• KSBB Journal
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• v.10 no.1
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• pp.78-88
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• 1995

The encapsulatpd A. niger grew up inside the capsule and mycelia penetrated through the pore of the capsule membrane. The mycelia on the capsule wall became loose when the carbon source and oxygen were deficient in the medium. On the contrary, the production rate increased and mycelia made a lump tightly when the carbon source and oxygen were sufficient. Namely, number of proper capsule of unit volume in the medium was existed. The phenomenon which was swelled of capsule membrane in cultivation could prevented by adding CaCl2 into the medium. According to the time adding CaCl2 into the medium, the production rate of citric acid was influenced. In case of adding CaCl2 into the medium at 7th day cultivation, the production yield of citric acid was increased about 40 percent higher than that of adding CaCl2 initially. The production yield of citric acid using encapsulated A. niger of flask culture was influenced with oxygen supply. The production yield of citric acid ($\Delta$p/$\Delta$s) of the flask culture was increased 3.88 time by using T-flask instead of parafilm sealed flask. Therefore, the productivity and consumption rate concerning production which was taken carbon source were increased when oxygen supply was sufficient. The production of citric acid using encapsulated A. niger was increased average 30 percent higher than that of bead in between 6th and 13th day cultivation.

• The Korean Journal of Mycology
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• v.14 no.2
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• pp.165-174
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• 1986

Conditions for production, fusion and reversion of protoplasts of Aspergillus niger were investigated, and an attempt was made to enhance fusion frequency. Auxotrophic mutants and morphological mutants were induced by U.V. irradiation $(9.9\;erg/mm^2,\;13min)$ on Aspergillus niger. Maximum yield of protoplasts was obtained from 21 hr cultured mycelia by using 1% driselase in 0.6 M KCl or 0.6 M $NH_4Cl$ as osmotic stabilizer. The optimal temperature for mycelium digestion was $30^{\circ}C$, and the optimal pH was 6.0. Protoplasts produced at different digestion period showed heterogeneity in size and vacuole content. Maximal frequency of protoplasts reversion was obtained on 0.6 M KCl stabilized agar medium at pH 5.0. Reversion frequencies of protoplasts produced for 3 hr and 1 hr mycelial digestion were 8.0% and 15.3%, respectively. The optimal concentration of PEG(m.w. 6000) for protoplast fusion was 30%, and that of $CaCl_2$ was $1{\sim}50\;mM$. The optimal pH and period for the reaction of PEG solution were 8.0 and 10 minutes, respectively. Fusion frequencies between auxotrophic protoplasts produced for 3 hr-mycelial digestion were $0.06{\sim}0.42%$, and those for 1 hr-mycelial digestion were $0.09{\sim}0.54%$.

• 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.

• KSBB Journal
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• v.14 no.6
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• pp.672-676
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• 1999

Encapsulated Aspergillus niger was prepared in order to inspect the effect of oxygen supply on the production of citric acid. A. niger cells which had been immobilized in the calcium alginate capsule grew and mycellia penetrated through the capsule membrane after two days of cultivation and covered over all of the capsule after eight days. The mycellia became loose when the nitrogen source was sufficient of oxygen was deficient. The larger amount of encapsulated cells were put into a given growth medium, the smaller quantity of citric acid was produced. The increase of volumetric oxygen transfer coefficient from 1.8 $hr^-$ to 2.55 $hr^-$ in the flask culture accelerated cell growth rate but did not influence the production of citric acid. The high oxygen supply rate($k_La:\;150\;hr^-$) in the concentric air lift reactor hastened the growth of cells and hindered the production of the citric acid. The reduction of nitrogen source level in the growth medium in the concentric air lift reactor increased citric acid production by 40 percent of that of flask cultivation and the culture period was shortened by 3 days. The variation of the geometry of the concentric air lift reactor did not influence the growth rate of encapsulated cells and production rate of citric acid.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.29-34
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• 1970

In order to prepare digested Protein source for the Weanling Food from soybean, an attempt was made to decompose steamed soybean protein to amino acids and peptides by protease and cellulase produced from Aspergillus niger and Aspergillus sojae. In this paper, the optimum condition for digestion of soybean protein were studied and also investigated the effects of decolorization of it. As the results, followings were obtained; 1. As steaming conditions, a treatment under 15 lb of pressure and 10 minutes of heating shows most effective. 2. The optimum pH of Asp, sojae enzyme for the digestion of soybean protein is 6.0, while that of Asp. niger enzyme is 4.4. In successievly-decomposing with Asp. sojae and Asp. niger, it shows the most effective on ratio of water-soluble-nitrogen to total nitrogen and amino-nitrogen to total nitrogen than any other separate treatments. 3. The suitable amount of the enzyme solution to that of the soybean substrate paste, in volume, is 1 : 2. 4. Digestion ratio of soybean protein indicates the gradual and steady effects of increasing time of digestion, but 8 hour-digestion regarding to putrefaction was suitable. 5. The most effective decolorization was successively passed on culumns of active carbon and anion exchanger (Dowex 2-x-8) at room temperature. In separate treatments, the effective order of decolorization was as follows; (Dowex 2-x-8)>Active carborn>Amberite IR-120 6. The powder type of the soy protein source obtained by concentration below $60^{\circ}C$ contains 12.51% of moisture, 66.31% of protein, 4.25% of fat, 12.75% of carbohydrate, 4.18% of ash.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.255-263
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• 2014

