• 한국수산과학회지
• /
• 제51권4호
• /
• pp.369-375
• /
• 2018

This study investigated the effects of selected seaweeds on rice koji preparation (rice inoculated with Aspergillus luchuensis) and enzyme activity. Four types of rice koji were prepared using one of three seaweeds (0.5% laver, 0.5% kelp and 0.5% green laver) or a control for 72 h. The changes in the moisture content, water activity, pH, total mold cell count, amylase and protease activities were measured. During preparation, there was no significant difference in the moisture content among the four kojis, whereas the pH in the kojis made with either laver or green laver decreased rapidly compared with the control (P<0.05). This seemed to result from the seaweeds promoting the growth of mold cells. In terms of the activities of both amylase and protease, the koji with laver was superior. Subsequently, the amylase and protease activities of the koji made with laver were evaluated at various pHs (3 to 9), temperatures ($15-55^{\circ}C$) and NaCl concentrations (0-10%). The activities of both enzymes decreased notably at pH 9 and the protease activity decreased at temperatures above $45^{\circ}C$. Although the activities of both enzymes decreased at greater than 2.5% NaCl, activity was present at 10% NaCl.

• Journal of Microbiology and Biotechnology
• /
• 제21권7호
• /
• pp.679-685
• /
• 2011

Xanthomonas oryzae pv. oryzae (Xoo) produces a putative effector, XoAvrBs2. We expressed XoAvrBs2 homologously in Xoo with a TAP-tag at the C-terminus to enable quantitative analysis of protein expression and secretion. Addition of rice leaf extracts from both Xoo-sensitive and Xoo-resistant rice cultivars to the Xoo cells induced expression of the XoAvrBs2 gene at the transcriptional and translational levels, and also stimulated a remarkable amount of XoAvrBs2 secretion into the medium. In a T3SS-defective Xoo mutant strain, secretion of the TAPtagged XoAvrBs2 was blocked. Thus, we elucidated the transcriptional and translational expressions of the XoAvrBs2 gene in Xoo was induced in vitro by the interaction with rice and the induced secretion of XoAvrBs2 was T3SSdependent. It is the first report to measure the homologous expression and secretion of XoAvrBs2 in vitro by rice leaf extract. Our system for the quantitative analysis of effector protein expression and secretion could be generally used for the study of host-pathogen interactions.

• 한국식품과학회지
• /
• 제34권6호
• /
• pp.1115-1122
• /
• 2002

시판되고 있는 두류 22 종류의 70% 에탄올 추출물을 제조하여, 이들의 항산화 활성, 화학적 변이원 mitomycin C에 대한 항변이원성, 세포독성, 변이원성 등을 포함하는 생리활성 효과를 비교 검정하였다. DPPH radical에 대한 전자공여능, hydroxy radical 소거능 및 지질 자동산화 억제효과 등은 모든 두류 품종이 거의 유사한 효과를 나타내었다. 예팔, 완두, 녹두, 백편두 등은 변이원 mitomycin C에 대해 유의할만한 수준의 항변이원성을 보였으며, 녹색나물콩, 녹두, 속피리 등은 지시 세포의 성장을 촉진하는 효과가 있었고, 속청과 청태는 변이원성을 억제하는 특성이 있었다. 백편두는 세포 성장과 돌연변이 유발 모두를 억제하는 것으로 나타나 추출물 자체가 독성을 가질 수도 있을 것으로 생각되었다. 결과적으로 본 연구의 목적이었던 기능성 밥 및 떡 제조를 위한 부재료로서의 두류 이용을 위해서는 예팥, 녹두 등을 이용하는 것이 바람직하리라고 생각된다.

• Molecules and Cells
• /
• 제42권10호
• /
• pp.711-720
• /
• 2019

Sink strength optimizes sucrose import, which is fundamental to support developing seed grains and increase crop yields, including those of rice (Oryza sativa). In this regard, little is known about the function of vacuolar invertase (VIN) in controlling sink strength and thereby seed size. Here, in rice we analyzed mutants of two VINs, OsVIN1 and OsVIN2, to examine their role during seed development. In a phenotypic analysis of the T-DNA insertion mutants, only the OsVIN2 mutant osvin2-1 exhibited reduced seed size and grain weight. Scanning electron microscopy analysis revealed that the small seed grains of osvin2-1 can be attributed to a reduction in spikelet size. A significant decrease in VIN activity and hexose level in the osvin2-1 spikelets interfered with spikelet growth. In addition, significant reduction in starch and increase in sucrose, which are characteristic features of reduced turnover and flux of sucrose due to impaired sink strength, were evident in the pre-storage stage of osvin2-1 developing grains. In situ hybridization analysis found that expression of OsVIN2 was predominant in the endocarp of developing grains. A genetically complemented line with a native genomic clone of OsVIN2 rescued reduced VIN activity and seed size. Two additional mutants, osvin2-2 and osvin2-3 generated by the CRISPR/Cas9 method, exhibited phenotypes similar to those of osvin2-1 in spikelet and seed size, VIN activity, and sugar metabolites. These results clearly demonstrate an important role of OsVIN2 as sink strength modulator that is critical for the maintenance of sucrose flux into developing seed grains.

