• Title/Summary/Keyword: forming agent

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Characterization of Three Antifungal Calcite-Forming Bacteria, Arthrobacter nicotianae KNUC2100, Bacillus thuringiensis KNUC2103, and Stenotrophomonas maltophilia KNUC2106, Derived from the Korean Islands, Dokdo and Their Application on Mortar

  • Park, Jong-Myong;Park, Sung-Jin;Ghim, Sa-Youl
    • Journal of Microbiology and Biotechnology
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    • v.23 no.9
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    • pp.1269-1278
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    • 2013
  • Crack remediation on the surface of cement mortar using microbiological calcium carbonate ($CaCO_3$) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-$CaCl_2$ media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed $CaCO_3$ precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials.

Effect of $ZnCl_2$ on Formation of Carbonized Phenol Resin Anode

  • Kim Han-Joo;Hong Ji-sook;Son Won-Ken;Park Soo-Gil;Oyama Noboru
    • Journal of the Korean Electrochemical Society
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    • v.3 no.2
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    • pp.85-89
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    • 2000
  • For replacing Li metal at Lithium ion Battery(LIB) system, we used carbon powder material which prepared by Pyrolysis of Phenol resin as starting material. It became amorphous carbon by Pyrolysis through it's self condensation by thermal treatment. Amorphous carbon can be doped with Li intercalation and deintercalation because it has wide interlayer. However, it has a problem with structural destroy due to weak carbon-carbon bond. So, we used $ZnCl_2$ as the pore-forming agent. This inorganic salt was used together with the resin serves not only as the pore-forming agent to form open pores, which grow into a three-dimensional network structure in the cured material, but also as the microstructure-controlling agent to form a loose structure doped with bulky dopants. We used SEM in order to find to difference of structure, and can calculate the distance of interlayer by XRD analysis. CV test showed oxidation and reduction.

Treatment Characteristics of Acid Mine Drainage by Porous Ceramics using Wood Flour as Pore-forming Agent (목분 기포제를 이용한 산업부산물 소재 다공성 세라믹에 의한 산성광산배수의 처리특성 연구)

  • Lee, Yeong-Nam;Yim, Soo-Bin
    • Journal of Environmental Science International
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    • v.27 no.2
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    • pp.109-122
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    • 2018
  • This study was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage by porous zeolite-slag ceramics (ZS ceramics) that was prepared by adding wood flour as pore-foaming agent while calcining the mixtures of natural zeolite and converter slag. The batch test showed that the removal efficiency of heavy metals by pellet-type porous ZS ceramics increased as the particle size of wood flour was decreased and as the weight mixing ratio of wood flour to ZS ceramics was increased. The optimal particle size and weight mixing ratio of wood flour were measured to be $75{\mu}m$ and 7~10%, respectively. The removal test with the porous ZS ceramics prepared in these optimal condition showed very high removal efficiencies: more than 98.4% for all heavy metals and 73.9% for sulfate ion. Relative to nonporous ZS ceramics, the increment of removal efficiency of heavy metals by porous ZS ceramics with $75{\mu}m$ and 10% wood flour was 5.8%, 60.5%, 36.9%, 87.7%, 10.3%, and 57.4% for Al, Cd, Cu, Mn, Pb, and Zn, respectively. The mechanism analysis of removal by the porous ZS ceramics suggested that the heavy metals and sulfate ion from acid mine drainage are eliminated by multiple reactions such as adsorption and/or ion exchange as well as precipitation and/or co-precipitation.

Antifungal Activity of Lichen-forming Fungi against Colletotrichum acutatum on Hot Pepper

