v.34 no.3
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• pp.128-130
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• 2006

The solid waste of sago industry using cassava was fermented by Aspergillus niger, Aspergillus terreus and Rhizopus stolonifer in solid state fermentation. Cassava waste contained 52 per cent starch and 2.9 per cent protein by dry weight. The amylase activity was maintained at a high level and the highest amylase activity was observed on the $8^{th}$ day in R. stolonifer mediated fermentation. R. stolonifer was more efficient than Aspergillus niger and Aspergillus terreus in bioconverting cassava waste into fungal protein (90.24 mg/g) by saccharifying 70% starch and releasing 44.5% reducing sugars in eight days of solid state fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.751-758
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• 1997

Fifty three microbes, mainly fungal genera, were isolated from sixteen Mejus of different region. From those collected isolates, Meju was manufactured and assayed for the activities of amylase and protease. Correlations between sensory evaluation and color measurement were investigated with Kanjang (soy sauce) prepared by each pure inoculation. Color of Kanjang was quite various depedning on fungal genera, but the taste was not quite related with the activity of amylase or protease. This fact might mean that taste of Kanjang depended on the complicate mechanistic action of enzyme for the substrate involved in the soybean hydrolysis. Thus, the taste of Kanjang origenated from Korean traditional Meju seems to belong to complex flora of participated fungal genera as well as Bacillus. sp.