• Title/Summary/Keyword: filtrate

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Phosphorus removal from dewatering centrate in wastewater treatment by struvite formation (스트루바이트 생성을 통한 하수슬러지 탈수여액 내 인 제거)

  • Kim, Sang-Hyoun;Park, Jong-Hun;Ju, Hyun-Jun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.2
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    • pp.71-78
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    • 2013
  • This study examined the feasibility of phosphorus removal from dewatering centrate/filtrate in wastewater treatment by struvite formation. Since dewatering centrate/filtrate obtained after anaerobic digestion contains a high content of ammonia, magesium addition and pH adjustment could remove phosphorous. The optimum magnesium dose, reaction time, settling time, and pH value was found at 2 mol Mg/mol $PO_4^{3-}$, 10 min, 120 min, and 8.5, respectively. A bench-scale continuous operation at the optimum condition showed 80% of total phosphorus removal and 82% of phosphate removal in dewatering centrate. The elemental composition and crystal structure of the chemical precipitate was similar to the reported values of struvite.

Effect of filtrates of Serpulina(Treponema) hyodysenteriae on the epithelium in colonic loops in swine (Serpulina(Treponema)hyodysenteriae 배양여과액의 돼지 공장 계제 점막에 미치는 영향)

  • Kang, Boo-hyon;Olander, Harvey J
    • Korean Journal of Veterinary Research
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    • v.33 no.3
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    • pp.429-442
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    • 1993
  • The cytotoxic effects of S hyodysenteriae strain B 204 on the mucosal surface were studied in surgically prepared ligated colonic loops in two male convenitonal mixed-breed pigs. In each one of four loops was inoculated with either sterile trypticase soy broth(TSB) of Serpulina, filtrate of Serpulina TSB culture. washed Serpulina cells or whole culture of Serpulina. Mucosal tissues were examined by transmission and scanning electron microscopy 24 and 48 hours after inoculation(p.i.). The filtrate did not induce any significant effect on the mucosal surface. The washed cells produced early lesions similar to those caused by the whole culture. These observations suggest that cytotoxins of the culture do not play a significant role in invasion of the epithelium in this experimental infection. The possible role of toxins associated with the organism at the site of interaction with the epithelial cells was not elucidated.

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Identification and Characterization of Myxobacteria from Korean Soil (국내토양에서 분리한 점액세균의 동정및 특성)

  • 김재헌;손승렬
    • Korean Journal of Microbiology
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    • v.37 no.4
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    • pp.239-244
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    • 2001
  • We isolated a Myxobacteria strain from a soil sample obtained from Mt. Daedoon located in Choongnam, Korea. This strain, ARJ, secreted slime while swarmed on the surface of CT medium. It produced greenish yellow pigment in liquid or solid media, and the swarming edge showed green florescence under U. V. at 366 nm. It formed fruiting bodies when nutrient was exhausted, which is one of the most imkportant characteristics of Myxobacteria. The fruiting bodies did not have a stalk and consisted of naked myxospores when examined under the scanning electron microscope. These traits lead us to believe that this strain is very close to Myxococcus virescens. It showed antimicrobial activity, especially against Gram positive bacteria. Culture filtrate showed the activity but this was not due to protein. The culture filtrate also had proteolytic activity in which at least two enzymes are involved.

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Recovery of Potassium and Flux Component in the Production Process of K2Ti6O13 Whisker (K2Ti6O13 whisker의 제조 공정에서 Potassium 및 Flux 성분의 회수)

  • Lee, Chul-Tae;Lee, Jin-Sik;Oh, Chi-Hoon;Kim, Young-Myoung
    • Applied Chemistry for Engineering
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    • v.7 no.6
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    • pp.1174-1180
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    • 1996
  • Potassium hexatitanate whisker was effectively prepared with calcination and flux method by using industrial $TiO_2$, $K_2CO_3$ and $K_2MoO_4$ as the starting materials. When it was synthesized by the calcination method, the filtrate after boiling water treatment was required a neutralization, as the pH of filtrate was higher than 9. Because K component was very small, recovery of K component was not economically suitable. In case of flux method, flux was recovered 96.1% of Mo component and 91.8% of K component at $K_2MoO_4$, for 10th treatment in boiling water of 100ml to 10g.

