• Title, Summary, Keyword: oxygen-tolerance

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Tolerance of Anaerobic Granular Sludge to Oxygen

  • Shiru Jia;Benyi Xiao;Choi, Du-Bok;Cho, Ki-An;Kim, Young-Sik
    • Korean Journal of Environmental Biology
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    • v.21 no.4
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    • pp.405-409
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    • 2003
  • To study the tolerant capacity of anaerobic granular sludge (AGS) to oxygen using semi -dynamic batch experiment, the aerating time, pH of the basal media, reductive inorganic materials, microorganism, and microorganism metabolite were investigated. When the aerating time was higher or lower than 0.5 h, the producing gas activity of sludge was lower than that of the control. The oxygen tolerance of the experimental sludge was the highest at the initial pH 7.2. The producing gas activity of sludge I was higher than that of sludge II. And storage at $4^{\circ}C$ can low the lose of the oxygen tolerance capacity of granular sludge. The producing gas activity of sludge was the highest when KI was added. The growth of aerobic microorganisms and some metabolite could increase the producing gas activity of granular sludge.

Experimental Studies on Oxygen Tolerance and Poisoning under Hyperbaric Oxygen Environment (고압산소환경(高壓酸素環境)에서의 산소중독(酸素中毒) 및 내성(耐性)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Lee, Won-Chang
    • Korean Journal of Veterinary Research
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    • v.9 no.1
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    • pp.11-22
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    • 1969
  • Experimental studies were performed to observe the difference in tolerance of small animals to oxygen poisoning, and also to examine the effects of certain drug for it. The three experimental groups consisted of mature rat group, immature rat group and mouse group. The animals were exposed to 5 atm. of 100% oxygen using hyperbaric chamber, and they were observed for oxygen poisoning by pulmonary and central nervous system manifestation. The tolerance to oxygen poisoning was represented by half fatality time in each experimental group. The drug applied was ammonium chloride $NH_4Cl$ and it was administered intraperitoneally in various dosages for particular attribution of its prophylactic effect. The following conclusions were made; 1. The immature rat group showed the higher degree of tolerance to oxygen poisoning, as evidenced by a more prolonged half fatality time in the group. No significant difference in the half fatality time between the mature rat and the mouse group was observed. 2. The fact that the immature group showed the higher degree of tolerance as compared with the mature rat group represented by delayed onset of convulsion. 3. There was a remarkable difference in the Lung Weight/Body Weight ratio between the experimental and control group. 4. The animals with a shorter half fatality time uniformally displayed an earlier onset of convulsive seizure as the sign of oxygen poisoning and a significant elevated Lung Weight/Body Weight ratio. 5. Ammonium chloride at the dosage of 450mg per kg body weight had the most pronounced prophylactic effect on oxygen poisoning.

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Effect of Oxygen and Unsaturated Fatty Acids on the Ethanol Tolerance of Yeast Strains

  • Ryu, Yeon-Woo;Jang, Heang-Wook
    • Journal of Microbiology and Biotechnology
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    • v.1 no.1
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    • pp.6-11
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    • 1991
  • This study deals with investigation of the ethanol tolerance of yeast strains with respect to fatty acid composition and intracelluar ethanol concentration during alcohol fermentation. The cell viabilities and fermentation abilities of Saccharomyces cerevisiae and Kluyveromyces fragilis were improved by aeration and addition of unsaturated fatty acids into growth medium. Aeration decreases the accumulation of ethanol, while increases unsaturated fatty acid contents inside yeast cells. Thus it was found that oxygen and unsaturated fatty acids play decisive roles in the increase of ethanol tolerance of yeasts.

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Activities of Oxidative Enzymes Related with Oxygen Tolerance in Bifidobacterium sp.

  • Shin, Soon-Young;Park, Jong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.7 no.5
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    • pp.356-359
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    • 1997
  • To study the relationship between oxygen tolerance and enzyme activity in the oxygen metabolism of bifidobacteria, the activities of catalase, superoxide dismutase (SOD), NADH oxidase and NADH peroxidase from six typical bifidobacteria and other bacteria were assayed by spectrophotometry. Catalase activity was hardly detected in any of the bifidobacteria tested. SOD activity was detected in every species including the Clostridium species. In particular SOD activity was notably high in the aerosensitive Bifidobacterium adolescentis. This fact indicates that SOD activity is not a critical factor to ensure aerotolerance. Aerosensitive B. adolescentis showed very low NADH oxidative enzyme activity whereas other aerotolerant bifidobacteria exhibited considerable activity for the enzymes. It seems that detoxification of $H_2O_2$ by NADH oxidative enzymes might be an important factor in improving for aerotolerant bifidobacteria survival rates in an oxygen environment.

