• Journal of Microbiology and Biotechnology
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• 제15권1호
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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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• 제6권1호
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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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• 제3권1호
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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.

• 한국미생물·생명공학회지
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• 제20권5호
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• pp.583-587
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• 1992

본 연구는 농용항생제인 kasugamycin의 생산을 위하여 S.kasugaensis의 배양조건 및 배지조성을 고찰하였다. Kasugamycin 발효시 최적 탄소원 및 질소원은 각각 soybean oil과 soybean flour였다. 배지 최적온도는 28'C, 최적 pH는 6.6이었다. 본 배양의 최적 접종 상태는 64-68시간 배양한 전배양액으로 접종하였으며, 발효중 물의 첨가는 생산성의 증가를 나타냈으나 소포제로서 silicone coil 첨가는 별 영향을 관찰할 수가 없었다.

• 한국식품과학회지
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• 제21권3호
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• pp.399-403
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• 1989

A. cylindracea의 균사 성장을 위한 영양배지 조성 및 배양조건을 최적화하였다. 최적 영양배지 조성은 starch 20.0g/l, bacto-soytone 4.0g/l, 그리고 yeast extract 6.0g/l였다. 무기염류 $KH_2PO_4\;0.46g/l,\;K_2HPO_4\;1.0g/l,\;MgSO_47H_2O\;0.5g/l$을 첨가한 배지의 pH는 5.8로_ 완충되었으며 무기염류를 첨가하지 않은 배지보다 균사성장이 양호하였다. 균사의 최적 배양온도는 $28^{\circ}C$였으며 최적 생장 pH는 6.0이었다. 균사 성장 온도범위는 $10-35^{\circ}C$로서 $40^{\circ}C$ 이상에서는 균사가 사멸하였다.

• 농약과학회지
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• 제14권2호
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• pp.138-147
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• 2010

소나무재선충에 대한 살선충 활성을 나타내는 Micromonospora sp. AW050027 균주를 최적의 배지에서 배양한 미생물배양액을 제제하여 포트 및 포장에서 살선충 효과를 확인하였다. 최적화된 배지조성은 리터당 glycerol 10 g, soybean meal 10 g, NaCl 1 g, $CaCO_3$ 2 g, $K_2HPO_4$ 0.125 g 이었으며, 활성균주를 배양하여 농축한 후 액상 및 분말 미생물제제를 제조하였다. 제제에는 소나무재선충 공생미생물에 대하여 가장 효과적으로 항균활성을 나타내는 kanamycin을 첨가하여 사용하였다. 포트시험, 예비포장 시험 및 본포장 시험을 통하여 소나무재선충 방제효과를 확인한 결과, 액상제제를 수간수사하여 처리한 경우 1회처리시 고사율 53%, 5회 분할처리시 28%로 분할처리가 1회처리보다 2배 가량 효과적이었고, 배양농축액을 분할처리한 경우에서는 대조구의 고사율 100%에 대하여 고사율 10% 이내로 가장 낮게 나타났다.

• 미생물학회지
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• 제40권3호
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• pp.217-220
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• 2004

Cordyceps militaris의 액체 배양시 cordycepin(3'-deoxyadenosine) 생성에 영향을 주는 물리화학적 조건 및 배지 조성의 영향을 조사하였다. 사용된 17종 균주 중에서 C. militaris KCTC 6862, C. militaris KCTC 16932 및 C. militaris DGUM 32003이 우수한 cordycepin생산성을 보여주었다. Cordycepin생산에 적합한 최적 온도와 PH는 각각 $24^{\circ}C$와 pH 6.0-10범위이었다. YM배지에 탄소원으로 glucose를, 질소원으로 tryptone을 각 1% 첨가하였을 매 우수한 cordycepin 생산을 보여주었다. Tryptone을 질소원으로 하는 YMG 액체배지에서 5일간 배양하였을 경우, 39mg/l의 cordycepin의 농도가 측정되었다. 0.1%의 다양한 인산원을 각각 첨가한 결과, cordycepin생산을 저해하였다.

• Corrosion Science and Technology
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• 제2권6호
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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.

• 한국미생물·생명공학회지
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• 제9권1호
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• pp.29-34
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• 1981

대장균으로부터 페니실린 아미다제의 생산을 최적화하기 위하여 배지조성 및 발효 중 효소생산에 미치는 제반영향들에 대하여 연구하였다. 최적배지조성은 3.5% 트립톤, 1.5% 글루타민산 소듐, 0.5% 이스트추출물 그리고 0.15%의 페닐초산이었다. 효소생산 유도물질로서 0.15%의 페닐초산을 발효초기에 가해줄 때 효소생산성이 약5배 증가하였다. 최적화된 배지 및 발효조건에서 발효 16시간만에 최대의 효소생산을 나타내었고 이때의 생산성은 약 102.5 units/l 발효액이었다. 이러한 최적조건에서 발효할 때 현재까지 보고된 효소생산성과 비교하여 상당한 생산능력의 향상을 보였다.

• Food Science and Biotechnology
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• 제18권2호
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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.