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Isolation and Characteristics of Biosurfactant Producing Bacterium, Bacillus sp. TBM 911-5 (Biosurfactant 생산균주 Bacillus sp. TBM 911-5의 분리 및 특성)

  • 김선희;정연주;이상철;유주순;주우홍;정수열;최시림;최용락
    • Journal of Life Science
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    • v.14 no.2
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    • pp.320-324
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    • 2004
  • The objective of this study was investigate the characteristic of biosurfactant produced from the isolated strain. The strain was isolated from soil samples and identified as Bacillus sp. TBM 911-5 by physiological characteristics and the partial nucleotide sequence analysis of 16S rDNA. We measured the surface tension every 6 hours for 80 hours. The surface tension of the culture filtrate of Bacillus sp. TBM 911-5 was decreased to 29 mN/m. Biosurfactant concentration was determined by diluting the culture filtrate until the critical micelle concentration (CMC). The biosurfactant emulsified hydrocarbons, vegetable oil and crude oil. Using soybean oil as substrate, the maximum emulsification activity and stability was obtained from the biosurfactant. The biosurfactant produced from Bacillus sp. TBM 911-5 had strong properties as an emulsifying agent and an emulsion-stabilizing agent.

Cloning and Characterization of Mannanase Gene from Bacillus subtilis WL-8 (Bacillus subtilis WL-8의 Mannanase 유전자 클로닝과 특성분석)

  • Yoon, Ki-Hong
    • Korean Journal of Microbiology
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    • v.46 no.2
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    • pp.207-212
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    • 2010
  • A bacterium producing the extracellular mannanase was isolated from Korean soybean paste. The isolate WL-8 has been identified as Bacillus subtilis on the basis on its 16S rRNA sequence, morphology and biochemical properties. The mannanase productivity of strain WL-8 was increased in LB broth by addition of wheat bran. The maximum mannanase productivity was reached to approximately 20 U/ml in LB medium supplemented with 6% wheat bran. A gene encoding the mannanase of WL-8 was cloned into Escherichia coli and its nucleotide sequence was subsequently determined. The mannanase gene consisted of 1,086 nucleotides encoding a polypeptide of 362 amino acid residues. The deduced amino acid sequence was highly homologous with those of several mannanases from B. subtilis belonging to GH family 26. Reaction temperature and pH profiles were investigated using the culture filtrate and cell-free extract of the recombinant E. coli carrying a WL-8 mannanase gene, respectively. Optimal conditions for the two fractions occurred at pH 5.5 and $60^{\circ}C$. The cell-free extract showed higher mannanase activity than the culture filtrate at above $60^{\circ}C$.

Production and Properties of Hemicellulases by a Cellulosimicrobium sp. Isolate (Cellulosimicrobium sp. 분리균의 Hemicellulases 생산성과 효소특성)

  • Yoon, Ki-Hong
    • Microbiology and Biotechnology Letters
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    • v.39 no.3
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    • pp.252-258
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    • 2011
  • A bacterial strain capable of hydrolyzing xylan and locust bean gum (LBG) was isolated from farm soil by enrichment culture using mixture of palm kernel meal (PKM) and wheat bran as carbon source. Nucleotide sequence of 16S rDNA amplified from the isolate YB-1107 showed high similarity with those of genus Cellulosimicrobium strains. Xylanase productivity was increased when the Cellulosimicrobium sp. YB-1107 was grown in the presence of wheat bran or oat spelt xylan, while mannanase productivity was increased drastically when grown in the presence of PKM or LBG. Particularly, maximum mannanase and xylanase activities were obtained in the culture filtrate of media containing 0.7% PKM or 1% wheat bran, respectively. Both enzyme activities were produced at stationary growth phase. Mannanase from the culture filtrate showed the highest activity at $55^{\circ}C$ and pH 6.5. Xylanase activity was optimal at $65^{\circ}C$ and pH 5.5. The predominant products resulting from the mannanase or xylanase hydrolysis were oligosaccharides for LBG or xylan, respectively. In addition, the enzymes could hydrolyze wheat bran and rice bran into oligosaccharides.

