• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.195-203
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• 2021

Aureobasidium pullulans, a black yeast, produces pullulan, a linear α-glucan composed of maltotriose repeating units linked by α(1→6)-glycosidic linkages. Pullulan can be widely used in food, cosmetic, and biotechnology industries. In this study, we isolated eight strains of A. pullulans from Forsythia koreana, Magnolia kobus DC., Spiraea prunifolia var. simpliciflora, Cornus officinalis, Cerasus, and Hippophae rhamnoides. Among them, A. pullulans MR was selected as the best pullulan producer. The effects of a carbon source, a nitrogen source, and pH on pullulan production were examined. The optimal cultivation conditions for pullulan production by A. pullulans MR were determined by response surface methodology as 15% sucrose, 0.4% soy peptone, and an initial pH of 7 at 26℃. Under these conditions, the predicted pullulan production was 47.6 g/L, which was very close to the experimental data (48.9 g/L).

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.189-196
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• 2011

The objective of this study was to investigate the effects of light intensity and electrical conductivity (EC) of nutrient solution during short day treatment in an ebb and flow systems on the growth and nutrient uptake of potted Kalanchoe blossfeldiana 'Rako' and the nutrient accumulation of growing medium. Nutrient concentrations in the growing medium were also analyzed to investigate the accumulation rates of macro-nutrients such as T-N, P, K, Ca, and Mg, respectively. To achieve the objectives, plants were fed with a nutrient solution with 1.2, 1.8, or $2.4dS{\cdot}m^{-1}$ under three daily photosynthetic photon flux (PPF) of 4.26, 5.51, or $9.75mol{\cdot}m^{-2}{\cdot}d^{-1}$. Both light intensity and EC of nutrient solution significantly influenced the crop growth. The elevation of PPFs resulted in the increase of plant growth. For each light condition, plant growth, such as dry and fresh weight and leaf area, was the highest when the electrical conductivity of nutrient solution was controlled to $2.4dS{\cdot}m^{-1}$. However, growth was acceptable in the EC ranges from 1.8 to $2.4dS{\cdot}m^{-1}$. Both light intensity and EC of nutrient solution significantly influenced the uptake of nutrients in the solution tanks and the accumulation of nutrients in the growing medium. As the EC of nutrient solution was elevated, the absorption rates of $NO_3^-$, $PO_4^{-3}$, $K^+$, and $Mg^{2+}$ by crops and accumulation of those in growing medium increased, but the light intensity did not significantly influence the absorption rates. Based on the above results, the regression models were suggested for anticipating the macro-nutrient accumulations in growing medium.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.171-178
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• 1981

In order to develope the suitable processing method of new alcohol fermented milk beverage, the lactic acid bacteria and the yeast were inoculated to various level of saccharide added milk. And the change of component and alcohol concentration in beverage were analysed and tested. The results obtained were summarized as follows: 1. By skim milk media was fermented by the 5 strains of lactic acid bacteria for 24 hours, most suitable acidity was appeared in the Str. lactis fermented beverage as 0.83% and the amino nitrogen contents was not much changed as 0.2mg/ml. 2. By the skim milk was added with 5% glucose, lactose and sucrose respectively and fermented by the Str. lactis and Cruyveromyces fragilis, the acidity and amino nitrogen contents in beverage were not changed significantly, but alcohol concentration was increased from 2.5% to 3.58%. 3. By the 5% to 15% sucrose added skim milk media was fermented by Cruyveromyces fragilis and Saccharomyces cerevisiae, the amino nitrogen concentration was not so much changed by increasing sucrose contents. And the alcohol concentration was increased from 2.12% to 8.15% by Cruyveromyces fragilis fermentation and from 0% to 7.45% by S.accharomyces cerevisiae fermentation. 4. Sensory evaluation was better in the Cruyveromyces fragilis fermented beverage than Saccharomyces cerevisiae fermented beverage. 5. The contents of moisture, crude protein, ash and the concentrate of alcohol of Str. lactis and Cruyveromyces fragilis fermented skim milk beverage were much similar to koumis.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.408-412
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• 2009

Daily last time of irrigation in perlite bag culture was investigated to get high water use efficiency (WUE) and fertilizer use efficiency (FUE) and also sustain high productivity for tomato. The water content in the substrate was higher as the last time of irrigation was later from 4 to 1hour before sunset. The growth were not significantly different in all treatments. The marketable yield was the highest in treatments of 1 or 2hours before sunset and the lowest in treatment of 4hours. In the result to investigate for 128days WUE and FUE were the lowest in treatment of 1hour before sunset but the highest in treatment of 3hours before sunset. In the conclusion, it looks best to end irrigation 2~3hours before sunset in the aspects of plant growth, yield, WUE, and FUE.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.530-534
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• 1990

A strain of actinomycetes, Thermoactinomyces sp. CH-53, was isolated from manure and composted livestock feces. Actinornycetes-feed additive was prepared with the solid wheat bran medium of Thermoactinomyces sp. CH-53 that grew vigorously on unsterilized poultry feces at $50^{\circ}C$. pH 6.5- 9.5 and moisture content of 55-65% and added at a rate of 1% (wtlwt) to the commercially assorted feed to be fed poultry. The excreted feces contained $10^7-10^8$. Thermoactinomyces sp. CH-53 cells per gram. Poultry feces malodour was got rid of during treatment. The effect on plant growth was evaluated on the basis of the amount of nitrogen as fertilizer under a loading of 0.2g N1600g soillpot. A11 samples were showed a promotion effect for plant growth. The treated poultry feces added from O.lg to 0.4g total nitrogen per 600g soil in a pat increased the growth of Brassica rapa var. perui-ridis.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.402-406
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• 2014

