• BMB Reports
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• 제42권6호
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• pp.344-349
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• 2009

Angiogenesis is crucial for solid tumor growth. By secreting angiogenic factors, tumor cells induce angiogenesis. However, targeting these angiogenic factors for cancer therapy is not always successful, suggesting that other factors may be involved in tumor angiogenesis. This work shows that 25 protein spots were differentially expressed by two-dimensional gel electrophoretic analysis when HepG2 cells induced endothelial cell differentiation to tube in vitro, and most of them were upregulated. Twenty-one proteins were identified with MALDITOF-MS, and the other four were identified by LTQ-MS/MS. Keratins were identified as one class of these upregulated proteins. Further study indicated that the expression of keratin 17 in cultured endothelial cells is likely microenvironment regulated, because its expression can be induced by HepG2 cells and bFGF as well as serum in culture media. Increased expression of keratins in endothelial cells, such as keratin 17, may contribute to the angiogenesis induced by HepG2 cells.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1102-1107
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• 2003

The ES cell can provide a useful system for studying differentiation and development in vitro and a powerful tool for producing transgenic animalds. To investigate the culture condition of chicken embryonic stem (CES) cells which can retain their multipotentiality or totipotency, three kinds of feeder layer cells, SNL cells, primary mice embryonic fibroblasts (PMEF) cells and primary chicken embryonic fibroblasts (PCEF) cells, were used as the feeder cells in media of DMEM supplemented with leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and stem cell factor (SCF) for co-culture with blastoderm cells from stage X embryos of chicken. The alkaline phosphatase (AKP) test, differentiation experiment in vitro and chimeric chicken production were carried out. The results showed that culture on feeder layer of PMEF yielded high quality CES cell colonies. The typical CES cells clone shape revealed as follows: nested aggregation (clone) with clear edge and round surface as well as close arrangement within the clone. Strong alkaline phosphatase (AKP) reactive cells were observed in the fourth passage cells. On the other hand, the fourth passage CES cells could differentiate into various cells in the absence of feeder layer cells and LIF in vitro. The third and fourth passage cells were injected into the subgerminal cavity of recipient embryos at stage X. Of 269 Hailan embryos injected with CES cells of Shouguang Chickens, 8.2% (22/269) survived to hatching, 5 feather chimeras had been produced. This suggests that an effective culture system established in this study can promote the growth of CES cells and maintain them in the state of undifferentiated and development, which lays a solid foundation for the application of CES cells and may provide an alternative tool for genetic modification of chickens.

• Preventive Nutrition and Food Science
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• 제14권4호
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• pp.335-342
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• 2009

Bioactive compounds were produced from carrot pomace by solid-state fermentation using Bacillus subtilis HA and Leuconostoc mesenteroides. The carrot pomace (CP) fermented by B. subtilis HA with 3% monosodium glutamate (MSG) showed higher production of various bioactive compounds, with 1.64 Pa·sn of consistency, 2.31% of mucilage content, 16.95 unit/g of fibrinolytic enzyme activity, 35.3 unit/g of proteolytic activity and 37.5 mg% of tyrosine content. The mucilage production was greatly dependent upon the concentration of MSG added. Most MSG added in CP was converted into mucilage (2.3%) including 0.83% poly-$gamma$-glutamic acid (PGA) with 1,505 kDa of molecular weight. The CP fermented secondly by Leuc. mesenteroides showed acidic pH and lower consistency. However, the fibrinolytic and proteolytic activities were increased. The secondly fermented CP showed the viable cell counts with $2.5{\time}108$ CFU/g of B. subtilis HA and $3.7{\time}109$ CFU/g of Leuc. mesenteroides, respectively. The freeze-dried fermented CP showed 2.88 Pa·sn of consistency, 24% of mucilage content and 104.9 unit/g of fibrinolytic enzyme activity, respectively. Also, the powder of fermented CP indicated viable cell counts of $8.0{\time}107$ CFU/g of B. subtilis and $4.0{\time}108$ CFU/g of Leuc. mesenteroides. Therefore, the fermented CP that was fortified with dietary fibers, fibrinolytic enzyme and probiotics could be utilized as valuable ingredients of functional foods in food or cosmetic industries.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.519-523
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• 1989

Aspergillus sp.로부터 glucoamylase를 생성키 위한 조건을 검토하였다. 곰팡이는 탄소원으로 soluble starch, 질소원으로 yeast extract를 사용했을 때 최대 효소생성을 얻을 수 있었다. 그리고, 탄소원 및 질소원의 농도에 따른 효소생성은 soluble starch를 5%, yeast extract를 1% 수준으로 사용했을 때 효소생성은 극대화하였다. 또한 배지의 초기 pH를 6.0, 그리고 배양온도를 28$^{\circ}C$로 유지했을 때 효소생성이 높았다. 고체배지를 사용했을 때에는, 밀기울 배지가 glucoamylase 생성을 위해서 가장 효과가 좋았다.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.368-371
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• 2009

In the course of screening for the melanogenesis inhibitors, aspochalasin I was isolated from solid-state culture of Aspergillus sp. Fb020460. Its structure was determined by spectroscopic analysis including mass spectroscopy and NMR analysis. Aspochalasin I potently inhibited melanogenesis in Mel-Ab cells with an $IC_{50}$ value of $22.4{\mu}M$ without cytotoxicity.

