• The Korean Journal of Mycology
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• v.6 no.2
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• pp.1-10
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• 1978

In de novo biosynthesis of the extracellulor enzymes-proteinsaes, alpha and gluc-amylases during the synchronized differentiation of Aspergillus niger in submerged culture and surface liquid culture were investigated. Gluc-amylase was synthesized in the stage of presporulation in which phialide formation is involved. Proteinase was synthesized both in the stages of conidiophore formation and presporulation. Alpha-amylase was synthesized during presporulation and sporulation stages, the activity of enzyme lasted for seven days on surface liquid culture. It seemed that the synthesis was occured in de novo partly repressed by the catabolite, and its nature was found to be constitutive since it is produced in non-starch medium. Polyacrylamide gel electrophoresis have shown that presporulating and sporulating body produced diverse types of the proteins whereas the earlier stages of vegetative body showed simpler profiles. The uptake of C-14 uracil into RNA and C-14 glutamate into protein were shown to be vigorous in presporulating body rather than those in sporulating body. Coincidence of alpha-amylase biosynthesis in de novo and sporulation may be significant in the study of differentiation in which gene expression is involved.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.13-18
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• 1978

In this study, enzymatic hydrolysis of the holocellulose from Alnus hirsuta (Spach) Rupr. (8-14 yr's) was investigated using crude cellulase preparations of Trichoderma viride Pers. ex. Fr. SANK 16374. And conducted on the optimum condition of the treated substrate for saccharification. A strain of Trichoderma viride Pers. ex. Fr. SANK 16374 was found to be highly efficient for the cellulase productivity, especially in the submerged culture process. The culture medium used in this experiment was prepared from an extract of wheat bran consisting also of $KH_2PO_410$, $(NH_4)_2$ $SO_4$ 3, $NaNO_3$ 3, and $MgSO_4$ $7H_2O$ 0.5g/l. Cellulose powder (Toyo filter paper, 60 mesh) was found to be an importent factar for inducing the cellulase formation. And the cellulase produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate (Fig. 1) Reducing sugar was determined by the Dinitrosalicylic acid (DNS) method, using reagents prepared according to the method of Sumner (1925). The results obtained were summerized as follows; 1. The method of delignification were treated by the Peracetic acid (PA) method, according to the method of Toyama (1970). The yield of holocellulose were decreased in accordance with increasing concentration of Peracetic acid solution; delignification of Alnus hirsuta Rupr. with 20% Peracetic acid was satisfied for 48 hours and 40%~60% peracetic acid was satisfied for 24 hrs: 2. The substrate (holocellulose) was changed easely into fine powder with enzymatic hydrolysis and cellulase exhibits optimum activity on the reducing sugar formation from substrate at the range of 60-100 mesh. 3. The reducing sugar formation increased in accordance with increasing dry temperature on holocellulose substrate was found to be $190{\pm}5^{\circ}C$. 4. The optimal heat treated time of holocellulose substrate was found to be 45 min. for the reducing sugar formation showed the best products. The reducing sugar formation did not show statisticaly significent diflerences at 5% levels by heat treated time for 45 min. and 60 min.

• The Korean Journal of Mycology
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• v.14 no.2
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• pp.131-139
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• 1986

Cultural and nutritional conditions for Lyophyllum decastes and its chemical composition in a synthetic medium were investigated. The optimal temperature and pH for the production of mycelium were $25^{\circ}C$ and pH 7.5. The mycelium yield was the highest on 15th day. Among the carbon sources, glucose and CMC were the best for the production of mycelium and their optimal concentrations were 3 and 6%, respectively. As an organic nitrogen, proteose peptone was the best and $(NH_4)_2HPO_4$ as an inorganic nitrogen was good. The optimal concentration of proteose peptone and $(NH_4)_2HPO_4$ were 2 and 0.2%, respectively. The optimal ratio of glucose to proteose peptone for production of mycelium was 10 : 1. Also, the optimal concentrations of $K_2HPO_4$ and $MgSO_4$ were 0.2 and 0.06%, respectively and that of $CaCl_2$ was 0.1%. Among the bioextracts, yeast extract was the most effective and its optimal concentration was 1.5%. In chemical components of the mycelium of Lyophyllum decastes, total sugar, crude protein and crude fat were 34.80, 28.35 and 2.50%, respectively. Its ash was 7.57% and crude fiber 11.99%.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.328-333
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• 2000

