• Journal of Microbiology and Biotechnology
• /
• 제20권11호
• /
• pp.1491-1499
• /
• 2010

Rhizosphere microorganisms possessing phytase activity are considered important for rendering phytate-phosphorus (P) available to plants. In the present study, the Citrobacter braakii phytase gene (appA) was overexpressed in rhizobacteria possessing plant growth promoting (PGP) traits, for increasing their potential as bioinoculants. AppA was cloned under the lac promoter in the broadhost-range expression vector pBBR1MCS-2. Transformation of the recombinant construct pCBappA resulted in high constitutive phytase activity in all of the eight rhizobacterial strains belonging to genera Pantoea, Citrobacter, Enterobacter, Pseudomonas (two strains), Rhizobium (two strains), and Ensifer that were studied. Transgenic rhizobacterial strains were found to display varying levels of phytase activity, ranging from 10-folds to 538-folds higher than the corresponding control strains. The transgenic derivative of Pseudomonas fluorescens CHA0, a well-characterized plant growth promoting rhizobacterium, showed the highest expression of phytase (~8 U/mg) activity in crude extracts. Although all transformants showed high phytase activity, rhizobacteria having the ability to secrete organic acid showed significantly higher release of P from Ca-phytate in buffered minimal media. AppA overexpressing rhizobacteria showed increased P content, and dry weight (shoot) or shoot/ root ratio of mung bean (Vigna radiata) plants, to different extents, when grown in semisolid agar (SSA) medium containing Na-phytate or Ca-phytate as the P sources. This is the first report of the overexpression of phytase in rhizobacterial strains and its exploitation for plant growth enhancement.

• Journal of Biosystems Engineering
• /
• 제39권3호
• /
• pp.235-243
• /
• 2014

Purpose: The aim of this study was to prepare and evaluate a natural material extracted from germinated brown rice (GBR). Herein, we evaluated whether the natural material could positively activate the biological effects seen during bone formation, including enhancement of metabolic activity, osteogenesis, and the expression of vascular endothelial growth factor (VEGF), one of the growth factors in human osteoblast-like cells. Methods: The natural material was created by a hot water extraction process after being soaked for 2~3 days in tap water and dried at $50^{\circ}C$. The material was characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) spectroscopy. The biological behaviors of the material were also investigated; we performed tests to assess cell cytotoxicity, metabolic activity, osteogenic markers related to bone formation, and VEGF. Results: The EDX, XRD, and FTIR results for the natural material indicated the presence of organic compounds. The natural material caused positive increases in cell metabolic activity and mineralized bone formation without cytotoxicity. The protein levels in the extract for the $6.25{\mu}g/mL$, $12.25{\mu}g/mL$, $25{\mu}g/mL$, $50{\mu}g/mL$, and $100{\mu}g/mL$ groups were significantly different from that for the control. Conclusions: The GBR-based natural material was easy to prepare and had characteristics of a potential biomaterial. The biocompatibility of this natural material was evaluated using in vitro techniques; our findings indicate that this novel material is promising for agricultural and biological applications.

• 생약학회지
• /
• 제46권1호
• /
• pp.84-92
• /
• 2015

Tyrosinase is a key enzyme to control the biosynthesis of melanin pigments and has two enzyme activities, namely of 1-tyrosine hydroxylase and of 1-dopa oxidase. Thus, tyrosinase is regarded as a target in skin-whitening and therapeutic intervention of local hyperpigmentation diseases. We have tested tyrosinase inhibitory activity on the water extracts of 50 species oriental medicinal plant. Among them, five medicinal plants, Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae were investigated strong inhibition effect. Five medicinal plants were fractionated using organic solvents (methylene chloride, ethyl acetate, n-butanol, water). Cinnamomi Cortex Spissus (ethyl acetate fraction) was investigated strong inhibition effect. Tyrosinase inhibitory activity below $IC_{50}\;40{\mu}g/ml$ is confirmed in five herbal plants that are Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae. Tyrosinase inhibitory levels ($IC_{50}\;{\mu}g/ml$) of each plants were 15.56, 35.02, 25.14, 15.20 and 39.77. We also investigate the effect of effective plant's fraction. in dose of $100{\mu}g/ml$, Cinnamomi Cortex Spissus (P-36) EtOAc fraction significant inhibitory effect over 50%. Clematidis Radix (P-35) and Cinnamomi Cortex Spissus (P-36) MC fraction inhibit tyrosinase each 36.60% and 43.21%. inhibitory rates of Fritillariae Thunbergii Bulbus (P-40) EtOAc and $H_2O$ fraction are 31.40% and 31.51%. Bulbus Fritillariae Cirrhosae (P-45) BuOH fraction regulate tyrosinase activity to 37.71%. We examined tyrosinase inhibitory activity of natural products and these results suggest that several herbs have potential as a new whitening material.

