• Title/Summary/Keyword: Incubation period

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수용성 황색색소를 분비하는 Bacillus sp. PY123균주의 분리 및 특성

  • 김지연;김광현
    • Microbiology and Biotechnology Letters
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    • v.25 no.5
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    • pp.454-458
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    • 1997
  • To develop a yellow pigment for a food-additive, a strain producing a water-soluble yellow pigment was isolated from phylloplane of tree leaf. The strain PY123 was identified a Bacillus sp. based on morphological and biochemical characterization such as a bacillus form, mortility, spore formation, Gram positive, and catalase production. The pigment production of the strain PY123 was increased about 3 times in patato broth containing 1% sucrose and 0.1 mM CoCl$_{2}$ than in only potato broth after incubation at 30$circ$C, for 2 days. When 0.1 mM CoCl$_{2}$, was added in potato broth containing 1% sucrose at late log phase during incubation of the strain PY123, cell growth was not inhibited, and the period at maximal pigment production of the strain PY123 was about 12hrs faster than in potato broth containing 1% sucrose and 0.1 mM CoCl$_{2}$, simultaniously.

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Effect of Endogenous IAA Transport on Adventitious Root Formation in Phaseolus vulgaris Hypocotyl Cuttings (강낭콩 하배축 절편의 부정근형성에 미치는 내재 IAA의 이동)

  • 조덕이
    • Journal of Plant Biology
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    • v.32 no.4
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    • pp.323-330
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    • 1989
  • This work was carried out to elucidate effects of endogenous and exogenous IAA transport on adventitious root formation in Phaseolus vulgaris hypocotyl cuttings. For inverted or normal incubation in distilled water, the adventitious root is always formed at the morphological base but not at the morphological apex. For inverted incubation, in both distilled water and certain chemical solution, the root formation is retarded more at the first stage (0-24 hr) than at the second stage (24-48 hr). When p-chlorophenoxyisobutyric acid (PCIB) was applied to the cuttings at the first stage, theroot formation was inhibited more than at the second stage. Treatment of 2,3,5-triiodobenzoic aicd (TIBA)markedly inhibited the adventitious root formation in Phaseolus vulgaris hypocotyl cuttings. This inhibition influenced the root according to the applied stage and period. Therefore, the root formation is more related to the stage of root primordium formation than to the stage of root elongation from the primordium. Inhibition of auxin transport oraction by TIBA or PCIB could also be reversed when hypocotyl cuttings are incubated in exogenously applied IAA solution.

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Studies on the modified dark incubation (암최청에 대한 연구)

  • 김윤식
    • Journal of Sericultural and Entomological Science
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    • v.10
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    • pp.59-62
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    • 1969
  • It is very important physiological and economical problems to hatching within a day by increasing hatching-ratio of silkworm eggs in sericulture, and modified dark incubating method was experimented in Japan. The author studied on the economical problems of that rather than physiological study. Hatching was induced and accelerated by illumination before hatching 5 days which incubated in the dark room after eye spot pigmented eggs emerged 10-20 percentage. It was increased by 80-90% in hatching-ratio, but the hatching was delayed a day. In autumn silkworm, newly hatched silkworms were hatched silkworms were hatched in the dark room because of high temperature period tough modified dark incubation was passed only 4 days. The author wonder which is more effective between effect of increasing the hatching-ratio and the health of silkworms.

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Effects of Individual Fatty Acids on Receptor-Mediated Binding, Internalization and Degradation of $[^{125}I]LDL$

