• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.64.1-64.1
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• 2008

• 한국농림기상학회지
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• 제7권3호
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• pp.220-226
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• 2005

오존 노출이 버즘나무의 광합성 특성에 미치는 영향을 조사하기 위하여, 2년생 버즘나무 유묘에 하루에 8시간씩 100 ppb의 오존을 처리하였다. 오존 처리를 진행하는 동안, 3주마다 버즘나무의 엽내 엽록소 함량과 광합성 특성을 측정하였다. 오존에 의한 잎의 가시적 피해는 나타나지 않았으며, 또한 엽내 엽록소 함량은 대조구와 뚜렷한 차이를 보이지 않았다. 그러나 광합성량, 기공전도도, 수분이용효율은 오존 처리 6주 후에 대조구보다 감소하였다. 한편 탄소고정효율과 광화학 효율은 오존 처리 3주와 6주 후에서 감소한 것으로 나타났다. 위의 결과를 토대로 볼 때, 탄소고정효율은 오존 스트레스에 가장 민감한 파라미터로 나타났으며, 이것은 오존 민감성을 평가하기 위한 매우 적당한 지표로 생각되었다.

• ALGAE
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• 제24권2호
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• pp.93-104
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• 2009

Imaging-PAM fluorometry was used to assess the chlorophyll a fluorescence parameter ${\Phi}_{PSII}$ (effective quantum yield) in Frcus vesiculosus. F. disttchus. ssp. distichus and AscophyIIum nodosum. The objective was to show variadon in fluorescence yield associated with age and frond organ, and to illustrate the spatial scales at which photosynthetic parameters vary on fucoid thalli. In addition, our species represented taxa in different but related genera, species with different ecoloeies (rock pool and non rock pool species), morphologies (with and without air bladders) and longevities (several to 20 or more years). A further objective was to determine the extent to which photosynthetic parameters reflected these differences- Effective quantum yield declined substantially with age in F. vesiculosus and F. distichus ssp. distichus, whereas ${\Phi}_{PSII}$ in A. nodosum was maximal after three years. In A. nodosum ${\Phi}_{PSII}$ was still high in branch segments at least seven years old. Older branches of A. nodosum showed relatively higher and more homogeneous photosynthetic capacity relative to Fucus species. Surfaces of air bladders in A. nodosum and F. vesicu- losus had ${\Phi}_{PSII}$ that was not significantly different from the highest rates, achieved in these species. The heterogene- ity of photosynthetic efficiency is consistent with morphological and developmental differences among the species and their ecology. in particular the longevity of A. nodosum fronds.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.962-971
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• 2002

The current study proposes a simple monodimensional model to estimate the linear growth rate of photosynthetic microorganisms in flat-plate photobioreactors (FPPBRs) during batch cultivation. As a model microorganism, Chlorella kessleri was cultivated photoautotrophically in FPPBRs using light-emitting diodes (LEDs) as the light sources to provide unidirectional irradiation in the photobioreactors. Various conditions were simulated by adjusting both the intensity of the light and the height of the culture. The validity of the proposed model was examined by comparing the linear growth rates measured with the predicted ones obtained from the proposed model. Accordingly, the value of $\frac{K\cdot\mu m}{\alpha\cdot L}log(I_0\cdot{I_s}^{\varepsilon 1)\cdot {I_c}^{-\varepsilon})$ was proposed as an approximate index for strategies to obtain the maximal lightn yield under light-limiting conditions for high-density algal cultures and as a control parameter to improve the photosynthetic productivity and efficiency.

• 한국초지조사료학회지
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• 제42권3호
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• pp.208-214
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• 2022

Drought stress is a condition that occurs frequently in the field, it reduces of the agricultural yield of field crops. The aim of the study was to screen drought-adapted genotype of Italian rye grass. The experiments were conducted between the two Italian ryegrass (Lolium multiflorum L.) cultivars viz. Hwasan (H) and Kowinearly (KE). The plants were exposed to drought for 14 days. The results suggest that the morphological traits and biomass yield of KE significantly affected by drought stress-induced oxidative stress as the hydrogen peroxide (H₂O₂) level was induced, while these parameters were unchanged or less affected in H. Furthermore, the cultivar H showed better adaptation by maintaining several physiological parameter including photosystem-II (Fv/Fm), water use efficiency (WUE) and relative water content (RWC%) level in response to drought stress. These results indicate that the cultivar H shows improved drought tolerance by generic variation, improving photosynthetic efficiency and reducing oxidative stress damages under drought stress. These findings can be useful to the breeder and farmer for improving drought tolerance in Italian rye grass through breeding programs.

• 한국해양바이오학회지
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• 제14권2호
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• pp.112-123
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• 2022

Photosynthetic bacteria (PSB) play an important role in water purification, and their application is beneficial for sustainable aquaculture. However, maintaining the microbial stability of PSB from subculturing to preservation is a challenging task. Since improvement in the microbial stability of PSB is a crucial parameter, optimized conditions for cell immobilization and lyophilization were investigated. In PSB immobilization, 0.1-M CaCl₂ was found to be the most effective divalent metal ion solution in terms of cost-effectiveness, resulting in beads with a 4-mm diameter and high loading (1.91×10⁹ CFU/mL) of viable cells. Maintenance of cell viability, external appearance, and color of PSB beads was best in 3.5% NaCl during storage. In lyophilization, the addition of skim milk (9%) and dextrose (2%) as cryoprotective additives allowed the highest cell viability. Over an 18-week shrimp breeding period, when optimally manufactured beads and lyophilized powder of PSB were applied to shrimp aquaculture water, NH⁴⁺, NO₃^-, and NO₂^- were more effectively removed by 55%, 100%, and 100%, respectively, compared to controls. Thus, microbial stability of PSB through optimized cell immobilization and lyophilization was successfully enhanced, enabling a wide application.

