• Title/Summary/Keyword: agar-free

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A Study on the Damageof Cellulose Fibres by Fungi (사상균에 의한 식물성 섬유의 손상도에 관한 연구)

  • 함옥상
    • Journal of the Korean Home Economics Association
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    • v.17 no.1
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    • pp.1-9
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    • 1979
  • The damaging effects of hemp and cotton by Aspergillus sp, and penicillum sp, which grow successfully on cotton were studied. The damages were measured after cultivated at $30^{\circ}C$ for 10 days the fabrics with Aspergillus sp,and Penicillum sp, respectically, in various conditions. The effects of cell-free extract produced from fungus were also investigated. The results of obtained could be summeried as follows : 1) Cultivation of fungi on fibre in malt extract agar was better than that in czapeck agar. 2) Tnsile strength of the fabrics was deteriortated most easily in czapeak agar at the rae of 49.8%. 3)Growth of fungi was promoted by starching the fibre but tensile strength was felled -off , however, by starching, propagation of fungi was superior on cotton to on hemp. 4) In case of hemp, propagation of fungi was inferior to in case of cotton but the tensile strength was deteriorated at the rate of 26-33%. 5) In case of starched hemp, the tensile strength was deteriorated Slowly in first 8 days, but after 8 days there was no particular change. There was no particular change of tensile strength by starching in cotton. 6) It seemed that a damage of fibre was accelerated because the fungus grow not only on the surface of fabrics but also the inner of those. 7) By treatment of cell-free produced form fungi, the tensile strength of hemp falled off at the rate of 50-65% in first 24 hours, since then the tensile strength was deteriorated slowly for 4 days, but after incubation for 4 days was not changed. But the tensile strength of cotton by cell-free extracts was not effected.

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Immobilization and Stability of Lipase from Mucor racemosus NRRL 3631

  • Adham, Nehad Zaki;Ahmed, Hanan Mostafa;Naim, Nadia
    • Journal of Microbiology and Biotechnology
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    • v.20 no.2
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    • pp.332-339
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    • 2010
  • The lipase from Mucor racemosus NRRL 3631 was partially purified by fractional precipitation using 60% ammonium sulfate, which resulted in a 8.33-fold purification. The partially purified lipase was then immobilized using different immobilization techniques: physical adsorption, ionic binding, and entrapment. Entrapment in a 4% agar proved to be the most suitable technique (82% yield), as the immobilized lipase was more stable at acidic and alkaline pHs than the free enzyme, plus 100% of the original activity was retained owing to the thermal stability of the immobilized enzyme after heat treatment for 60 min at $45^{\circ}C$. The calculated half-lives (472.5, 433.12, and 268.5 min at 50, 55, and $60^{\circ}C$, respectively) and the activation energy (9.85 kcal/mol) for the immobilized enzyme were higher than those for the free enzyme. Under the selected conditions, the immobilized enzyme had a higher $K_m$ (11.11 mM) and lower $V_{max}$ (105.26 U/mg protein) when compared with the free enzyme (8.33 mM and 125.0 U/mg protein, respectively). The operational stability of the biocatalyst was tested for both the hydrolysis of triglycerides and esterification of fatty acids with glycerol. After 4 cycles, the immobilized lipase retained approximately 50% and 80% of its original activity in the hydrolysis and esterification reactions, respectively.

Study on the Chlorine-Resistant Bacteria Isolated from Water Pipe Network (상수도관망에서 분리한 잔류염소 내성균에 관한 연구)

  • Hyun, Jae-Yeoul;Yoon, Jong-Ho
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.334-341
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    • 2011
  • The free residual chlorine of tap water samples, collected from 266 faucets on the water pipe network in Daegu City, was between 0.1 and 0.79 mg/L. On microorganic tests, general bacteria and the coliform goup were not detected and thus the tap water was turned out to be fit to drink. In particular, samples of which free residual chlorine was 0.1 mg/L and over were cultured in R2A agar media at $25^{\circ}C$ for 7 days, and as a result heterotrophic bacteria were detected in 65.9% of samples; (1). The closer tap water got to the faucet from the stilling basin, the lower residual chlorine concentration became but the more the bacterial count became. And, more bacteria were detected in the R2A agar medium than in the PCA medium. (2). In the case of separated strains, most colonies were reddish or yellowish. 16S rRNA sequence was identified as Methylobacterium sp. and Williamsia sp., and yellow strain was identified as Sphingomonas sp., Sphingobium sp., Novosphingobium sp., Blastomonas sp., Rhodococcus sp. and Microbacterium sp. White strain was identified as Staphylococcus sp. (3). Sterilized tap water in polyethylene bottles was inoculated with separated strain and was left as it was for 2 months. As a result, bio-film was observed in tap water inoculated with Methylobacterium sp. and Sphingomonas sp. It was found that heterotrophic bacteria increased when free residual chlorine was removed from tap water in the water pipe network. Thus, there is a need to determine a base value for heterotrophic bacteria in order to check the cleanliness of tap water in the water pipe network.

