• Applied Biological Chemistry
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• v.18 no.3
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• pp.109-116
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• 1975

In order to utilize the agricultural waste products for animal feeds, two high xylanase producing mold strains were selected from various sources of samples. The optimum conditions of xylanase production and the characteristics of the mold enzyme were investigated,and summarized as follows. 1. Two Aspergillus niger strains (experimental No. 1701 and 430) showed the high xylanase activity. 2. The highest xylanase production was obtained at pH 5.0-6.0 in two days. 3. Xylanase production in strain 1701 was increase with the addition of carboxy methyl cellulose, $NH_4H_2PO_4$ and corn steep liquor as carbon sources and natural nutrients, as respectively, while the other carbon, nitrogen, phosphate sources, natural nutrients and minerals gave no remarkable effect. In the strain 430, the enzyme procuction was not effected with the above substrate sources. 4. Maximum xylan hydrolysis reaction with the crude enzyme extract (33.3% v/v) was obtained in the 2% substrate concentration at pH 5.0 and $60^{\circ}C$ in three hours in both strains. 5. Maximum xylan hydrolysis rate was 95% at the optimum conditions for xylanase activity.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.877-888
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• 2023

We studied the proteolysis and conducted a sensory evaluation of fermented sausages using strains derived from Kimchi [Pediococcus pentosaceus-SMFM2021-GK1 (GK1); P. pentosaceus-SMFM2021-NK3 (NK3)], Doenjang [Debaryomyces hansenii-SMFM2021-D1 (D1)], and spontaneous fermented sausage [Penicillium nalgiovense-SMFM2021-S6 (S6)]. Fermented sausages were classified as commercial starter culture (CST), mixed with GK1, D1, and S6 (GKDS), and mixed with NK3, D1, and S6 (NKDS). The protein content and pH of GKDS and NKDS were significantly higher than those of CST on days 3 and 31, respectively (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the NKDS had higher molecular weight proteins than the GKDS and CST. The myofibrillar protein solubility of the GKDS and NKDS was significantly higher than that of the CST on day 31 (p<0.05). The GKDS displayed significantly higher pepsin and trypsin digestion than the NKDS on day 31 (p<0.05). The hardness, chewiness, gumminess, and cohesiveness of the GKDS were not significantly different from those of the CST. The GKDS exhibited the highest values for flavor, tenderness, texture, and overall acceptability. According to this study, sausages fermented using lactic acid bacteria (GK1), yeast (D1), and mold (S6) derived from Korean fermented foods displayed high proteolysis and excellent sensory evaluation results.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.283-288
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• 1995

This study was carried out to investigate the toxic action of herbicide, paraquat(1,1'-dimethyl-4,4'-bipyridylium-dichloride), against microorganisms. The toxic effect of paraquat was observed mainly using Escherichia coli(KCTC 1039), as follows; Growth of aerobic microorganisms which comprise 4 strains of bacteria and 2 strains of yeast and 4 strains of mold was inhibited drastically in the presence of 1.0mM paraquat But the growth of anaerobic bacteria was not affected by the chemical. When actively growing cells of E. coli were exposed to the paraquat at the concentration higher than 1.0 mM, they rapidly lost their ability to form colony and clearly formed inhibitory zone by well test More than 50% of the cells were killed by 1.0 mM paraquat treatment, even at immediate addition of paraquat to the medium.

• Korean Journal of Food Science and Technology
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• v.5 no.4
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• pp.224-230
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• 1973

The culture used wheat bran as media for four kind of mold strains such as Aspergillus oryzae, Aspergillus kawachii, Aspergillus usamii and Rhizopus javanicus to examine which strain could higher the activity of amylase most which is used for alcohol fermentation. It also provided three different kind of wheat bran media containing starch of 47%, 51% and 55% respectively for each strain. For each media it also added three different kind of nitrogen sources; ammonium sulfate, casein, and ammonium sulfate and casein equally mixed. Each nitrogen source added was subordinately differentiated into three different percentages, 2%, 4% and 6% respectively, except the 2% for the ammonium sulfate. The results obtained were summarized as follows (1) The activity of ${\alpha}-amylase$ was highest in the media of starch value 47% of wheat bran with 6% of casein added. (2) The activity of ${\beta}-amylase$ was highest in the media of starch value 51% of wheat bran with 2% of the equal mixture of ammonium sulfate and casein added. (3) The activities of both ${\alpha}-amylase$ and ${\beta}-amylase$ of Aspergillus usamii were highest in the media of starch value 47% wheat bran with no addition of nitrogen source. (4) Of the four strains examined, the activities of ${\alpha}-amylase$ and ${\beta}-amylase$ cultured in Rhizopus javanicus were both relatively higher. (5) The activities of ${\alpha}-amylase$ and ${\beta}-amylase$ of the strains examined became lower as the percentage of starch contents increased except in Rhizopus javanicus.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1038-1044
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• 1997

The mode of the combined effect of adipic acid and medium chain monoglycerides was investigated by using nine strain. Though monoglycerides alone had little antibacterial activity against gram negative strains, the combined use with adipic acid showed much higher activity against others of gram positive strains as well as gram negative strains. But exceptionally, it seemed difficult practically to prevent the growth of lactic acid bacteria completely by the combined use of adipic acid and monoglyceride. For yeast and mold, monoglycerides alone had a high activity but adipic acid had a little activity. In antibacterial mechanism, we thought that adipic acid acted on the cell envelope and then monoglyceride acted on the altered cell.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1142-1145
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• 1996

