• Title/Summary/Keyword: Water agar

Search Result 425, Processing Time 0.028 seconds

Investigation of Antimicrobial Activity of Brown Algae Extracts and the Thermal and pH Effects on Their Activity

  • Lee, So-Young;Kim, Jin-Hee;Song, Eu-Jin;Kim, Koth-Bong-Woo-Ri;Hong, Yong-Ki;Lim, Sung-Mee;Ahn, Dong-Hyun
    • Food Science and Biotechnology
    • /
    • v.18 no.2
    • /
    • pp.506-512
    • /
    • 2009
  • The antimicrobial activity of water and ethanol extracts from 30 species of algae was measured using the agar diffusion method and minimum inhibitory concentration (MIC) test. In agar diffusion method, the 95% ethanol extracts from 12 of the algae showed growth inhibition against the tested microorganisms. In particular, Ishige okamurai, Ecklonia stolonifera, Sargassum siliquastrum, Sargassum thunbergii, Colpomenia bullosa, and Ecklonia cava had strong antibacterial activities against Gram-positive bacteria at 4 mg/mL. In the results of the MIC test, S. siliquastrum showed the most antimicrobial activity, where its MIC values ranged from 0.005 to 0.0075% against Listeria monocytogenes, Clostridium perfringens, and Basillus subtilis. In the thermal stability test, for the ethanol extracts of I. okamurai, E. cava, S. siliquastrum, S. thunbergii, and C. bullosa, the extracts proved to maintain high antimicrobial activities when they were treated at $121^{\circ}C$ for 15 min. In the pH stability test, the antimicrobial activity of the S. siliquastrum ethanol extract was stable from pH 2 to 10, whereas the activity of the other species ethanol extracts were weakened under pH 10 against several microbes.

Processing of Squeezed-Type Cockle Shell By-Product Paste (새조개 처리동결 가공부산물을 이용한 페이스트 젓갈 제조)

  • 배태진;강훈이
    • The Korean Journal of Food And Nutrition
    • /
    • v.10 no.4
    • /
    • pp.528-532
    • /
    • 1997
  • A fermented squeezed-type paste was processed in order to highly effective utilization of cockle shell by-product, and improvement on rheological properties and texture of hydrolysate by used additives. The cockly shell by-products were homogenized with addition of water and enzymatically hydrolyzed at 5$0^{\circ}C$ for 8 hours added 4% Protease N.P.(Pacific Chemical Co.). And the hydrolysate was thermally treated for the purpose of flavor improvement, enzyme inactivation and pasteurization product at 10$0^{\circ}C$ for 1 hour, with 4% glucose. To make improvement of rheological properties, used complex additive with 0.5% alginic acid, 1% pectin and 0.2% agar were very effective. And stability of mixing was 98.1% after centrifuged at 10,000 rpm for 60 minutes. The chemical composition of moisture, total carbohydrate, total nitrogen and amino type nitrogen in the fermented squeeze-type cockle shell by-product paste were 57.7%, 20.6%, 1,458mg% and 1,187mg%, respectively. And the ratio of amino type nitrogen in total nitrogen was 81.4%.

  • PDF

Rapid Screening Method of Peroxidase by Colorimetric Assay and Screening of 2, 4-DCP Degradable Strains (발색법에 의한 Peroxidase의 신속한 스크리닝법과 2, 4-DCP 분해균주의 스크리닝)