  • Choue, Ryo-Won;Cho, Byung-Hee Simon
    • BMB Reports
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    • v.30 no.1
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    • pp.1-6
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    • 1997
  • The ability of Hep-G2 cells to process $[^{125}I]LDL$ under basal conditions was investigated. The receptor-binding and internalization of $[^{125}I]LDL$ increased with the time of incubation in a saturable manner. After 4 h of incubation, 31.4 ng of $[^{125}I]LDL$ was cell bound. The cells rapidly internalized $[^{125}I]LDL$ via specific, receptor-mediated endocytosis. The amount of internalized $[^{125}I]LDL$ reached a maximun of 96.7 ng at 2 h of incubation and remained constant for the next 2 h. The rate of degradation of internalized $[^{125}I]LDL$ proceeded in a linear manner over the entire 4 h of incubation after an initial lag period. The effects of individial fatty acids (C18:0. C18:1, C18:2. and C18:3), differing in their degree of unsaturation. on the receptor-binding, internalization and degradation of $[^{125}I]LDL$ were also investigated. Inclusion of 1.0 mM of each fatty acid into the culture medium significantly increased $[^{125}I]LDL$ metabolism in Hep-G2 cells. Among the fatty acids tested, stearic acid had the least effect on the receptor-binding activity. There were no significant differences among the unsaturated fatty acids in LDL-receptor binding. The effect of individual fatty acids on the $[^{125}I]LDL$ uptake was similar to that of the receptor-binding. showing a significantly lower effect with stearic acid. The amount of degraded material of internalized $[^{125}I]LDL$ was the lowest with stearic acid when it was compared with unsaturated fatty acids.

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On the Red Cell Fragility in the Normal and Anemic Professional Blood Donors (건강인(健康人) 및 직업적(職業的) 매혈(賣血)로 인(因)한 실혈성(失血性) 빈혈자(貧血者)의 적혈구(赤血球) 취약성(脆弱性)에 관(關)하여)

  • Lee, Suck-Kang;Yoo, Kwang-Soo;Kim, Hyung-Kyu;Kwak, Dong-Soo
    • The Korean Journal of Physiology
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    • v.5 no.2
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    • pp.1-7
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    • 1971
  • The osmotic and mechanical red cell fragility of the professional blood donors, who were found to be anemic as the result of frequent and repeated blood loss the past 5-6 years, were compared with that of the normal person while incubating the blood at $4-6^{\circ}C$ for 28 days. The fragility was expressed as % hemolysis occured during the incubation, and the following results were obtained: 1. The osmotic fragility in the normal persons (i.e, ; control group) progressively increased as the incubation became longer, and % hemolysis in 0.42% NaCl solution at 0, 10, 15, 21 and 28 incubation day was 31.90, 50.20, 41.68, 43.50 and 55.40 respectively. The mechanical fragility. in the normal red cells ranged between the minimum of 0.00% to the maximum of 5.80% both in 0.90 and 0.66% of NaCl solutions. 2. The hemolysis curve obtained in the red cell osmotic fragility from three cases of the anemic persons (i.e,; experimental group) showed a significant left side shift comparing with the normal in general which indicates that the fragility was more increased in the experimental group. The mechanical fragility in the experimental group ranged between the minimum 0.00% to the maximum 19.00% both in 0.90 and 0.66% of NaCl solutions. 3. The red cells of the chronic anemic person due to the frequent blood loss as the professional blood donor exhibit significantly marked increase both in osmotic and mechanical fragility comparing with the normal, and the tendency was more prominent as the incubation period became longer.

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Isolation and Identification of a Lactic Acid Bacterial Strain KJ-108 and Its Capability for Deodorizing Malodorous Gases Under Anaerobic Culture Conditions

