• KSBB Journal
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• 제11권1호
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• pp.107-114
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• 1996

당근세포(Daucus carota)로 부터 체세포배 생산성 증대를 위하여 체세포 배 현탁 배양액으로부터 추출한 세포외 분비물질을 이용하여 다음과 같은 효과를 측정하였다.: 분자량의 차이, 세포외 분비 물질 추출 시기, 주입시기, 주입농도에 따른 각종 체세포 배 생산성 증감 효과. 체세포배 생산량은 최대 1,500개/ml까지 얻었으며, 10kDa 이상 분자량이 포함된 세포외 분비물질을 초기에 주입시켰을 때 생산성이 특히 증가함을 보여 주었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.422-430
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• 2000

Mechanism of lignin biodegradation caused by basidiomycetes and the history of lignin biodegradation studies were briefly reviewed. The important roles of fungal extracellular ligninolytic enzymes such as lignin and manganese peroxidases (LiP and MnP) were also summarized. These enzymes were unique in their catalytic mechanisms and substrate specificities. Either LiP or MnP system is capable of oxidizing a variety of aromatic substrates via a one-electron oxidation. Extracellular fungal system for aromatic degradation is non-specific, which recently attracts many people working a bioremediation field. On the other hand, an intracellular degradation system for aromatic compounds is rather specific in the fungal cell. Structurally similar compounds were prepared and metabolized, indicating that an intracellular degradation strategy consisted of the cellular systems for substrate recognition and metabolic response. It was assumed that lignin-degrading fungi might be needed to develop multiple metabolic pathways for a variety of aromatic compounds caused by the action of non-specific ligninolytic enzymes on lignin. Our recent results on chemical stress responsible factors analyzed using mRNA differential display techniques were also mentioned.

• 미생물학회지
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• 제24권1호
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• pp.32-37
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• 1986

In fermentation studies it revealed that Streptomyces sp. SMF 3001 started to synthesize extracellular alkaline protease from early exponential phase of cell growth. The biosynthesis of the alkaline protease was greatly induced by skim milk as a sola nitrogen source and further stimulation was observed under inorganic sulphur limited culture. However, it was found that the biosynthesis was apparently repressed by $NH_4^+$ and free amino acids, specially by cysteine. It was considered that the strain SMF 301 of Streptomyces sp. would produce the alkaline protease for the uptake of sulphur compounds from protein contained in the culture broth.

• KSBB Journal
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• 제8권5호
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• pp.504-507
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• 1993

Control culture에서 embryo 생성률이 6개월 동안 1000embryos/ml에서 500embryo/ml로 감소되었다. 이러한 현상을 극복하기 위한 방법으로 embryo 배양액에서 추출된 세포외 물질의 첨가는 embryo 생생률을 control culture와 비 교 하여 최 대 (2500embryos/ml)까지 증가시켰다. 또한 세포외 단백질이 embryo 수율 향상에 기인하는 것으로 추측된다.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.274-279
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• 1995

Ethyl caproate, one of the major flavor compounds deciding the quality of sake (Japanese wine), is produced during the brewing by the action of alcohol acyltransferase and esterases of sake yeast and koji mold. Extracellular esterases of Aspergillus oryzae required for ethyl caproate synthesis were purified partially. The enzymes had different optimum pH and affinity toward substrates. Substrate preferences and inhibition features showed the three enzymes to be B-type esterases or carboxylesterases (EC 3.1.1.1).

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.217-217
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• 1994

Calcium entry blockers, capable of inhibiting transmembrane influx of extracellular calcium through specific calcium channels, are useful drugs in the treatment of angina pectoris, hypertension, cardiac arrythmia, and various cardiovascular disorders. Compounds having isoquinoline structures have recently been reported to possess calcium antagonistic action. Therefore, in the present study, we have attempted to synthesize some isoquinoline and related compound.; in order to search for potentially effective chemicals acting on cardiovascular system, and evaluated their pharmacological properties focusing on calcium antagonistic actions. Almost all of the compounds so far synthesized, had inhibitory action against phenylephrine or high potassium-induced contraction in vascular smooth muscle with different degrees of potencies depending on their structures, However, some of tetrahydroisoquinoline analogs showed directly inhibit calcium current in isolated rabbit cardiac myocytes examined by patch clamp techniques. The pharmacological properties of these compounds need more intensive investigation as to whether these chemicals may have developed as a new cardiovascular active drugs. Therefore, we are now under investigation of the mechanism of action of these compounds.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.134-140
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• 1994