  • Ryu, Kang;Lee, Eun-Kyu
    • KSBB Journal
    • /
    • v.23 no.6
    • /
    • pp.484-488
    • /
    • 2008
  • Chlorinated phenols are widely used by the chemical industry as intermediate products in synthesis and previously were frequently applied to various industry fields. Peroxidases catalyze the peroxide-dependent oxidation of a range of inorganic and organic compounds. Peroxidase was shown to mineralize a variety of recalcitrant aromatic compounds and to oxidize a number of polycyclic aromatic and phenolic compounds. Among monomeric phenolic and nonphenolic compounds, peroxidase is known to oxidize its compounds. In this study, a colorimetric assay was developed to quantitatively evaluate the peroxidase activity for rapid screening. Color products of different intensity were developed proportionally to the peroxidase activity on agar plate and 96-well plate. This method correlates well with the RP-HPLC result. Using this screening method, 12 colonies of strain was screened which survived at high concentration of 2,4-DCP (1000 ppm) and with peroxidase activity for the $7^{th}$ round screening step on agar plate. These strains were utilized 2,4-DCP as a sole carbon source and produced peroxidase. After the screening test, four of the bacteria have significant better effect of COD removal on dye waste-water. COD removal of these was from 44% to 61%, respectively.

Study on Oxytetracycline Resistant Bacteria in the Surface Water Environment (하천에서의 Oxytetracycline 내성주에 관한 연구)

  • Kim, Young Jin;Kim, Jong Oh
    • Journal of Environmental Health Sciences
    • /
    • v.41 no.1
    • /
    • pp.40-48
    • /
    • 2015
  • Objectives: This study aims to understand the concentration, diversity, and antibiotic characteristics of oxytetracycline resistant bacteria present in a surface water environment. Methods: Water sampling was performed in Cheongmi Stream in Gyeonggi-do, Korea in February and August 2014. Water samples collected from two sites were plated in triplicate on tryptic soy agar plates with 30 mg/L of oxytetracycline. Oxytetracycline resistant bacteria were selected from surface water in Cheongmi Stream and were subjected to 16S rDNA analysis for oxytetracycline resistant species determination. Identified resistant strains were tested for resistance to various antibiotics. Results: Results from this study indicate that the dominant resistant organisms in this aquatic environment are from family Acinetobacter and family Aeromonas. As to culturable heterotrophic bacteria, Oxytetracycline resistant bacteria were present 0.45-0.93% during winter and 0.08-0.38% during summer. Most oxytetracycline resistant bacteria exhibited resistance to more than ten of the antibiotics studied. The diversity of oxytetracycline resistant bacteria in winter was higher than in summer. Conclusion: Most of these resistant bacteria are Gram negative and are closely related to pathogenic species. These results suggest that increasing multi-antibiotic resistant bacteria in the surface water environment has a close relation to the reckless use of antibiotics in livestock.

Isolation and Identification of an Anaerobic Dissimilatory Fe(III)-Reducing Bacterium, Shewanella putrefaciens IR-1

  • Hyun, Moon-Sik;Kim, Byung-Hong;Chang, In-Seop;Park, Hyung-Soo;Kim, Hyung-Joo;Kim, Gwang-Tae;Kim, Mi-a;Park, Doo-Hyun
    • Journal of Microbiology
    • /
    • v.37 no.4
    • /
    • pp.206-212
    • /
    • 1999
  • In order to isolate a Fe(III)-reducer from the natural environment, soil samples were collected from various patty fields and enriched with ferric citrate as a source of Fe(III) under anaerobic condition. Since the enrichment culture was serially performed, the Fe(III)-reduction activity was serially diluted and cultivated on an agar plate containing lactate and ferric citrate in an anaerobic glove box. A Gram negative, motile, rod-shaped and facultative anaerobic Fe(III)-reducer was isolated based on its highest Fe(III)-reduction activity, Bacterial growth was coupled with oxidation of lactate to Fe(III)-reduction, but the isolate fermented pyruvate without Fe(III), The isolate reduced an insoluble ferric iron (FeOOH) as well as a soluble ferric iron (ferric citrate). Using the BBL crystal enteric/non-fermentor identification kit and 16S rDNA sequence analysis, the isolate was identified as Shewanella putrefaciens IR-1.