  • Wei, Xinli;Jeon, Hae-Sook;Han, Keon-Seon;Koh, Young-Jin;Hur, Jae-Seoun
    • The Plant Pathology Journal
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    • v.24 no.2
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    • pp.202-206
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    • 2008
  • Antifungal activity of Korean and Chinese lichen-forming fungi (LFF) was evaluated against plant pathogenic fungus of Colletotrichum acutatum, causal agent of anthracnose on hot pepper. This is the first attempt to evaluate antifungal activity of LFF, instead of lichen thalli, against C. acutatum. Total 100 LFF were isolated from the lichens with discharged spore method or tissue culture method. Among the 100 isolates, 8 LFF showed more than 50% of inhibition rates of mycelial growth of the target pathogen. Especially, Lecanora argentata was highly effective in inhibition of mycelial growth of C. accutatum at the rate of 68%. Antifungal activity of other LFF was in the order of Cetrelia japonica (61.4%), Ramalina conduplicans (59.5%), Umbilicaria esculenta (59.5%), Ramalina litoralis (56.7%), Cetrelia braunsiana (56.5%), Nephromopsis pallescensn (56.1%), and Parmelia simplicior (53.8%). Among the tested LFF, 61 isolates of LFF exhibited moderate antifungal activity against the target pathogen at the inhibition rates from 30 to 50%. Antifungal activity of the LFF against C. acutatum was variable at the species level rather than genus level of LFF. This study suggests that LFF can be served as a promising bioresource to develop novel biofungicides.

Bacteriophage-like Particles Induced by Mitomycin C in Bacillus circulans F-2 (Mitomycin C에 의해 유도되는 Bacillus cirulans F-2의 Bacteriophage-like 입자)

  • 김철호;권석태;이대실;타니구치하지메
    • Microbiology and Biotechnology Letters
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    • v.18 no.3
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    • pp.221-226
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    • 1990
  • To detect prophages and bacterioeins, twenty strains of Bacillus circulans were treated with mitomycin C. The resulted lysates were subjected to electron microscopy, and also examined for killing and plaque-forming activities. Fifteen strains showed killing activity on two or more strains of Bacillue circulans. Killing agents were centrifuged in linear 5 to 20% sucrose gradient, and studied with electron microscopy which revealed the presence of particles.They looked morphologically like phage tail of 190 nm long with fiber (FA9, FA5) or without fiber (FA1, FA6), T even phage-like particle with a head of 50 nm in diameter and a tail of 140 nm long (FA7), or T7 phage-like particle with a head of 70 nm in diameter and a tail of 20 nm long (FA17). The killing agent of FA17 showed phage-forming activity on several strains different from killing sensitive strains of Bacillus circulans.

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Application of Alkaliphilic Biofilm-Forming Bacteria to Improve Compressive Strength of Cement-Sand Mortar

  • Park, Sung-Jin;Chun, Woo-Young;Kim, Wha-Jung;Ghim, Sa-Youl
    • Journal of Microbiology and Biotechnology
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    • v.22 no.3
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    • pp.385-389
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    • 2012
  • The application of microorganisms in the field of construction material is rapidly increasing worldwide; however, almost all studies that were investigated were bacterial sources with mineral-producing activity and not with organic substances. The difference in the efficiency of using bacteria as an organic agent is that it could improve the durability of cement material. This study aimed to assess the use of biofilm-forming microorganisms as binding agents to increase the compressive strength of cement-sand material. We isolated 13 alkaliphilic biofilmforming bacteria (ABB) from a cement tetrapod block in the West Sea, Korea. Using 16S RNA sequence analysis, the ABB were partially identified as Bacillus algicola KNUC501 and Exiguobacterium marinum KNUC513. KNUC513 was selected for further study following analysis of pH and biofilm formation. Cement-sand mortar cubes containing KNUC513 exhibited greater compressive strength than mineral-forming bacteria (Sporosarcina pasteurii and Arthrobacter crystallopoietes KNUC403). To determine the biofilm effect, Dnase I was used to suppress the biofilm formation of KNUC513. Field emission scanning electron microscopy image revealed the direct involvement of organic-inorganic substance in cement-sand mortar.

Isolation and indentification of soil bacteria for biocontrol the Cockroach(Blattella germanica L.) (바퀴(Blattella germanica L.)의 생물학적 제어를 위한 토양세균의 분리 및 동정)

  • 이광배;몽룡곤
    • Journal of environmental and Sanitary engineering
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    • v.8 no.1
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    • pp.129-138
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    • 1993
  • The marked spread of the cockraches of recent years has raised a great social problem in urban areas. The cockroach have to remove1 because transmit a disease to human as pest insect, but particulars are not yet reported on biological control agent for the cockroach removal. This study was tried for the first time on biological control for the cockroach removal. The obtained results were as follows : 1. The isolated were spore-forming bacillus 1098 strain in soil. The No. 109(TH 109) strain of the among spore-forming bacillus was showed the poisonous against Cockroach. 2. The biological characteristics and flagella antigenicity of the strain is similar to Bacillus thur-ingiensis subsp. indiana. 3. TH 109 strain have the delta-endotoxin of cuboid shap. 4. This delta-endotoxin of product by TH 109 strain was toxic to the cockroach(Blattella gemzanica. L).

