• KSBB Journal
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• v.8 no.4
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• pp.364-369
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• 1993

The biodegradability of some anionic surfactants were investigated using biological oxygen consumption measurement at different temperatures. As test surfactants, soap, alkyl sulfate (AS), alpha olefin sulfonate (AOS), alkyl polyoxyethylene sulfate (AES), linear alkylbezene sulfonate(LAS), microbial surfactants such as sophorose lipid (sopholipid) and spiculisporic acid (S-acid), were used. The test solution were incubated at $5^{\circ}C$, $18^{\circ}C$ and $32^{\circ}C$, respectively. The comparative rates of biodegradation were in accordance with the results obtained from the surface tension measurement and methylene blue method. The results of comparative blodegradabilities of the surfactants were as follows; soap, AS>AES>AOS>LAS at $18^{\circ}C$ and $32^{\circ}C$. However, at$ 5^{\circ}C$, the biodegradation rate of soap was better than other surfactants. Considering the actual environment of the river, it was concluded that the biological oxygen consumption rate method at lower temperature was more practical than the current method such as methylene blue assay with adapted shaking flask culture at $25^{\circ}C$

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.398-406
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• 2013

For the maximal production of aphicidal metabolites produced by the Beauveria bassiana Bb08, statistical methods such as the Box-Behnken experimental design and response surface methodology were used. The fungal culture filtrate was sprayed towards 3-star aphids and the mortality was examined. After the statistical analysis of the aphid mortality, the optimal culture conditions were found to be a culture temperature of $26.2^{\circ}C$, medium pH 5.9, flask shaking speed of 209.0 rpm, and culture time of 5.9 days. The expected mortality on days 4, 5, and 6 after spraying the filtrate on to the aphids were 76.8%, 84.9%, and 89.4%, respectively. All 4 factors of the culture conditions significantly affected the production of the aphicidal metabolites, and the order of significance was temperature, pH, culture time and shaking speed.

• The Korean Journal of Mycology
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• v.33 no.1
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• pp.22-29
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• 2005

The main objectives of this research were to study the cultural and nutritional characteristics of Tricholoma matsutake and to establish its liquid culture system. The optimum growth of T. matsutake was observed in HA and TMM agar media. Similarly highest growth was observed in PDB and TMM liquid media. The optimal temperature for the mycelial growth was $25^{\circ}C$. The most suitable carbon source was dextrin among 12 different carbon sources tested. Yeast extract and peptone were best nitrogen sources among 17 different sources tested. The optimum mineral salts were $Fe_{2}(SO_{4})_{3}{\cdot}H_{2}O$ and KCl among 9 different sources tested. Shaking culture gave higher mycelial growth compared to stationary culture. Similarly, optimum medium amount for shaking culture was 100 ml per 250 ml flask. The highest mycelial growth was obtained when $5{\sim}7$ mycelial discs were inoculated in 100 ml of medium and incubated for $8{\sim}9$ weeks, respectively. The highest proportion of mycelial growth was observed at 40 : 1 ratio of medium to inoculum volume in 8 l air-lift fermenter.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.297-302
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• 2004

A chitinase-producing bacterium was isolated from seashore mud around Beobseongpo in Chunmam province through the use of a selective enrichment culture. The best chitinase producing strain was isolated and identified as Serratia marcescens KY from its characteristics. For effective production of chitinase, optimum pH, temperature, and agitation speed were investigated in flask cultures. The optimum pH using Serratia marcescens KY was between pH 6 and 7 and the chitinase produced was 37.9 unit/mL. On the other hand, the optimal pH of the Serratia marcescens ATCC 27117 was 7.5, and the produced amount of chitinase was 35.2 unit/mL. The optimal temperature for chitinase production for Serratia marcescens KY and Serratia marcescens ATCC 27117 was $30^{\circ}$. The cell growth pattern at different temperature was almost identical to the chitinase production. To investigate the optimal shaking speed under optimal culture, speeds were varied in the range of 0∼300 rpm. The maximum production of chitinase was carried at 200 rpm although the cell growth was the highest at 150 rpm. It indicates that oxygen adjustment is required for the maximum chitinase production. Using optimal conditions, batch cultures for comparing Serratia marcescens KY and Serratia marcescens ATCC 27117 were carried out in a 5 L fermentor. The oxygen consumption was increased with the increase of culture. Especially, at 120 h of culture Serratia marcescens KY and Serratia marcescens ATCC 27117 produced 38.3 unit/mL, and 33.5 unit/mL, respectively.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.46-50
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• 2007

Transformed hairy roots were induced from in vitro grown plantlets of Trichosanthes kirilowii by infection with Agrobacterium rhizogenes strain ATCC15834. Transformed hairy roots exhibited active growth with high branching of roots on plant growth regulators-free medium. Cloned line (TR-03) of hairy root was tested for its growth and extracellular protein accumulation in medium under various culture conditions. Among the culture media tested, a full-strength MS medium had a pronounced effect on root biomass and extracelluar protein accumulation in medium. The maximum root biomass (2.4 g DRW/flask) and extracellular total protein contents $(28.3ug/m\ell)$ in medium was obtained at inoculum size of 2 g (FRW) and in MS medium supplemented with 4% sucrose. In addition, the optimal shaking speed for root growth and extracellular protein accumulation in medium were 100 rpm. The total extracellualr protein concentration reached a maximum of $28.3ug/m\ell$ at 4 weeks and decreased thereafter. Protein translation inhibitory activity was observed in culture broths and reached levels of 21.3 unit. These studies demonstrate that the transformed hairy roots can be utilized for the in vitro production of ribosome-inactivating proteins.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.366-374
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• 2015