  • KIM, JEONG-DONG;JUNG-HOON YOON;YONG-HA PARK;DAE-WEON LEE;KYOU-SEUNG LEE;CHANG-HYUN CHOI;WON-YEOP PARK;KOOK-HEE KANG
    • Journal of Microbiology and Biotechnology
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    • v.13 no.2
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    • pp.207-216
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    • 2003
  • A number of different sources, such as composts, leachates, and pig feces samples, were collected from different pig farms in Korea, and several microorganisms were screened for their ability to deodorize the malodorous gases. Consequently, a novel malodorous gases-deodorizing bacterial strain, KJ-108. was isolated, because it was highly abundant in nitrate-supplemented minimal medium ($MM-NO_3^-$) under anaerobic culture conditions. Airtight crimp-sealed serum bottles containing $MM-NO_3^-$ , medium were inoculated with KJ-108. Nitrate concentration was decreased rapidly after 20 h of incubation, and incubation was carried out until nitrite production reached almost zero. Taxonomic identification, including 16S rDNA base sequencing and phylogenetic analysis, indicated that the isolate had $100\%$ homology in its 165 rDNA base sequence with Lactobacillus pentosus. Among the volatile fatty acids, acetic acid contained in large amounts in fresh piggery slurry was decreased by about $40\%$ after 50 h incubation with strain KJ-108. n-Butyric acid, n-valeric acid, and isovaleric acid were gradually decreased, and isobutyric acid and capronic acid were dramatically eliminated at theinitial period with the treatment. Moreover, NH, removal efficiency reached a maximum of $98.5\%$ after 50 h of incubation, but the concentration of $H_2S$ was not changed.

Biohydrogenation of Linoleic Acid and Stearic Acid Production by Mixed Rumen Fungi and Bacteria (반추위내 서식하는 혼합곰팡이와 박테리아에 의한 Linoleic Acid 가수소화반응과 Stearic Acid 생산에 관한 연구)

  • Nam, In-Sik
    • Korean Journal of Microbiology
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    • v.43 no.2
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    • pp.100-105
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    • 2007
  • The objective of this study was to confirm biohydrogenation of linoleic acid and stearic acid production by mixed men fungi and bacteria. In mixed fungal biohydrogenation study, when linoleic acid solution was added to fungal culture (after 24 hr pre-incubation), all linoleic acids were converted to trans-11 vaccenic acid via cis-9, trans-11 conjugated linoleic acid production within 24 hr period of incubation. All linoleic acid solution was hydrogenated to trans-11 vaccenic acid within 24 hr incubation and this was continued until the end of incubation (48 hr). Both treatments (added linoleic acid solution or the same amount of solution without containing linoleic acid into fungal cultures) produced the similar amount of stearic acid. In contrast, 100% of linoleic acid solution was hydrogenated to stearic acid in mixed bacterial culture. It is concluded that the end product of mixed fungal biohydrogenation of linoleic acid is trans-11 vaccenic acid whereas mixed bacteria produced stearic acid as an end product of their biohydrogenation.

Survival and Performance of Two Cellulose-Degrading Microbial Systems Inoculated into Wheat Straw-Amended Soil

  • Li, Peipei;Zhang, Dongdong;Wang, Xiaojuan;Wang, Xiaofen;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.1
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    • pp.126-132
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    • 2012
  • A cellulose-degrading composite microbial system containing a mixture of microbes was previously shown to demonstrate a high straw-degrading capacity. To estimate its potential utilization as an inoculant to accelerate straw biodegradation after returning straw to the field, two cellulose-degrading composite microbial systems named ADS3 and WSD5 were inoculated into wheat straw-amended soil in the laboratory. The microbial survival of the inoculant was confirmed by a denaturing gradient gel electrophoresis (DGGE) analysis, whereas the enhancement of straw degradation in soil was assessed by measuring the mineralization of the soil organic matter and the soil cellulase activity. The results indicated that most of the DGGE bands from ADS3 were detected after inoculation into straw-amended autoclaved soil, yet only certain bands from ADS3 and WSD5 were detected after inoculation into straw-amended non-autoclaved soil during five weeks of incubation; some bands were detected during the first two weeks after inoculation, and then disappeared in later stages. Organic matter mineralization was significantly higher in the soil inoculants ADS3 and WSD5 than in the uninoculated controls during the first week, yet the enhanced degradation did not persist during the subsequent incubation. Similar to the increase in soil organic matter, the cellulase activity also increased during the first week in the ADS3 and WSD5 treatments, yet decreased during the remainder of the incubation period. Thus, it was concluded that, although the survival and performance of the two inoculants did not persist in the soil, a significant enhancement of degradation was present during the early stage of incubation.

