• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.173-173
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• 2022

In this study, we investigated whether there is another amaranth GBSS isoform in an attempt to characterize the synthesis of amylose in the pericarp. We used I2/KI staining to analyze the temporal and spatial starch accumulation patterns during seed development. The spatiotemporal starch accumulation patterns in developing seeds were observed by staining with I2/KI. Starch granules were observed in the pericarp in the initial developmental stage (3 DAP). A few starch granules were detected in the perisperm in the early-late developmental stage (8 DAP), during which the pericarp starch contents rapidly decreased. Starch granules were distributed throughout the perisperm in the mid-late developmental stage (15 DAP). Similar results were reported for other cereal crops, including barley, rice, and sorghum. Starch granules in the pericarp are synthesized during the early seed developmental stages but are absent in mature seeds. We recently reported that starch deposits in the perisperm of developing amaranth seeds are detectable only after the initial developmental stage. Prior to this stage, the pericarp is the major site of starch deposition. A recent study suggested that GBSSII isoforms are responsible for amylose synthesis in pericarps.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.267-274
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• 2018

Lipids in microalgae are energy-rich compounds and considered as an attractive feedstock for biodiesel production. To redirect carbon flux from competing pathways to the fatty acid synthesis pathway of Tetraselmis sp., we used three types of chemical inhibitors that can block the starch synthesis pathway or photorespiration, under nitrogen-sufficient and nitrogen-deficient conditions. The starch synthesis pathway in chloroplasts and the cytosol can be inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea and 1,2-cyclohexane diamine tetraacetic acid (CDTA), respectively. Degradation of glycine into ammonia during photorespiration was blocked by aminooxyacetate (AOA) to maintain biomass concentration. Inhibition of starch synthesis pathways in the cytosol by CDTA increased fatty acid productivity by 27% under nitrogen deficiency, whereas the blocking of photorespiration in mitochondria by AOA was increased by 35% under nitrogen-sufficient conditions. The results of this study indicate that blocking starch or photorespiration pathways may redirect the carbon flux to fatty acid synthesis.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.231-235
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• 2018

In this study, we demonstrate the conversion of starch to (R,R)-2,3-butanediol (2,3-BD) in a hybrid cell-free synthesis system containing a mixture of lysates derived from Escherichia coli (E. coli) and cyanobacteria. A sufficient pool of pyruvate required for the synthesis of 2,3-BD was generated by combining metabolic pathways of cyanobacteria and E. coli. Successful synthesis of 2,3-BD was achieved by additional modifications of the hybrid cell-free system with the enzymes required to convert pyruvate to 2,3-BD. The results demonstrate a new approach to harness biological pathways to expand the scope of cell-free metabolic engineering by cross-species combinations of cell lysates.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.514-520
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• 1991

Extrusion시켜 구조변형시킨 전분(질)을 기질로 cyclodextrin glucanotransferse(CGTase)를 활용하여 액화과정을 거치지 않고 직접 cyclodextrin을 합성하는 불용성 extrusion된 전분-수용성 CGTase로 구성된 불균일상 효소반응계에 관하여 연구하였다. Extrusion된 전분을 기질로 이용할 경우 기존의 액화전분을 기질로하는 균일상 효소반응계에서 보다 현저히 증가된 CD 농도, 수율 그리고 합성속도를 얻을 수 있었으며, extrusion된 전분 기질농도가 100g/l일 때 CD생성량과 수율은 각각 54g/l와 0.54였다.

• 생약학회지
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• 제17권2호
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• pp.134-138
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• 1986

Based on a tracer study, starch phosphorylase was implicated as an agent in the starch synthesis in sweet potato roots. The enzyme was purified from the tissue as a cluster of isozymes with an average mw of 205K (fresh roots) or 159K (roots stored for 3 mon.). On SDS polyacrylamide gel electrophoresis, one large subunit of 98K mw and several small ones of 47${\sim}57K mw were observed. From the mw data and the results of peptide mapping and immunoelectrophoretic blotting using mono- and polyclonal antibodies, it was deduced that a large part of the large subunit was cleaved at the middle part of the peptide chain to give rise to the small subunits, and on storage, the enzyme molecules were further modified by proteolysis. During the course of phosphorylase purification, a proteinaceous inhibitor of the enzyme was isolated. It had a mw of 250K and was composed of 5 identical subunits of 51K mw. In the direction of starch synthesis, the inhibitor showed a noncompetitive kinetics with a Ki of $1.3{\times}10^{-6}\;M$. By immunohistochemical methods, both the enzyme and the inhibitor were located on the cell wall and amyloplast. Crossreacting materials of the inhibitor were present in spinach leaf, potato tuber and rice grain. These findings indicate the wide occurrence of the inhibitor and also imply its possible participation in regulating starch phosphorylase activity in vivo.