A Study on the development of high-fiber supplements for the diabetic patients (I) -Effect of Seaweed Supplementation on the Gastrointestinal Function and Diabetic Symptom Control in Streptozotocin-induced Diabetic Rats- (당뇨병 환자를 위한 고식이섬유 보충물의 개발을 위한 연구(I) -해조류 투여가 당뇨쥐의 장기능과 증세호전도에 미치는 영향-)

  • 이혜성
    • Journal of Nutrition and Health
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    • v.29 no.3
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    • pp.286-295
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    • 1996
  • The present study was conducted to evaluate the usefulness of four kinds of seaweeds (mixture of purple laver & sea lettuce, sea tangle, sea mustard, agar agar) as a high- fiber supplment in the therapeutic deit for the diabetic patients. Seven groups of normal and streptozotocin-induced diabetic rats were fed dietary fiber-free control diet or one of experimental diets containing 7% of one of the four seaweeds for 6 weeks. The effect of seaweeds supplementation on the body weight change, gastrointestinal function, and the control of diabetic symptoms were examined and compared with the effect of fiber-free diet or pectin diet used as references. The body weight gains of all the diabetic groups were significantly suppressed compared to the normal group. Feed efficiency ratios and body weight gains of seaweed groups were relatively higher than those of the pectin group. Sea tangle appeared to have an effect of alleviating the typical diabetic symptoms such as polyphasia, polydipsia, polyuria, urinary glucose excretion and hyperglycemia indicating its beneficial acition of improving glucose metabolism even though the degree of effectiveness was less than that with pectin. All the supplemntations of seaweeds and pectin ressulted in the significant changes in gastronitestinal functins ; shortening of GI transit time, increase of fecal volume and the length of intestine. Based on their effects of the significant changes in GI function in may be suggested that seaweeds may influence the process of digestion and absorption of nutrients in diabetic animals.

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Effective Supply of Substrate for Hydrogen Production by Immobilized Cells of Rhodopseudornonas sphaeroides (Rhodopseudomonas sphaeroides의 고정화균체에 의한 수소생산의 효율적 기질 공급)

  • 김진상;홍용기;신일식;조학래;장동석
    • Microbiology and Biotechnology Letters
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    • v.20 no.1
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    • pp.79-84
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    • 1992
  • The Photosynthetic bacterium, Rhodopseudomonas sphaeroides strain B6 was irnmobilized on agar gel. The optimum concentration of agar for hydrogen production was 2% (w/v). Maximum rates of hydrogen production by immobilized (300 ml of gel; 2.85 rng dry cells/ml) and free cells (1l culture; 0.87 mg dry cells/ml) were 47.5 and 48.0 ml/hr/culture, respectively. However, when both cultures were fed by 10 mmoles of lactate as limited electron donor at the later period of incubation, the activity of hydrogen production by free cells was significantly decreased but, immobilized cells continued hydrogen production with almost the same initial rate. Wc examined hydrogen production by immobilized cells of strain B6 under periodic illumination for 12 hr-intervals. When the culture was periodically fed by basal medium containing 9.3 rnmoles of DL-lactate and 1.86 mmoles of L-glutamate as consumed electron donor and nitrogen source, respectively, for every one liter of hydrogen produced, hydrogen was evolved continuously with the average rate of 510 ml/day/300 ml gel (2.9 rng dry cellslml) during the incubation time for 228 hr.

