• Title/Summary/Keyword: Biological agent

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Comparative Study on the Protective Functions of Clothes (의복의 보호론에 관한 이론적 고찰)

  • Lim Sook Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.9 no.3
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    • pp.71-78
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    • 1985
  • This research is designed to systemize the protection theory as well as to supplement the missing theory by organizing various studies on the protective functions of celothes by domestic and foreign scholers of clothing. Human environments is classified two standpoints : (1) Physical environments, and (2) man built psychological environments including socio-physical environments, socio-biological environments, behavioral environments, socio-psychological environments and institution environments. Clothes acting as a physical protection might be of (1) extreme air temperature: Parka; (2) high relative humidity: raincoat; (3) air movement: windbreaker; (4) radiation: space suit; (5) atmospheric pressure: deep sea diver suit; (6) mechanical agent: bullet proof vest; (7) physical agent: (8) chemical agent: (9) biological agent: surgeon's gown, cap, and mask. Also dresses act to support the body comfort, health and the well-being; corset for bad back patient, wrist band for people with weak wrist, bottom half of pressure suit for people with low blood pressure. Clothes acting as a psychological protection might be of (1) influence of magic and of spirits: (2) moral danger; (3) the general unfriendliness of the world as a whole; a reassurance against the lack of love. Clothes should provide the maximum of satisfaction in accordance with the full recognition of reality. The reality should aim at the formulation of general laws concerning the most pleasing forms, colors, and styles to suit. The complex physiological anatomical and psychological aspects of individual personalities.

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Biological control of Pythium blight of turfgrass in golf green by Trichoderma harzianum ABGC-95 (Trichoderma harzianum ABGC-95를 이용한 골프그린에 발생하는 Pythium 마름병의 생물적 방제)

  • 염주립
    • Asian Journal of Turfgrass Science
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    • v.13 no.4
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    • pp.223-234
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    • 1999
  • Antibiotic activity of selected biocontrol agent Trichoderma harzianum ABGS-95 showed 59% to P. graminicola, 65% to P. aphanidermatum and 57% to Rhizoctonia solani compare to non-treated control. ABGC-95 showed resistant to major agrochemicals such as metalaxyl+mancozeb, etridiazole, propamocarb, toclofos methly, terbuconazole, pencycuron and flutolanil. The biocontrol agent T. harzianum ABGC-95 grew vigorously in low nutrient media and water agar. And sand mixture with wheat bran or mowing debris of zoysia grass also provided good growth of the organism. Application of sand mixture of Trichoderma spp. into aeration cores in golf showed most effective biocontrol of pythium blight. Top dressing application of T. harzianum ABGC-95 reached 83% control efficient while spray application of same biocontrol agent showed only 69% control. The biocontrol agent ABGC-95 successfully suppressed the population density of Pythium spp. in soil. The population density of total Pythium spp. in ABGC-95 treated soil was sustained almost same population at beginning(early May) up to end of August, while the population in untreated control plot was increased 5 times that of beginning and even 10 times in pathogen accumulated soil.

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Characterization of Rajath Bhasma and Evaluation of Its Toxicity in Zebrafish Embryos and Its Antimicrobial Activity

  • Kalimuthu, Kalishwaralal;Kim, Ji Min;Subburaman, Chandramohan;Kwon, Woo Young;Hwang, Sung Hyun;Jeong, Sehan;Jo, Min Geun;Kim, Hyung Joo;Park, Ki Soo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.6
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    • pp.920-925
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    • 2020
  • In India, nanotechnology has been used in therapeutic applications for several millennia. One example of a traditional nanomedicine is Rajath Bhasma (also called calcined silver ash), which is used as an antimicrobial and for the treatment of various ailments and conditions such as memory loss, eye diseases, and dehydration. In this study, we aimed to characterize the physical composition and morphology of Rajath Bhasma and its suitability for use as a non-toxic antimicrobial agent. First, Rajath Bhasma was physically characterized via i) Fourier-transform infrared spectroscopy to analyze the surface functional groups, ii) scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy to observe the morphology and elemental composition, and iii) X-ray diffraction to determine the crystalline phases. Thereafter, functional characterization was performed through toxicity screening using zebrafish embryos and through antimicrobial activity assessment against gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. Rajath Bhasma was found to harbor alkene, hydroxyl, aldehyde, and amide functional groups originating from biological components on its surface. The main component of Rajath Bhasma is silver, with particle size of 170-210 nm, and existing in the form of spherical aggregates with pure crystalline silver structures. Furthermore, Rajath Bhasma did not exert toxic effects on zebrafish embryos at concentrations below 5 ㎍/ml and exhibited effective antimicrobial activity against both gram-positive and gram-negative bacteria. The present results indicate that Rajath Bhasma is a potentially effective antimicrobial agent without toxicity when used at concentrations below 5 ㎍/ml.

