단백 효소 가수분해물의 천연 항균제로서의 응용성을 검토하기 위하여 casein에 5종의 단백질 가수분해 효소를 작용시켜 얻어진 가수 분해물의 항균활성을 측정하고 활성이 가장 높은 가수분해물을 부분 정제하여 그 응용성을 검토하였다. Casein에 5종 단백질 분해효소를 작용시켜 얻은 가수분해물의 항균활성은 Aspergillus oryzae protease에 의한 것이 가장 높았다. 효소처리에 의하여 얻어진 가수분해 물을 30,000, 10,000, 3,000 membrane filter로 한외여과 하였을 때 항균활성은 3,000이하 분획물에 대부분 함유되어 있었으며 공시균주에 대한 최소저해농도는 $1.0~1.5;mg/mL$이었다. Aspergillus oryzae pretense로 작용시킨 casein 가수분해물은 $121^{circ}C$에서 10분간 가열했을 때도 그 항균 활성을 유지하는 것으로 보아 열에 안정하였다. 가수분해물을 HPLC로 220 nm 280 nm에서 검출된 peak 별로 수집하여 항균활성을 측정 한 결과 retention time 12.6, 13.2 분에서 분취된 peptide가 활성이 있었다. 가수분해 동결건조물을 된장에 첨가하였을 때 미생물의 생육이 저해되었으며 실용성이 있었다.
This study was carried out to produce antimicrobial peptides from casein using various proteases. To examine whether the hydrolysis of casein would produce antimicrobial substance and the application as natural antimicrobial material, casein was hydrolyzed by five different proteases. The casein hydrolysate was fractionated with regenerated membrane filter (molecular weight cut-off 30,000 10,000 and 3,000) and antimicrobial activity was measured for each fraction. Antimicrobial activity appeared great in the fraction below 3,000 molecular weight The fraction was re-fractionated by high performance liquid chromatography and substance of main peak (retention time: 13.2 min) collected was used as a sample to measure antimicrobial activity. Among the casein hydrolysates produced by protease, antimicrobial activity was observed the greatest in hydrolysate treated with Aspergillus oryzae protease. The minimum inhibition concentrations of the Asp. oryzae protease hydrolysate were 1.0-1.5 mg/mL. This hydrolysate was a heat stable peptide since antimicrobial activity was maintained after treating with heat for 20 min at $121^{circ}C$.