Objectives: This study evaluated the fungicidal efficacy of a fumigant containing 20% ortho-phenylphenol against Trichophytone mentagrophytes (T. mentagrophytes), Candida albicans (C. albicans) and Aspergillus niger (A. niger). Methods: Five replicates of each carrier were contaminated by depositing 0.05 mL of each fungal suspension. After drying, two carriers without exposure to the fumigant and three carriers with exposure to the fumigant were left in a sealed room ($25m^3$) at $21{\pm}0.5^{\circ}C$ and $60{\pm}10%$ relative humidity for 15 hours. Immediately after removal from the test room, each carrier was transferred into recovery diluent and suspended, diluted and inoculated. After incubation, the numbers of each colony were counted, and the parameter values (N, T, d) were calculated. Results: The working culture suspension number (N value) of T. mentagrophytes, C. albicans and A. niger were $1.0{\times}10^8$, $1.2{\times}10^8$ and $5.7{\times}10^7CFU/mL$, respectively. All the colony numbers on the carriers exposed to the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of fungal test suspensions by pour plate method), 0.5N2 (the number of fungal test suspensions by filter membrane method) and 0.5N1, respectively. In addition, all mean numbers of test strains recovered on the control-carriers (T value) were over $10^6CFU/mL$. For the fungicidal effect of the fumigant, all numbers of fungal reductions after exposure of the fumigant (d value) were 4 logCFU/mL. Conclusions: The present study showed that fumigant containing 20% ortho-phenylphenol has effective fungicidal activity against T. mentagrophytes, C. albicans and A. niger.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.295-302
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• 1989

This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was maked that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste $(S_0)$, soaked soybean-soypaste $(S_1)$, roasted soybean-soypaste $(S_2)$, and steamed soybean-soypaste $(S_3)$ from soybean (60%), rice koji (30%) and salt (10%) respectively in order to investigate the changes of enzymes activity(amylase, protease, lipase and lipoxygenase activity) during fermentation of them. The results obtained were summarized as follows; Amylase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_2>S_3$ in the soybean treatments. Protease activity was in the order of natural fermented microorganisms>Asp. niger>Asp. oryzae>Asp. awamori in the microorganisms, and $S_3>S_2>S_1>S_0$ in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of $S_0>S_1>S_3>S_2$ in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_3>S_2$ in the treatments.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.237-241
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• 2005

Scopolamine and hyoscyamine are important anticholinergic compounds obtained from Hyoscyamus niger. Adventitious roots induced from rhizome of H. niger and roots were cultured in SH medium supplemented with 3% (w/v) sucrose and 0.5 mg/L IBA. Roots were grown rapidly after 10 days of cultures. Scopolamine production was increased 7 times and hyoscyamine production was increased 12 times after 10 day of cultures. SH medium was best in root growth. But, highest scopolamine productivity was observed in WPM medium, followed White medium and best hyoscyamine productivity was resulted in MS medium. Sucrose was increased scopolamine and hyoscyamine production were increased the medium supplemented by sucrose comparing to than those by other carbon sources.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.111-117
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• 1974

Studies were carried out on the practical use of Naringinase and some chracteristics of Naringin solublizing enzme which might hydrolyae naringin to purunin. Obtained results were as follows. 1. Selected strain for Naringinase producing was identified to be Aspergillus niger S-1 and its naringinase was applied to chinese citron processing to remove the bitter taste. 2. Of the naringinase, naringin solubilizing enzyme was purified on a DEAE-Sephadex A-50 column and crystalized from acetone and ammonium sulfate. 3. Hydrolized naringin which has higher solubility rather than naringin or naringenin were identified by thin layer chromatography. 4. Hydrolyzed naringin and naringin were separatly determinated by ethylacetate extraction and this result was compared with sensory test.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.140-146
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• 1991

Mutation experiments were performed to select the mutant of Aspergillus niger 55, which had lost almost all the ability to produce transglucosidases but retained that of high productivity of raw meal saccharifying enzyme, by means of successive induction with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), ultraviolet(UV) light, and ${\gamma}$-rays. Also, we used the mutant enrichment techniques, such as liquid culture-filtration procedure and differential heat sensitivity of conidia, in order to increase the possibility of obtaining a mutant. The glucoamylase productivity of mutant PFST-38 was 11 times higher than that of the parent strain. The mutant PFST-38 was morphologically identical to the parent strain, except for the size of conidia, the tendency to form conidia and the lenght of conidiophore. Asp. niger mutant PFST-38 apeared to be useful for the submerged production of the raw corn meal saccharifying enzyme.