Herein, we established a repeated-batch process for ethanol production from glycerol by immobilized Pachysolen tannophilus. The aim of this study was to develop a more practical and applicable ethanol production process for biofuel. In particular, using industrial-grade medium ingredients, the microaeration rate was optimized for maximization of the ethanol production, and the relevant metabolic parameters were then analyzed. The microaeration rate of 0.11 vvm, which is far lower than those occurring in a shaking flask culture, was found to be the optimal value for ethanol production from glycerol. In addition, it was found that, among those tested, Celite was a more appropriate carrier for the immobilization of P. tannophilus to induce production of ethanol from glycerol. Finally, through a repeated-batch culture, the ethanol yield (Y_e/g) of 0.126 ± 0.017 g-ethanol/g-glycerol (n = 4) was obtained, and this value was remarkably comparable with a previous report. In the future, it is expected that the results of this study will be applied for the development of a more practical and profitable long-term ethanol production process, thanks to the industrial-grade medium preparation, simple immobilization method, and easy repeated-batch operation.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.119-123
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• 1980

Culture conditions of yellow pigment in Monascus sp. were studied. According to the studies of culture conditions optimum condition was found to be pH 4.5, 3 days of incubation with 3% of sucrose as carbon source, 0.2 ％ of yeast extract as nitrogen source and 75m1 of medium in the 500m1 erlenmyer flask by rotary shaking (rpm 180) at 180 r.p.m. Effective levels of inorganic compounds were found to be 0.25 % of potassium phosphate monobasic and 0.1 ％ of Magnesium sulfate.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.84-86
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• 2014

Mass production of biocontrol agent is an essential step for its commercial use. Media composition and culture conditions for production of Bacillus amyloliquefaciens SKU-78, a potential biocontrol agent against bacterial wilts, were optimized by a flask culture. Low cost media combining nitrogen and carbon sources were tested. Maximum cell growth (> $2{\times}10^9$ CFU/ml) was obtained in a medium of 5% soy flour combined with 3% corn starch after 24 h cultivation. The optimum initial pH, temperature and shaking speed was 5.5, $30^{\circ}C$ and 150-250 rpm, respectively. Fermentation of SKU-78 was scaled up in 30 L fermenter and the profiles of cell density, pH, dissolved oxygen and spore formation were recorded. After 8 h lag phase, exponential growth occurred and reached at maximum viable cell number ($1.2{\times}10^{11}$ CFU/ml) after 20 h. The SKU-78 strain grown in a low cost medium exhibited the high suppression of bacterial wilts. The results indicate that SKU-78 strain can be produced in a low cost medium and provide a basis for scaling up to industrial level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.252-258
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• 1998

The strain producing biosurfactant was isolated from soil smples. The isolated strain was identified as the genus Nocardia through its morphological, cultural and physiolgical characteristics. A high concentration of the biosurfactant by Nocardia sp. L-417 was obtained after 4 days of cultivation in the culture medium containing 3% n-hexadecane, 0.1% $NaNO_3$, 0.02% $K_2HOP_4$, 0.01% $H_2PO_4$, 0.01% $MgSO_4$.$7H_2O$, 0.01% $CaCl_2$, 0.02% yeast extract, and 0.02% tryptone. The optimum pH and temperature for biosurfactant production were pH 6.0 and $30^{\circ}C$, respectively. Furthermore, most biosurfactans were produced during the exponential growth phase, and this fact indicated that the biosurfactans production was growth-associated. The biosurfactant showed the good emulsification activities on various emulsifying substrates such as bunker A, paraffin, corn oil which are used widely in industries.

• Mycobiology
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• v.35 no.2
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• pp.54-61
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• 2007

Two isolates of Tricholoma matsutake T-008 and T-034, preserved in Entomopathogenic Fungal Culture Collection (EFCC) of Korea, were used in the present study. The isolates had 100% Bootstrap homology with Tricholoma matsutake U62964 and T. matsutake AB188557 and AF309538 preserved in Gene Bank of NCBI. Mycelial growth of T. matsutake was highest in TMM and MYA at $25^{\circ}C$. The highest dry wt. of mycelium was obtained after 65 days of culture, when 6 mycelial discs were inoculated in 100 ml of broth in 250 ml shaking flask. Mycelial mats were observed in clumped condition at the inoculation sites of pine forest after two weeks of inoculation. After 5 months of inoculation, mycelia mats were observed growing inside soil and walls of a few inoculation sites, while mycelial mats growth up to $5{\sim}8$ cm were observed in the roots of pine tree after 6 months. The survival rate of the inoculum was about 40% of the total inoculation sites. The survival rate was found below 20% when the mycelium was inoculated in the summer. The reasons for low survival rates of the mycelium were mainly due to dry season and the soil-borne small animals such as earthworm and mole. After one year of inoculation, no external difference was observed between the artificially inoculated mycelia and the naturally existing mycelia of T. matsutake. The present study showed that fruiting bodies of T. matsutake could be produced by artificial inoculation under the appropriate environmental conditions.