• Korean Journal of Microbiology
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• v.22 no.4
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• pp.215-222
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• 1984

A fungus producing cell wall lytic enzyme for Rhodotorula glutinis was isolated from local soil and identified partially as a species of Aspergillus fumigatus group. Thd cell wall lytic enzyme was an inducible exoenzyme and composed of at least lytic polysaccharidase and protease which act cooperatively in the lysis of intact cells. The lytic polysaccharidase was not able to hydrolyze ${\beta}-1,\;3\;and\;{\beta}-1$, 6-glucan which have the same types of bond as found in the cell wall of Ascomycetous yeasts. The lytic polysaccharidase alone was sufficient to hydrolyze the fractionated cell wall (alkali-insoluble residues) of R. glutinis, whereas it showed low activity against intact cells.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.299-303
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• 1996

Isolation, identification, and culture conditions of a lytic enzyme producing microorganism against Lacto- bacillus plantarum were investigated. The selected strain was gram-positive, rod (0.7 $\times$ 2.7 $\mu$m in size), and non-motile. The strain did not have any flagella and spores. According to its cultural and physiological characteristics, the strain was identified as Bacillus sp. The optimal pH and temperature for the production of lytic enzyme were 8.0 and 30$\circ$C, respectively. The maximum enzyme activity showed 1.5 units/ml in the medium composed of 1% peptone and 0.1% NaCl.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.33-38
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• 2002

Purification and characterization of enzyme property of a cell-wall lytic enzyme against Lactobacillus plantarum were carried out. Final specific activity of purified enzyme was 5.8 units/mg and purity of the enzyme was increased 8.3 fold compared with the enzyme activity in culture broth. The molecular weight of purified enzyme was estimated to be 60,000 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis. Optimal pH and temperature for the activity of this enzyme were 3.0 and 4$0^{\circ}C$, respectively. The cell-wall lytic enzyme activity was maintained at 3$0^{\circ}C$ when treating the enzyme for 30 mins, whereas the activity was decreased to 80% of the maximum level at 4$0^{\circ}C$ The enzyme activity exhibited good stability at the range of pH 4~7.

• Animal Bioscience
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• v.36 no.8
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• pp.1285-1292
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• 2023

Objective: The objective of this study was to develop a novel endolysin (PanLys.1) for the specific killing of the ruminal hyper-ammonia-producing bacterium Peptostreptococcus anaerobius (P. anaerobius). Methods: Whole genome sequences of P. anaerobius strains and related bacteriophages were collected from the National Center for Biotechnology Information database, and the candidate gene for PanLys.1 was isolated based on amino acid sequences and conserved domain database (CDD) analysis. The gene was overexpressed using a pET system in Escherichia coli BL21 (DE3). The lytic activity of PanLys.1 was evaluated under various conditions (dosage, pH, temperature, NaCl, and metal ions) to determine the optimal lytic activity conditions. Finally, the killing activity of PanLys.1 against P. anaerobius was confirmed using an in vitro rumen fermentation system. Results: CDD analysis showed that PanLys.1 has a modular design with a catalytic domain, amidase-2, at the N-terminal, and a cell wall binding domain, from the CW-7 superfamily, at the C-terminal. The lytic activity of PanLys.1 against P. anaerobius was the highest at pH 8.0 (p<0.05) and was maintained at 37℃ to 45℃, and 0 to 250 mM NaCl. The activity of PanLys.1 significantly decreased (p<0.05) after Mn²⁺ or Zn²⁺ treatment. The relative abundance of P. anaerobius did not decrease after administration PanLys.1 under in vitro rumen conditions. Conclusion: The application of PanLys.1 to modulate P. anaerobius in the rumen might not be feasible because its lytic activity was not observed in in vitro rumen system.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.678-686
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• 1996

To improve the preservation of Kimchi, we isolated Lactobacillus plantarum lytic enzyme-producing strain from soil, and the enzyme was purified and characterized. From the observation of cultural and morpho- logical characteristics, the isolated strain was identified as Metarrisium anisopliae (Metschn.) Sorok. The enzyme was purified to 75-folds with 40% yields through affinity adsorption and CM-Sephadex C-50 column chromatog- raphy. The optimum pH and temperature for lytic activity are 4.0 and 40$\circ$C, respectively, and the enzyme acitvity is stable between pH 3.0 and 9.0, and up to 50$\circ$C. The enzyme is a monomeric protein with molecular weight of 40,000 daltons by SDS-PAGE and gel filtration. The enzyme is endopeptidase which breaks the peptide linkage of Lactobacillus plantarum peptidoglycan. The lytic action spectra confirmed that Leuconostoc mesenteroides, a useful strain for the fermentation of Kimchi, is not lysed by the enzyme. The enzyme activity is inhibited by N-bromosuccinimide (NBS), which probably indicates the involvement of tryptophan residue in active site of the enzyme, and also inhibited by Ag$^{+}$. The amino acid composition analysis showed that the enzyme contains more acidic amino acids than basic ones, and composition of alanine, glycine, proline and tyrosines was very high.

