• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.66-71
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• 2005

Doxorubicin is a clinically important anticancer polyketide compound that is typically produced by Streptomyces peucetius var. caesius. To improve doxorubicin productivity by S. peucetius, a doxorubicin pathway-specific regulatory gene, dnrI, was cloned into a high-copy-number plasmid containing a catechol promoter system. The S. peucetius containing the recombinant plasmid exhibited approximately 9.5-fold higher doxorubicin productivity compared with the wild-type S. peucetius. The doxorubicin productivity by this recombinant S. peucetius strain was further improved through the optimization of culture media composition. Based on the Fractional Factorial Design (FFD), cornstarch, $K_2HPO_4$, and $MgSO_4$ were identified to be the key factors influencing doxorubicin productivity. The Response Surface Method (RSM) results based on 20 independent culture conditions with varying amounts of key factors predicted the highest theoretical doxorubicin productivity of 11.1 mg/l with corn starch of 46.33 g/l, $K_2HPO_4$ of 4.63 g/l, and $MgSO_4$ of 9.26 g/l. The doxorubicin productivity of the recombinant S. peucetius strain with the RSM-based optimized culture condition was experimentally verified to be 11.46 mg/l, which was approximately 30.8-fold higher productivity compared with the wild-type S. peucetius without culture media optimization.

• KSBB Journal
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• v.6 no.1
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• pp.91-98
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• 1991

The media compositions and culture conditions were optimized for mycelial growth of Coriolus versicolor and Lentinus edodes. Media composition for optimal growth of Coriolus versicolor was 2.0% glucose 0.4% peptone and 0.6% yeast extract. Media composition for optimal growth of Lenttnus edodes was 2.0% glucose 2.0% starch 0.4% bacto-soytone and 0.6% yeast extract. The media supplemented with KH2PO4, 0.046% KH2PO4 0.1% and MgSO4, .7H2O 0.05% supported better mycelial growth than the media without mineral salts. The optimum temperature for mycelial growth ranged from $25^{\circ}C$-28$^{\circ}C$. The optimum pH range for mycelial growth of Coriolus versicolor was 5.2~5.6 while that of Lentinus edodes appeared to be 5.75.

• Journal of Computational Design and Engineering
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• v.3 no.1
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• pp.71-90
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• 2016

Steel nitriding is a thermo-chemical process leading to surface hardening and improvement in fatigue properties. The process is strongly influenced by many different variables such as steel composition, nitrogen potential, temperature, time, and quenching media. In the present study, the influence of such parameters affecting physic-chemical and mechanical properties of nitride steels was evaluated. The aim was to streamline the process by numerical-experimental analysis allowing defining the optimal conditions for the success of the process. Input parameters-output results correlations were calculated through the employment of a multi-objective optimization software, modeFRONTIER (Esteco). The mechanical and microstructural results belonging to the nitriding process, performed with different processing conditions for various steels, are presented. The data were employed to obtain the analytical equations describing nitriding behavior as a function of nitriding parameters and steel composition. The obtained model was validated, through control designs, and optimized by taking into account physical and processing conditions.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.583-587
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• 1992

This study was conducted in order to optimize the media composition and cultural conditions for kasugamycin production by Streptomyces kasugaensis. The optimum culture conditions are pH 6.6 (before sterilization) and $28^{\circ}C$ for the production of kasugamycin. The kasugamycin concentration was not increased when silicone oil as antifoam agent was added. The addition of water during the cultivation in the various media showed a positive effect for the production of kasugamycin.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.399-403
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• 1989

Studies were made to optimize the meida composition and cultural conditions for the mycelial growth of Agrocybe cylindracea. Media composition for optimal growth was found to be starch 20.0g/l, bacto-soytone 4.0g/l. The media supplemented with $KH_2PO_4\;0.46g/l,\;K_2HPO_4\;1.0g/l,\;MgSO_47H_2O\;0.5g/l$ supported mycelial growth better than the media without mineral salts. Optimum temperature and pH for the growth was $28^{\circ}C$, and 6.0 respectively. Temperature range for the mycelial growth appeared to be $10-35^{\circ}C$ and the mycelium evidently lost the vitality at $40^{\circ}C$.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.138-147
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• 2010

