• Journal of Life Science
• /
• v.21 no.1
• /
• pp.159-164
• /
• 2011

Microbial whole-cell biosensors can be excellent analytical tools for monitoring environmental pollutants. They are constructed by fusing reporter genes (e.g., lux, gfp or lacZ) to inducible regulatory genes which are responsive to the relevant pollutants, such as aromatic hydrocarbons and heavy metals. A large spectrum of microbial biosensors has been developed using recombinant DNA technology and applied in fields as diverse as environmental monitoring, medicine, food processing, agriculture, and defense. Furthermore, their sensitivity and target range could be improved by modification of regulatory genes. Recently, microbial biosensor cells have been immobilized on chips, optic fibers, and other platforms of high-throughput cell arrays. This paper reviews recent advances and future trends of genetically modified microbial biosensors used for monitoring of specific environmental pollutants.

• YAKHAK HOEJI
• /
• v.21 no.3
• /
• pp.167-171
• /
• 1977

A new assay method for delta-l-dehydrogenated-3-ketoco-rticosteroid in the presence of proteinous material or whole-cell-enzyme and 3-ketocorticosteroid has been developed. This method makes use of the linear relationship between the ratio of absorbances at 265 nm and at 242 nm and the fractional concentration of delta-1-3-ketosteroid. Theoretical values were calculated based on the absorbances of proteinous material at fixed concentrations of the 3-ketosteroid and delta-1-dehydrogenated-3-ketosteroid. The values obtained experimentally showed good agreement with the values obtained experimentally showed good agreement with the values theoretically predicted. The new assay method developed for the steroid mixtiure containing proteinous material is of some practical importance. The use of such assay method enables one to determine the enzyme activity and the rate of enzyme reaction or conversion rather quickly, easily and accurately. By the use of this assay method, the reaction kinetics of whole-cell-enzyme has also been studied. It was found that it followed the simple Michaelis-Menten type enzyme kinetics. Also the reversibility of this reaction with actively metabolizing cell was examined. It was found that delta-l-dehydrogenated-3-ketosteroid could not be hydrogenated reversibly to 3-ketosteroid by this enzyme system.

• Development and Reproduction
• /
• v.26 no.1
• /
• pp.13-21
• /
• 2022

Neurokinin B (NKB) is a neuropeptide involved in the regulation of reproductive endocrine system of vertebrate animals, including fish. However, the pathway of NKB action in fish has not been clearly elucidated. In order to clarify the effect of NKB and NKF (neurokinin F) on gonadotropic hormone (GTH) gene expression in the pituitary, we studied the changes of LHβ and FSHβ gene expressions by using two different pituitary culture methods (whole pituitary culture or dispersed pituitary cell culture). Pituitaries were removed from mature female and male Nile tilapia. Changes of LHβ and FSHβ gene expressions were measured and compared after the treatment with NKB or NKF peptides at concentrations 0 to 1,000 nM. Expression of GTH genes in the whole pituitary cultures treated with NKB or NKF peptides did not show significant difference except in female at one concentration when treated with NKF. On the contrary, there were significant changes of GTH gene expressions in the dispersed pituitary cell cultures when treated with NKB and NKF peptides. These results suggest that dispersed pituitary cell culture is more relevant than whole pituitary culture in studying the function of pituitary, and that NKB and NKF could act directly on the pituitary to regulate the expression of GTH genes.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2006.05a
• /
• pp.94-95
• /
• 2006

• The Journal of the Korean Society for Microbiology
• /
• v.18 no.1
• /
• pp.73-85
• /
• 1983

The advantages of the enzyme-linked immunosorbent assay(ELISA) are its sensitivity and its simplicity in detecting IgM and IgG antibodies. For applying the ELISA to the diagnosis of typhoid fever, first of all, experiments were performed to determine which concentration of killed whole cell antigens and lipopolysaccharide(LPS) antigens of S. typhi(0.901 w) were optimally coated to the wells of the polystyrene and polyvinylchloride microplate, using the hyperimmune sera from rabbits against S. typhi. By using both kinds of antigens of S. typhi adsorbed to the ELISA microplate, the changing patterns of IgG and IgM antibodies in the sera from rabbits responding to the killed whole cell antigens of S. typhi(0901 w) during the prolonged immunization were serially traced by the ELISA. At the same time, the level of antibodies against S. typhi in sera fron patients with typhoid fever and from normal healthy persons were measured by the ELISA employing the killed whole cell antigens and LPS antigens as the coating antigens. The results obtained were summerized as follow: 1. The optimal concentration of the killed whole cell antigens, which were more easily adsorbed to the polystyrene plate than the polyvinylchloride plate, was $10^8cells/ml$ of carbonate buffer(pH. 9.6) on the wells of the polystyrene plate when treated at $37^{\circ}C$ for 4 hours. On the other hand, the optimal concentration of lipopolysaccharide antigens, which were adsorbed only to the polyvinylchloride plate, was $100{\mu}g/ml$ of carbonate buffer(pH. 9.6) on the wells of the polyvinylchloride plate when treated at $37^{\circ}C$ for 4 hours. 2. IgM antibody response were dominating in rabbits responding to the killed whole cell antigens of S. typhi(0.901 w), and were more specific to the LPS antigens than to the killed whole cell antigens in the ELISA. Good correlations were made between the IgM titers by the ELISA and the aggglutinating titers of sera from the immunized rabbits. 3. Both IgG and IgM agglutination titers by the ELISA in sera from most of patients with typhoid fever were above 1:320 but those in sera from most of normal, healthy persons were below 1:80. 4. There were close correlations between the antibody titers by the ELISA and the agglutinating titers to the killed whole cell antigens in the tested human sera, IgM titers being more correlated with the agglutinating titers than IgG titers. But a little correlations were made between the antibody titers by the ELISA and the agglutinating titers to the LPS antigens. 5. IgM titers in the tested human sera were similar to IgG titers detected by the ELISA employing the killd whole cells antigens and the LPS antigens. 6. Good correlations were made between the antibody titers demonstrated by the ELISA performed on the killed whole cell antigens and the LPS antigens as the different, coating antigens on the ELISA microplates.

