• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.44-51
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• 1999

Proteolytic bacteria isolated from fermented anchovy jeotkal were immobilized in capsule type with $0.8\%$ sodium alginate and $CaCl_2/carboxymethyl$ cellulose (CMC). For making the immobilized capsule, the optimal concentration of both $CaCl_2$ and CMC, with respect to the membrane hardness and the growth of proteolytic bacteria in capsule, were $2.0\%$ at following conditions: flow rate of $CaCl_2/CMC$ solution and cell suspension were respectively 3.54 ml/min and 0.15 ml/min when inside diameter of inner and outer capillary tube in immobilizing apparatus were 0.32mm, 0.74mm, respectively. The density of proteolytic bacteria in capsule reached maximum, i.e. $10^8-10^9cells$/capsule during culture under optimal conditions in TPY broth, and these were $10^2-10^4$ times higher than these of before culture. During culture of proteolytic bacteria immobilized in capsule type (PBImC) for 72hrs, few growing cells were lost in the outer medium.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.321-324
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• 2000

Cell culture of Angelica gigas Nakai producing decursin and decursinol angelate as secondary metabolites were preserved in liquid nitrogen after pre-freezing in deep $freezer(-70^{\circ}C)$. The development of optimal procedure for cryopreservation was investigated by using cryoprotectant and pre-treatment before cooling. 0.7 M sucrose was found be the optimum osmotic pre-conditioning culture medium compared to mannitol, sorbitol and NaCl with the same osmotic pressure. In pre-culture medium, cells in exponential phase, supported the best growth after cryopreservation. Effective cryoprotectant was proved to be a mixture of sucrose, glycerol, DMSO. Higher concentration of cryoprotectant was better for cell viability. The highest relative cell viability established after the development of optimal procedure was 65%.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.460-465
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• 2003

A bacterium, named as strain KL34, producing extracellular pectinase was isolated from soil. The mophological cheracteristics of the isolated bacterium were gram-negative, rod-shaped and endospore unformed. Production of pectinase of strain KL34 was induced only by polygalacturonic acid added to the culture media as a sole carbon source. Pectinase activity of KL34 reached a maximum value in the culture conditions of pH 8.5 at $25^{\circ}C$. Optimal medium for pectinase production was determined to the composition of 2% polygalacturonic acid, 0.25% yeast extract, 0.02% $K_2HPO_4$, 0.02% $CaCl_2$, and 0.05% KCl per liter. The pectinase activity in the culture supernatant reached the highest amount of 54 U/ml after 3 days cultivation in the optimal media.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.380-388
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• 2018

Neural stem cells (NSCs) have the ability to self-renew and differentiate into multiple nervous system cell types. During embryonic development, the concentrations of soluble biological molecules have a critical role in controlling cell proliferation, migration, differentiation and apoptosis. In an effort to find optimal culture conditions for the generation of desired cell types in vitro, we used a microfluidic chip-generated growth factor gradient system. In the current study, NSCs in the microfluidic device remained healthy during the entire period of cell culture, and proliferated and differentiated in response to the concentration gradient of growth factors (epithermal growth factor and basic fibroblast growth factor). We also showed that overexpression of ASCL1 in NSCs increased neuronal differentiation depending on the concentration gradient of growth factors generated in the microfluidic gradient chip. The microfluidic system allowed us to study concentration-dependent effects of growth factors within a single device, while a traditional system requires multiple independent cultures using fixed growth factor concentrations. Our study suggests that the microfluidic gradient-generating chip is a powerful tool for determining the optimal culture conditions.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.329-333
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• 2000

Alkaline bacterium producing a high pro-tease activity at low temperature was isolated by using enrichment culture from soil samples and identified as Bacil-lus sp. WRD-1 Cell growth was maximal at 10 hours and the optimal initial pH and culture time of culture condition for enzyme production was pH 7 and 10 hours, respectively. Temperature range of high enzyme activity were $10~40^{\circ}C$. The optimal pH and temperature for the enzyme activity were pH9 and $30^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.93-100
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• 2020