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Immunomodulatory Activity of the Water Extract from Medicinal Mushroom Inonotus obliquus

  • Kim, Yeon-Ran
    • Mycobiology
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    • v.33 no.3
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    • pp.158-162
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    • 2005
  • The immunomodulatory effect of aqueous extract of Inonotus obliquus, called as Chaga, was tested on bone marrow cells from chemically immunosuppressed mice. The Chaga water extract was daily administered for 24 days to mice that had been treated with cyclophosphamide (400 mg/kg body weight), immunosuppressive alkylating agent. The number of colony-forming unit (CFU)-granulocytes/macrophages (GM) and erythroid burst-forming unit (BFU-E), increased almost to the levels seen in non-treated control as early as 8 days after treatment. Oral administration of the extract highly increased serum levels of IL-6. Also, the level of $TNF-{\alpha}$ was elevated by the chemical treatment in control mice, whereas was maintained at the background level in the extract-treated mice, indicating that the extract might effectively suppress $TNF-{\alpha}$ related pathologic conditions. These results strongly suggest the great potential of the aqueous extract from Inonotus obliquus as immune enhancer during chemotherapy.

Viscosity Study to Optimize a Slurry of Alumina Mixed with Hollow Microspheres

  • Bukhari, Syed Zaighum Abbas;Ha, Jang-Hoon;Lee, Jongman;Song, In-Hyuck
    • Journal of the Korean Ceramic Society
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    • v.52 no.6
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    • pp.403-409
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    • 2015
  • Porous alumina ceramics are involved in many industrial applications due to the exceptional properties of these products. This study addresses the preparation of porous alumina ceramics using hollow microspheres as a pore-forming agent and slip casting as a green-body-forming technique. A uniform distribution of pores is a basic requirement of a porous material. This study investigates three different slurry systems, i.e., as-prepared alumina slurry, alumina slurry electrostatically dispersed by hydrochloric acid (HCl), and slurry dispersed by the commercial dispersant 'Darvan C-N'. At a low viscosity, the hollow microspheres in the slurry tend to float, which causes a non-uniform pore distribution. To avoid this phenomenon, the viscosity of the slurry was increased to the extent that the movement of hollow microspheres ceased in the slurry. As a result, a uniform pore distribution was achieved.

Effect of Polysaccharide Extracted from Panax ginseng on Murine Hematopoiesis (인삼 다당체가 생쥐의 조혈과정에 미치는 영향)

  • 송지영;이세윤;정인성;윤연숙
    • Journal of Ginseng Research
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    • v.25 no.2
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    • pp.63-67
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    • 2001
  • We previously reported that acidic polysaccharide from Panax ginseng induced the proliferation lymphocytes and the generation of activated killer cells. Here we found that polysaccharide (PG-75) precipitated with 75% EtOH from water extract of Panax ginseng also has both in vitron and in vivo hematopoietic activities. In vitro studied with bone marrow cells from BALB/c mouse revealed that PG-75 had direct effect on hematopoietic colony-forming cell(CFC) growth, increased granulocyte macrophage-colony forming cell numbers by 1.59 fold over than non-treated. the ability of PG-75 to modulate hematopoiesis in vivo was evaluated the bone marrow and spleen celluarity, granulocyte-macrophage progenitor cells. BALB/c female mice were administered G-75 intraperitoneally, PG-75 was found to significantly increase the number of BM cells, spleen cells, GM-CFU on 3 hours after injection. PG-75 was also able to induce significant augmentation of GM-CSF and IFN-${\gamma}$, production in sera. These studies illustrate than PG-75 has hematopoietic activities and that this agent may be useful in the prevention and/or treatment of radio- or chemotherapy-associated myelosuppression.

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