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Antioxidant Activity and Tolerance to Reactive Oxygen Species of Lactobacillus spp. (Lactobacill spp. 의 황산화 효과 및 활성산소에 대한 내성)

  • Kim, H.S.;Jeong, S.G.;Chae, H.S.;Ham, J.S.;Ahn, C.N.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.46 no.6
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    • pp.1007-1012
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    • 2004
  • The four Lactobacillus spp. were investigated for their antioxidant properties, including antioxidant activity, tolerance to reactive oxygen species, hydroxy radical scavenging activity and ferrous iron che1ating activity. Also, activities of superoxide dismutase and glutathione peroxidase were investigated. From the results of this work, the intact cell and cell lysate of L. casei KCTC 3260 were exhibited highest antioxidant activity. L. casei KCTC 3260 also showed strong tolerance to reactive oxygen species. This strain showed highest glutathione peroxidase activity among the tested strains.

Screening of Cholesterol-lowering Bifidobacterium from Guizhou Xiang Pigs, and Evaluation of Its Tolerance to Oxygen, Acid, and Bile

  • Zhang, Rujiao;He, Laping;Zhang, Ling;Li, Cuiqin;Zhu, Qiujin
    • Food Science of Animal Resources
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    • v.36 no.1
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    • pp.37-43
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    • 2016
  • Cardiovascular and cerebrovascular diseases seriously harm human health, and Bifidobacterium is the most beneficial probiotic in the gastrointestinal tract of humans. This work aimed to screen cholesterol-lowering Bifidobacterium from Guizhou Xiang Pig and evaluate its tolerance to oxygen, acid, and bile. Twenty-seven aerotolerant strains with similar colony to Bifidobacterium were isolated through incubation at 37℃ in 20% (v/v) CO2-80% (v/v) atmospheric air by using Mupirocin lithium modified MRS agar medium, modified PTYG with added CaCO3, and modified PTYG supplemented with X-gal. Ten strains with cholesterol-lowering rates above 20% (w/w) were used for further screening. The selected strains’ tolerance to acid and bile was then determined. A combination of colony and cell morphology, physiological, and biochemical experiments, as well as 16S rRNA gene-sequence analysis, was performed. Results suggested that BZ25 with excellent characteristics of high cholesterol-removal rate of 36.32% (w/w), as well as tolerance to acid and bile, was identified as Bifidobacterium animalis subsp. lactis. To further evaluate Bifidobacterium BZ25’s growth characteristic and tolerance to oxygen, culture experiments were performed in liquid medium and an agar plate. Findings suggested that BZ25 grew well both in environmental 20% (v/v) CO2-80% (v/v) atmospheric air and in 100% atmospheric air because BZ25 reached an absorbance of 1.185 at 600 nm in 100% atmospheric air. Moreover, BZ25 was aerotolerant and can grow in an agar medium under the environmental condition of 100% atmospheric air. This study can lay a preliminary foundation for the potential industrial applications of BZ25.

Differential Frost Tolerance and Enzymatic Activities in the Leaves and Immature Fruits of Loquat (Eriobotrya japonica Lindl.)

  • Zheng, Guohua;Niu, Xianqian;Zhang, Jinbiao;Wu, Hanwen;Lin, Xiuxiang;Pan, Dongming
    • Horticultural Science & Technology
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    • v.33 no.3
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    • pp.309-316
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    • 2015
  • In this experiment, five commercial cultivars and one wild species of loquat were used to investigate frost tolerance and enzymatic activities in leaves and young fruits under cold stress at $-3^{\circ}C$. The frost injury, malondialdehyde (MDA) content, and oxygen-scavenging enzyme activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were studied. This results showed that the wild species 'Wild Oak-leaf' loquat was the most frost tolerant among accessions tested, followed by the cultivar 'Golden Block'. Other cultivars, 'Wu Gong Bai', 'Taicheng 4', 'Xiangzhong 11' and 'Zaozhong 6', were relatively weak in frost tolerance. The enzymatic activities of SOD, POD and CAT increased initially and then decreased as the exposure time increased. However, the enzymatic peak occurred later in the frost-tolerant accession than in the frost-sensitive accession. The correlation coefficients of MDA contents between leaves and immature fruits were from 0.93 to 0.99 in the five commercial loquat cultivars. For the 'Wild Oak-leaf' loquat, the correlation coefficients of MDA and POD were 0.98 and 0.95, respectively, but the coefficients for SOD, CAT and APX were relatively low. In general, there were good correlations between loquat leaves and immature fruits in MDA content and enzyme activities. These results indicate that analysis of these physiological and biochemical activities in loquat leaves could potentially be used to predict the cold tolerance in loquat at immature fruit stage and to accelerate breeding programs for cold tolerance in loquat.

