• 한국토양비료학회지
• /
• 제44권4호
• /
• pp.581-590
• /
• 2011

Organic farming is rapidly expanding worldwide. Crop growth in organic systems greatly depends on the functions performed by soil microbes, and nutrient supply weed suppression by green manure crops input. Four red-pepper production systems were compared: 1) bare ground (conventional system); 2) hairy vetch monoculture; 3) rye monoculture; and 4) hairy vetch-rye mixture. Soil inorganic N reached the peak at 30 DAI and hairy vetch monoculture was the highest ($192mg\;kg^{-1}$) and soil total carbon was fluctuated sporadically during the experiment. Carbohydrate and phenolic compounds in soil kept significantly higher in green manure crops systems from 10 DBI to 30 DAI, however the level was the maximum at 10 DBI (carbohydrate) and 30 DAI (phenolic comounds). Incorporation of green manure crops residue enhanced soil microbial biomass C and N throughout the growing season except that MBN in rye was reduced after incorporation. Green manure crops systems suppressed weed occurrence and, in particular, it was prominent in rye monoculture. Mineral elements composition and production in red-pepper fruits were markedly decreased in green manure crops systems although hairy vetch monoculture has come close to bare ground (NPK-applied). Therefore, it was suggested that higher biomass production should be performed not only to improve soil quality and suppress weeds but to yield suitable red-pepper fruits in green manure crops-based organic farming.

• Journal of Applied Biological Chemistry
• /
• 제50권1호
• /
• pp.22-28
• /
• 2007

Most of the uplands in alpine regions during off-season are left as bare soil and thus vulnerable to severe erosion due to the inherent topographical conditions. Appropriate management strategy to cope with this problem is urgently needed, yet few researches have been reported on the effects of winter cover crop and management on soil erosion. We assessed effects of ryegrass (Lolium multiflorum) as cover crop, green manure or mulching residue on soil erosion and quality through field and segment plot lysimeter experiments in alpine uplands. Ryegrass successfully adopted to winter in alpine region based on biomass, nutrient contents, and vigors of top and root systems. Incorporation of ryegrass into soil maintained soil fertility, nutrient uptake, and yield of cabbage exerting potential use as green manure. Cultivation of ryegrass suppressed occurrence of Chinese cabbage pests. Surface coverage by ryegrass as cover crop and mulching residue significantly reduced soil loss up to 96%, when combined with soil conservation management practices. Results revealed maintaining cover crop over winter was beneficial in reducing soil erosion, and sustaining soil quality and Chinese cabbage productivity. This study suggested winter cover crop, followed by green manure and mulching, and conservation tillage system could be one of the best management practices in alpine sloping uplands cultivating Chinese cabbage.

• 한국토양비료학회지
• /
• 제47권6호
• /
• pp.586-593
• /
• 2014

Newly reclaimed tidal land is known to be in low status of soil fertility. The incorporation of crop residue is an effective method to improve soil properties and fertility in reclaimed saline soils. The objective of this study was to evaluate the efficiency of rice straw (RS) application to improve physico-chemical properties of saline-sodic soil and its contribution to productivity of whole crop barley. Increasing rate of rice straw improved growth parameter related to yield of whole crop barley, which increased tiller number significantly (p<0.05).The yield increased by 15% (F.W) and 9% (D.W) in rice straw-amended plots. The content of soil organic matter (SOM) in the surface soil (0-20cm) with rice straw incorporation increased by 5~9% (RS 2.5~RS 7.5) compared to RS 0, in which the content of SOM decreased after two consecutive cultivations. Rice straw incorporation promoted soil physico-chemical properties and nutrient-availability of the test crop, as indicated in change in soil bulk density, porosity and increased nutrient uptake of plant. Especially, the P content and uptake of whole crop barley increased with increasing the rate of rice straw application. In conclusion, the rice straw application at rates of $5.0-7.5ton{\cdot}ha^{-1}$ in reclaimed saline soils effectively improved soil properties and crop productivity, which has potentials to reduce the loss of chemical fertilizers and facilitate the favorable condition for crop growth under adverse soil condition.