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Production of Salicylic Acid from Naphthalene by Immobilized Pseudomonas sp. Strain NGK1

  • Shinde, Manohar;Kim, Chi-Kyung;Karegoudar, Timmanagouda-Baramanagouda
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.482-487
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    • 1999
  • The Pseudomonas sp. strain NGK1 (NCIM 5120) was immobilized in calcium alginate, agar, and polyacrylamide gel matrices. The salicylic acid-producing capacity of freely suspended cells was compared with immobilized cells in batches with a shake culture and continuous culture system in a packed bed reactor. Freely suspended cells ($4\times10^{10}cfu/ml$) produced 12 mM of salicylic acid, whereas cells immobilized in calcium alginate ($1.8\times10^{11}$cfu/g beads), agar ($1.8\times10^{11}$cfu/g beads), and polyacrylamide ($1.6\times10^{11}$cfu/g beads) produced 15, 11, and 16mM of salicylic acid, respectively, from naphthalene at an initial concentration of 25 mM. The continuous production of salicylic acid from naphthalene was investigated in a continuous packed bed reactor with two different cell populations. The longevity of the salicylic acid-producing activity of the immobilized cells from naphthalene was also studied in semi continuous fermentations. The immobilized cells could be reused 18, 13, and more than 20 times without losing salicylic acid-producing activity in calcium alginate-,agar-, and polyacrylamide-entrapped cells, respectively. The study reveals a more efficient utilization of naphthalene and salicylic acid production by the immobilized Pseudomonas sp. strain NGK1 as compared to the free cells.

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Development Ability of Bovine Early Embryo Blastomere In Vitro in Embedding Matrix (체외생산 소 초기배 할구세포의 Embedding Matrix에서의 발생능력)

  • 이홍준;서승운;이상호;송해범
    • Journal of Embryo Transfer
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    • v.10 no.2
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    • pp.171-175
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    • 1995
  • This study was performed to establish the condition and the methods for the techniques of insertion the isolated blastomere cells into cytoplasm, in order to research the develop-mental ability of bovine embryo blastomere cells in vitro produced. After 24h in vitro ovary maturation with the ovaries from a slaughter house, in vitro fertilization was performed to the vital sperms which their mobility were decided by percoll gradient method, with 2~8 cell stage embryos, the blastomeres were isolated in $Ca^2$+. $Mg^2$+-free PBS, and following that embedded into agar and alginate solution, respectively. The rates of in vitro develop-ment are as follows ; in agar embedded 11 among 120(9.2%) 1 /2~1 /3 blastomers cleaved and 6 among 93(6.5%) 1 /4~1 /8 blastomeres cleaved. In sodium alginate-embedded 14 among 84(16.7%) 1 /2~1 /3 blastomeres cleaved and 6 among 85(7.1%) 1 /4~1 /8 blastomeres cleaved. In case of Na-alginate, the rate of the cells were better than those of agar. The results suggest that the techniques for embeeding the isolated blastomeres into gel may help cloning of bovine early embryo without nuclear transplantation.

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Application of Immobilization Technology in Solubilization of Rock Phosphate

  • Walpola, Buddhi Charana;Kim, Ah Young;Jeon, Ju Hyeon;Yoon, Min-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.4
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    • pp.249-253
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    • 2014
  • Phosphates solubilizing bacterial strains belong to Pantoea, Burkholderia and Enterobacter were isolated and employed in assessing their solubilization ability of Ca phosphate and ER phosphate (Eppawala Rock Phosphate). Among the bacterial strains used, PSB-13 (Pantoea rodasii) showed higher Ca-phosphate solubilization ($1100{\mu}g\;ml^{-1}$) as well as rock phosphate solubilization ($168{\mu}g\;ml^{-1}$). The strain was then immobilized in agar to further assess its phosphate solubilization ability. According to the results, agar encapsulated strain solubilized 0.3%, 7.31%, 20.24%, and 20.62% more Ca-phosphate and 11.53%, 15.29%, 28.48%, 36.55% (respectively in 4 cycles) more ER-phosphate than free cells. The reuse efficiency of agar entrapped bacterial cells for Ca-phosphate and ER-phosphate solubilization was greater than that by freely suspended bacterial cells. In conclusion, immobilization could enhance the phosphate solubilization capacity of the strains and thus could be used effectively in enhancing solubilization of ER phosphate.