  • PDF

Preservation of Marine Heterotrophic Bacteria by Using a Deep-freezing Method

  • Park, Shin-Hye;Lee, Hyun-Sang;Lee, Hong-Kum
    • Journal of Microbiology
    • /
    • v.39 no.3
    • /
    • pp.240-243
    • /
    • 2001
  • The effect of cryoprotectants and suspending solutions on the preservation of marine heterotophic bacteria was investigated. Six halotolerant and four halophilic bacterial isolates suspended in either distilled water or artificial seawater were preserved in glycerol and dimethylsulfoxide at -70$\^{C}$, respectively. After one year of preservation, the recovery rates on the appropriate agar plates were estimated. The survival rate was found to be dependent on the strain tested, regardless of the preservation conditions tested.

  • PDF

미생물에 의한 치자 Iridoid 배당체 변환 청색소의 생산

  • 양승각;전기붕
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.13 no.1
    • /
    • pp.36-44
    • /
    • 1987
  • Seven bacterial strains capable of conversing Gardenia irridoidglucoside into blue color was isolated on nutrient agar plates with 0.1% water extracted solution of Gardenia's dryad seed. In the seven, strain No. C2 was most effective in the production of blue color. The optimal conditions in production of blue color were when initial pH of medium was 7.0 and cultivation temperature was 35$^{\circ}C$. In 5 $\ell$-Jar fermantor, the powder of blue color was produced about 15% (W/W). And the color was relatively stable in our test.

  • PDF

Study on Antibiotic Resistant Bacteria in Surface Water Receiving Pharmaceutical Complex Effluent (제약공단 방류수 유입 하천에서의 항생제 내성 bacteria에 관한 연구)

  • Kim, Young Jin;Kim, Young Gyu
    • Journal of Environmental Health Sciences
    • /
    • v.42 no.6
    • /
    • pp.409-418
    • /
    • 2016
  • Objectives: The purpose of this study was to characterize penicillin G resistant bacteria in surface water from pharmaceutical complex effluent. Methods: Surface water was sampled from pharmaceutical complex effluent in Gyeonggi-do Province, Korea in March 2015. Water samples were plated in triplicate on tryptic soy agar plates with 32 mg/L of penicillin G. Penicillin G resistant bacteria were selected from the effluent and subjected to 16S rRNA analysis for the penicillin G resistant species determination. Identified resistant strains were tested for resistance to various antibiotics. Results: Penicillin G resistant bacteria were present at 8.0% in terms of culturable heterotrophic bacteria. Identified penicillin G resistant bacteria exhibited resistance to more than nine of the antibiotics studied. These resistant bacteria are gram negative and are closely related to pathogenic species. Conclusion: Multi-antibiotic resistant bacteria in the surface water of pharmaceutical complex effluent suggest the need for disinfection and advanced oxidation processed for pharmaceutical effluent.

Macrophomina phaseolina Detected in Seeds of Sesamum indicum and It's Pathogenicity (참깨 종자에서 검출된 Macrophomina phaseolina와 그의 병원성에 관하여)

  • YU S.H.;Park J.S.
    • Korean journal of applied entomology
    • /
    • v.19 no.3 s.44
    • /
    • pp.135-140
    • /
    • 1980
  • Out of 12 seed samples of Sesamum indicum L. tested, Macrophomina phaseolina (Tassi.) Goid was detected in 7 samples for the first time in Korea. Detailed descriptions of the habit character and pycnidial and pycnospore morphology of this fungus were described. Pycnidia of this fungus were not formed on agar media but they were formed on Water Agar Leaf Media under fluorescent light. M. phaseolina caused heavy reduction in seed germination and seedling stand of sesame and produced charcoal rot symptom on potato tubers. It was also detected from over wintered plant debris and diseased seedlings in the field.

  • PDF

A Basic Study on the Variation of Temperature Characteristics for Attenuation Coefficient and Sound Velocity in Biological Tissues

  • Park, Heung-Ho
    • Journal of Biomedical Engineering Research
    • /
    • v.14 no.3
    • /
    • pp.273-282
    • /
    • 1993
  • This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

  • PDF