• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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• pp.61-70
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• 1987

Authors have isolated phages of V. parahaemolyticus from shellfish and investigated some of their characteristics. The results obtained were as follows: Twenty-three phage strains(9.2%) out of 250 specimens were isolated. Plaques of phages were small, clear or turbid and $0.5{\sim}1.5mm$ in diameter. The electron micrographs of K3 phages showed two morphology; one was a hexagonal head about 105nm with a tail about 12nm, the other was a hexagonnal head about 60nm with a tail about 25nm. The host ranges of pahges were limited to V. parahaemolyticus strains and there appeared to be no relationship between the K serotypes of V. parahaemolyticus strains and the host ranges of the phage isolates. The adsorption rate of phages were more than 80% for $10{\sim}15$ minutes, the inactivation rate at $60^{\circ}C$ was more than 99% for $40{\sim}45$ minutes. The pH stability range was between 6.0 and 8.0. The inactivation rate of phages by UV irradiation was more than 99% for $45{\sim}75$ seconds.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1704-1707
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• 2007

Monitoring of the phage-host system of Microlunatus phosphovorus indigenous in activated sludge was attempted. A laboratory-scale activated sludge process was operated for 5 weeks with synthetic wastewater. The phage-host system population in the process was monitored by plaque assay and FISH methods at every 3 days. During the process operation, the phage-host system populations were more or less steady, except for 1 week in the middle of the operation. In that period, initially M. phosphovorus decreased significantly and its lytic bacteriophages increased, and then M. phosphovorus increased back to its original level while its lytic bacteriophages decreased. This observation suggests that lytic bacteriophages should be considered as one of the biological factors affecting the bacterial population dynamics in activated sludge processes.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.605-610
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• 1996

The bacteriophage from the fresh oyster, Crassostrea Virginica which is specific to the marine bacterium was isolated and characterized. Among the foci different vibrio species and the five different serotypes of Vibrio parahaemolyticus host strains tested, only two strains of the parahaemolyticus possessing K17, K52 antigens were highly sensitive to the phage. The size of the isolated plaque was 0.4mm and the electron microscopic head size of the isolated phage was about 67 nm long and 83 nm wide. PFU/ml was 1.25$\times$ $10^{11}$. The phase was sensitive to chloroform but resistant to acetone or methanol. The assay of the isolated phase nucleic acid was deoxyribonucleic acid. The restriction enzyme pattern showed 14 fragment from Hind III and 4 fragments from Eco R I. Two different antigenic groups showed-similar restriction enzyme patterns.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.1-14
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• 2009

This study was to review the classification, detection and control of bacteriophage in fermented dairy products. Bacteriophage has lytic and/or lysogenic life cycles. Epidemiologically speaking, detected major phages are c2, 936 and p335. Among them p335 has been the largest concern in dairy industry. Traditionally, various analytical technologies, such as spot, starter activity, indicator test, ATP measurement and conductimetric analysis, have been used for the phage detection. In recent years, advanced methods such as flow cytometric method, petrifilm, enzyme linked immunosorbent assay (ELISA) and multiflex PCR diagnostic kit have been deveoloped. The phage contamination has been controlled by using heat, high-pressure treatment, and the combinations of heat and pressure, and/or chemical. Also some starter cultures with phage-resistant character have been developed to minimize the concentration of phages in dairy product. Bacteriophage inhibition media such as calcium medium was also mentioned. To prevent the contamination of bacteriophage in dairy industry, further researches on the detection and control of phage, and phage resistant starters are necessary in the future.

• BMB Reports
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• v.29 no.5
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• pp.448-454
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• 1996

Bacteriophage ${\phi}FC1$ is a temperate phage which was identified as a prophage in the Enterococcus faecalis KBL703 chromosome. Phage ${\phi}FC1$ integrates into the host chromosome by site-specific recombination. The phage attachment site P (attP) was localized within the 0.65-kb XhoI-HindIII fragment and the nucleotide sequence of the region was determined. An open reading frame (mj1) which adjoined the phage attachment site encoded a deduced protein related to the site-specific recombinase family. The organization of this region was comparable to other site-specific recombination systems. The molecular weight of the expressed MJ1 in E. coli was in good agreement with the predicted 53,537 Da of the mj1 gene product. Elucidation of the phage-specific integration process in this study would provide useful genetic tools such as a chromosomal integration system.