• 미생물학회지
• /
• 제50권1호
• /
• pp.1-7
• /
• 2014

생명체에서 비천연 아미노산을 단백질의 특정 위치에 삽입하는 방법으로 orthogonal suppressor tRNA와 여기에 비천연 아미노산을 특이적으로 결합시킬 수 있는 유전자 변형된 aminoacyl-tRNA synthetase (ARS)가 활용되고 있다. 이 기술개발을 위해서는 돌연변이를 유발한 ARS library로부터 비천연 아미노산만을 특이적으로 결합시킬 수 있는 변형된 ARS를 탐색하기 위한 선별시스템이 필요하다. 본 논문에서는 대장균에서 작용하는 2단계로 구성된 새로운 선별시스템을 개발하였다. 먼저 양성선별 시스템은 27번 잔기를 amber 코돈으로 치환한 Chloramphenicol acetyl transferase 유전자로 구성되어 있으며, 이유전자의 amber suppression에 의해 chloramphenicol 배지에서 생존함에 따라 활성을 나타내는 ARS를 최고 $9.0{\times}10^5$배로 농축할 수 있었다. 반면 음성선별 시스템은 대장균의 Topoisomerase II의 기능을 억제하는 단백질을 암호화하는 control of cell death B (ccdB) 유전자의 N-말단 앞에 3개의 amber 코돈을 삽입하여 제작하였다. 이 음성선별 시스템을 가진 대장균에 orthogonal pair인 Saccharomyces cerevisiae tyrosyl-tRNA synthetase (Scc TyrRS)와 amber suppressor tRNA를 형질전환하면 amber suppression으로 CcdB가 발현되어 대장균의 성장이 억제되는 것을 확인하였으며, 천연 아미노산에 대한 특이성을 가진 ARS를 효과적으로 제거하는 것을 관찰하였다. 따라서, 양성선별 및 음성선별 시스템을 순차적으로 거침으로써 무작위적으로 아미노산에 대한 특이성을 변형시킨 ARS 라이브러리로부터 비천연 아미노산을 suppressor tRNA에 특이적으로 결합하는 유전자 변형 ARS를 탐색하는데 유용하게 사용될 수 있을 것이다.

• 한국자원식물학회지
• /
• 제20권1호
• /
• pp.38-42
• /
• 2007

The present study was conducted to investigate the translocation of polyphenols, especially catechin derivatives, from mushroom medium mixed with green tea residues into fruiting body of Pleurotus eryngii. Pleurotus eryngii was grown on the media incorporated by mixing or surface-treated with dry materials including leaf petioles and young stems or leaves of green tea. The dry materials treated in medium did not affect plant height and fresh weight of Pleurotus eryngii body. From the samples of Pleurotus eryngii, the eight main catechin derivatives (-)-gallocatechin(GC), (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG), and (-)-catechin gallate (EGCG), and caffeine were analyzed quantitatively by HPLC. The results showed that EGC in Pleurotus eryngii was 45% more detected, when incorporated with the dry materials, than untreated control. Especially, content of EGCG was increased in surface-treated Pleurotus eryngii up to 3.2 ppm, while it was not detected or reduced in control and other treatments. Caffeine content was greatly increased regardless of treatment method, compared with control (0.1ppm), showing 44 fold-amount in Pleurotus eryngii at early growth stage when incorporated with the dry materials into medium. The results indicates that functional catechin derivatives of green tea would be partly translocated into Pleurotus eryngii throught incorporation and surface treatment with residues of green tea plants.

• Journal of Microbiology and Biotechnology
• /
• 제21권8호
• /
• pp.802-807
• /
• 2011

Cationic liposomes have been actively used as gene delivery vehicle because of their minimal toxicity, but their relatively low efficiency of gene delivery is the major disadvantage of these vectors. Recently, cysteine residue incorporation to HIV-1 Tat peptide increased liposomemediated transfection compared with unmodified Tat peptide. Therefore, we designed a novel modified Tat peptide having a homodimeric (Tat-CTHD, Tat-NTHD) and closed structure (cyclic Tat) simply by using the disulfide bond between cysteines to develop a more efficient and safe nonviral gene delivery system. The mixing of Tat-CTHD and Tat-NTHD with DNA before mixing with lipofectamine increased the transfection efficiency compared with unmodified Tat peptide and lipofectamine only in MCF-7 breast cancer cells and rat vascular smooth muscle cells. However, cyclic Tat did not show any improvement in the transfection efficiency. In the gel retardation assay, Tat-CTHD and Tat-NTHD showed more strong binding with DNA than unmodified Tat and cyclic Tat peptide. This enhancement was only shown when Tat-CTHD and Tat-NTHD were mixed with DNA before mixing with lipofectamine. The effects of Tat- CTHD and Tat-NTHD were also valid in the experiment using DOTAP and DMRIE instead of lipofectamine. We could not find any significant cytotoxicity in the working concentration and more usage of these peptides. In conclusion, we have designed a novel transfection-enhancing peptide by easy homodimerization of Tat peptide, and the simple mix of these novel peptides with DNA increased the gene transfer of cationic lipids more efficiently with no additional cytotoxicity.

• 한국작물학회지
• /
• 제47권2호
• /
• pp.132-136
• /
• 2002

The rice straw managements are essential for maintaining soil fertility as well as reducing chemical fertilizer application in paddy field. A field experiment was conducted on moderately well draining alluvial paddy soil to investigate the decomposition pattern of rice straw. The mesh bags containing the rice straw harvested in the previous year were placed at soil surface and buried into around 10cm depth and recovered periodically for determining the straw decomposition. Pot experiments were conducted to investigate the fates of N released from $^{15}$ N-labeled rice straw under different levels of N fertilizer application. The overall decomposition patterns of rice straw were similar for the two incorporation depths in transplanted paddy field. The straw incorporated at transplanting date showed weight loss of about 50%, 70% and 90% after 2 months, 5 months, and 2 years, respectively. The decompositions of straw cell wall components showed somewhat different pattern. The decompositions of cellulose and silica were similar to that of dry weight while the decomposition of lignin was slower than that of cellulose and silica. N was released from rice straw 42% and 65 % of the initial N after one month and after five months, respectively. P release was faster than N release. Recoveries of rice straw-$^{15}$ N by rice plants were 10.2, 13.4 and 14.9% in 0, 120 and 240 mg N pot$^{-1}$ , respectively. Soil recoveries of rice straw $^{15}$ N were 17.3, 20.6 and 18.9% in 0, 120 and 240mg N pot$^{-1}$ , respectively.