Growth, Clonability, and Radiation Resistance of Esophageal Carcinoma-derived Stem-like Cells

  • Li, Jian-Cheng;Liu, Di;Yang, Yan;Wang, Xiao-Ying;Pan, Ding-Long;Qiu, Zi-Dan;Su, Ying;Pan, Jian-Ji
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.8
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    • pp.4891-4896
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    • 2013
  • Objective: To separate/enrich tumor stem-like cells from the human esophageal carcinoma cell line OE-19 by using serum-free suspension culture and to identify their biological characteristics and radiation resistance. Methods: OE-19 cells were cultivated using adherent and suspension culture methods. The tumor stem-like phenotype of CD44 expression was detected using flow cytometry. We examined growth characteristics, cloning capacity in soft agar, and radiation resistance of 2 groups of cells. Results: Suspended cells in serum-free medium formed spheres that were enriched for CD44 expression. CD44 was expressed in 62.5% of suspended cells, but only in 11.7% of adherent cells. The suspended cells had greater capacity for proliferation and colony formation in soft agar than the adherent cells. When the suspended and adherent cells were irradiated at 5 Gy, 10 Gy, or 15 Gy, the proportion of CD44+ suspended cells strongly and weakly positive for CD44 was 77.8%, 66.5%, 57.5%; and 21.7%, 31.6%, 41.4%, respectively. In contrast, the proportion of CD44+ adherent cells strongly positive for CD44 was 18.9%, 14.%, and 9.95%, respectively. When the irradiation dose was increased to 30 Gy, the survival of the suspended and adherent cells was significantly reduced, and viable CD44+ cells were not detected. Conclusion: Suspended cell spheres generated from OE-19 esophageal carcinoma cells in serum-free stem medium are enriched in tumor stem-like cells. CD44 may be a marker for these cells.

Production of Citrus Plants from Ovule Cell Culture and Verification of CTV - free Plants (배주배양 세포로부터 감귤 식물체의 획득 및 감귤 트리스테자 바이러스 무병주 검증)

  • Jin, Seong Beom;Park, Jae Ho;Park, Suk Man;Lee, Dong Hoon;Yun, Su Hyun
    • Horticultural Science & Technology
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    • v.35 no.1
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    • pp.121-130
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    • 2017
  • This study was carried out to investigate a method for producing cultured virus - free ovules for breeding high - quality Citrus cultivars. Ovules from the immature fruits of three citrus cultivars native to Jeju (Dongjeongkyool, Cheongkyool, and Jikak) and two cultivars of Citrus unshiu Marc. (Miyagawa wase and Haryejosaeng) that were thought to be infected with Citrus tristeza virus (CTV) were cultured on MS2 medium (Murashige - Skoog [MS] basal medium containing $500mg{\cdot}L^{-1}$ malt extract, $50g{\cdot}L^{-1}$ sucrose, $1.0 mg{\cdot}L^{-1}$ kinetin, and $8g{\cdot}L^{-1}$ agar). After four weeks of culture, 10, 21, 13, 5, and 7 somatic embryos and 2, 4, 2, 4, and 5 white callus cells (surrounding green somatic embryos) were obtained from Dongjeongkyool, Cheongkyool, Jikak, Miyagawa wase, and Haryejosaeng, respectively. After six weeks of culture, somatic embryos were obtained from cultured cells grown on MT basal medium supplemented with malt extract ($500mg{\cdot}L^{-1}$), lactose ($70g{\cdot}L^{-1}$), and agar ($16g{\cdot}L^{-1}$). Over 60% of the somatic embryos from citrus cultivars native to Jeju developed into normal plants on MS basal medium supplemented with malt extract ($500mg{\cdot}L^{-1}$), sucrose ($50g{\cdot}L^{-1}$), and agar ($8g{\cdot}L^{-1}$) after 10 weeks of culture. Normal plants were regenerated from two Citrus unshiu Marc. cultivars on MT basal medium supplemented with sorbitol (1.0 M), galactose (1.0 M), $GA_3$ ($1.0mg{\cdot}L^{-1}$), and Gelrite ($3g{\cdot}L^{-1}$). The absence of virus in plants generated from cultured ovules was confirmed by RT - PCR and antigen - antibody reactions. Therefore, virus - free Citrus cells can be obtained for breeding high - quality citrus cultivars using the biotechnological technique evaluated in this study.