• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.473-476
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• 2002

A lignin degradation bacteria, symbiotic bacteria was isolated from the gut of Sympetrum depressiusculum and tested for its lignin degrading activity using lignin model compounds and related aromatic compounds. The strain was identified as Serratia marcescens HY-5 based on the 165 rDNA, cellular fatty acid composition, biochemical and physiological characteristics. S. marcescens showed 40-50% lignin degrading activity in the media that contained vaillin, guaiacol and dealkaline lignin. S. marcescens showed three ligninase activities [Jaccase, lignin peroxidase(LiP) and Manganase peroxidase(MnP)]. Addition of dealkaline lignin to the basal media increased about 6fold of laccase activity. Vanillic acid or vanillin increase 1.3fold of MnP activity and p-coumaric acid increased 12fold of LiP activity which added to the basal medium.

• KSBB Journal
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• 제10권2호
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• pp.183-190
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• 1995

효소를 이용한 펄프의 전 처리가 펄프의 표백 효 과에 미치는 영향을 조사하였다. 펄프의 kappa number 감소율은, 효소를 사용하지 않고 IN NaOH 용액으로 추출하였을 경우에는 13.7% 였으나 xyla nase(EC 3.2.1.8, Pulpzyme HB)를 사용하여 전 처 리를 하였을 경우에는 IN NaOH 추출 후 25.2%로 증가하였다. Xylanase와 함께 peroxidase mc 1.11.1.7, Novozyme 502) 빛 $H_2O_2$(O.lmM)를 사용하여 전 처리를 하였을 때, 페놀성 물질을 radical carrier 로 사용할 수 있는 가능성을 조사하였다. Radical carner로서 guaiacol(ImM)을 사용하면 kappa number의 감소율이 29.6%로 증가하였다. 그러나 phenol, p-chlorophenol 등을 radical carrier로서 샤용하거나 높은 농도의 $H_2O_2$(ImM)를 사용할 경우 에는 kappa number의 감소율은 줄어들므로 radi cal의 생성 속도 및 radical의 안정성이 중요한 변수 가 됨을 알 수 있었다.

• The Korean Journal of Ecology
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• 제25권6호
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• pp.371-377
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• 2002

Leaves of two-week old seedlings of tomato (Lycopersicon esculentum) were treated with various concentrations (0, 0.2 and 0.4 $\mu$g/1) of 2,4,5-trichlorobiphenyl (PCB-29) and subsequent growth of seedlings, symptoms of oxidative stress and activities of antioxidant enzymes were investigated. Compared with the non-treated control, foliar application of PCB-29 decreased both biomass and superoxide ($O_2$) radical production but increased hydrogen peroxide production and lipid peroxidation such as malondialdehyde (MDA) formation with increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX). Further studies on the isozymes of SOD, peroxidase (POD) and APX showed that all three isozymes of SOD such as Mn-SOD, Fe-SOD and Cu/Zn-SOD, two among four isozymes of POD and all three isozymes of APX were selectively increased in response to PCB. Therefore, we suggest that a possible cause for the reduction of seedling growth by PCB exposure is the oxidative stress including over production of hydrogen peroxide and the selective expression of specific isozymes of some antioxidant enzymes.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1540-1548
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• 2012

Manganese peroxidase (MnP) was isolated from the culture filtrate of the wood log mushroom Stereum ostrea (S. ostrea), grown on Koroljova medium, and then purified by ammonium sulfate [70% (w/v)] fractionation, DEAE-cellulose anion exchange chromatography, and Sephadex G-100 column chromatography, with an attainment of 88.6-fold purification and the recovery of 22.8% of initial activity. According to SDS-PAGE the molecular mass of the MnP was 40 kDa. The optimal pH and temperature were found to be 4.5 and $35^{\circ}C$, respectively. The enzyme was stable even after exposure to a pH range of 4.5 to 6.0, and at temperatures of up to $35^{\circ}C$ at a pH of 4.5 for 1h. The $K_m$ and $V_{max}$ values for the substrate phenol red were found to be $8{\mu}m$ and 111.14 U/mg of protein, respectively. The MnP also oxidized other substrates such as guaiacol, DMP, and veratryl alcohol. Sodium azide, EDTA, SDS, $Cu^{2+}$, and $Fe^{2+}$, at 1-5 mM, strongly inhibited enzyme activity, whereas $Ca^{2+}$ and $Zn^{2+}$ increased enzyme activity. The participation of the purified enzyme in the decolorization of dyes suggests that S. ostrea manganese peroxidase could be effectively employed in textile industries.