Overexpression of OsNAC17 enhances drought tolerance in rice

  • Kim, Tae Hwan;Kim, Ju-Kon
    • Proceedings of the Korean Society of Crop Science Conference
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    • pp.168-168
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    • 2017
  • Drought conditions during cultivation reduce agricultural production yield less than a theoretical maximum yield under normal condition. Plant specific NAC transcription factors in rice are known to play an essential roles in stress resistance transcriptional regulation. In this study, we report the rice (Oryza sativa L japonica) NAM, AFTF and CUC transcription factor OsNAC17, which is predominantly induced by abiotic stress in leaf, was contribute to the drought tolerance mediated reactive oxygen species (ROS) in transgenic rice plants. Constitutive (PGD1) promoter was introduced to overexpress OsNAC17 and produced the transgenic PDG1:OsNAC17. Overexpression of OsNAC17 throughout the whole plant improved drought resistance phenotype at the vegetative stage. Morphological characteristics such as grain yield, grain filling rate, and total grain weight improved by 22~64% over wild type plants under drought conditions during the reproductive stage. The improved drought tolerance in transgenic rice was involved in reducing stomatal density up to 15% than in wild type plants and in increasing reactive oxygen species-scavenging enzyme. DEG profiling experiment identified 119 up-regulated genes by more than twofold (P<0.01). These genes included UDP-glycosyltransferase family protein, similar to 2-alkenal reductase (NADPH-dependent oxireductase), similar to retinol dehydrogenase 12, Lipoxygenase, and NB-ARC domain containing protein related in cell death. Furthermore, OsNAC17 was act as a transcriptional activator, which has an activation domain in C-terminal region. These result demonstrate that the overexpression of OsNAC17 improve drought tolerance by regulating ROS scavenging enzymes and by reducing stomatal density

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Development of Cell Entrapment Technology for the Improvement of Bifidobacterium Viability (Bifidobacterium의 생존력 증대를 위한 세포포집기술개발)

  • Park, Hui-Gyeong;Bae, Gi-Seong;Heo, Tae-Ryeon
    • KSBB Journal
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    • v.14 no.4
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    • pp.389-395
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    • 1999
  • Bifidobcterium spp. can provide human being with several beneficial physiological. Therefor, there has been a considerable interest in products Bifidobcterium spp. dietary supplements or as starter cultures for probiotic products that may assint in the improvement of health on the human. But indusrial applications have been limited because Bifidobcterium spp. are sensitive to acidic pH due to organic acid produced by themselves and various conditions. The objective of this study was to establish new method for improvement of Bifidobcterium viability by entrapment im calcium alginate beads. We have a plan to select the most suitable polymer through the comparison with acid tolerance oxygen tolerance and theological properties of polymer. Increase of the viable number of Bifidobcterium induced increasing acid tolerance and oxygen tolernce trough the development of entrapment technique. The 4%, 3030mm diameter) sodium alginate beads led to the best survivability under acid condition. Especially, addition of 6% mannitol, 6% glycerol or 6% sorbitol to the sodium alginate helped a beneficial effect on viability against acid, bile salt, hydrogen peroxide and cold strage. The number of viability of entrapeede cells by retreatment was 96 fold higher than non-entrapeed cells after 5 hours of storage under pH 3 acidic condition. These experimental data clearly demonstrate that a whole cell immobilization by entrapment in calcium alginate beads is an important survival mechanism enable to withstand environmental stresses as the acidic condition, hydrogen peroxide toxicity and frozen state.

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Oxygen Permeability and Resistance to Carbon Dioxide of SrCo0.8Fe0.1Nb0.1O3-δ Ceramic Membrane (SrCo0.8Fe0.1Nb0.1O3-δ 세라믹 분리막의 산소투과 특성 및 이산화탄소에 대한 내성)

  • Kim, Eun Ju;Park, Se Hyoung;Park, Jung Hoon;Baek, Il Hyun
    • Membrane Journal
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    • v.25 no.5
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    • pp.415-421
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    • 2015
  • $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ oxide was synthesized by solid state reaction method. Dense ceramic membrane was prepared using as-prepared powder by pressing and sintering at $1250^{\circ}C$. XRD result of membrane showed single perovskite structure. The oxygen permeability were measured under 0.21 atm of oxygen partial pressure ($P_{O_2}$) and between 800 and $950^{\circ}C$. The oxygen permeation flux of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ membrane was increased with the increasing temperature. The maximum oxygen permeation flux was $1.839mL/min{\cdot}cm^2$ at $950^{\circ}C$. Long period permeability experiment was carried out to confirm the phase stability and $CO_2$-tolerance of membrane containing Nb in the condition of air with $CO_2$ (500 ppm) as feed stream at $900^{\circ}C$. The phase stability and $CO_2$-tolerance of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ were investigated by XRD and TG analysis. The result of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ which exposed carbon dioxide for 100 hours indicated 8wt% of $SrCO_3$. But it was known that the level of $SrCO_3$ production dose not have a significant effect on oxygen permeability.