A dissolution enzyme which dissolves the cell wall of Streptococcus mutans, a causative bacteria of dental caries, and a microorganism

摘要

The present invention relates to a cell wall lysis enzyme which selectively acts on the cell wall of Streptococcus mutans, which is a causative agent of dental caries, to dissolve bacteria and a microorganism producing the same.;The present inventors have searched for a lytic enzyme that dissolves the cell wall of Streptococcus mutans for use as an additive such as food and a toothpaste or a medicine, The cell wall lytic enzyme - producing microorganisms were isolated from the soil and identified as Bacillusp. The characteristics of the strains and the characteristics of the enzymes were examined and found to be different from those of the existing production strains. This strain produces two types of lytic enzymes, each of which is a protein with a molecular weight of 27,000 daltons (Da) and a single subunit of 45,000 daltons (Da). The optimal pH of each reaction is in the range of pH 6 and 8, and the optimum temperature is in the range of 30 ° C and 60 ° C, stable in the pH range of 5-11 and stable up to 60 ° C. Examples of the production medium include a carbon source such as seodang sugar, fructose, glucose and starch, a natural medium such as NH4 ⁺ salt, urea, protein, a nitrogen source such as soybean meal, amino acid, corn steep liquor, peptone, juice, Mg ⁺ salt, Respectively. Each of the enzymes is an endopeptodase that decomposes the amino acid bond of peptidoglycan among the cell wall components of Streptococcus mutans, and is produced by the conventional Bacillus subtilis ATCC 6051 (L-alanine amidase) and Bacillus subtilis 168 (molecular weight 30,000 daltons) produced by Streptococcus mutans cell wall dissolving element having a molecular weight of 50,000 daltons (Da) It is presumed to be a novel enzyme other than N-acetyl muramoyi-L-alanine amidase.