• The Journal of Korean Society of Virology
• /
• v.28 no.4
• /
• pp.295-302
• /
• 1998

The RNA genome of poliovirus encodes a long polyprotein precursor and this polyprotein is cleaved proteolytically by viral protease to yield mature proteins. The mature proteins derived from the P1 polyprotein precursor are the component of capsids. To further delineate the process of capsid assembly and encapsidation, in a first attempt, a cell line which expresses the authentic P1 polyprotein was established. CV-1 cells were transfected with the pRCRSVS1P1 plasmid DNA which contains 5'ncr sequences, whole authentic capsid gene of poliovirus and neomycin resistance gene. These cells were treated with G418 for 3 months, and eventually G418 resistant cells were selected and formed colonies. Each colony was picked and grown in the media containing G418. DNA analysis indicated that 1 of 13 neomycin resistant cell lines (R2-18) contains whole poliovirus P1 capsid gene segment which was incorporated into the genome. Immuneprecipitation of cell lysates with sera from rabbit immunized with inactivateded Sabin type 1 particles demonstrated the constitutive expression of the poliovirus P1 capsid protein from R2-18.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.12
• /
• pp.2237-2240
• /
• 2017

In the present study, we investigated the effect of tyndallized HY7712 (tHY7712) on the expression of Th cell specific transcription factors and cytokines in whole-body ${\gamma}$-irradiated mice. Oral administration of tHY7712 strongly recovered the ${\gamma}$-irradiation-suppressed expression of helper T (Th) cell- and regulatory T cell-related transcription factors and cytokines, such as T-bet, Foxp3, IFN-${\gamma}$, TNF-${\alpha}$, and IL-10, and suppressed Th2 cell-associated transcription factor and cytokine GATA3 and IL-5, respectively. Furthermore, compared with the control, tHY7712 treatment also restored ${\gamma}$-irradiation-impaired natural killer and cytotoxic T cell activities against YAC-1 tumor cells to 97.8% and 98.6%, respectively.

• Korean Journal of Pharmacognosy
• /
• v.40 no.1
• /
• pp.41-45
• /
• 2009

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzhemier's disease. Neuropathologically, PD is characterized by the selective loss of dopaminergic neurons. The neuronal toxicity of cytosolic excess dopamine (DA) has been described in many studies using several cell lines. In dopaminergic neurons, cytosolic excess DA is easily oxidized via monoamine oxidase (MAO)-B, tyrosinase or by auto-oxidation to produce neurotoxic metabolites such as DA quinone. So, in the present study, we induced cell death by treatment of DA ($600{\mu}M$) in human neuroblastoma SH-SY5Y cell which was treated samples before 24 hr, and cell viability was measured by fluorescence activated cell sorter (FACs) analysis. Of those tested, the extracts of Poria cocos (赤茯笭)(whole), Gastrodia elata (rhizomes), Eucommia ulmoides (炒)(barks), Syneilesis palmata (whole), Acorus gramineus (rhizomes), Ligustrum japonicum (leaves) showed neuroprotective effects in dose dependent manner.

• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.385-385
• /
• 2005

• KSBB Journal
• /
• v.26 no.3
• /
• pp.199-205
• /
• 2011

Using tetrameric ${\beta}$-galactosidase as a model protein, anchoring motives were screened in Bacillus subtilis spore display system. Eleven spore coat proteins were selected considering their expression levels and the location in the spore coat layer. After chromosomal single-copy homologous integration in the amyE site of Bacillus subtilis chromosome, cotE and cotG were chosen as possible spore surface anchoring motives with their higher whole cell ${\beta}$-galactosidase activity. PAGE and Wester blot of extracted fraction of outer layer of purified spore, which express CotE-LacZ or CotG-LacZ fusion verified the existence of exact size of fusion protein and its location in outer coat layer of purified spore. ${\beta}$-galactosidase activity of spore with CotE-LacZ or CotG-LacZ fusion reached its highest value around 16~20 h of culture time in terms of whole cell and purified spore. After intensive spore purification with lysozyme treatment and renografin treatment, spore of BJH135, which expresses CotE-LacZ, retained only 1~2% of its whole cell ${\beta}$-galactosidase activity. Whereas spore of BJH136, which has cotG-lacZ cassette in the chromosome, retained 10~15% of its whole cell ${\beta}$-galactosidase activity, proving minor perturbation of CotG-LacZ, when incorporated in the spore coat layer of Bacillus subtilis compared to CotE-LacZ. Usage of Bacillus subtilis WB700, of which 7 proteases are knocked-out and thereby resulting in 99.7% decrease in protease activity of the host, did not prevent the proteolytic degradation of spore surface expressed CotG-LacZ fusion protein.