• Korean Journal of Microbiology
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• v.16 no.2
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• pp.71-78
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• 1978

Bacillus subtilis var. 816 was used for manufacturing fermented soybean which in turn is used as flavoring agent. Fermentation of soyebean or flat wheat was occasionally failed. It was elucidated that failure was due to the presence of bacteriophage. According to Hemphill and Whitely (1975), this bacteriphage might be belonged to the viulent phage group I as it is similar to SP82G, ${\phi}25$. In fact, the phenomena of the increase of moisture, disappenarance of mucin and existence of undersirable bacteria was attributed to the contamination of the above phage during the course of fermentation of soybean or flat wheat. Particularly disapparance of mucin was sufficiently correlated by the replication of the bacteriophage. The above phage can grow in the range of $30^{\circ}C\;to\;70^{\circ}C$. The optimum temperature was $40^{\circ}C{\sim}50^{\circ}C$. The optimum pH range was between pH 7.4 and pH 8.0. It is noticeable that staphylococci was replicating simultaneously with the phage. The head of 816 phage is hexagonal with a diameter of $10{\times}165{\sim}10{\times}240\;nm$. The end of the tail is enlaged. It has a size of 25 nm and this end areas are spreaded widely as fingers.

• BMB Reports
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• v.38 no.3
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• pp.290-293
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• 2005

In order to investigate the epitope of basic fibroblast growth factor (bFGF) and its immunogenicity, the epitopes of bFGF were screened from the phage display library with monoclonal antibody GF22, which can neutralize the bio-activity of bFGF. By three rounds of screening, the positive phage clones with bFGF epitopes were selected, which can effectively block the bFGF to bind with GF22. Sequence analysis showed that the epitopes shared a highly conservative sequence (Leu-Pro-Pro/Leu-Gly-His-Phe/Ile-Lys). The sequence of PPGHFK was located at 22-27 of the bFGF. The specific immuno-response of mouse could be highly induced by phage clones with the epitopes. And the anti-bFGF activity induced by LPGHFK was 3 times higher than the original sequence, which showed that the mimetic peptide LPLGHIK might be used as a tumor vaccine in the prevention and treatment of tumor.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1473-1480
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• 2016

This study focused on the variations in the non-coding sequences between ctxB and rstR of various CTX phages. The non-coding sequences of CTX-1 and CTX-cla are phage type-specific. The length of the non-coding region of CTX-1 and CTX-cla is 601 and 730 nucleotides, respectively. The non-coding sequence of CTX phage could be divided into three regions. There is a phage type-specific Variable region between two homologous Common regions (Common regions 1 and 2). The non-coding sequence of RS1 element is similar to CTX-1 except that Common region 1 is replaced by a short RS1-specific sequence. The non-coding sequences of CTX-2 and CTX-cla are homologous, indicating the non-coding sequence of CTX-2 is derived from CTX-cla. The non-coding region of CTX-O139 is similar to CTX-cla and CTX-2; however, it contains an extra phage type-specific sequence between Common region 2 and rstR. The variations in the non-coding sequences of CTX phages might be associated with the difference in the replication efficiency and the directionality in the integration into the V. cholerae chromosome.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.287-292
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• 2019

Pseudomonas tolaasii causes brown blotch disease on the oyster mushroom (Pleurotus ostreatus). Various pathogenic strains of P. tolaasii were isolated and divided into three subtypes, $P1{\alpha}$, $P1{\beta}$, and $P1{\gamma}$. For phage therapy, bacteriophages against to these subtype strains were applied to mushroom cultivation and very successful to prevent from the disease. In this study, bacteriophages were isolated against the representative strains of subtype pathogens and their polyclonal antibodies were synthesized to investigate structural relationship among capsid proteins of phages. Phage preparations over $10^{10}pfu/mL$ were injected to rabbit thigh muscle and polyclonal antibodies were obtained after three times of boost injection. Titers of the antibodies obtained were over $2{\times}10^7Ab/mL$ for the phage ${\phi}6264$, $1{\times}10^6Ab/mL$ for the phage ${\phi}HK2$, and $1{\times}10^7Ab/mL$ for the phage ${\phi}HK19$ and phage ${\phi}HK23$. High specific activities were observed between antibodies and the corresponding bacteriophages. Some cross-reactivities between the antibodies and non-corresponding bacteriophages were also measured. Antibody $Ab{\phi}6264$ inactivated all phages of $P1{\alpha}$ subtype and only phage ${\phi}HK16$ among $P1{\beta}$ subtype phages. Antibody $Ab{\phi}HK23$ of $P1{\gamma}$ subtype neutralized all phages of $P1{\beta}$ subtype as well as the phage ${\phi}HK23$, showing the widest phage-inactivation range. When the structural-similarity studies of phages were investigated by using phage antibodies, closeness obtained by phylogenetic analysis of 16S rRNA genes of pathogenic strains were quite different from that of polyclonal antibody-specific structural similarity of phage capsid proteins. In conclusion, there is weak correlation between the host strain specificity of bacteriophage and its capsid structural similarity measured by phage antibodies.

• Journal of Microbiology
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• v.37 no.2
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• pp.97-101
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• 1999

Random hexapeptide library on the surface of filamentous bacteriophage was constructed using the SurfZAP vector. The size of the library was approximately 105. The peptide insert was flanked by two cysteines to constrain the peptide structure with a disulfide bond. This library was screened for the topoisomerase II binding peptide. Dramatic enrichment of the fusion phage over the VCS M13 helper phage was demonstrated by bio-panning affinity selection.