• 한국어병학회지
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• 제22권3호
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• pp.317-326
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• 2009

This study has shown the screening of anti-bacterial activity of three Indian medicinal plant choloroform : methanol (50:50) solvent leaf extracts (i.e. Azadirachta indica, Ocimum sanctum, and Curcuma longa) with different concentrations (10, 5, 2.5, 1.25, 0.625, 0.312, and 0.156 mg/ml) under in vitro conditions against fish pathogenic bacteria, Aeromonas hydrophila, Streptococcus iniae, Vibrio harveyi, V. anguillarum, and Edwardsiella tarda isolated from olive flounder farms, Jeju Island, South Korea. The anti-microbial activity of the A. indica and O. sanctum extracts yielded the zones of growth inhibition (ZI) was 3 and 1mm against A. hydrophila at concentration of 0.156 mg/ml when compared to that of tetracycline standard (3 mm). At highest concentration (10 mg/ml) of A. indica, O. sanctum, and C. longa, high inhibition was 9, 7, and 6 mm when compared to that of tetracycline (11 mm) against A. hydrophila. The minimum inhibitory concentration (MIC) of A. indica, O. sanctum, and C. longa at 0.156 mg/ml that yield 9, 10, and 13 CFU/ml for A. hydrophila, 16, 22, and 25 CFU/ml for S. iniae and 18, 22, and 23 CFU/ml for E. tarda compared to the tetracycline. At highest concentration (10 mg/ml) of the three extracts was better inhibiting the growth of A. hydrophila, S. iniae and E. tarda. A. indica, O. sanctum, and C. longa were determined to the potential antioxidant activityon the basis of their scavenging activity of the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. A. indica extract was 0.625 mg/ml which indicated that the strong anti-oxidant activity. However, O. sanctum and C. longa extracts showed weak anti-oxidant activity at this concentration. Hence, in vitro assay among the pathogens, A. hydropila is better inhibitory activity of the extracts. It is evident that the Indian medicinal plants extracts were subjected to its effectiveness against A. hydrophila, S. iniae, and E.tarda at low concentrations. The obtained results in the present study suggested that the Indian plant extracts is a prevention tools for Korean olive flounder aquaculture pathogens and its need further advance investigation.

• Mycobiology
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• 제36권2호
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• pp.121-133
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• 2008

Aspergillus niger isolated from Allium sativum was used at large scale fermentation (150 mg flavone/200ml medium) to obtain suitable amounts of the products, efficient for identification. Then spectral analysis (UV, IR, $^1H$-NMR, $^{13}C$-NMR) and mass spectrometry were performed for the two products, which contributed to the identification process. The metabolite (1) was identified as 2'-hydroxydihydrochalcone, and the metabolite (2) was identified as 2'-hydroxyphenylmethylketone, which were more active than flavone itself. Antioxidant activities of the two isolated metabolites were tested compared with ascorbic acid. Antioxidant activity of metabolite (1) was recorded 64.58% which represented 79% of the antioxidant activity of ascorbic acid, and metabolite (2) was recorded 54.16% (67% of ascorbic acid activity). However, the antioxidant activity of flavone was recorded 37.50% which represented 46% of ascorbic acid activity. The transformed products of flavone have anti-microbial activity against Pseudomonas aeruginosa, Aspergillus flavus and Candida albicans, with MIC was recorded $250{\mu}g/ml$ for metabolite (2) against all three organism and 500, 300, and $300{\mu}g/ml$ for metabolite (1) against tested microorganisms (P. aeruginosa, Escherichia coli, Bacillus subtilis, and Klebsiella pneumonia, Fusarium moniliforme, A. flavus, Saccharomyces cerviceae, Kluveromyces lactis and C. albicans) at this order.

