• 한국균학회지
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• 제15권1호
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• pp.14-18
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• 1987

This experiment was undertaken to investigate proper conditions for protoplast formation from Lyophyllum ulmarium. Combination of Novozym 234, ${\beta}-Glucuronidase$ and ${\beta}-D-Glucanase$ with 0.6 M Sucrose was the most effective for isolation of protoplasts. The optimal reaction time of mycelium with the lytic mixture was 3 hrs in shaking condition at 120 strokes $min-^1$. When the mycelium of L. ulmarium was cultured for 6 days on yeast glucose agar medium at $25^{\circ}C$, the formation of protoplasts was effective. The yeast glucose agar medium stabilized with 0.6 M sucrose was the most effective for reversion of protoplasts.

• 한국IT서비스학회지
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• 제3권2호
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• pp.25-37
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• 2004

SME's(Small and Medium-sized Enterprises) have limited resources to build information systems on their own. They do not have effective information systems and not utilize e-business technology enough. The government thus have provided various supports for SME's IT developments. However, those supports do not seem so effective that SME's can operate appropriate information systems and do e-business well. The objective of this study is to develop conceptual policies for the government. We suggest an integrated government support which consists of three core stratigies: one-stop service center, outsourcing of public service, and triggering strategy. In order for the government support to be effective, the government should serve SME's needs continuously and professionally.

• 대한안전경영과학회지
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• 제9권2호
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• pp.19-31
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• 2007

If you examine the Industrial Disaster Analysis Content that occurs every year in the small and medium enterprise, industrial disaster occurs because of manager's lack of safety and worker's unprepared safety education. Therefore effective safety education systems are needed to offer adequate knowledge and technology to the workers. On this research, to give an effective education way to decrease industrial disaster we administered to the workers who are in charge of 300 workplace in Incheon area to search actual condition of industrial disaster and to disclose a link between industrial disaster and industrial safety education. We put in effect on frequency study and examined x2 using SPSSWIN 10.0. On the research, the results shows that the industrial safety education and training are in effect regularly and the satisfaction are low. But the manager's satisfactions are high through safety education. So it shows that we need to find a way to put in effect safety education to satisfy the workers.

• 지질공학
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• 제12권3호
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• pp.319-332
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• 2002

본 연구는 화강암이 분포하는 연구지역을 대상으로 수리지질 단위층을 등연속체매질로서 설정하고, 각 단위층의 유효수리전도도를 산출하기 위한 것이다. 이를 위하여 3"직경의 4개 시추공과 다중패커시스템을 설치하였으며, 단열분포특성조사, 정압주입/수위강하시험, 전공 순간충격시험, 그리고 격리구간 내 펄스시험이 수행되었다. 수리지질 단위층을 정의하기 위하여 단열분포특성을 기초로 하여 일차적으로 상하부 단위층의 경계설정을 시도하였고, 수리전도도 변화특성을 이차적인 요소로 대비하였다. 연구에 적용된 수리시험 결과의 차이와 효과적인 암반 투수성 평가방법에 대한 논의도 이루어졌다. 상부 수리지질 단위층의 유효수리전도도는 정압주입/수위강하시험의 경우 5.27E-10 m/s~7.57E-10 m/s의 범위를 가지며, 하부 영역에서는 2.45E-10 m/s~6.81E-10 m/s의 범위를 갖는다.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.231-235
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• 1989

부착성 동물세포인 recombinant human embryonic kidney cell line 293을 5% FBS가 함유된 DME/F12(3:1) mixture 배지에서 배양할 경우 static culture에서와는 달리 미립담체 배양에서는 낮은 부착효율과 spreading의 저해현상이 관찰되었다. Cell line 293의 미립담체 배양에 있어서 배지내의 serum은 세포의 미립담체에 대한 부착속도(attach-ment rate)를 감소시킬 분만 아니라 세포의 증식을 저해한다는 사실을 확인하였다. 이러한 경우, conditioned microcarrier를 이용함으로써 미립담체로부터 세포의 탈착을 어느 정도 막을 수 있었다. 특히 autocrine growth factor를 생성하는 hepatoma cell line인 HpG 2 cell을 배양하여 얻은 conditioned medium을 serum-free medium에 첨가하여 사용함으로써 세포의 정상적인 성장 분만 아니라 growth-stimulation을 유도할 수 있었다.

• 한국자원식물학회지
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• 제11권
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• pp.40-47
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• 1998

When the leaves, roots and stem segments of seedling of Polygonatum odoratum were cultured on Murashige and Skoog medium with 2.0mg/l BAP, stem segments were the most efficient explants for adventitious shoot inductino. To observe the efficient combination of growth regulators on the adventitious shoot formation , stem segments were cultured on MS medium with various kinds of cytokinins (BAP, kinetin, zeatin). From this experiment, cytokinin treatement was prerequisite for theadventitious shoot formatino,especially BAP was the most effective. Auxin (NAA or IBA) in combination with cyotokinin highly enhanced the adventitious shoot formation. Twenty five percents of explants produced the adventitious shoots on medium with 2.0mg/l BAP solely, while 83% of explants produced the adventitious shoots on medium with 2.0mg/l BAP and 0.1mg/l IBA. Root formationform adventitious shoot was promoted after transfer to 1/2 MS medium supplemented with 0.1mg/l IBA and 0.5mg/l zeatin, thereafter the plantlets with shoots and roots were cultured on 1/2MS medium lacking growth regulators. When the stem segments were cultured to MS medium with 1.0mg/l 2,4 NAA and IBA , yellow and nodulous cali were formed from the stem segments which were developed into adventitious roots. These roots were actively grew after transferred to MS liquid medium lacking growth regulators.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.603-613
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• 2021