Biosurfactant as a microbial pesticide

  • Lee, Baek-Seok;Choi, Sung-Won;Choi, Ki-Hyun;Lee, Jae-Ho;Kim, Eun-Ki
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.40-44
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    • 2003
  • Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

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Enhancement Characteristics of Gadolinium Contrast Agent in the Rat Inner Ear Perilymph through CSF microcirculation (뇌척수액 미세순환을 통한 래트 내이 외림프의 가돌리늄 조영제 증강 특성)

  • Kim, Min Jung;Lee, Sang-Yeol;Lee, Hui Joong;Lee, Taekwan;Chang, Yongmin
    • Journal of Biomedical Engineering Research
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    • v.43 no.4
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    • pp.193-198
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    • 2022
  • Contrast enhanced magnetic resonance imaging using gadolinium-based contrast agent (GBCA) is a very useful in vivo technique to visualize the inner ear pathology including endolymphatic hydrops. Although systemic intravenous (IV) administration can visualize the perilymph space, the visualization was possible by indirect passage of contrast agent through blood-perilymph barrier. All animal experimental procedures were performed under anesthesia with 5% isoflurane. Lipopolysaccharide (LPS) was instilled into the left tympanic cavity through the tympanic membrane using a sterile 27gauge needle to induce hydrops model. Tucker-Davis Technologies system was used to measure Auditory Brainstem Responses (ABRs). For intracerebroven-tricular (ICV) administration, 25 µmol of GADOVIST (Bayer, Berlin, Germany) was used and diluted GADOVIST injection was 10 µl. MR imaging was acquired with a 9.4 Tesla MRI scanner. Transmit-receive volume coil with 40 mm inner diameter and 75 mm out diameter was used. ICV administration well demonstrated the strong enhancement along the cerebrospinal fluid (CSF) microcirculation pathway including CSF fluid in the subarachnoid space and CSF space of the inner ear structures. On the other hand, IV administration showed no contrast enhancement along the CSF microcirculation pathway and showed weak enhancement in the inner ear structures. In case of rat hydrops model, ICV administration showed that the reduced contrast enhancement in the perilymph space of the hydrops induced inner ear compared to the contrast enhancement in the perilymph space of the normal inner ear. New systemic ICV administration method provide contrast enhancement of GBCA in the inner ear through CSF microcirculation pathway.

Biological control of grapevine crown gall (포도나무 줄기 혹병의 생물학적 방제)

  • Chung, Kwang-Jin;Shim, Jae-Seop;Chung, Bong-Koo
    • The Korean Journal of Pesticide Science
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    • v.2 no.2
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    • pp.97-101
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    • 1998
  • Agrobacterium vitis causes a crown gall disease in grapevine and that is one of the major hindrances for the wide cultivation and production of grapevine. We studied the possibility of biological control using selected biological control agent. One isolate from the infected soil, named as strain 27, was able to inhibit the biovar 1; A. tumefaciens C58 and Ach5, biovar 2; A. rhizogenes 13264, and biovar 3; A. vitis, in vitro and in vivo test. The putative biological control agent, A. radiobacter strain 27 was carrying the plasmid and the size of isolated plasmid was very similar to that of pAgK84 of A. radiobacter K84.

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Colorimetric Detection of Chelating Agents Using Polydiacetylene Vesicles (폴리다이아세틸렌 베시클을 이용한 킬레이트제의 색전이 검출)

  • Park, Moo-Kyung;Kim, Kyung-Woo;Ahn, Dong-June;Oh, Min-Kyu
    • Korean Chemical Engineering Research
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    • v.49 no.3
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    • pp.348-351
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    • 2011
  • In this research, we developed a sensor system which can easily detect several chelating agents using polydiacetylene(PDA) vesicles. In comparison to other sensors, PDA based sensor has several advantages. First, detection method is much simpler and faster because it does not require any labeling step in the experiment procedure. Second, significant color-transition from blue to red based upon external stimulus allows us the detection by naked eyes. Finally, it is also possible to perform quantitative analysis of the concentration of the chelating agent by measuring the colorimetric response. In this paper, five types of chelating agents were used, including EDTA, EGTA, NTA, DCTA and DTPA. Among them, EDTA and DCTA triggered especially strong color-transition. In conclusion, this study has led to a successful development of a color transition-based PDA sensor system for easy and rapid detection of chelating agents.

Biological Control of Turfgrass Diseases by Pseudomonas cepacia AF-2001 (Pseudomonas cepacia AF-2001을 이용한 잔디병의 생물학적 방제)

  • 서정우;장준환;이철훈;심규열;김현수
    • Asian Journal of Turfgrass Science
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    • v.13 no.1
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    • pp.55-66
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    • 1999
  • Effect of an antagonistic bacterium AF-2001, Pseudomonas cepacia, on control of turfgrass diseases as brown patch, Pythium blight, dollar spot, and large patch were evaluated in vitro and in vivo. Results obtained in this study are summarized as follows. 1. Pseudomonas cepacia AF-2001 showed antagonism against to the pathogens causing brown patch, Pythium blighe, dollar spot and large patch. Especially, the biological agent showed strong antagonistic effect on the causal pathogens of brown patch, dollar spot, and anthracnose, but weak on Pythium blight 2. Populotion density of P. cepacia AR-2001 decreased ra;idly in turfgrass soils. Initial population of the agent was 2.4$\times$107 cfu/g soil, however, decreased to 1.4$\times$103, 6$\times$102 and 0 cfu/g soil on 10, 20, and 30 days after application, respectively. 3. Under the controlled controlled conditions of $27^{\circ}C$ and 95% RH, P. cepacia AR-2001 showed 100% control efficacy on brown patch either by pre-treatment or post-treatment of infection. However, Pythium blight was controlled about 94% by pre-treatment and only 29% by post-treatment 4. In field trials, P. cepacia AF-2001 did not suppress large patch and the control efficacy on other turfgrass diseases was lower than agro-chemicals such as tebuconazole and metalaxyl. Control efficacy of brown patch, Pythium and dollar spot by the biological agent was 57.4%, 40.4%, 61.5~87%, respectively. 5. Growth, color and texture of creeping bentgrass were not differ significantly between AF-2001 treatment and untreated control.

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