• KSBB Journal
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• 제13권5호
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• pp.469-476
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• 1998

Among 31 water-born microbial strains isolated from various sites in Korea, strain DJ-4 was selected as a test organism for toxicity measurements in that its growth was completely inhibited by the presence of 668.4 mg/L of chloroform and 297.5 mg/L of toluene in the liquid LB medium whereas others did not. It was observed that lag periods and specific growth rates of DJ-4 batch vial cultures were prolonged and decreased, respectively, by phenol, benzene, toluene, ethylbenzene, p-xylene, perchloroethylene, trichloroethylene, and chloroform at the concentrations between 3.6 and 417.8 mg/L. There changes were found to be linear with respect to the concentrations of the toxic compounds. From the first-order regression equations, 50% effective concentrations (EC50${\mu}$ for concentrations of toxic compounds causing 50% decrease of specific growth rates and EC50lag for 50% increase of length of lag periods) were calculated for each compounds. By comparing DJ-4 EC50${\mu}$ values with Daphnia LC50's from a literature for benzene, ethylbenzene, toluene, and trichloroethlyene, it was concluded that microbial specific growth could be a new, fast, and reliable parameter for toxicity tests.

• 한국식품위생안전성학회지
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• 제9권4호
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• pp.191-198
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• 1994

The major purpose of the present study is to syrvey vegetables, meats, seafoods, processed foods and imported foods for the presence of Listeria spp. and to prevent listeriosis caused by the contamination of Listeria monocytogenes. Listeria spp. was not found in vegetables and processed foods. The optimum growth condition of isolates indentified as Listeria monocytogenes was pH 7.0 and 37$^{\circ}C$. the antimicrobial effect of grapefruit seed extract(GFSE) was observed in the level of more than 100ppm by disk method. When 1ml(2.5$\times$106 CFU/ml) of Listeria monocytogenes was inoculated and incubated for 3 days at 3$0^{\circ}C$, the total cell number of the organism was 4.5$\times$109 in the control, 7.2$\times$103 in 100 $\mu\textrm{g}$/ml of GFSE medium, and 3.5 $\mu\textrm{g}$/ml of GFSE medium. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed microbial cell membrane the function of which was destroyed by treating with the dilute solutions of GFSE. It could be confirmed that GFSE completely inhibited the growth of the test strain of Listeria monocytogenes.

• 한국안광학회지
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• 제5권1호
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• pp.95-99
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• 2000

소프트 콘택트렌즈 착용자 80명 중 다목적 용액을 사용하는 렌즈 관리체계에서 렌즈 보관용기의 미생물 오염을 조사하였다. 조사대상 중 72명(90%, 다목적용액 사용자 포함)은 화학소독을 6명(7%)은 과산화수소 소독을 그리고 2명(3%)은 열 소독을 실시하고 있었다. 다목적 용액을 사용하는 관리체계는 조사대상 중 59%이었다. 수거하여 조사한 총 80개의 렌즈 보관용기 중 68%(54개)에서 미생물 요염이 나타났다. 보관용기는 사용기간이 오래된 것일수록 오염률이 더 높았다. 다목적 용액을 사용하는 관리체계에서 오염된 31개(57%)의 보관용기 중 1종류의 균주가 검출된 경우가 4개(13%), 2종류의 균주가 검출된 경우가 15개(48%) 그리고 3종류 이상의 균주가 검출된 경우가 12개(39%)이었다. 오염된 렌즈 보관용기로부터 Pscudomonas. Scrratia. Bacillus. E. coil. Aspergillus 등이 분리 동정되었다. 다목적 용액 관리체계에서 소프트 콘택트렌즈 보관용기의 미생물 오염률이 높기 때문에 렌즈를 보다 효과적이고 위생적으로 관리하여야 하는 것이 중요하고 특히 주기적으로 자주 렌즈 보관용기를 교체하므로서 보관용기 내에서의 미생물의 증식을 방지하는 것이 바람직하리라 생각된다.