• 공업화학
• /
• 제16권2호
• /
• pp.180-186
• /
• 2005

본 논문은 유기물과 중금속이 함께 포함되어 있는 폐수 슬러지의 시멘트 고형화를 위해 포졸란물질인 실리카흄을 고화보조재로 사용한 연구결과이다. 실리카흄을 고화보조재로 사용할 경우 고화체의 일축압축강도는 현저히 증가하는 결과를 보여주었으며, 실리카흄의 시멘트 대체가 전체 배합물의 15%까지 증가하였을 때 일축압축강도는 실리카흄을 전혀 사용하지 않았을 경우에 비하여 66.7%까지 증가하는 결과를 보여주었다. 또한 시멘트가 실리카흄으로 대체되는 양이 증가하면서 총 유기탄소와 중금속인 크롬의 용출량은 감소하는 결과를 보여주었으며, 배합물 중 실리카흄이 5%를 차지할 때 중성의 용출액에서 총 유기탄소의 85%가 용출억제되었으며, 산성의 용출액에서 0.76 mg-Cr/g-Cr의 크롬만이 용출되었다. 전자주사현미경과 X-선 회절분석, 적외선 분광분석 등을 이용한 미세구조분석 결과 실리카흄은 시멘트경화 초기에 크링커 입자를 피복하여 초결(initial setting)과 수화를 저해하는 에트링가이트(ettringite)의 형성을 감소시키는 것으로 나타났다. 본 연구결과 중금속과 유기물이 혼합된 슬러지의 시멘트 고형화에 있어서 실리카흄의 첨가는 유기물질이 시멘트 수화반응에 미치는 악영향을 억제하고 중금속 및 유기물의 용출을 감소시키는 것으로 나타났다.

• Advances in concrete construction
• /
• 제14권1호
• /
• pp.1-13
• /
• 2022

Due to the physical-chemical characteristics of some bottom ash (BA), there are technical, economic and environmental limitations to find a destination that will add value to it. In Brazil, this residue is eventually used for filling coal extraction pits or remains in sedimentation ponds, creating a susceptible panorama to environmental issues. The geopolymers binders are one of the alternatives to the proper use high amounts of these materials. In this work, geopolymeric binder pastes were produced with BA mixed to activators with different alkali contents (expressed as %Na₂O), as well as the incorporation of soluble silicates (Ms content). The production of binary geopolymeric pastes based on the use of two industrial wastes: fluid catalytic cracking (FCC) and aluminum anodizing sludge (AAS), was also assessed. The content in mass of BA/FCC and BA/AAS ranged from 100/0, 90/10; 80/20 and 70/30. Systems with soluble silicates as activator in a molar ratio SiO₂/Na₂O of 1.0 (Ms = 1.0) and Na₂O content of 15%, showed the best results of mechanical strength (42 MPa at day 28^th). The improvement is up to 5X when compared to NaOH based systems. For systems with partial replacement of BA of 10% of AAS and 20% of FCC (80/20), the presence of soluble silicates was also effective to increase compressive strength.

• 대한화장품학회:학술대회논문집
• /
• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
• /
• pp.501-519
• /
• 2003

Silk Sericin(SS) is a natural protein extracted from cocoon of bombix mori and shows moisturizing effect to the skin due to a number of hydroxyl groups in the structure. But its application to cosmetics is limited due to its poor solubility in water. In order to solve this drawback and expand its application to cosmetics, polyethyleneglycol(PEG) was conjugated with sericin by reacting activated polyethyleneglycol(ActPEG). Reaction site of sericin is tyrosine residue, which was determined by using $^1$H-NMR. Random coil structure of sericin was transformed to beta-sheet structure by conjugating polyethyleneglycol. It was confirmed that melting point of sericin-PEG conjugate was lowered compared to that of each sericin and PEG due to the interaction between sericin and PEG in crystalline structure. Self-assembled sericin-PEG nanoparticle was obtained by dialyzing with alcohol solution of sericin-PEG conjugate against water. The particle is spherical and has 200-400nm of size. The moisturizing ability of sericin-PEG nanoparticle was much higher than that of sericin itself. Incorporation of vitamin A into sericin-PEG nanoparticle was carried out by diafiltration method. The content of incorporated Vitamin A in sericin-PEG nanoparticle was 8.9 wt％. Releasing behaviour of vitamin A incorporated into nanoparticle was tested in phosphate buffer, pH 7.4 at 37$^{\circ}C$. and half-life of Vitamin A release was 43hrs. Sericin-PEG nanoparticle exhibited higher moisturing effect than sericin itself and distilled water, respectively. No toxicity and irritation were observed in animal tests. It can be expected that the self-assembled sericin-PEG nanoparticle can be developed for cosmetics.