Long term-storage of citrus oranges after harvest has been hindered mainly by molds The goal of this research was to collect and identify those molds, which would help find a way to extend shelf-life after harvest. During the period of 1994 to 1995, fourteen different strains were isolated and purified from putrefied fruit (Citrus unshiu var.) that was stored at room temperature under open air. The storage disease was caused by the following molds: Penicillium italicum, 25.8%, Monilia candida, 19.8%; Alternaria citri, 18.1%; Mucor hiemalis, 11.0%; Phomopsis citri, 6.6%; Botrytis cinerea. 5.5%; Phoma citricarpa, 3.8%; Glomerella cingulata, 3.8%; P. digitatum, 1.1%; other molds, 4.5%; Most of the strains showed pectinolytic activity and putrefaction. These citrus fruit-putrefying molds will be used as target strains for the control of microorganisms during post-harvest storage.

• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.217-223
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• 1979

Six strains of mold which had high saccharifying and acid-productive ability were isolated from wild sources. The strain M-80 among them and Aspergillus kawachii, which was generally used as rice makkulli koji were used for this studies. The results obtained were summarized as follows. 1) $\alpha$-amylase activities of the strain M-80 and Asp, kawachii showed similarly as about 140W. V., while $\beta$-amylase activity of M-80 was 54 A. U. and Asp. kawachii was 40 A. U. 2) Acid protease activity of M-80 was higher then Asp. kawachii but alkaline protease activity was lower Asp. kawachii respectively. 3) The contents of total acid, ethanol and fusel oil in makkulli brewing with M-80 were higher those of Asp. kawachii and methanol contents of the tested two strains were about 33mg/％. 4) Fifteen kinds of free amino acid were detected from makkulli brewing of two strains, and free amino acid contents of M-80 were 10％ higher than those of Asp. kawachii.

• Mycobiology
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• v.51 no.3
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• pp.139-147
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• 2023

Aspergillus sojae has long been considered a domesticated strain of Aspergillus parasiticus. This study delineated relationships among the two species and an Aspergillus PWE36 isolate. Of 25 examined clustered aflatoxin genes of PWE36, 20 gene sequences were identical to those of A. sojae, but all had variations to those of A. parasiticus. Additionally, PWE36 developmental genes of conidiation and sclerotial formation, overall, shared higher degrees of nucleotide sequence identity with A. sojae genes than with A. parasiticus genes. Examination of defective cyclopiazonic acid gene clusters revealed that the PWE36 deletion pattern was identical only to those of A. sojae. Using A. sojae SMF134 genome sequence as a reference, visualization of locally collinear blocks indicated that PWE36 shared higher genome sequence homologies with A. sojae than with A. parasiticus. Phylogenetic inference based on genome-wide single nucleotide polymorphisms (SNPs) and total SNP counts showed that A. sojae strains formed a monophyletic clade and were clonal. Two (Argentinian and Ugandan) A. parasiticus isolates but not including an Ethiopian isolate formed a monophyletic clade, which showed that A. parasiticus population is genetically diverse and distant to A. sojae. PWE36 and A. sojae shared a most recent common ancestor (MRCA). The estimated divergence time for PWE36 and A. sojae was about 0.4 mya. Unlike Aspergillus oryzae, another koji mold that includes genetically diverse populations, the findings that current A. sojae strains formed a monophyletic group and shared the MRCA with PWE36 allow A. sojae to be continuously treated as a species for food safety reasons.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.709-734
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• 2001

The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerzing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity ($40.0{\times}25.0mm$, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly(methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued bench-curing up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at $50^{\circ}C$, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn: 1. The mean shrinkage strains reached $-3095{\mu}{\epsilon},\;-1796{\mu}{\epsilon}$ and $-2959{\mu}{\epsilon}$ for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached $56.7^{\circ}C,\;41.3^{\circ}C$ and $56.1^{\circ}C$ for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly(methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to $-31.8{\mu}{\epsilon}/sec,\;-15.9{\mu}{\epsilon}/sec$ and $-31.8{\mu}{\epsilon}/sec$ for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. From the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly(methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly(methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).

• Horticultural Science & Technology
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• v.31 no.6
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• pp.740-747
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• 2013

Leaf mold symptoms were found on commercial tomato cultivars carrying the Cf-9, a resistance gene to leaf mold pathogen Fulvia fulva in 2012 at Buyeo, Chungnam in Korea. Fifteen-fungal isolates were obtained from four Cf-9 cultivars of tomato including 'Cutie', 'otaerangdia', 'Unicorn' and 'Rapito'. Due to their same morphological appearances and colony color, nine isolates were selected and identified as F. fulva based on molecular analysis of the internal transcribed spacer rDNA sequence. Pathogenicity of the 15 isolates on five commercial cultivars carrying Cf-4, Cf-5, and Cf-9 were tested. All the isolates showed strong pathogenicity on Cf-9 cultivars, 'Cutie' and 'Dotaerangdia', and Cf-5 cultivar, 'Yoyocaptain'. In contrast, on Cf-4 cultivar, 'Superdotaerang', five isolates were virulent and the other isolates were not. In addition, two fungal isolates, infecting Cf-9 cultivar and non-infecting Cf-4 cultivar, were selected and their pathogenicity was tested on 17 commercial cultivars reported as tomato having Cf-9 resistance gene. Among them, 15 cultivars were susceptible and 2 cultivars were resistant. It is likely that the two cultivars include other resistance gene. To our knowledge, this is the first report on the occurrence of Cf-9 infecting F. fulfva strains in Korea.