• 생명과학회지
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• 제12권5호
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• pp.610-621
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• 2002

미생물 유전체(genome)들 사이의 보존된 유전자 (con-served gene)를 밝히는 것은 생명의 본질을 이해하는데 있어 다양한 의미를 갖는다고 할 수 있을 것이다. 본 연구에서는 보존적 유전자를 찾아내고, distance value를 이용하여 구한 보존성의 정도 C(conservation score)를 이용하여 종간의 유전자 변이의 정도를 단백질 관점에서 분석하였다. 분석에 사용된 자료는 COGs 데이티베이스의 총 43종의 미생물 유전체들이며, 이들은 총 n,009개의 유전자들을 포함하는 3,852 개의 ortholog들로 구성되어있었다. 분석 결과 43종의 미생물 유전체에 대하여 총 $\ulcorner$2개의 유전자들이 보존적인 것으로 나타났으며, 이들 중 72.2%인 52종의 유전자가 단백질 합성에 관련되는 것으로 나타났다. 이들 보존적 유전자들에 대하여 보존성의 정도 C를 계산하여 보존성의 순위를 얻었으며, 가장 잘 보존된 유전자는 CTPase-trans-lation elogation factor (COG0050)로 나타났다. 그리고 72개의 보존적 유전자가 나타내는 CU 모두를 이용한 분석결과 고세균(archaea)과 진정세균(bacteria)이 각각 독자적인 그룹을 형성하는 것을 관찰하였다. 본 연구의 결과에서 도출한 72개의 보존적 유전자는 생명체의 본질적 기능에 중요한 역할을 담당하는 것으로 사료되었고, 생명체의 진화 과정에서 이 유전자들이 보존된 이유와 기능적 연계에 대한 생물학적 연구에 기초 자료를 제공할 것으로 판단되어 진다.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.143-154
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• 2009

Single nucleotide polymorphisms (SNPs) are the most frequent form of variation in the genome of any organism. Owing to their greater abundance, they are considered useful for identifying cultivars, construction of higher density linkage maps, and detection of genes (QTLs) associated with complex agronomic traits and diseases. Although, SNPs have been used recently for constructing a high density genetic map in silkworm and a set of 118 SNPs have been identified in tasar silkworms, not much progress has been made in sericulture to utilize the vast potential of SNPs. Thus, this review mainly focuses on some of the important methods of SNP discovery, validation and genotyping. Emphasis has also been given to the possible uses of SNP genotyping in the improvement of silkworms and their host plants.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.807-822
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• 2016

Starting as a glutamate producer, Corynebacterium glutamicum has played a variety of roles in the industrial production of amino acids, one of the most important areas of white biotechnology. From shortly after its genome information became available, C. glutamicum has been applied in various production processes for value-added chemicals, fuels, and polymers, as a key organism in industrial biotechnology alongside the surprising progress in systems biology and metabolic engineering. In addition, recent studies have suggested another potential for C. glutamicum as a synthetic biology platform chassis that could move the new era of industrial microbial biotechnology beyond the classical field. Here, we review the recent progress and perspectives in relation to C. glutamicum, which demonstrate it as one of the most promising and valuable workhorses in the field of industrial biotechnology.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.490-494
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• 1997

A variety of microbial strains isolated from soil were tested for their ability to produce D-tagatose from D-galactose. An organism that can convert D-galactose into D-tagatose was selected and was identified as Enterobacter agglomerans. The cells grown on the induction medium containing 20 g/l arabinose were found to the best conversion potential among different carbohydrates and the conversion yield was about 15% when 20 gll galactose was used. The isolated crystals were obtained from the culture broth after the purification process such as treatment of ion resins, crystallization, and drying. The recovery yield was 70% after the purification. The crystals were identified as D-tagatose by the infrared spectroscopy, HPLC, specific optical rotation, and melting point.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.209-213
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• 1995

During the screening of inhibitors of melanin biosynthesis from microbial secondary metabolites, a fungal strain MR-93 which was capable of producing high level of an inhibitor was selected from plant leaf. Based on taxonomic studies, the fungus could be classified as a strain of Trichoderma sp.. The active compound (MR-93D) was purified from the culture broth by Diaion HP-20 column chromatography, ethylacetate extraction, Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as 4-hydroxy-8-isocyano-l-oxaspiro[4-4]cyclonon-8-en-2- one by spectroscopic methods of UV, $^{1}$H-NMR, ESIMS and IR. MR-93D showed a strong tyrosinase inhibitory activity with 0.03 $\mu$g/m of IC$_{50}$ value. It also inhibited melanin biosynthesis with 35 mm inhibition zone at 30 $\mu$g/paper disc in Streptomyces bikiniensis, a bacterium used as an indicator organism in this work.