• Applied Biological Chemistry
• /
• 제47권4호
• /
• pp.426-429
• /
• 2004

An easy, sensitive and rapid method for the analysis of phytol, a strong ACAT (Acyl-CoA: Cholesterol Acyltransferase) inhibitory diterpenoid, was established. The pre-treatment of sample for GC analysis of phytol includes aq. MeOH extraction, partition of the extracts between EtOAc and water, and filtration of organic phase through Supelclean LC-Si SPE tube. The GC analysis of phytol for a variety of Lactuca sativa was carried out on DB-5 capillary column with flame ionization detector (FID). The consistency in phytol contents according to each variety was not shown. Especially, Jeoktoma, as RS-2 type, showed the highest phytol content.

• 한국해양바이오학회지
• /
• 제1권4호
• /
• pp.260-267
• /
• 2006

재조합 Agrobacterium tumefaciens균주를 사용한 Liquid Culture Assay는 quorum sensing autoinducer를 검색하는 생물학적 분석 방법으로 개발되었다. 그러나 이 시스템에 사용되는 해양천연물 시료들이 일반적으로 낮은 수용액에 대한 용해도를 갖기 때문에 활성검색에 걸림돌이 되고 있다. 시료의 용해도는 유기용매 혹은 계면활성제의 첨가로 증가될 수 있으나, 유기용매나 계면활성제 자체가 검색결과의 정확한 해석을 방해할 수 있으므로 적절한 조건의 확립이 매우 중요하다. Methanol, ethanol, 1-propanol, DMSO와 DMF를 0~10% 농도 범위에서 재조합 A. tumefaciens균주에 대한 세포 성장에 미치는 영향과 ${\beta}$-galactosidase activity에 미치는 영향을 살펴본 결과 methanol 2%이하의 농도가 가장 적합하였으며, 계면활성제의 경우, Tween 20, Tween 80보다는 Triton X-100이 약 0.05% 농도에서 세포내로의 활성물질의 전달효율을 높이는데 효과적이었다.

• 한국잡초학회지
• /
• 제17권4호
• /
• pp.407-412
• /
• 1997

약용작물의 allelopathy 효과를 구명하기 위하여 메탄올 추출물을 이용하여 생물검정한 결과 피의 발아, 신초 및 뿌리생육 억제는 공시식물, 사용부위, 사용농도에 따라 다르게 나타났는데 피의 발아, 신초 생장 및 뿌리는 천궁 및 감초 뿌리추출물에 의해서 가장 억제가 되었다. 1g 농도에서 피의 발아, 신초생장, 뿌리생장이 각각 88%, 95%, 100%, 감초추출물에서 87%, 96%, 100% 억제되었다. 천궁의 부위별 억제정도는 뿌리에서 가장 크게 나타났는데 0.5g에서 피는 완전히 억제가 되었으나 줄기 잎추출물에서는 억제효과가 크지 않았다. 용매극성별 피의 억제 정도는 에틸아세테이트에서 가장 크게 억제되었다. 피의 발아는 3분획 모두 억제가 되지 않았으나 신초 및 뿌리생장은 에틸아세테이트분획이 에틸에테르나 메탄올 분획보다 억제가 더 컸다. 이상의 결과에서 천궁뿌리에 함유하고 있는 allelochemicals은 중간정도의 극성을 띤 물질일 것으로 사료되며 allelochemicals의 분리정제에 귀중한 재료가 될 것으로 사료된다.

• 한국식품과학회지
• /
• 제26권5호
• /
• pp.622-626
• /
• 1994

Propolis를 몇 가지 용매로 추출하여 분획물을 얻고 이를 palm oil과 lard에 단독으로 혹은 synergist와 함께 첨가하여 항산화 효과를 Rancimat을 이용하여 측정하였다. 용매별 추출,수율은 68.1%(75% ethanol), 75.5%(99% ethanol), 67.4%(methanol), 86.7%(chloroform), 72.6%(ethyl acetate), 65.6%(butanol)였다. Methanol 추출물이 항산화 효과가 가장 우수 하였고 palm oil 보다는 lard에서 더욱 효과적이었다. Ethanol(75%) 추출물을 chloroform, ethyl acetate, butanol 및 water 순으로 분획 하였을 때 ethyl acetate 분획물은 조추출물보다 항산화 효과가 상승하였다. 또 ethyl acetate fraction 600 ppm에 synergist로 ascorbic acid(200ppm)을 palm oil에 첨가 했을 때와 ${\dalta}-toocopherol(200ppm)$을 lard에 첨가했을 때 높은 항산화 상승 효과를 보였다.

