• Journal of Microbiology
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• v.42 no.3
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• pp.194-199
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• 2004

Investigation of the expression of the riboflavin (rib) genes, which are found immediately downstream of luxG in the lux operon in Photobacterium phosphoreum, provides more information relevant to the evolution of bioluminescence, as well as to the regulation of supply of flavin substrate for bacterial bioluminescence reactions. In order to answer the question of whether or not the transcriptions of lux and rib genes are integrated, a transcriptional termination assay was performed with P. phoxphoreum DNA, containing the possible stem-loop structures, located in the intergenic region of luxF and luxE ($\Omega$$\_$A/), of luxG and ribE ($\Omega$$\_$B/), and downstream of ribA ($\Omega$$\_$c/). The expression of the CAT (Chloram-phenicol Acetyl Transferase) reporter gene was remarkably decreased upon the insertion of the stem-loop structure ($\Omega$$\_$c/) into the strong lux promoter and the reporter gene. However, the insertion of the structure ($\Omega$$\_$B/) into the intergenic region of the lux and the rib genes caused no significant change in expression from the CAT gene. In addition, the single stranded DNA in the same region was protected by the P. phosphoreum mRNA from the Sl nuclease protection assay. These results suggest that lux genes and rib genes are part of the same operon in P. phosphoreum.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.127-132
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• 1986

Soybean nodule extract was prepared and tested for the effectiveness in the induction of asymbiotic nitrogen fixation of R. japonicum P-168. A Asymbiotic nitrogenase activity was increased over twice when glutamate was replaced by nodule extract in the induction media. Independently of the induction media, the nitrogenase activity in the assay media was also enhanced by the addition of nodule extract ($100-400{\mu}g$ protein/ml). The amount of ethylene in the assay media reached the highest point after 8 days incubation of R-168 and was decreased thereafter. The growth of R. japonicum R-168 was sensitive to the concentration of nodule extract. As a while, the effect of soybean root extract was not detected both in the induction of nitrogenase activity and in the growth of R. japonicum R-168.

• Journal of Microbiology
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• v.38 no.3
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• pp.150-155
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• 2000

A bioluminescent assay method for detecting the activity of phospholipase C(PLC; phosphatidyl choline cholinephosphohydrolase, EC 3.1.4.3) was developed using bioluminescent marine bacteria. Phospholipase C from Bacillus cereus and sn-1,2- dimyristoyl glycerol was further hydrolyzed with lipase from Candida ecylidracea. The hydrolyzed myristic acid was quantified using a dark mutant of Vibrio harveyi (designated as M-17). The in vivo light intensity of which was stimulated specifically up to one thousand fold in the presence of myristic acid. The rates of the hdrolysis of the DMPC substrate by the phospholipase measured by the luminescence method were linear with time and the were estalished to detect as little as 0.1 mUnit of phospholipase C and 5 nM of myristic acid production.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.54-58
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• 2007

Fermented soybean, Chungkookjang contains microorganism, enzyme, and diverse bioactive compounds. Isoflavones in Chungkookjang might suppress breast and prostate cancers. Using HPLC and Mass analyses, it was found that 100% ethanol extract of Chungkookjang contains aglycone forms such as genistein, daidzein, and glycitein. 8-OH-genistein, 8-OH-daidzein were not found. There are two estrogen receptors, $ER{\alpha},ER{\beta}$. $ER{\alpha}$ might stimulate proliferation of breast and prostate cancer cells, and $ER{\beta}$ might suppress their growth. Using yeast transactivation assay under the control of human ER expression, it was demonstrated that isoflavones in Chungkookjang can stimulate $ER{\beta}_{1}$, selectively.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.321-324
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• 2007

The changes in antigenicity during cultivation of streptomycetes were determined by immunodiffusion assay and indirect ELISA. New precipitin lines in immunodiffusion assay began to appear in the growth period of the soluble pigment production and became thickened thereafter. The increase in the antigenicity was also confirmed by ELISA. The antigenic development was relatively weak for S. lavendulae and S. viridochromogenes while that was strong for S. lavendulae and S. viridochromogenes. The results indicated that Streptomyces strains, even though not proved for some strains, changed the compositions of cell envelope during submerged growth and this could be estimated quantitatively by serological method.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.517-523
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• 1989

This study was undertaken to establish reliable diagnostic-procedures for the microbiological monitoring of laboratory animals. Murine(mice and rats) antibodies against hemagglutinating virus of Japan(HVJ), mouse hepatitis virus(MHV) and Mycoplasma pulmonis(Mp) were detected sensitively and specifically in experimentally and naturally infected animals' sera by an indirect enzyme-linked immunosorbent assay(ELISA), using urease conjugated antimurine immunoglobulin. The sensitivity and specificity of the complement fixation test which has been apllied widely for serodiagnosis of HVJ, MHV and Mp infections were apparently lower than those of ELISA. From these results, the ELISA was found to be available for the serodiagnosis of HVJ, MHV and Mp infections in mice and rats.