The spore of Aspergillus niger KCTC-6144 was immobilized on alginate gel beads. When pumpkin powder was used with glucose for a medium of citric acid fermentation by Aspergillus niger beads, the beaded Aspergilus niger grew up inside the bead and mycelia penetrated through the pore of the bead membrane. The bead size became largely from 2.0∼2.5mm to 6∼8mm after growing at 30$\^{C}$ for 4 days. Studies of optimum culture conditions on citric acid fermentation using Aspergillus niger beads on pumpkin medium (pumpkin powder 1% +glucose 7%, pH 6.0) were carried out in submerged cultures on 250m1 Erlenmeyer flask. As a result, it was found that to reinforce 12% as carbon source was good for citric acid production and that 1% pumpkin powder was good as nitrogen and mineral source in orbital shaker (150rpm) at 30$\^{C}$ for 5 days. The optimum initial pH on citric acid production was pH 6.0 and it was found that 100 beads of immobilized Aspergillus niger was adequate for citric acid production in a 250ml Erlenmeyer flask containing 50m3 of pumpkin medium solution with orbital shaker at 30$\^{C}$ for 5 days. We also found that maximal production of citric acid was 23.5g/ℓ at optimal condition (at 30$\^{C}$ for 5 days, pH 6.0, and 100 beads and medium containing 1% pumpkin powder plus 12% glucose).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.327-338
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• 2012

Liquiritigenin and isoliquiritigenin are the major flavonoids present in licorice. These flavonoid compounds were prepared by submerged culture of Grifola frondosa (G. frondosa) HB0071 mycelia producing ${\beta}$-glucosidase in the aqueous extract of licorice. The contents of liquiritigenin and isoliquiritigenin were increased during the fermentation. This fungus produced a high ${\beta}$-glucosidase (activity of 91.5 mU/mL), thereby achieving high amounts of liquiritigenin and isoliquiritigenin ($568.5{\mu}g/mL$ and $89.6{\mu}g/mL$), respectively at 96 h. A reversed- phase high-performance liquid chromatography method was established for simultaneous determination of liquiritigenin and isoliquiritigenin in fermented licorice extract (FLEx). The anti-inflammatory activities were investigated by licorice extract (LEx) before and after fermentation with G. frondosa HB0071. The treatment of UVB-irradiated HaCaT keratinocytes with FLEx resulted in a dose-dependent decrease in the expression level of cyclooxygenase-2 (COX-2) mRNA. Furthermore, FLEx dose-dependently decreased mRNA of the pro-inflammatory cytokines of IL-$1{\beta}$ and IL-6 in UVB-irradiated HaCaT cells. These results suggest that FLEx may mitigate the effects of skin inflammation by reducing UVB-induced adverse skin reactions.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.145-152
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• 1994

In order to investigate the cultural characteristics of Lentinus lepideus, media, pH, carbon sources, nitrogen sources, vitamin and organic acids were tested in submerged culture. It grew well in GPB(broth), and the optimum temperature and pH was $25^{\circ}C$ and 4.2, respectively. The carbon sources such as galactose belong to monosaccharide and maltose belong to disaccharide were effective for mycelial growth. Peptone which is compound nitrogen source was good for mycelial yield but the other nitrogen sources were not effective. Among the various vitamins, pyridoxine is suitable for mycelial yield. Among the various organic acids, citric acid promoted the mycelial yield but acetic acid interrupted the mycelial growth of L. lepideus.