• Food Science and Biotechnology
• /
• 제15권1호
• /
• pp.33-38
• /
• 2006

This study was performed to provide basic rheological data of dandelion root concentrates in order to predict their processing aptitude and usefulness as functional foods material. The hot water and 70% ethanol extracts of dandelion root were concentrated at 5, 20, and 50 Brix, and their static viscosity, dynamic viscosity, and Arrhenius plots were investigated. Almost all hot water concentrates showed the typical flow properties of a pseudoplastic fluid, but evaluation using the power law model indicated that the 70% ethanol concentrates showed a flow behavior close to a Newtonian fluid. The apparent viscosity of hot water and 70% ethanol concentrates decreased with increasing temperature. Yield stresses of hot water and 70% ethanol concentrates by Herschel-Bulkley model application were in the range of 0.026 - 1.368 Pa and 0.022 - 0.238 Pa, respectively. The effect of temperature and concentration on the apparent viscosity was examined by Arrhenius equation. The activation energies of hot water and 70% ethanol concentrates were in the range of $8.762-23.778{\times}10^3\;J/mol{\cdot}kg$ and $3.217-20.384{\times}10^3\;J/mol{\cdot}kg$ with increasing concentration, respectively. Storage (G') and loss (G") moduli were generally increased with increasing frequency. For the 70% ethanol concentrates, G" predominated over G' at all applied frequencies and so they showed the typical flow behavior of a low molecular solution. However, for the hot water concentrates, G' predominated over G" at more than 1.9 rad/sec (cross-over point) and so they showed the typical flow behavior of a macromolecular solution.

• Journal of Microbiology
• /
• 제44권2호
• /
• pp.185-191
• /
• 2006

The photosynthetic bacterium, Rhodospirillum rubrum S1, when grown under anaerobic conditions, generated three different types of catalases. In this study, we purified and characterized the highest molecular weight catalase from the three catalases. The total specific catalase activity of the crude cell extracts was 88 U/mg. After the completion of the final purification step, the specific activity of the purified catalase was 1,256 U/mg. The purified catalase evidenced an estimated molecular mass of 318 kDa, consisting of four identical subunits, each of 79 kDa. The purified enzyme exhibited an apparent Km value of 30.4 mM and a Vmax of 2,564 U against hydrogen peroxide. The enzyme also exhibited a broad optimal pH $(5.0{\sim}9.0)$, and remained stable over a broad temperature range $(20^{\circ}C{\sim}60^{\circ}C)$. It maintained 90% activity against organic solvents (ethanol/chloroform) known hydroperoxidase inhibitors, and exhibited no detectable peroxidase activity. The catalase activity of the purified enzyme was reduced to 19 % of full activity as the result of the administration of 10 mM 3-amino-1,2,4-triazole, a heme-containing catalase inhibitor. Sodium cyanide, sodium azide, and hydroxylamine, all of which are known heme protein inhibitors, inhibited catalase activity by 50 % at concentrations of $11.5{\mu}M,\;0.52{\mu}M,\;and\;0.11{\mu}M$, respectively. In accordance with these findings, the enzyme was identified as a type of monofunctional catalase.

• Applied Biological Chemistry
• /
• 제39권6호
• /
• pp.424-429
• /
• 1996

유색미 쌀겨가 화학적 변이원에 의한 유전독성을 억제하는 작용기작을 유색미 품종인 수원415호 쌀겨의 유기용매추출물과 변이원인 mitomycin C를 이용하여 조사하였다. 70%에탄올 분획 및 클로로포름분획에서 수원 415호는 대조구로 사용된 추청에 비하여 변이원에 대한 억제활성이 월등히 높았음에도 불구하고 항산화활성은 추청보다 다소 낮은 결과로 보아 항산화작용과는 다른 억제기작이 존재함을 추정할 수 있었다. E. coli를 지시세포로 유색미 쌀겨 추출물의 mitomycin C에 대한 변이원성 억제기작을 조사한 결과, desmutagen으로 작용할 가능성이 크다는 사실을 알았고, 쌀겨 추출물과 mitomycin C를 반응시킨 후 반응액 중에 존재하는 유리상태의 mitomycin C를 정량한 결과, 유색미의 쌀겨 추출물이 mitomycin C에 직접 결합하여 변이원을 흡착함으로써 세포에 대한 유전독성을 억제할 것으로 생각되었다.