Studies on the Decomposition of Environmental Pollutants by Utilizing Microorganisms (미생물을 이용한 환경오염원의 분해에 관한 연구 II)

  • 이재구;김기철;김창한
    • Korean Journal of Microbiology
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    • v.20 no.2
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    • pp.53-66
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    • 1982
  • 1. When Chong Ju and Chung Ju soils possessing different physicochemical properties were treated with 500 ppm of TOK and incubated in flooded anaerobic condition for 2, 4, and 6 months, respectively, they produced 4-Chloro-4'-amino diphenyl ether, 2,4-Dichloro-4'-amino diphenyl ether(amin-TOK), N-[4'-(4-Chlorophenoxy)] phenyl acetamide, and N-[4'-(4-Chlorophenoxy)] phenyl formamide as the metabolities. This result indicates that TOK undergose the reduction of its $NO_2\;to\;NH_2$ group, dechlorination, acetylation, and formylation under this condition. The cleavage of ether linkage does not occur. In addition, TOK degrades more readily in Chung Ju soil which is characterized by pH 6.43 and higher contents of $Ca^{++}$ and C.E.C. than in Chong Ju soil which is lower in pH, $Ca^{++}$, and C.E.C. 2. In the aerobic incubation of TOK of 25ppm in Chung Ju soil suspension for 21 days, the ratio of the resulting metabolites, TOK : amino-TOK : 4-Chloro-4'-amino diphenyl ether was 100 : 130 : 76. Meanwhile, in the 42 day incubation, the ratio was 100 : 19 : 5, which indicates that TOK in aerobic condition dose not necessrily degrade as a function of the incubation period. 3. The citrate buffer extract of Chung Ju soil has the capability of degrading TOK, which was verified to be due to the action of the microorganisms involved. 4. Twelye strains of soil bacteria were isolated from the TOK-treated soils. In the incubation of TOK in pure cultures of the respective isolates, the strain T-1-1 isolated from Chong Ju soil had almost no degradability whereas the strain T-2-3 was the most potent. The degradation of TOK by the isolates constituted mostly the reduction of the nitro group to amino group. 5. In a test for the degradability of TOK by some selected microorganisms, Pseudomonas species were more potent than fungi. Yet, Isolate B which had been isolated from Chung Ju soil suspension was the most potent.

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Available Organic Carbon Controls Nitrification and Immobilization of Ammonium in an Acid Loam-Textured Soil

  • Choi, Woo-Jung;Lee, Sang-Mo;Han, Gwang-Hyun;Yoon, Kwang-Sik;Jung, Jae-Woon;Lim, Sang-Sun;Kwak, Jin-Hyeob
    • Journal of Applied Biological Chemistry
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    • v.49 no.1
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    • pp.28-32
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    • 2006
  • Effect of organic-C on immobilization and nitrification patterns in acidic soil was examined during 20 weeks incubation period to verify if organic amendments such as composted material can increase soil retention of N by stimulating microbial immobilization of $NH_4^+$. Four treatments were laid out: control without fertilizer N and glucose (treatment code: S), ammonium sulfate (SN), ammonium sulfate with single glucose at the commencement (0 week) of incubation (SNG), and ammonium sulfate with double glucose at 0 and 4 weeks of incubation (SNGG). Glucose application (SNG) significantly increased microbial immobilization of $NH_4^+$ within 1 week of incubation over SN. Immobilization was followed by remineralization thereafter; however, second-application of glucose (SNGG) restored $NH_4^+$ immobilization. At the same time, nitrification was significantly inhibited by glucose application as indicated by consistently low $NO_3^-$ concentration in SNG and SNGG soils, suggesting that microbial assimilation of $NH_4^+$ is predominant compared to nitrification when available C-source is abundant. These results suggest application of chemical fertilizer-N with organic amendment would have beneficial effect on soil-N retention and environmental conservation by reducing production of $NO_3^-$ which is likely to be lost through leaching or denitrification.