• The Korean Journal of Mycology
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• v.15 no.2
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• pp.108-115
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• 1987

Nutritional characteristics and cultural conditions for trehalose synthesis and mycelial yield of Pleurotus sajor-caju and Pleurotus ostreatus 201 in submerged culture were investigated. The results were as follows: Among the carbon sources, glucose was most excellent for trehalose synthesis and mycelial yield. The optimal concentration of glucose was 1%. Among the nitrogen sources, peptone was most excellent for trehalose synthesis and mycelial yield. The optimal concentration of peptone was 0.05%. The optimal concentration of $KH_2PO_4$ and $MgSO_47H_2O$ for trehalose synthesis and mycelial yield was 0.1%,0.04% and 0.2%,0.04-0.08%, respective­ly. The optimal temperature and pH for trehalose synthesis were $25^{\circ}C$ and pH 5.5. but optimal temperature and pH for mycelial yield were $30^{\circ}C$ and pH 5.5. The maximum yield of trehalose was obtanined after 10 day cultivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.561-567
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• 1987

The purpose of this study was to find out the removal capacity of harmful ammonia by different filter media in the submerged biological filters in a given space of chamber. Four materials, pile cloth, corrugated skylight roofing plate, embossed plastic plate, and gravel, were used as the experimental filter media. Each filter medium was placed in two aquariums, each aquarium measuring $90cm\times60cm\times60cm\;(depth)$. Under the normal operating condition, the average of mean ammonia removal rates during the first and second functioning periods by each filter material which occupied tile space in the filter chamber (aquarium) was as follows: 1. Pile cloth: $8.381\;g{\cdot}m^{-3}.\;day^{-1}$ 2. Corrugated skylight roofing plate: $7.834\;g{\cdot}m^{-3}.\;day^{-1}$ 3. Embossed plastic plate: $7.797\;g{\cdot}m^{-3}.\;day^{-1}$ 4. Gravel: $7.051\;g{\cdot}m^{-3}.\;day^{-1}$ Thus, there were no significant differences between the media, but at the time of practical application of these materials, some other factors such as investment cost, easiness for the removal of excess detritus accumulated in tile interstices of filter media, etc. should be fallen into consideration. When large units are required, in particular, removal of excess detritus from tile gravel bed is extremely difficult, and in case of pile cloth filters the installation work is much complicated and a problem in supporting the structure when drained also exists. In these respects, corrugated skylight roofing plate and embossed plastic plate seem to be more optimal, but again in practice the local situation for the availability and the price of the materials should be rechecked and the fitness of tile materials in the particular filter chambers under use or under consideration for construction must be taken into account.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.350-354
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• 1985

For the purpose of studying the possibility to use the barley as a raw material in vinegar manufacturing process, several factors related to the fermentation of acetic acid were investigated. The optimum quantity of sweet liquor prepared by koji method in medium was 30-40%. When koji of A. oryzae, commercial enzyme products and malt were used for the saccharification of the barley, the production rates of acetic acid during log period were 0.056%/hr, 0.025%/hr, 0.03896/hr and lag period were 22 hours, 48.5 hours and 25 hours, respectively. These results indicate that the saccharifying method using koji of A. oryzae is superior to that by the commercial enzyme products or malt for the acetic acid fementation. The optimum initial acidity was 2% and the proper initial ethanol degree were 4-6% in metium. In a submerged culture process using a jar fermentor, lag period was 15 hours, and acetic acid fermetation period was about 45 hours. In the sensory test of barley vinegar and commercial vinegar of the market, barley vinegar was superior to the vinegar in market with respect to tastes.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.160-166
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• 2010

A homothallic filamentous fungus Aspergillus nidulans has been used as the a model organism for studying growth and development for eukaryotic system. Various studies about specific transcription factors have been performed for elucidating the molecular mechanisms of growth, asexual and sexual developmental processes. Among them, the fkhE gene (AN2025.3) is located in chromosome VII and contains an ORF encoding 718 amino acid polypeptide intervening with two short introns. The cDNA sequencing revealed that at least four types of alternative splicing events were occurred when the fkhE gene was transcribed. The putative FkhE polypeptide contains a conserved forkhead domain and a bipartite nuclear localization signal at it's N-terminus and C-terminus, respectively. Deletion of fkhE resulted in impaired conidiophore formation in a solid medium. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhE deletion mutant produced conidiophores and conidia under the submerged culture, indicating that the fkhE gene is involved in asexual developmental process similar to the fkhF gene.