• Journal of Microbiology
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• v.34 no.4
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• pp.374-378
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• 1996

In the aquatic fungus Allomyces macrogynus the effects of $Ca^{2+}$ and cAMP on the intracellular signal transduction of zoospore germination were studied using in vitro protein phosphorylation assay system. An endogenously phosphorylated protein (p50) having molecular weight of 50 kDa on SDS-PAGE was found in soluble fractions of both zoospore and mycelium. In zoospore extract, the endogenous phosphorylation of p50 was weak without any effectors, but was enhanced by $Ca^{2+}$ and even more by cAMP. Phosphorylation of the same protein in mycelial extract was high only in the absence of cAMP. Irrespective of the presence of $Ca^{2+}$ and cAMP, its phosphorylation was antagonistically suppressed in assay of combined zoospore and mycelial extracts. These results suggest that p50 is interconvertible in phosphorylation/dephosphorylation as a novel protein involved in germination of A. macrogynus. The antagonistic effect of cAMP to the phosphorylation of p50s from different developmental stages may be important in the regulation of cellular differentiation.

• YAKHAK HOEJI
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• v.8 no.3
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• pp.80-84
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• 1964

The purpose of this investigation is to observe tha variation of vitamin $B_{12}$, nicotinic acid and folic acid contents in relation to the growing years of Panax Ginseng roots. The contents of the vitamins were estiamted microbiologically with Lactobacillus leichmannii, Lactobacillus arabinosus and Streptococcus faecalis, respectively. It is found that the content of vitamin $B_{12}$ in Panax Ginseng roots somewhat increases according to their growing years except 3-year-old roots. It is probable that the lower content in these roots should be due to the cultivating soil. The content of nicotinic acid in all the roots is not significantly different. The result of paper chromatography using the concentrated extract of the roots suggests that there exists some other substance besides nicotinic acid and nicotinamide, of which Rf value is 0.5 in comparison with the Rf 0.75 of nicotinic acid and nicotinamide. It is thought that this substance stimulate the growth of L. arabinosus. The content of folic acid is significantly different. The content level is the highest in the 4-year-old roots and the lowest in the 6-year-old roots.

• Journal of Microbiology
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• v.38 no.2
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• pp.88-92
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• 2000

A human ribosomal protein S3 (rpS3), which also functions as a DNA repair enzyme(UV endonuclease III), was expressed in a methylotrophic yeast, Pichia pastoris, and biochemically characterized. UV endonuclease activity was preiously characterized, and this activity of mammalian rpS3 was found to be non-specfic upon purification and storage. Under the Pichia expression system, the subcloned cDNA of the human rpS3 gene revealed a peptide of 42 kDa by SDS-PAGE and Western blot. The secreted form of human rpS3 rendered no endonuclease activity while the intracellular form showed UV specific endonuclease activity by the nick circle assay.

• Journal of Microbiology
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• v.38 no.2
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• pp.105-108
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• 2000

Oligonucleotide primers amplifying a 344 bp fragment on the integrin-like protein alpha-INT1p gene (${\alpha}$INT1) of Candida albicans were synthesized for screenign of C. albicans from clinicalsamples by the polymerase chain reaction (PCR). The PCR specifically amplified DNA from C. albicans and none from any other Candida, fungal, or human DNA in standard used here. The PCR assay showed that the primers (LH1 and LH2) were specific for 26 isolates of C. albicans from clinical smaples, whereas the positive fragment, 344 bp, was not amplified from 15 clinical isolates including 14 other medically important Candida species and an isolate of Saccharomyces cerevisiae. PCR was conducted on the urine samples of 20 patients and 4 samples were C. albicans positive. The detection limit of the PCR assay for C. albicans was shown to be approximately 10 cells/ml saline. The PCR system using 344 bp ${\alpha}$INT1 as a target is more specific and rapid than the conventional culture method, and the sensitive detection method is applicable to clinical diagnosis of C. albicans infections.