• The Korean Journal of Food And Nutrition
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• v.6 no.4
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• pp.294-300
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• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of saccharogenic amylase during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Tikju and Yakju in Korea. The optimum cultural temperature for the production of saccharogenic amylase by this mold was 36$^{\circ}C$, and at this temperature it needed 40 hours of cultivation for maximum production of this enzyme. It was favorable for high production of both organic acid and saccharogenic amylase to shift the cultural temperature form initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. The production of saccharogenic amylase was low when the water content of steamed rice was below 35%, but its production was high at 40~60% of water content. When the quantity of conidial inoculation was too small, the production of saccharogenic amylase was low in initial phase, but it was retrived after 40 hours of cultivation. When koji-thickness was over 3cm, the production of saccharogenic amylase was markedly restricted. The saccharogenic amylase of this koji was stable at pH 2~7, and showed high activity at pH 2~5.

• Korean Journal of Microbiology
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• v.11 no.2
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• pp.89-100
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• 1973

Dextrinogenic and saccharogenic amylase activities of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their amylase activities are surveyed from taxnomical, ecological, and physiological viewpoints. Among the 151 strains of Rhizopus, strain number 49 exhibiting most prominent saccharogenic amylase activity is selected as a best strain, and strain number 17 is selected as a best strain for dextrinogenic amylase activity. Amylase activities of Rhizopus are so variable in different strains even in the same species. In general, however, R. japonicus, R. liquefaciens, and R. shanghaiensis show high saccharogenic amylase activities, and R.chiuniang, R.achlamydosporus, and R.bahrnensis show high dextrinogenic amylase activities, while R.nigricans exhibits lower activities for both amylase. The strains isolated from kneaded cereals, such as "meju" and "kockja", exhibited very strong dextrinogenic and saccharogenic amylase activities as compared with the strains isolated from other sunstrates. The mean value of dextrinogenic amylase activities of the strains from southern inland region and saccharogenic amylase activities of the strains from middle coast region are, more or less, higher than those of the strains from the other regions. In the culture at 30.deg.C, those strains which exhibit better mycelial and air mycelial growth than sporangial formation show very high dextrinogenic and saccharogenic amylase activities. amylase activities.

• The Korean Journal of Food And Nutrition
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• v.7 no.1
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• pp.51-57
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• 1994

A nuluk, a Korean traditional koji for brewing, was made with wheat flour and Aspergillus usamii mot. shirousamii S1 which had strong abilities in producing amylase and protease. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivities of saccharogenic and dextrogenic enzymes were improved when nuluk was made with unsteamed wheat flour as compared with steamed one, but those of proteolytic enzyme and organic acid were reduced. The addition of water containing 0.5% of hydrochloric acid was unfavorable for the production of saccharogenic, dextrogenic and proteolytic enzymes. The optimum ratios of water added to wheat flour for the production of saccharogenic enzyme and proteolytic enzyme were 32% and 28%, respectively on the basis of wheat flour. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively. The activity of saccharogenic enzyme reached its maximum after 120 hours of cultivation at 36$^{\circ}C$, but that of proteolytic enzyme 96 hours. The productivity of saccharogenic enzyme was enhanced when the nuluk was molded after 24 hours of precultivation but that of proteolytic enzyme was reduced as compared with no molding.

• The Korean Journal of Food And Nutrition
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• v.6 no.2
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• pp.96-102
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• 1993

A Nuluk, a Korean traditional koji for brewing, was made with wheat flour and Rhizopus japonicus T2 which had a good aroma and strong abilities in producing saccharogenic and proteolytic enzymes, and cultural conditions for the production of those two enzymes were tested. The productivity of saccharogenic enzyme was markedly improved when Nuluk was made with unsteamed wheat flour as compared with that with steamed one, but that of acid protease was reduced. The addition of water containing 0.5% hydrochloric acid was unfavorable for the production of saccharogenic enzyme and neutral protease. The optimum ratio of water added to wheat flour for the production of saccharogenic enzyme and proteolytic enzyme was 28% on the basis of wheat flour. The productivity of saccharogenic enzyme was enhanced "when the Nuluk was molded after 10~20 hours precultivation but that of proteolytic enzyme was reduced as compared with no molding. The optimum temperature for the production of saccharogenic enzyme was 28f and that of proteolyic enzyme was also 28$^{\circ}C$. The optimum cultural time for the production of saccharogenic enzyme was 36 ~72 hours at 3$0^{\circ}C$ and that of proteolytic enzyme was 36 hours.ours.

• The Korean Journal of Food And Nutrition
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• v.6 no.2
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• pp.89-95
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• 1993

A Nuluk, a Korean traditional Koji for brewing, was made with wheat flour and Aspergillus oryzae L2 which had a good aroma and strong abilities In producing saccharogenic and dextrogenic enzymes. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivity of dextrogenic enzyme was improved when Nuluk was made with unsteamed wheat flour as compared with steamed one, but that of proteolytic enzyme was reduced. The addition of water containing 0.5% hydrochloric acid was unfavorable for the production of those two enzymes. The optimum ratio of water added to wheat flour for the production of those two enzymes was 28$^{\circ}C$ on the basis of wheat flour, The productivity of saccharogenic enzyme was enhanced when the Nuluk was molded after 20 hours of precultivation, but that of proteolytic enzyme was reduced as compared with no molding. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively.