Nematicidal and Plant Growth-Promoting Activity of Enterobacter asburiae HK169: Genome Analysis Provides Insight into Its Biological Activities

  • Oh, Mira;Han, Jae Woo;Lee, Chanhui;Choi, Gyung Ja;Kim, Hun
    • Journal of Microbiology and Biotechnology
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    • v.28 no.6
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    • pp.968-975
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    • 2018
  • In the course of screening for microbes with nematicidal activity, we found that Enterobacter asburiae HK169 displayed promising nematicidal activity against the root-knot nematode Meloidogyne incognita, along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of M. incognita within 48 h. In addition, the nematicidal activity of the culture filtrate was dramatically reduced by a protease inhibitor, suggesting that proteolytic enzymes contribute to the nematicidal activity of HK169. In order to obtain genomic information about the HK169 isolate related to its nematicidal and plant growth-promoting activities, we sequenced and analyzed the whole genome of the HK169 isolate, and the resulting information provided evidence that the HK169 isolate has nematicidal and plant growth-promoting activities. Taken together, these observations enable the future application of E. asburiae HK169 as a biocontrol agent for nematode control and promote our understanding of the beneficial interactions between E. asburiae HK169 and plants.

Biological Control of Gom-chwi (Ligularia fischeri) Phytophthora Root Rot with Enterobacter asburiae ObRS-5 to Suppress Zoosporangia Formation and Zoospores Germination

  • Kim, Dayeon;Lee, Sang Yeob;Ahn, Seong Ho;Han, Ji Hee;Park, Jin Woo
    • The Plant Pathology Journal
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    • v.36 no.3
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    • pp.244-254
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    • 2020
  • Gom-chwi (Ligularia fischeri) is severely infected with Phytophthora drechsleri, the causal organism of Phytophthora root rot, an economically important crop disease that needs management throughout the cultivation period. In the present study, Phytophthora root rot was controlled by using bacterial isolates from rhizosphere soils collected from various plants and screened for antagonistic activity against P. drechsleri. A total of 172 bacterial strains were isolated, of which, 49 strains showed antagonistic activities by dual culture assay. In the seedling assay, six out of the 49 strains showed a predominant effect on suppressing P. drechsleri. Among the six strains, the ObRS-5 strain showed remarkable against P. drechsleri when treated with seed dipping or soil drenching. The ObRS-5 strain was identified as Enterobacter asburiae based on 16S ribosomal RNA gene sequences analysis. The bacterial cells of E. asburiae ObRS-5 significantly suppressed sporangium formation and zoospore germination in P. drechsleri by 87.4% and 66.7%, respectively. In addition, culture filtrate of E. asburiae ObRS-5 also significantly inhibited sporangium formation and zoospore germination by 97.0% and 67.6%, respectively. Soil drenched bacterial cells, filtrate, and culture solution of E. asburiae ObRS-5 effectively suppressed Phytophthora root rot by 63.2%, 57.9%, and 81.1%, respectively. Thus, E. asburiae ObRS-5 could be used as a potential agent for the biological control of Phytophthora root rot infecting gom-chwi.

Experimental Study and Modelling on Membrane Fouling in Taylor Vortex Flow Microfiltration (테일러 와류 정밀여과에서 막오염의 실험적 연구 및 모델링)

  • 박진용;김현우;최창균
    • Membrane Journal
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    • v.13 no.2
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    • pp.88-100
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    • 2003
  • A change of filtrate flux in Taylor vortex flow filtration was investigated experimentally by rotating speed of inner cellulose ester membrane cylinder (average pore size: 1.2 ${\mu}m$), slurry concentration, and particle size. The filtrate flux was a direct proportion relation with TMP, but an inverse relation with resistances. A change of cake resistance with time was examined by rotating speed, slurry concentration, and particle size. Initial resistance increased dramatically as raising slurry concentration, and the pseudo-steady state was maintained at high resistance value. However, times to reach the pseudo-steady state did not depend on slurry concentration. The resistance was larger as smaller particle size, because possibility of pore blocking inside membrane could be higher and shear effect should be lower as smaller particle size. A model equation suggested in this study was composed of particle deposition and removal terms, and could confirm well experimental data using average values of experimental coefficients.