• 한국식품저장유통학회지
• /
• 제11권1호
• /
• pp.117-121
• /
• 2004

본 연구에서는 시판되고 있는 식초를 이용하여 6종의 식품 유해세근에 대한 항균력을 비교하였다. 그 결과, 감식초와 현미식초는 합성식초에 비해 S. aureu, M. luteus, S. enteritidius 및 E. coli에서 항균 활성이 높게 나타났으며, 현미식초가 감식초에 비해 식품유해세균에 대한 항균활성이 비교적 더 높게 나타났다. 현미식초의 농도에 따른 항균활성을 조사한 결과 5종의 그람양성 세균 및 음성 세균 모두 10$\mu$L/mL 이상의 농도에서 생육이 거의 억제되었으나, V. purahaermolyticus는 15$\mu$L/mL 농도에서 생육이 거의 정지되어, 현미식초는 식품 부패균과 대장균 생육억제에 우수한 것으로 나타났다. 식초처리에 의한 미생물의 형태 변화를 전자 현미경으로 관찰한 결과 S. aureu, E coli 모두 세포가 팽윤되고 일부 세포벽이 완전히 파괴된 형태를 관찰할 수 있어 식초처리로 인해 세균의 생육이 억제되는 것을 알 수 있었다.

• 한국식물병리학회지
• /
• 제3권2호
• /
• pp.100-107
• /
• 1987

동일한 벼 품종은 수분함량이 다른 토양에서 재배했을 경우, 도열병에 대한 감수성에 차이가 생기는데 그 원인을 조사하기 위하여 잎 표피에서 분생포자발아 및 부착기형성까지의 도열병균 침입전 행동을 광학현미경과 주사전자현미경(SEM)으로 관찰하였다. 수분함량이 다른 토양에서 자란 벼 잎 사이에 표피세포의 외부형태, 잎 표피에서의 분생포자발아관의 생장 및 생장방향, 부착기의 형태 및 크기는 차이가 없었다. 부착기는 토양수분처리와 상관없이 기동세포$(35\~48\%)$위에 가　 많이 형성되었고 단세포$(19\~27\%)$, 장세포 및 공변세포$(13\~20\%)$의 순이었다. 모분상의 부착기형성은 관찰되지 않았다. 본 시험결과, 수분함량이 다른 토양에서 자란 벼 사이에 나타나는 도열병에 대한 감수성의 차이는 도열병균의 침입전 행동에서 기인하는 것이 아닌 것으로 생각된다.

• 한국식품영양과학회지
• /
• 제44권11호
• /
• pp.1759-1762
• /
• 2015

시판 막걸리에서 분리한 균주(Lactobacillus paracasei ssp. paracasei M13-65-3)로 타락을 제조하였다. M13-65-3균주를 이용하여 제조한 타락 추출물에 의하여 T lymphocyte인 Jurkat 세포의 증식이 촉진되었고 피부세포의 멜라닌 생성이 억제되었다. 본 연구의 결과는 타락이 면역 증강 기능성과 피부색소 조절 기능성을 보유할 가능성을 제시하고 있다.

• KSBB Journal
• /
• 제26권5호
• /
• pp.386-392
• /
• 2011

Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig), an immunosuppressive agent, was expressed in transgenic rice cells using RAmy3D promoter and RAmy1A signal peptide for the inducible production and secretion into culture media by sugar depletion. In this study, sodium butyrate was used as a small molecular enhancer (SME) to enhance the production of hCTLA4Ig in transgenic rice cell suspension cultures. When 1 mM sodium butyrate was added in sugar-free media, relative viability was not reduced, while the productivity was improved 1.3-fold. In addition, by supplementing 87 mM sodium pyruvate as an alternative energy source during the production phase, death rate of the cells was decreased. When sodium pyruvate was not added, most cells became dead at day 6. However, by adding sodium pyruvate, 18% of viability can be maintained until day 10 and the production of hCTLA4Ig was enhanced 1.4-fold. When the combination of sodium pyruvate and sodium butyrate at optimum concentrations was added, the highest viability and hCTLA4Ig production could be obtained. The highest level of hCTLA4Ig reached up to 35 mg/L at day 10.

• Molecules and Cells
• /
• 제39권5호
• /
• pp.426-438
• /
• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• KSBB Journal
• /
• 제32권2호
• /
• pp.83-89
• /
• 2017

Gamma (${\gamma}$)-oryzanol is a substance abundant in rice, which is widely cultivated in Asian countries. In this study, we evaluated the effect of ${\gamma}$-oryzanol treatment on proliferation and apoptosis of AGS human gastric carcinoma cells. AGS cells were treated with ${\gamma}$-oryzanol for 72 h in a dose dependent manner. Treatment of ${\gamma}$-oryzanol (50, 100, and $200{\mu}g/mL$) resulted in decreased AGS cell proliferation and increased number of cells in the sub-G1 population. Additionally, apoptotic cells were investigated by annexin V staining and mitochondrial membrane potential assays. Our results indicated that ${\gamma}$-oryzanol treatment increased the number of annexin V-positive cells and depolarized cells. This demonstrated that ${\gamma}$-oryzanol is effective for the induction of apoptosis in AGS cells. We next examined the expression of promising anticancer drug target molecules, including PTEN and HSP90. We found that treatment of ${\gamma}$-oryzanol induced the expression of PTEN in AGS cells. Under the same treatment conditions, ${\gamma}$-oryzanol reduced the expression of HSP90 in AGS cells. These results suggest that ${\gamma}$-oryzanol-induced apoptosis was accompanied by changes in regulation of PTEN and HSP90 in AGS cells. Taken together, ${\gamma}$-oryzanol could be used as a functional substance for the prevention of gastric cancer.