• 한국미생물·생명공학회지
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• 제13권3호
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• pp.303-309
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• 1985

Continuous production of hydrogen by Ca alginate-immobilized photosynthetic bacteria was studied in a packed-bed bioreactor. The dilution rate and input concentration of carbonaces substrate were selected as operating parameters. To choose the strain for immobilization, hydrogen productivities of Rhodopseudomonas caposulata 10006 and Rhodospirillum rubrum KS-301 were compared through preliminary batch cultures of their free cells: the former was found to show better hydrogen productivity in spite of its lower specific growth rate. For the continuous production of hydrogen by immobilized R capsulata, the optimum dilution rate was about 0.84 h$^{-1}$ . The Immobilized tells gave better hydrogen yield and conversion efficiency than free ones. And a kinetic parameter K'$_{m}$ was determined for the packed-bed bioreactor, being practically constant for a specific range of dilution rates.s.

• 한국농림기상학회지
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• 제12권3호
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• pp.173-182
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• 2010

본 연구는 오존에 노출된 회화나무 8 가계에서 측정한 생리적 지표들을 대상으로, 오존에 대한 민감성을 평가하고, 이 결과들을 종합하여 가계 간 차이를 구명하고자 실시하였다. 회화나무(Sophora japonica L.) 8가계를 대상으로 오존 처리 후, 광합성 특성, 엽록소 함량, 항산화효소 활성 및 MDA 함량을 측정하였고, 각 측정 지표들의 표준화 지수를 이용하여 내성 순위를 결정하였다. 탄소고정효율은 6번 가계를 제외한 모든 가계에서 오존 처리 후 뚜렷하게 감소하였으며, 탄소고정효율의 감소율은 -38%에서 -67% 범위를 보였다. 또한 순양자수율은 7번 가계를 제외한 모든 가계에서 오존 처리 후 뚜렷한 감소를 보였으며, 감소율은 -27%에서 -61%를 나타냈다. 엽록소 a를 비롯한 광색소 함량의 가계 간 차이는 컸으나, 오존 처리 효과는 나타나지 않았다. 오존 처리 후, SOD 활성의 증가율은 7%에서 64%로, 가계 간 차이가 뚜렷하였다. APX 활성은 모든 가계에서 오존 처리 후 증가하였으며, 7번 가계가 가장 큰 활성 증가율(218%)을 보였다. 표준화 지수를 기준으로 할 때, 6번 가계의 내성 수준이 가장 낮았으며, 7번 가계의 내성 수준이 가장 높았다. 6번 가계는 오존 처리 후 탄소고정효율을 비롯한 광합성 특성의 감소율과 광색소 함량의 감소율이 높게 나타난 반면, 내성을 나타내는 항산화효소의 활성 증가가 매우 적었다. 반대로 내성 수준이 높은 7번 가계는 오존 처리 후 광합성 특성의 감소율이 다른 가계에 비해 적었으며, 광색소 함량은 오히려 오존처리 후 증가하였고, 항산화효소의 증가율도 다른 가계에 비해 높게 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권3호
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• pp.189-193
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• 2001

Critical cell density (CCD), the maximum cell concentration without mutual shading in algal cultures, can be used as a new operating parameter for high-density algal cultures and for the application of the flashing light effect on illuminated algal cultures. CCD is a function of average cell volume and light illumination area. The CCD is thus proposed as an index of estimation of mutual shading in algal cultures. Where cell densities are below the CCD, all the cells in photobioreactors can undergo photosysnthesis at their maximum rate. At cell densities over CCD, mutual shading will occur and some cells in the illumination chamber cannot grow photoautotrophically. When the cell concentration is higher than the CCD, specific oxygen production rates under flashing light were higher than those under continuous light. The CCD was found to be a useful engineering parameter for the application of flashing light, particularly in high-density algal cultures.

• 한국산림과학회지
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• 제99권6호
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• pp.878-884
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• 2010

오존에 노출된 갈참나무 4가계의 오존 내성 차이와 생리적 지표들의 오존 민감성은 광합성 특성, 광색소 함량, MDA 함량 및 항산화효소 활성과 같은 생리적 지표들을 표준화하여 결정하였다. 오존 처리 후, 갈참나무의 잎내 탄소고정효율 감소는 4가계 모두에서 관찰되었으며, 그들의 감소율은 대조구의 -24.1%에서 -56.9% 범위를 보였다. 광색소 함량은 가계 간 및 처리 간 차이가 뚜렷하였으며, 총 엽록소 함량의 감소는 SU4 가계에서 가장 높았고 (-40.6%), US2 가계에서 가장 낮았다(-18.8%). APX 활성은 가계 간 및 처리 간 차이를 뚜렷하게 보였으며, US2 가계를 제외한 3가계에서 대조구보다 높게 나타났다. 생리적 지표들을 기준으로 한, 갈참나무 4가계의 오존 내성은 US1 > SU4 > US2 > SU1의 순으로 나타났다. 결론적으로 광합성 특성, 광색소 함량과 APX 활성은 갈참나무의 오존 스트레스 내성을 평가하는데 적절한 지표로 판단된다.