Nematicidal activity against pine wood nematode, Bursaphelenchus xylophilus, was tested in the pot and field by the treatment of microbial formulation after media optimization. The optimized media composition was glycerol 10 g, soybean meal 10 g, NaCl 1 g, $CaCO_3$ 2 g, $K_2HPO_4$ 0.125 g per liter and microbial complex formulation was made with liquid and powder type. Most effective antibiotics against symbiotic microorganism with nematode, kanamycin, was added to the formulation. The control effects against pine wood nematodes were checked by pot test and field test. In the result of treatment by trunk injection, five times treatment was more effective than one time and the treatment with the formulation of concentrated culture supernatant was the most effective in the nematicidal activity showing below 10% mortality in pine tree.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.217-220
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• 2004

The effect of media composition and culture condition on mycelial growth and cordycepin (3'-deoxyadenosine) production was determined using Cordyceps spp. Among the strains of C. militaris and C. sinensis tested, C. militaris KCTC 6862, C. militaris DGUM 32003 and C. militaris KCTC 16932 were excellent for the production of cordycepin. The optimal temperature and pH for production of cordycepin were $24^{\circ}C$ and pH ranged from 6.0 to 10, respectively. Among various sources of carbon and nitrogen tested, glucose and tryptone were very excellent for the production of cordycepin, respectively. After 5days cultivation with 1% of tryptone with nitrogen source, 39mg/l of cordycepin was produced. However, addition of phosphorus sources reduced the production of cordycepin.

• Corrosion Science and Technology
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• v.2 no.6
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• pp.260-265
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• 2003

The experimental methods to rapidly and stably reproduce Microbially Influenced Corrosion (MIC) of stainless steel by sulfate-reducing bacteria such as Desulfovibrio vulgaris were developed. In this study, using two types of stainless steel, 304 and 444, obtained from Pohang Steel & Iron Co., Ltd. (POSCO)., three major factors were tested; overall medium composition, dilution ratio, and chloride concentration. In the overall medium tests, three different media were prepared according to $FeSO_4$ concentration; PM (original Postgate's medium No. 2), MPM 1 (modified PM, no $FeSO_4$, MPM 2 (modified PM, 1/10 $FeSO_4$). The effects of various dilution ratios (3, 1, 1/3, 1/10, 1/30, and 1/100 times) and chloride concentrations (0.0067M, 0.01M, 0.05M, and 0.1M) were examined during 2 months cultivation. Through SEM (Scanning Electron Microscopy) observation, the diluted and modified media, particularly the $1/3{\times}MPM$ I medium, showed more micro-pitting points on surfaces compared to the original PM medium. High concentrations of chloride ions (above 0.05M) were not adequate for observation of MIC since those brought about non-microbiologically induced corrosion. From this study, the optimization of medium composition was very effective to routinely observe MIC in a laboratory system.

• Microbiology and Biotechnology Letters
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• v.9 no.1
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• pp.29-34
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• 1981

To maximize the production of penicillin amidase from Estherichia coli (ATCC 9637), the media composition and several factors affecting the engyme production during fermentation were studied. The optimal media composition was found to be; 3.5% tryptone, 1.5% monosodium glutamate and 0.5% yeast extract. The addition of 0.15% phenylacetic acid as an enzyme inducer at the initial stage of cultivation increased the engyme productivity about 5 fold. It was found that the engyme activity reached maximum within 16hr of cultivation. The maximum production of the enzyme obtained was about 102.5 units/l broth under the optimized condition. The enzyme production was markedly increased by the optimization as compared with those previously reported.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.442-448
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• 2009

In this study Bacillus subtilis PTCC 1023 was used for the production of protopectinase using soybean based media. The use of isolated soybean protein (ISP) and soybean flour resulted in similar protopectinase production and growth rates. The effect of medium composition on protopectinase production was studied using central composite design (CCD) methodology. The change in the concentration of ISP (1-7%), glucose (0-10%), and phosphate (0.1-0.3 M) was found to affect the protopectinase activity (response variable) after 24 hr of cultivation. In the range studied, ISP and glucose had a negative effect on the response variable, whereas phosphate had a positive effect. A statistically significant interaction was identified between phosphate and ISP, suggesting that correct optimization of medium formulation in this case can only be obtained using factorial design of experiments. Protopectinase activity exceeding 215 U/mL was obtained in a medium containing 4% ISP, 0.3M phosphate, and no added sugar.