• KSBB Journal
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• v.23 no.3
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• pp.187-192
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• 2008

Lysozyme-producing microorganisms were isolated to obtain bacteria which can efficiently solubilize microbial cells. Cells of normal and chloroform-treated Escherichia coli and Micrococcus Iysodeikticus were used as model substrates to isolate lysozyme-producing microorganisms and investigate the efficiency of cell lysis. The culture supernatant of the isolate New1 (98% similarity of 16S rDNA sequence with Thermomonas haemolytica) showed different lytic characteristics for different substrates. Thermal treatment (autoclave) of substrate cells showed a significant effect on cell solubilization by culture supernatant of the New1. For autoclaved substrate cells, E. coli, M. Iysodeikticus and chloroform-treated E. coli were solubilized by 58.7%, 49.4% and 79.1%, respectively, in the culture supernatant of New1. The lytic activity of New1 was mainly caused by lysozyme produced by the isolate. It was also showed that New1 exhibited high protease activity and a little cellulase activity.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.445-451
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• 1996

The strain YCH-37, which produces yeast cell wall lytlc enzyme, was isolated from soil. From the microscopic observation, morphological and cultural characteristics, this strain was identified to fungus, Dicyma sp. So, we named this strain as Dicyma sp. YCH-37. The lytic enzyme effectively lysed Salmonella typhimurium among intact living bacteria and Torulopsis, Hansenula, Zygosaccharomyces among intact living yeast, as well as autoclaved yeast strains. The yeast cell wall lytic enzyme was succesively purified to 204 folds with 13% yields through yeast glucan affinity adsorption and DEAE-cellulose column chromatography. The enzyme was identified to monomeric protein with molecular weight of 25,000 daltons from the results of SDS-PAGE and gel filtration. The optimum pH and temperature for the yeast lytic activity were 8.0 and 50$\circ$C, respectively. The enzyme was stable up to 40$\circ$C, and between pH 4.0-pH 10.0.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.123-129
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• 1977

A potent lytic strain was selected by an extensive screening test of microorganisms isolated from soils and sewages on the medium containing baker's yeast as a carbon source. This strain (M-10) was identified to a strain of Humicola sp. by the Genera of Fungi (Clements, 1964). The strain was cultured on the basal medium composed of 2% of baker's yeast, 0.3% of $K_2HPO_4$, 0.01% of $MgSO_4{\cdot}7H_2O$, 0.1% of yeast extract in a shaking incubator. Cultural conditions for lytic enzyme production has been studied, and the results obtained were as follows: 1. The Optimal conditions for lytic enzyme production were: initial pH 5.5 to 6.0, temperature $33^{\circ}C$ in shaking culture. 2. Among the various carbon sources, baker's yeast (4%) was the best for lytic enzyme production, increasing the level of activity eight, times higher than when grown on glucose (1%). 3. The most effective concentration of $K_2HPO_4\;and\;MgSO_4{\cdot}7H_2O$ in the basal medium for lytic enzyme production was 0.1% and 0.01% respectively. 4. When the strain was cultured under the optimal conditions, the production of lytic enzyme was maximized in 72 hours.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.223-228
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• 1989

Natural killer (NK) cells are a heteroguneous subpopulation of lymphocytes that spontaneously exhibit cytotoxic activity against various virus-Infected and neoplastic target cells without prior exposure to a specific antigen. It was thought that NK calls play an important role in immunosurvrillanre against viral agents and tumors, and in prevention of metastasis. Recently, several reports have indicated evidence that ginseng extracts show a significant stimulatory effect on the humoral and cellular immune responses. This evidence gives support to the suggestion that the anticarcinogenic effect of ginseng may be due to the effect of ginseng on the immunological system. Treatment with total, diol, and triol saponin resulted in an increase in NK cytotoxic activity, but no enhancement of the lytic activity due to the natural killer cytotoxic factor (NKCF). Therefore, these results suggest that the augmentation of NK activity by ginseng saponin fractions may not be due to the activation of NKCF lytic activity.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.87-94
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• 2003

The lytic activity of the set of swine and chicken phages which were derived from lysogenic Staphylococcus hyicus strains of swine and chicken origin was compared by means of S. hyicus isolated from swine, chicken and cattle. Of the 80 strains each from swine and chicken, 71 (88.8%) of strains from swine and all the strains of chicken origin were found to be lysogenic. Swine phages showed wider range of lytic activity to the examined strains than that of chicken phages. Using chicken phages at $100{\times}routine$ test dilution (RTD), 25.0%, 85.6% and 50.0% of swine, chicken and bovine strains were lysed, respectively. However, when the set of swine phages was used at $100{\times}RTD$, higher frequency of the typable strains was found in strains of swine and chicken origin (73.8% and 90.2%). Phage F12 and L16 from chicken set were found to be highly active with chicken and bovine strains. On the contrary, all the swine strains were completely resistant to lysis by the two phages at $100{\times}RTD$. Thirteen (12.5%) of 104 S. aureus strains, 1 (1.8%) of 55 S. simudance strains, 31 (58.5%) of 53 S. chromo genes strains, and none of 31 strains of other coagulase-negative Staphylococcus species isolated from bovine mastitis were typable with the set of swine phages.