• 한국초지조사료학회지
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• 제34권1호
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• pp.15-20
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• 2014

To investigate lignification process and its physiological significance under water-deficit condition, the responses of peroxidases, polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) in relation to leaf water status to the short term of water deficit treatment in the leaves with different maturities in forage rape were measured. The significant decrease in relative water content (RWC) and leaf osmotic potential (${\Psi}{\pi}$) were apparent after 5 d of water-deficit treatment. The activity of guaiacol peroxidase (GPOD), ascorbate peroxidase (APOD), coniferyl alcohol peroxidase (CPOD), and syringaldazine peroxidase (SPOD) was depressed especially in middle and old leaves when compared with that of control leaves. On the other hand, in young leaves, a significant increase in CPOD (+34%) and SPOD (+24%) activity as affected by water-deficit treatment was apparent. The activation of PAL and PPO was observed in middle and old leaves for PAL and in young and middle leaves for PPO. These results suggest that peroxidases in middle and old leaves did not involve in lignification under mild water-deficit stress, whereas CPOD and SPOD in young leaves participate in lignification by a coordination with PAL and PPO to incorporate phenol and lignin into the cell walls.

• 한국초지조사료학회지
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• 제42권2호
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• pp.114-119
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• 2022

The objective of this study was to determine phosphorus effects on drought stress-induced oxidative stress in Kentucky bluegrass. Drought stress was induced by reducing of water to plants in pots. Two types of phosphorus were applied as potassium phosphate (P) or potassium phosphonate (PA). Application of phosphorus was efficient to ameliorate the adverse effects of drought. Osmotic potential, total chlorophyll and carotenoid content were significantly decreased by drought stress, but was relieved by P or PA application. Superoxide (O₂^•-) concentration was significantly increased more than 14-fold under drought-stressed plants, was accompanied with increase of hydrogen peroxide (H₂O₂) and lipid peroxidation (MDA). However, malondialdehyde (MDA) was much less in P or PA applied plants under drought stress condition. Activities of catalase (CAT), ascorbate peroxidase (APX) and guaiacol-peroxidase (GPX) were largely increased by drought stress and its increase rate was much higher in P or PA applied plants except APX. These results indicate that drought stress-induced oxidative stress is alleviated by P or PA application due to the increase of activities of antioxidant enzymes.

• Journal of Plant Biotechnology
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• 제32권4호
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• pp.293-300
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• 2005

배추 유식물 제 1엽의 생장에 미치는 sodium nitroprusside(SNP: NO 공여체)의 생리적 효과를 NO에 의한 세포 분열조절의 가능성 수준에서 조사하였다. 배추 유식물에 서로 다른 농도의 SNP (0, 200, 500 및 $1000\;{\mu}M$)를 8일간 처리하고 배양한 결과 $200\;{\mu}M$ SNP 농도에서 최대 잎 생장을 보이면서 처리농도 의존 방식으로 잎의 생장에 영향을 끼쳤다. 잎의 생장반응과 일치하여, 잎의 엽록소 및 수용성 단백질 함량은 $200\;{\mu}M$농도에서 최대로 증가하여 각각 대조구의 142%와 134%수준을 보였으나, 오히려 $1000\;{\mu}M$처리농도에서는 엽록소의 경우 미미한 감소와 그리고 단백질 함량에서는 13%의 감소가 일어났다. 게다가, 잎 조직의 DNA와 RNA 함량 역시 $200\;{\mu}M$ 처리시 최대로 증가하여 각각 대조구의 142% 및 139% 수준을 보였으나, 반면에 $1000\;{\mu}M$ 농도에서는 각각 대조구의 80% 및 84% 수준까지 감소되었다. 세포벽 합성과 관련된 효소 활성도 변화에서 phenylalanine ammonia-lyase와 guaiacol peroxidase 활성도는 $200\;{\mu}M$ SNP 처리시 대조구에 비해 각각 최대 212%와 134% 증가 하였으나, $1000\;{\mu}M$ 농도에서는 두 효소 활성도 모두 유의한 변화를 보이지 않았다. 결론적으로, 이들 결과는 효과적인 농도에서의 SNP 처리에 의한 배추 제 1엽의 생장 촉진 현상은 세포분열 유도에 대한 NO의 능력에 기인될 수 있음을 제시하는 것이다.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1790-1797
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• 2017