A bacterial strain inhibiting the growth of Vibrio anguillarum, the causative agent of vibriosis, was isolated from fish intestines. The isolated strain HS36 was identified as Aerococcus urinaeequi based on the characteristics of the genus according to Bergey's Manual of Systematic Bacteriology and by 16S rRNA sequencing. The growth rate and antibacterial activity of strain HS36 in shaking culture were higher than those in static culture, while the optimal pH and temperature for antibacterial activity were 7.0 and 30℃, respectively. The active antibacterial substance was purified from a culture broth of A. urinaeequi HS36 by Sephadex G-75 gel chromatography, Sephadex G-25 gel chromatography, and reverse-phase high-performance liquid chromatography. Its molecular weight, as estimated by Tricine SDS-polyacrylamide gel electrophoresis, was approximately 1,000 Da. The antibacterial substance produced by strain HS36 was stable after incubation for 1 h at 100℃. Although its antibacterial activity was optimal at pH 6-8, activity was retained at a pH range from 2 to 11. The purified antibacterial substance was inactivated by proteinase K, papain, and β-amylase treatment. The newly purified antibacterial substance, classified as a class II bacteriocin, inhibited the growth of Klebsiella pneumoniae, Salmonella enterica, and Vibrio alginolyticus.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.1-5
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• 1993

The strain which produced glutathione was isolated from soil samples. The isolated strain was identified as the genus Candida through its morphological. cultural and physiological characteristics. The highest production of glutathione by Candida sp. was obtained after cultivation with shaking for 36 hours in the culture medium containing fructose 1.0%, yeast extract 4.0%. NaCI 0.04%, thiamine-HCI $5{\mu}g$/ml, and L-cysteine 0.04%. The optimal pH and temperature for the glutathione production were pH 6.0 and $25^{\circ}C$, respectively. The glutathione production by Candida sp. under the optimal culture condition was $92{\mu}g/ml$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.155-160
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• 2003

The optimum cultural conditions for production of red pigment from Monascus anka KCTC 6121 on solid culture were studied. The optimal conditions were found that the strain was cultivated on polished rice with 25% initial moisture content, at 3$0^{\circ}C$, 90% humidity for 12 days. It was also found that the maximum red pigment was extracted when the final culture was left in 80% ethanol for 2 days. The light stability of the extracted red pigment was relative stable since the discoloration rate was less than 8% in 30 days under the indirect light.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.177-182
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• 2002

A biosurfactant-producing microorganism was isolated from activated sludge by enrichment culture when grown on a minimal salt medium containing n-hexadecane as a sole carbon source. This microorganism was identified as Pseudomonas sp. and it was named Pseudomonas sp. EL-G527. It's optimal culture condition is 2% n-hexadecane, 0.2% NH$_4$NO$_3$, 0.3% KH$_2$PO$_4$, 0.3% $K_2$HPO$_4$, 0.02% MgSO$_4$ㆍ7$H_2O$, 0.0025% CaCk$_2$ㆍ6$H_2O$, 0.0015% FeSO$_4$ㆍ7$H_2O$ in 1$\ell$ distilled water and initial pH 7.0. Cultivation was initiated with a 2% inoculum obtained from starter cultures grown in 30 $m\ell$ of the same medium in 250 $m\ell$ flask. They were cultivated at 3$0^{\circ}C$ in reciprocal shaking incubator and the highest biosurfactant production was observed after 4 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.139-142
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• 1998

To obtain informations for construction of a mass culture system, factors affecting on the specific growth rate of marine Chlorella sp. purchased from the Chungmu Laboratory of the South Sea Fisheries Institute, the National Fisheries Research and Development Agency were investigated using a vertical tubular photobioreactor (VT-PBR) system. Optimal temperature, illumination intensity, air- and $CO_{2-}$ flow rate for Chlorella sp. were $20^{\circ}C$, 6,000 lux, 0,56 vvm and 0.028 vvm, respectively.