This research improved the growth potential of Bifidobacterium animalis subsp lactis strain JNU306, a commercial medium that is appropriate for large-scale production, in yeast extract, soy peptone, glucose, L-cysteine, and ferrous sulfate. Response surface methodology (RSM) was used to optimize the components of this medium, using a central composite design and subsequent analyses. A second-order polynomial regression model, which was fitted to the data at first, significantly lacked fitness. Thus, through further analyses, the model with linear and quadratic terms plus two-way, three-way, and four-way interactions was selected as the final model. Through this model, the optimized medium composition was found as 2.8791% yeast extract, 2.8030% peptone soy, 0.6196% glucose, 0.2823% L-cysteine, and 0.0055% ferrous sulfate, w/v. This optimized medium ensured that the maximum biomass was no lower than the biomass from the commonly used blood-liver (BL) medium. The application of RSM improved the biomass production of this strain in a more cost-effective way by creating an optimum medium. This result shows that B. animalis subsp lactis JNU306 may be used as a commercial starter culture in manufacturing probiotics, including dairy products.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.289-295
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• 2005

In this study, the cultural medium used for the efficient production of $\gamma$-PGA with a newly isolated Bacillus sp. RKY3 was optimized. It was necessary to supplement the culture medium with L-glutamic acid and an additional carbon source in order to induce the effective production of $\gamma$-PGA. The amount of $\gamma$-PGA increased with the addition of L-glutamic acid to the medium. The addition of 90 g/L L-glutamic acid to the medium resulted in the maximal yield of $\gamma$-PGA (83.2 g/L). The optimum nitrogen source was determined to be peptone, but corn steep liquor, a cheap nutrient, was also found to be effective for $\gamma$-PGA production. Both the $\gamma$-PGA production and cell growth increased rapidly with the addition of small amounts of $K_2HPO_4$ and $MgSO_4\cdot7H_{2}O$. Bacillus sp. RKY3 appears to require $Mg^{2+}$, rather than $Mn^{2+}$, for $\gamma$-PGA production, which is distinct from the production protocols associated with other, previously reported bacteria. Bacillus sp. RKY3 may also have contributed some minor $\gamma$-PGA depolymerase activity, resulting in the reduction of the molecular weight of the produced $\gamma$-PGA at the end of fermentation.

• 한국미생물·생명공학회지
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• 제27권5호
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• pp.378-384
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• 1999

Protopectinase (PPases) are heterologous group of enzymes that degrade pectin from the insoluble protopection which is constituent of the middle lamella and primary cell wall of higher plants by restricted depolymerization. From the previous report[6], enzymatically separated plant cells, which are produced from plant tissues by PPases treatment, showed well-conserved cellular components with their rigid cell wall and this characteristic is applicable to preparation of novel food material. The purpose of this study is to investigate the effect of medium composition of PPase production from Bacillus subtilis EK11 which was selected as a PPase producer. Various carbon sources and concentrations on PPase production were studied and corn starch at 0.7% was the most effective for production of PPase. Among the nitrogen sources, yeast extract was the most effective for PPase production and the effect of (NH4)2SO4 was notable as inotganic nitrogen source. Inorganic compounds such as KH2PO4, K2HPO4, Na3-citrate.2H2O and MgSO4 were optimized for PPase production. PPase activity was inhibited by the adition of Ba2+ or Zn2+. The optimal medium for PPase production was devised: 0.7% corn starch, 0.3% yeast extract, 1.4% KH2PO4, 0.6% K2HPO4, 0.1% Na3-citrate.2H2O and 0.02% MgSO4. PPase production by using the optimum medium was carried out with shaking cultivation at 37$^{\circ}C$. The maximum PPase activity of 256unit/ml could be obtained after the cultivation for 48hrs. The activity was increased about 2.2timesthan the activity, 112 unit/ml, in basal medium.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.174-178
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• 2009

Presently, we report a simple, reproducible and high frequency plant regeneration in Hibiscus syriacus L. using axillary buds. H. syriacus was regenerated from axillary buds directly or through a callus phase. Regenerated shoots were directly induced from young and fresh axillary buds cultured on Murashige and Skoog medium (MS) supplemented with 0.01 mg/L of the growth regulator thidiazuron (TDZ) after 2 weeks of culture. Directly induced shoots were transferred to hormone-free MS medium and root development was observed after 6 weeks. On the other hand, old and stale axillary buds were regenerated to shoots via callus induction on MS medium containing 0.01–2 mg/L TDZ after 4 weeks. A TDZ concentration of 0.01 mg/L was most effective in callus formation. Green callus was transferred to MS medium containing 0.01 mg/L α-naphthalene acetic acid (NAA) and 0.5 mg/L benzylaminopurine (BA). After 4 weeks, callus had developed into multiple shoots. Plantlets were formed from 10 week cultures of single shoots on hormone-free MS medium. Regenerated plantlets were cultured on MS medium for one month and then transferred to pots containing garden soil. Potted plants were acclimatized for one month and grown to maturity under greenhouse conditions. The present study has shown that various concentrations of plant growth regulator can be effective for in vitro plant regeneration of H. syriacus. The direct and indirect regeneration protocol presented here will be useful for understanding the manipulation and propagation of H. syriacus.