The present study was carried out to evaluate the potential of lignocellulosic byproducts for the production of citric acid through solid-state fermentation by Aspergillus niger NRRL 567. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation conditions and media constituents. The results obtained from the optimization indicated that $30^{\circ}C$, 70% moisture content, 0.5~1.0 mm particle size, pH 5.5 and 4% methanol were found to be the optimum condition at 72 hr fermentation. The application the optimization resulted in an improvement of maximum citric acid production from 74.5 to 206.0 g/kg dry material (DM) from wheat straw. The optimal condition was used to produce citric acid from A. niger grown on different lignocellulosic byproducts, including wheat straw, corn stover and peat moss. A. niger produced the highest citric acid levels of 231.8, 213.8 and 240.2 g/kg DM at 120 hr fermentation, respectively.

• The Korean Journal of Mycology
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• v.24 no.2 s.77
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• pp.149-154
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• 1996

Effects of various kinds of sawdusts, supplements and culture conditions on activities of several enzymes such as protease, phenoloxidase and cellulase produced from mycelium of P. ostreatus grown on sawdust medium were studied and the results are as follows; Higher specific activity of these enzymes was observed when oak tree sawdust and poplar tree sawdust were supplemented with rice bran or wheat bran at rate of 30%, 20% and 10% in total volume respectively. Higher total activities of protease, phenoloxidase and cellulase were observed at 70% of the moisture contents of culture media, while lower activity of these enzymes was observed with 40% moisture contents of sawdust culture medium. The pH 4 and 9 of the sawdust media appeared to be optimum pH for the. production of protease while pH 5 and 7 were optimal for the production of phenoloxidase. The pH 6 of the sawdust medium was optimal for the production of cellulase. The optimum incubating temperature for the production of protease, phenoloxidase and cellulase was $25^{\circ}C$. Higher total activities of protease and phenoloxidase were observed when culture medium was added with wood vinegar at the control, and 0.5% for cellulase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.187-194
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• 1992

Rhizopus oryzae CJ-2114 was selected for its strong polygalacturonase activity among various strains of mold found in soil. It was found that the production of polygalacturonase reached to maximum when the wheat bran medium containing 1% albumin, 1% sorbitol and 0.2% (NH$_4$)$_2$C$_2$O$_4$was cultured for 96 hrs at 3$0^{\circ}C$. Polygalacturonase was purified 11.13 fold from Rhizopus oryzae CJ-2114. The purification procedures include ammonium sulfate treatment, gel filtration on Sephadex G-75, G-150 and DEAE-cellulose ion exchange chromatography. Yield of the enzyme purification was 40.3% .Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. When the purified enzyme was applied to SDS-poly-acrylamide gel electrophoresis, the molecular weight was estimated to be 47,000. The amino acid composition indicated relatively high contents of glutamic acid and glyrine.

• Journal of Mushroom
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• v.6 no.1
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• pp.20-26
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• 2008

The stromatal forms of T. fuciformis and the mycelia of Hypoxylon sp. were collected. The DNA sequence in the ITS region of the 5.8S ribosomal genes of isolated strain KG103 was very similar to that of T. fuciformis AF042409 with a homology of over 98% in the EMBL/GenBank database through BLAST searching. A second isolate, No KG201, one of the symbiotic strains for cultivating T. fuciformis also exhibited high homology with Annulohhypoxylon stygium AJ390406. Potato Dextrose Medium exhibited the best mycelial growth of 14 mm/14 days and 85 mm/14 days for T. fuciformis and its symbiotic fungi, respectively. Optimum culture conditions for the micelial growth were pH 5 at $25^{\circ}C$. For the optimization of artificial cultivation of T. fuciformis in bottle with sawdust medium, several conditions such as type of sawdust, supplements, pH, moisture content, and incubation temperature were investigated. T. fuciformis and symbiotic fungi showed fast mycelial growth on corn cob media (77 and 52%) followed by oak tree sawdust and cotton seed meal. The optimal temperature for mycelial growth of T. fuciformis and symbiotic fungi on corn cob media was $25^{\circ}C$ at 55% of moisture content.

• Microbiology and Biotechnology Letters
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• v.9 no.2
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• pp.71-75
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• 1981

Studies were made to optimize the simultaneous hydrolysis-fermentation (SSF) process for the production of ethanol from rice straw. Trichoderma sp. KI 7-2 was selected to produced cellulase by solid culture for SSF. Ethanol production was highest when the SSF process utilized koji culture of the fungus grown on a medium of wheat bran-rice straw 3 : 2 mixture with moisture content of 50% adjusted to pH 4.5 for 7 days as the enzyme source. It was found that pretreatment of the substrate is not necessary. To ferment 1g of rice straw by SSF 2.47 units of cellulase were required, and the initial yeast concentration of 2.5$\times$10$^{7}$ cell/$m\ell$ was found to be sufficient. Optimum pH and temperature for the process were 4.5 and 4$0^{\circ}C$, respectively. It was also found that higher ethanol concentration in the broth can be obtained by the addition of substrate or substrate and enzyme to SSF broth.