An antagonistic bacterium Pseudomonas stutzeri YPL-1 liberated extracellular chitinase and $\beta$-1,3-glucanase which are key enzymes in the decomposition of fungal hyphal walls. The lytic enzymes caused abnormal swelling and retreating at the hyphal tips of plant pathogenic fungus Fusarium solani in a dual culture. Scanning electron microscopy revealed the hyphal degradation of F. solani in the regions interacting with P. stutzeri YPL-1. The production of chitinase and properties of a crude preparation of the enzyme from P. stutzeri YPL-1 were investigated. Peak of the chitinase activity was detected after 4 hr of cultivation. The enzyme had optimum temperature and pH of 50$^{\circ}C$ and pH 5.3, respectively. The enzyme was stable in the pH range of 3.5 to 6.0 up to 50$^{\circ}C$. The enzyme was significantly inhibited by metal compounds such as $HgCl_2$, but was stimulated by $CoCl_2$. P. stutzeri YPL-1 produced high levels of the enzyme after 84 hr of incubation. Among the tested carbon sources, chitin was the most effective for the enzyme production, at the concentration level of 3%. As a source of nitrogen, peptone was the best for the enzyme production, at the concentration level of 4%. The maximum amount of enzyme was produced by cultivating the bacterium at a medium of initial pH 6.8.

• Biomaterials and Biomechanics in Bioengineering
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• 제1권3호
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• pp.163-174
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• 2014

The objective of this study is to prepare an artificial extracellular matrix (ECM) for cell culture by using polymer hydrogels. The polymer used is a cytocompatible water-soluble phospholipid polymer: poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-n-butyl methacrylate-p-nitrophenyloxycarbonyl poly(ethylene oxide) methacrylate (MEONP)] (PMBN). The hydrogels are prepared using a cross-linking reaction between PMBN and diamine compounds, which can easily react to the MEONP moiety under mild conditions. The most favorable diamine is the bis(3-aminopropyl) poly(ethylene oxide) (APEO). The effects of cross-linking density and the chemical structure of cross-linking molecules on the mechanical properties of the hydrogel are evaluated. The storage modulus of the hydrogel is tailored by tuning the PMBN concentration and the MEONP/amino group ratio. The porous structure of the hydrogel networks depends not only on these parameters but also on the reaction temperature. We prepare a hydrogel with $40-50{\mu}m$ diameter pores and more than 90 wt% swelling. The permeation of proteins through the hydrogel increases dramatically with an increase in pore size. To induce cell adhesion, the cell-attaching oligopeptide, RGDS, is immobilized onto the hydrogel using MEONP residue. Bovine pulmonary artery endothelial cells (BPAECs) are cultured on the hydrogel matrix and are able to migrate into the artificial matrix. Hence, the RGDS-modified PMBN hydrogel matrix with cross-linked APEO functions as an artificial ECM for growing cells for applications in tissue engineering.

• Mycobiology
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• 제38권4호
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• pp.238-248
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• 2010

This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the differential effect of white rot fungi on the degradation of single and mixtures of pesticides using fungi such as Trametes versicolor and Phanerochaete chrysosporium. We also explore the formulation and delivery of fungal bioremedial inoculants to terrestrial ecosystems as well as the use of spent mushroom compost as an approach. Future areas for research and potential exploitation of new techniques are also considered.

• 환경생물
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• 제17권1호
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• pp.59-69
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• 1999

동해 연안역의 부영양화 상태 및 종속영양세균에 의한 유기물질 분해능을 조사하기 위해서 대진, 갈남, 포항, 울산의 4개 지역의 연안역을 대상으로 1994년 7월부터 1995년 4월까지 4회에 걸쳐 종속영양세균군집, 오염의 신호화합물, 세균의 생산력, 종속영양활성도 및 세포외 효소활성도 등을 분석하였다. 중금속내성균의 수는 포항에서 가장 높게 나타났으며, 각종 유기인을 이용하는 세균군집을 조사한 결과 유기인(C-P)화합물이 많이 포함될 것으로 예상되는 산업폐수, 가정하수 및 농업폐수 등이 많이 유입되는 정점에서 이들 유기인 화합물을 분해하고 산화 환원시키는 세균군집이 높게 나타났다. 이들 세균의 출현빈도는 산업폐수, 가정하수 그리고 농업용수의 유입예측지표로 활용될 수 있으리라 생각된다. 세포외 효소활성도는 울산 처용암에서 가장 높았으며 대진에서 가장 낮게 나타났다. 이러한 결과는 종속영양 세균수와 세균의 생산성 등과 정의 상관관계를 나타내었다. Poly-P와 DNA의 경우, 정점별로는 포항이 가장 높았고, 울산, 갈남, 대진 순으로 나타났다. 이는 종속영양세균의 분포양상과 매우 일치하는 것으로 조사되었다. 종속영양 활성도는 정점별, 계절별 변화가 매우 심하였다. 세균의 생산력은 하계에 가장 높고 추계와 동계에 낮았다가 춘계에 다시 높아지는 경향을 나타나 종속영양세균의 계절적 변화양상과 유사한 경향을 보였다. 결과적으로 세균의 군집, poly-P함량, 세균의 생산력, 종속영양활성도 및 세포외 효소활성도 등의 분석자료는 부영양화 상태 및 유기물질의 순환과정을 파악할 수 있는 지표로 이용될 수 있다.