In the present study, we demonstrate that the growth of salt-stressed pepper plants is improved by inoculation with plant growth-promoting rhizobacteria (PGPR). Three PGPR strains (Microbacterium oleivorans KNUC7074, Brevibacterium iodinum KNUC7183, and Rhizobium massiliae KNUC7586) were isolated from the rhizosphere of pepper plants growing in saline soil, and pepper plants inoculated with these PGPR strains exhibited significantly greater plant height, fresh weight, dry weight, and total chlorophyll content than non-inoculated plants. In addition, salt-stressed pepper plants that were inoculated with B. iodinum KNUC7183 and R. massiliae KNUC7586 possessed significantly different total soluble sugar and proline contents from non-inoculated controls, and the activity of several antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, and catalase) was also elevated in PGPR-treated plants under salt stress. Overall, these results suggest that the inoculation of pepper plants with M. oleivorans KNUC7074, B. iodinum KNUC7183, and R. massiliae KNUC7586 can alleviate the harmful effects of salt stress on plant growth.

• Plant Biotechnology Reports
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• 제4권2호
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• pp.109-116
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• 2010

Morinda citrifolia adventitious roots were cultured in shake flasks using Murashige and Skoog medium with different types and concentrations of auxin and cytokinin. Root (fresh weight and dry weight) accumulation was enhanced at 5 $mg\;l^{-1}$ indole butyric acid (IBA) and at 7 and 9 $mg\;l^{-1}$ naphthalene acetic acid (NAA). On the other hand, 9 $mg\;l^{-1}$ NAA decreased the anthraquinone, phenolic and flavonoid contents more severely than 9 $mg\;l^{-1}$ IBA. When adventitious roots were treated with kinetin (0.1, 0.3 and 0.5 $mg\;l^{-1}$) and thidiazuron (TDZ; 0.1, 0.3 and 0.5 $mg\;l^{-1}$) in combination with 5 $mg\;l^{-1}$ IBA, fresh weight and dry weight decreased but secondary metabolite content increased. The secondary metabolite content (including 1,1-diphenyl-2-picrylhydrazyl activity) increased more in TDZ-treated than in kinetin-treated roots. Antioxidative enzymes such as catalase (CAT) and guaiacol peroxidase (G-POD), which play important roles in plant defense, also increased. A strong decrease in ascorbate peroxidase activity resulted in a high accumulation of hydrogen peroxide. This indicates that adventitious roots can grow under stress conditions with induced CAT and G-POD activities and higher accumulations of secondary metabolites. These results suggest that 5 $mg\;l^{-1}$ IBA supplementation is useful for growth and secondary metabolite production in adventitious roots of M. citrifolia.

• 한국잡초학회지
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• 제18권1호
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• pp.54-62
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• 1998

본 실험은 식물생장조절제인 ABA와 IAA를 처리가 오존에 의한 가시적 피해 경감효과에 미치는 영향과, 항산화물질의 함량 및 항산화효소의 활성과의 관련성을 조사하기 위하여 담배품종 NC82를 공시하여, 파종후 60일 된 개체에 ABA와 IAA를 각각 $10^{-3}$M 및 $10^{-5}$M의 농도로 엽면처리한 후 0.3ppm의 농도로 하루 6시간씩 7일간 오존을 처리하여 다음과 같은 결과를 얻었다. 1. 담배에서 ABA와 IAA의 처리는 오존의 가시적 피해증상을 감소시키는 결과를 나타냈으며 오존 처리구에서는 모두 담배의 생육에는 큰 영향을 주지 않았으나 초장의 경우 IAA $10^{-3}$M의 처리구에서 다소 증가하였다. 2. 엽록소 함량은 오존처리후의 일수가 증가함에 따라 감소하는 경향을 보였으나 ABA와 IAA처리는 오존처리구에서 엽록소함량의 감소를 작게 하였다. 3. 오존에 3일간 처리한 담배는 산화형 ascorbate가 환원형 ascorbate 보다 높게 나타났으며 ABA와 IAA를 처리한 구에서는 오존 처리구보다 산화형 ascorbate가 낮게 나타났으나 7일간 오존을 처리한 구에서는 처리간에는 차이가 나타나지 않았다. 4. 3일간 오존 처리시 superoxide dismutase(SOD) 활성은 무처리구에 비하여 증가하였고 ABA 및 IAA $10^{-3}$M에서는 다른 처리구에 비하여 증가가 뚜렷하였으며, 7일간 처리에서도 SOD의 활성이 증가하였으나 식물생장조절제의 처리 효과는 나타나지 않았다. 5. Ascorbate peroxidase와 guaiac이 peroxidase 활성은 오존무처리구에서도 모두 증가하였으나, 7일간 처리시는 두 효소 모두 처리간에는 변화가 없었다.