• Elastomers and Composites
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• 제45권4호
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• pp.272-279
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• 2010

전분은 친환경적인 천연자원이다. 건축 재료로서 활용 가능한 전분-아크릴 코팅졸을 유화중합으로 합성하였다. 제조된 합성물은 IR, $^1H$-NMR을 이용하여 구조를 분석하였고, X-ray Diffraction, 발포 시험, 백색도 시험, 광택도 시험과 인장 강도를 측정을 통하여 물리적 특성을 조사하였다. 전분-아크릴 폴리머 메트릭스에서 전분의 무정형 상태는 XRD결과로 알 수 있었다. 에멀젼을 60% $CaCO_3$ 수용액과 1%, 3%, 5% 발포제와 배합하였다. 그 결과 전분과 발포제의 양이 증가할수록 발포율이 증가하였다. 전분과 발포제의 양이 증가하면 인장 강도가 증가하였다. 그러나 전분과 발포제의 증가로 인해 백색도와 광택도는 감소하였다.

• 한국작물학회지
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• 제62권2호
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• pp.124-133
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• 2017

등숙기 고온에 따른 전분합성 및 동화산물 전류 특성에 미치는 영향을 분석한 결과는 다음과 같다. 1. 등숙기 평균온도가 약 $3^{\circ}C$ 상승함에 따라 등숙기간은 약 5일정도 단축되었으며, 천립중이 약 4.2 g 정도 감소하였고, 전분함량이 감소함에 따라 상대적으로 단백질 함량이 증가하는 경향을 보였다. 2. 등숙기 고온($+3^{\circ}C$)에 따라 전분합성 최대속도는 약 11%정도 증가하였지만, 전분합성속도가 최대가 되는 시점은 약 3일, 전분합성 완료 시점은 약 4일정도 앞당겨지는 경향을 보였다. 3. 전분합성 각 단계에 관여하는 유전자의 발현양상은 앞에서의 전분합성과 마찬가지로 고온처리에서 초기 발현량이 증가하였지만, 발현 지속정도가 빠르게 감소하는 경향을 확인하였으며, 특히 soluble starch synthase의 감소가 두드러졌다. 4. 동화산물의 이삭분배 속도는 전분합성속도와 마찬가지로 고온처리구에서 증가하였지만, 줄기 및 지엽에서의 분배비율은 고온처리구에서 급격하게 감소한 결과를 보아 동화산물의 전류속도가 고온처리구에서 빨라진 것으로 생각된다. 5. 엽신의 노화속도(Nr)는 온도가 상승할수록 크게 증가하였음을 확인할 수 있었으며, 노화속도가 등숙이 거의 완료된 이후에 크게 증가하는 것으로 보아, 고온에 따른 등숙기간의 단축은 엽신의 노화 기간에 영향을 받지 않는 것으로 생각된다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.67-68
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• 2003

Native corn starch and montmorillonite caly nanocomposites were prepared using the glycerol as the plasticizer. These were characterized by mechanical analysis, X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The tensile strength increased with the clay content to a maximum point and then decreased due to gapping between the two phases. Dispersion of the layered silicate within the starch was verified using X-ray diffraction pattern. Examination of these materials by scanning electron showed that intercalates have good wetting to the starch surface.

• 폴리머
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• 제34권1호
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• pp.58-62
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• 2010

전분을 매트릭스 고분자로 하여 아크릴 단량체를 유화중합 방법으로 그래프트 중합하였다. 에멀젼의 점도와 입자경은 전분 함량이 증가함에 따라 전분의 히드록시기가 물과 상호작용하고 고분자 입자가 분산매인 물 쪽으로 팽윤함으로 인해 증가하였다. 에멀젼의 화학적 안정성은 전분 함량이 증가할수록 양호하였으나 내수성과 내알칼리성은 전분 함량이 증가할수록 친수성이 증가하면서 감소하였다. 탄산칼슘을 포함한 전분-아크릴 에멀젼 배합물의 불투명도는 전분의 함광이 증가함에 따라 전분 고유의 색깔에 의해 감소하였고 도막의 상태는 전분의 함량이 증가함에 따라 도막의 무정형 상태가 증가하면서 균열이 없는 매끈한 외관을 나타내었다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1995년도 추계 학술발표회
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• pp.99-100
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• 1995