• 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.

• 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.

• 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.26 no.2
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• pp.117-121
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• 1998

Bacteriophage SC 921 of Lactobacillus plantarum, isolated from kimchi, showed high lytic effects at 0.2 M.O.I. level. The phage particle contained 4 major proteins (48, 34, 32, 29 kDa). Intact DNA of phage SC 921 is a double stranded linear molecule, and the genomic size is approximately 66.5 kilobase pairs (kbp). Restriction analysis of the genome showed that Sma I gave single site cut and Xba I gave 2 site cuts, while Cla I, Kpn I, and EcoR I formed 4, 5, and 6 cuts, respectively. Hind III digested phage DNA to many fragments. A restriction map of genomic DNA was constructed using the restriction endonuclease Kpn I, Sma I, and Xba I. Bacteriophage SC 921 was compared with B2 phage which had been reported to infect Lactobacillus plantarum ATCC 8014(KCCM l1322). Bacteriophage SC 921 differs from B2 phage at least in thr size of its genome and phage particle proteins.