• 한국전기전자재료학회논문지
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• 제25권3호
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• pp.213-217
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• 2012

In this study, we have investigated the holographic grating formation on Ag-doped amorphous As-Ge-Se-S thin films. The dependence of diffraction efficiency as afunction of Ag layer thickness has been investigated in this amorphous chalcogenide films. Holographic gratings was formed using [P:P] polarized Diode Pumped Solid State laser (DPSS, 532.0 nm). The diffraction efficiency was obtained by +1st order intensity. The results were shown that the diffraction efficiency of Ag/AsGeSeS double layer thin films for the Ag thickness, the maximum grating diffraction efficiency using 60 nm Ag layer is 0.96%.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.987-996
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• 2009

Aspergillus niger GH1 previously isolated and identified by our group as a wild tannase producer was grown under solid-state (SSC) and submerged culture (SmC) conditions to select the enzyme production system. For tannase purification, extracellular tannase was produced under SSC using polyurethane foam as the inert support. Tannase was purified to apparent homogeneity by ultrafiltration, anion-exchange chromatography, and gel filtration that led to a purified enzyme with a specific activity of 238.14 IU/mg protein with a final yield of 0.3% and a purification fold of 46. Three bands were found on the SDS-PAG with molecular masses of 50, 75, and 100 kDa. PI of 3.5 and 7.1% N-glycosylation were noted. Temperature and pH optima were 600e and 6.0 [methyl 3,4,5-trihydroxybenzoate (MTB) as substrate], respectively. Tannase was found with a $K_M$ value of $0.41{\times}10^{-4}M$ and the value of $V_{max}$ was $11.03{\mu}$moL/min at $60^{\circ}C$ for MTB. Effects of several metal salts, solvents, surfactants, and typical enzyme inhibitors on tannase activity were evaluated to establish the novelty of the enzyme. Finally, the tannase from A. niger GH1 was significantly inhibited by PMSF (phenylmethylsulfonyl fluoride), and therefore, it is possible to consider the presence of a serine or cysteine residue in the catalytic site.

• 한국균학회지
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• 제25권2호통권81호
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• pp.133-142
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• 1997

Phellinus igniarius의 화학합성배지 조성 및 배양조건의 최적화 실험을 실시하였다. 또한 곡물에서 담자균사체를 배양하는 고체재료 발효방법을 개발함으로써, 기능성식품의 이용 가능성을 검토한 결과는 다음과 같다. Phellinus igniarius의 최적 영양배지로는 malt extract 7.0%, bacto soytone 0.3%, yeast extract 0.2%의 조합이었다. 그러나 대부분의 버섯 영양배지에 공통으로 첨가되는 무기염류$(KH_2PO_4,\;0.046%,\;K_2HPO_4\;0.1%,\;MgSO_4{\cdot}7H_2O\;0.05%)$의 첨가는 균사생장에 별 영향을 미치지 않는 것으로 나타났다. 균사생장의 최적 배양온도는 $28^{\circ}C$였으며, 균사생장 최적 pH는 7.0으로 나타났다. 담자균사체의 대량배양 조건 실험을 실시한 결과, 냉침에 의해 최대수화에 도달한 곡물을 배양용기에 담고, 액체배양 후 균질화한 담자균사체를 곡물에 접종함으로써 접종초기 짧은 시간에 균사가 완전히 활착 되도록 할 수 있었다. 또한 균사 배양중기에 멸균 증류수를 첨가함으로써 균사의 활력을 유지시킬 수 있었다. Phellinus igniarius가 배양된 곡물에서 균사체량을 나타내는 glucosamine의 함량은 율무>보리>흑태>밀>메주콩>현미>수수>찹쌀의 순이었다.

• 한국식품영양과학회지
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• 제39권6호
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• pp.872-879
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• 2010

조직대두단백을 이용하여 B. subtilis HA에 의한 장기간 동안 고체 발효를 통해 얻어진 발효물의 품질, 항산화 활성 및 물성 변화를 평가하였다. 발효시간에 따라 발효물의 색도는 L값은 감소하고 a, b 값은 증가하였으며 수용성 추출물의 갈색도는 발효 48시간까지는 서서히 증가하나 그 후에는 변화가 없는 것으로 나타났다. TVP 발효물의 물과 70% 에탄올 추출물의 DPPH radical 소거 활성 측정 결과 발효 24시간째 70% 에탄올 추출물의 $ IC_{50}$값이 0.99 mg/mL로 가장 활성이 우수하였고 발효시간이 길어져도 활성이 증가하지 않았다. 또한 ABTS radical 소거 활성도 70% 에탄올 추출물이 발효 72시간째 $ IC_{50}$값이 1.68 mg/g으로 가장 높았다. TVP 발효물의 점조도는 발효 48시간째 7.89 $Pa{\cdot}s^n$으로 가장 높았고 그 후에는 감소하는 것으로 나타났으며 점질물 함량은 발효 24시간째 26.49%로 가장 높은 함량을 보인 후 감소하는 것으로 나타났다. 발효물의 점탄성은 발효 48시간째 가장 높았으며 이후 감소하였고 탄성(G')보다 점성(G")이 높은 것으로 나타났다. $\gamma$-PGA 함량은 발효시간이 증가하면서 증가하는 경향을 보이면서 168시간에 37.72% 생산되었고, 분자량은 발효시간이 경과될수록 감소하였다. Levan 함량은 발효 초기인 12시간째 7.83%에서 발효시간이 경과할수록 감소하는 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.288-305
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• 2000

A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects-the basics of yeast flocculation, the development of "new" flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer's yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous $\beta$-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculating bioreactors and discussing potential new uses of these systems.e systems.