• Journal of Microbiology
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• v.43 no.6
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• pp.561-568
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• 2005

A newly-isolated thermophilic strain of the zygomycete fungus Rhizomucor pusillus 13.36 produced highly active dextrinogenic and saccharogenic enzymes. Cassava pulp was a good alternative substrate for amylase production. Dextrinogenic and saccharogenic amylases exhibited optimum activities at a pH of 4.0-4.5 and 5.0 respectively and at a temperature of $75^{\circ}C$. The enzymes were highly thermostable, with no detectable loss of saccharogenic or dextrinogenic activity after 1 hand 6 h at $60^{\circ}C$, respectively. The saccharogenic activity was inhibited by $Ca^{2+}$ while the dextrinogenic was indifferent to this ion. Both activities were inhibited by $Fe^{2+}\;and\;Cu^{2+}$ Hydrolysis of soluble starch by the crude enzyme yielded $66\%$ glucose, $19.5\%$ maltose, $7.7\%$ maltotriose and $6.6\%$ oligosaccharides.

• Mycobiology
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• v.39 no.4
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• pp.278-282
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• 2011

The objective of this study was to find useful fungi with ${\alpha}$-amylase activity from the Korean traditional nuruk for the quality of traditional Korean alcoholic beverage. In this study, 165 samples of traditional nuruk were collected from 170 regions throughout Korea and the fungi were isolated to a total of 384 strains. In order to investigate the effect of microflora on nuruk, ${\alpha}$-amylase activity, saccharogenic power (SP), starch hydrolysis activity and acid producing activity were evaluated. Ten strains were selected by ${\alpha}$-amylase activity, which ranged from 458.47 to 1,202.75 U/g. The size of the discolored zone for the starch hydrolysis activity of each fungus ranged from 0.3 to 2 cm. The SP of the 10 strains ranged from 228.8 to 433.4 SP. Of the 10 stains, three were identified as Aspergillus oryzae, two as Aspergillus flavus, two as Lichtheimia sp., one as Rhizopus oryzae and two as other strains. The total aflatoxins present in the nuruks were examined using enzyme-linked immunosorbent assay. The 10 nuruks had less than 1.11 ppb of aflatoxins.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.231-235
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• 1970

1. Purification of amylase system produced from Humicola sp. by a submerged culture eras carried out. 2. By DEAE-Cellulose column chromatography amylase system was separated into two fractions eluted at 0.05M and 0.5M phosphate buffer solution of pH 6.0. 3. The saccharogenic amylase was mostly composed of. the fraction of 0.05M phosphate buffer solution of pH 6.0 while the dextrinogenic amylase was perseted in fraction of 0.5M phosphate buffer solution of pH 6.0 4. It was found that the optimum pH of this saccharogenic amylase was within the range of from 4.5 to 5.5, stable pH was within the range of from 4.0 to 9.0 and optimum temperature was $60-65^{\circ}C$. This amylase was stable at $70^{\circ}C$ for ten minutes but completely inactivated $80^{\circ}C$ above.

• Korean Journal of Microbiology
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• v.3 no.2
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• pp.9-14
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• 1965

The enzyme-producing potentials of industrially important strains of Aspergillus spp. were studied. Irradiation of three original isolates of Aspergillus oryzae to ultra-violet rays resulted in the production of mutants which differed from the parent riboflavin and vitamin $B_{12}$ in culture media. 1. Irradition three strains of Aspergillus oryzae to ultraviolet light produced mutants and two strains of them were selected for soy sauce brewing. 2. The two strains are the physiological mutants of Aspergillus oryzae. Both were found to have superior enzyme activity to their relatives. 3. Aspergillus oryzae UV-induced mutant 172-722 and 569-713 were more powerful than others in the production of riboflavin and vitamin $B_{12}$. The enzyme activity of these strain were high and decreased only slightly even in 20 percent solution of NaCl. 4. Aspergillus oryzae UV-induced mutant 172-722 had more powerful protease producibility in wheat bran media than in modified Czapek's solution. On the contrary, Aspergillus oryzae UV-induced mutant 569-713 had more powerful producibility of saccharogenic and dextrinogenic amylase in modified Czapek's solution than in mold bran. 5. Aspergillus oryzae UV-induced mutant 172-722 formed the spore rapidly and Aspergillus oryzae UV-induced mutant 569-713 did ordinarily. 6. It is found from the results that Aspergillus oryzae UV-induced mutant 172-722 is valuable material for the manufacture of soy sauce because of its high protease activity in 20 percent solution of NaCl. Aspergillus oryzae UV-induced mutant 569-713 is suitable for soy bean mash and for fermented red pepper sauce for its high saccharogenic and dextrinogenic amylase activity in 20 percent solution of sodium chloride.

• Applied Biological Chemistry
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• v.8
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• pp.45-50
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• 1967

Starch was liquefied by the bacteriological ${\alpha}-amylase$ and saccharified separately by four strains of mold as saccharogenic enzymes, then thise was fermented for research the fermentation rates, the usefulness of application of four strains of mold and the S.P to need in proportion increasing of concentration of mixed-starches for brewing in this experiment. The obtained results were as follows: 1) In the ability of saccharificatien, fermentation and acid resistance, Aspergillus usamii mut shirousamii, which were used to produce the koji, were excellent, however, Rhizopus delemar had heavy pollution in a lot of production of koji, were-as its qualities as enzyme was good. 2) The necessary S.P in proportion to the concentration of mixed-starch for brewing was found in this experiment in which was fermented in the various concentration of the adding S.P and the mixed-starches for brewing. 3) In the experiment of almost manufacture scale, the S.P needed essentially in the saccharogenic formentation was found and the usefulness of the necessary S.P was observed, and in fact in the manufacture scale it was safer to add the S.P more than 1.2% because it must be considered that the ability of enzymes is reduced by heat or acid. 4) The period of fermentation was shorten because the conditions for yeast propagation were excellent as a results of starches being liquefied by bacteriological amylase, and saccharified by molds as saccharogenic enzymes.